The polymers based on dynamic borate bonds had certain self-healing ability and multiple responses to stimuli, and they could respond to biological signal changes by inducing topological recombination of physical/chemical structures in the materials. A variety of natural/non-natural polymer materials based on three different transesterification mechanisms of borate esters were reviewed in this paper, namely hydrolysis/re-esterification, transesterification between diol and borate and transesterification between borate and borate. It was a strategy to design a more stable tetrahedral borate structure through the synergistic effect of traditional covalent bond and borate dynamic covalent bond to solve the borate ester polymer short plate. Application potential of borate-based polymers in many fields was summarized, such as biomedicine, sensors and recyclable materials. The synergistic of borate ester bond and other dynamic bonds to prepare ideal polymer materials was mainly emphasized, such as hydrogels, organic gels, liquid crystal materials, recyclable nanomaterials, etc.

As a kind of polymer material with versatile product forms, polyurethane is widely used in many applications. Developing technologies that can use green and renewable raw materials as feedstock has become a research hotspot, as well as great significance to the polyurethane research in the future. Based on the relevant literatures of the last decade, this paper focuses on the basic methods and research progress for the synthesis of bio-based polyols and isocyanates from common renewable alternatives, such as vegetable oil(castor oil, soybean oil, tung oil, palm oil, etc.), lignocellulose, rosin, natural phenols(cardanol and tannin), sugars and other biomass resources. In addition, the research status of non-isocyanates was mentioned, and the unique advantages of these materials for the preparation of bio-polyurethane were listed. This article also comprehensively examines the future hurdles that hinder the utilization of these materials, and then the development prospects of bio-based polyurethane materials in different fields are outlooked.

Biomass-based carbon materials had the advantages of low cost, wide source, good electrical conductivity, and good electrochemical stability. Through heteroatom doping, the performance of biomass-based carbon materials was further improved. This paper summarized the methods of introducing heteroatoms into biomass-based carbon materials(in-situ doping and diffusion doping) and their respective advantages and disadvantages. The types of heteroatom doping(nitrogen doping, oxygen doping, phosphorus doping, sulfur doping, halogen doping, and multi-element co-doping) and the effects of heteroatom doping on the structure and properties of biomass-based carbon materials were briefly described. The applications of heteroatom doped carbon materials in energy storage, adsorption separation, and catalytic oxidation were reviewed, and the development direction of heteroatom-doped biomass-based carbon materials was also prospected.

Hydrogen-rich syngas production from biomass gasification is considered as one of the most promising hydrogen production methods because of its clean and renewable raw materials and the diversity of product application. Catalysts play an important role in controlling the composition of biomass gasification products and the pyrolysis of tar. In this paper, the methods of hydrogen production from fossil energy, water decomposition, and biomass were reviewed, and the advantages, limitations, and existing problems of hydrogen production from biomass gasification were also analyzed. And, the influence factors of biomass gasification(gasification agent, reaction temperature, and catalyst) and the kinds of catalyst and its characteristics which used for biomass gasification(nickel-based, dolomite and alkali, and alkaline earth metal catalysts) were emphatically introduced. The research status of biomass gasification for making hydrogen rich syngas and catalysts in China and abroad were analyzed, and the prospects of the development of catalytic gasification for making hydrogen-rich syngas were discussed. The problems to be solved and the research direction were proposed.

Environment protection, energy saving, and high efficiency are the main research directions for thermal insulation materials in the future, and the development of thermal insulation materials based on biomass is the future trend. Biomass-based porous materials refer to the porous materials prepared from renewable biomass as the precursor, which have the wide raw materials and diverse preparation methods. They have excellent characteristics, such as high porosity, low density, light weight, and so on, which has great application potential in the field of thermal insulation. In this paper, the heat preservation mechanism of the porous materials was overviewed, and the research progress on the cellulose, starch, chitosan, plant protein porous material in recent years was reviewed. The surfactant foaming method, freeze-drying method, pore-forming agent method, mould hot pressing method, solvent exchange phase separation in the application of biomass-based porous material preparation were also highlighted. Finally, the existing problems of biomass-based porous insulation materials are analyzed, and the future research directions of porous insulation materials are also prospected.

Biomass is important renewable resources, mainly containing cellulose, hemicellulose, and lignin. Hemicellulose is the second most abundant component in plant cell walls, and it can be hydrolyzed to prepare important chemicals and modified to prepare multifunctional materials. This article reviews the research progress of molecular simulation of biomass hemicellulose, including the molecular simulation study of the morphology of hemicellulose macromolecules and its binding mode to cellulose, and the molecular simulation research on the preparation of chemicals and materials from hemicellulose. It can be concluded that the interaction of hemicellulose with cellulose and lignin in the cell wall and its macromolecular morphology have significant influence on the extraction and utilization of cellulose, hemicellulose, and lignin. Molecular simulation is helpful to understand the process mechanism and has important theoretical guiding significance for the improvement of reaction efficiency. Finally, the development and application of molecular simulation in hemicellulose research are prospected. The blank areas of hemicellulose molecular simulation are pointed out, mainly including the production of bio-oil by hemicellulose liquefaction, xylose isomerization to produce xylulose, the binding interaction between hemicellulose and lignin, and other hemicellulose-based materials, which requires further exploration and research.

Conversion of biomass into high value-added chemicals was an effective way to solve the current problems of fossil energy depletion and global warming. 5-Hydroxymethylfurfural(HMF) was considered as one of the most important platform compounds, which could be used to prepare many high value organic compounds through oxidation, hydrogenation, and ring-opening reactions. Among its derivatives, 2, 5-furandicarboxylic acid(FDCA) could be regarded as the most promising chemical, which could replace the widely used petroleum-based polyester terephthalic acid(PTA) to synthesize biodegradable polyester polyethylene furanoate(PEF). This article systematically reviewed the new processes for preparing FDCA from HMF through electrocatalytic oxidation, photocatalytic oxidation, and biocatalysis. These catalytic methods were different from traditional pyrolysis catalytic methods, which did not requiring high temperature and pressure as well as harmful solvents and expensive catalysts, and had the characteristics of high efficiency, greenness, and sustainability. However, there were still some problems, such as electrocatalysis needed special and stable electrolytes and high requirements for instruments and equipment; photocatalysis had the problems of high cost and low energy conversion rate; biocatalysis had long preparation cycles and the inhibited intermediates. By analyzing the results obtained by these methods and the existing problems, it provided feasible ideas for the efficient catalytic conversion of FDCA in the future.

Before determining the specific surface area and pore volume of woody activated carbon, the activated carbon was pre-treated with degassing, and the effect of pre-treatment conditions(desorption temperature and desorption time) on the specific surface area and pore volume of activated carbon was investigated. The obtained results were compared with those measured under the recommended conditions of the instrument. The results showed that the desorption temperature and time had little influence on the specific surface area and pore volume of physical activated carbon. It was owing to the preparation temperature of physical activated carbon was high few functional groups, the structure was mainly microporous, the adsorption type was mainly physical adsorption, and the adsorption and desorption speeds were fast. The optimum pretreatment condition of physical activated carbon was desorbed at a temperature of 150 ℃ for 3 hours. Compared with the pretreatment conditions of 350 ℃ and 24 hours recommended in the instruction manual of ASAP 2460, pretreatment time was significantly shortened, the power consumption was reduced, and the detection efficiency was improved. The degassing temperature and time had a great influence on the specific surface area and micro-pore of chemical wood activated carbon, and the suitable pretreatment condition was 300 ℃ for 12 h. The main reason was that the preparation temperature of activated carbon by phosphoric acid method was relatively low, and there were many heteroatoms and the surface chemical groups. Physical and chemical adsorption were easy to occur simultaneously, which required higher temperature and longer time for degassing. When the degassing temperature was too high, the adsorbate in the pores would be carbonized to form carbonaceous particles that blocked the pores. At the same time, part of the physical adsorption would be converted into chemical adsorption at a higher activation energy, which would reduce the analysis results.

As a kind of renewable forest product resource with abundant yield and low price, rosin is widely used in food, agriculture, rubber, ink, coating, and other fields. The tricyclic diterpene structure of rosin possesses extreme hydrophobicity, and hydrophilic groups can be introduced into rosin by means of catalytic isomerism, Diels-Alder addition, and other means to prepare high value-added and biodegradable green surfactants. Rosin-based surfactant literatures and patents published in China and abroad were retrieved from four categories: anionic, cationic, nonionic and amphoteric surfactants. The surfactants with the anion of carboxylate, sulfonates, sulfates, and phosphates, and the cation of quaternary, polyols and polyoxyethylene nonionic surfactants, and betaine and amine oxide amphoteric ionic surfactants were analyzed especially. The industrialization development of new technologies and new products of rosin-based surfactants were discussed, and the potential application fields of rosin-based surfactants instead of traditional surfactant were proposed. Meanwhile, the research and industrialization development of rosin-based surfactants were also evaluated and prospected.

As the most abundant renewable resource on the earth, lignocellulosic biomass not only has huge reserves but also has a significant advantage on carbon balance in the utilization process. It has gradually become one of the most promising renewable energy sources. Among the lignocellulose lignin is the largest and only renewable aromatic compound raw material in the nature. It plays a very important role in the conversion of biomass fuels, especially the depolymerization production of benzene chemical products. Based on the brief chemical structure description of lignin, this paper summarized the depolymerization methods of lignin in recent years, such as high-temperature thermal depolymerization, biological enzyme depolymerization, catalytic thermal depolymerization, photocatalytic depolymerization, and solvent pyrolysis. The mechanism, advantages and disadvantages of acid and alkali catalytic system as well as hydrogenation and oxidation catalytic system in the process of liquid-phase catalysis were deeply analyzed. Additionally, the problems existed in the depolymerization methods of lignin at this stage were also summarized, and the developing direction in the future was proposed.

Using corn straw as raw material, the characteristics and kinetics of its pyrolysis were studied by TG. The physicochemical properties of corn straw before and after pyrolysis were analzed according to the TG and DTG curves. Activation energy of corn straw pyrolysis were calculated using the isoconversional models of Flynn-Wall-Ozawa(FWO) and Kissinger-Akahira-Sunose(KAS), and the thermal degradation mechanism was investigated by the master-plot and Coats-Redfern(C-R) methods. The results showed that the pyrolysis process of corn straw could be divided into 4 stages: drying dehydration stage, transition stage, main pyrolysis stage, and carbonization stage. The pyrolysis curve shifted to the high temperature side with the increasing heating rate. The apparent activation energies calculated by FWO and KAS were 181.7 and 181.5 kJ/mol, respectively. The pyrolysis mechanism equation of corn straw was calculated using the master-plot method and C-R method, which follows Avrami-Erofeev equation. When α=0.1-0.5, n=3, f(α)=1/3(1-α)[-ln(1-α)]^-2, and when α=0.5-0.7, n=2, f(α)=1/2(1-α)[-ln(1-α)]^-1.

Biomass had negative carbon properties and met the requirements of green development as a typical renewable energy. Under relatively mild conditions, hydrothermal carbonization was the process of converting biomass into various functional carbon materials. This paper discussed recent advances of biomass-based porous carbon materials by the hydrothermal transformation from biomass, such as monosaccharides(glucose, fructose, and xylose), lignocellulosic fibers(cellulose, hemicellulose, and lignin) and chitosan. The effects of temperature, reaction time and raw material concentration on its structure and properties were mainly discussed, as well as its applications in gas adsorption, dye adsorption and heavy metal ion adsorption. The authors proposed future research directions for the hydrothermal synthesis of high performance and environmentally friendly porous carbon materials from biomass.

Nitrogen-doped activated carbon(NAC) was prepared by synchronous doping method using phosphoric acid lignin-based activated carbon(LAC) as raw material, melamine as nitrogen source and KOH as activator. The structure and composition of the modified activated carbon were characterized by BET, XRD, Raman spectroscopy and XPS characterization. The electrochemical performance of the modified activated carbon as the electrode material of supercapacitor in several electrolytes with different properties was tested by electrochemical characterization, and the influence mechanism of the electrolyte on the electrochemical performance of electrode material was preliminatively explored. The results indicated that the modified activated carbon has abundant pore structure, with specific surface area of 2 332 m²/g, micropore volume of 1.37 cm³/g, middle pore volume of 0.74 cm³/g, average pore size of 2.79 nm, and nitrogen content of 7.5%, of which graphite-like nitrogen(N-Q) structure content of 34.6%. The rich pore structure and nitrogen content greatly improved the electrochemical performance of activated carbon, and it exhibited high specific capacitance in the aqueous electrolyte. The maximum specific capacitance was 424 F/g at the current density of 1 A/g. In organic electrolyte, its specific capacitance was only 87 F/g at a current density of 1 A/g, while it had higher energy density owing to the wider operating voltage window(0-2.5 V). The results showed that the performance of activated carbon electrode material in aqueous electrolyte was mainly determined by the hydration ion radius of electrolyte, while the performance in organic electrolyte was mainly affected by the viscosity of electrolyte.

At present, there were some problems existing in the large-scale production of domestic agricultural straw waste biomass pyrolysis carbonization equipment, such as unstable operation, low straw carbonization yield and difficult recovery, etc. Using rice husk and corn straw molding particles as raw materials, the situation of long-time continuous carbonization in this large-scale continuous biomass carbonization equipment was studied, and the applicability and stability of this equipment were analyzed systematically. The equipment was composed of a carbonization unit, a gas separation unit, and a biochar discharge unit. The carbonization unit adopted a double-layer sleeve structure, where the inner layer was a carbonization chamber and the outer layer was a gas heating chamber. The high calorific value biomass gas produced by biomass carbonization was recovered and then combustion-heated to realize the continuous operation of pyrolysis carbonization process. The results showed that the design of the biomass carbonization equipment was reasonable, which could satisfy the carbonization of different raw materials and realize the continuous and stable carbonization of rice husk and corn stalk particles for a long time. The carbonization capacity could reach 490 kg/h. When the carbonization temperature was controlled at around 500 ℃, the yield of biochar was more than 37%. After pyrolysis, the solid, liquid, and gas phases were completely separated, and the gas was recycled.

Biochar was prepared by high-temperature pyrolysis with bulk agricultural waste corn straws as raw material, and the performance of biochar on heavy metal removal was investigated through the adsorption experiments of lead and cadmium in water.The results showed that the corn straw biochar obtained at 800 ℃ was mainly in the form of block and rod, the pore structure was micropores, and the alkali metals and alkaline earth metals in the ash were dominated. The maximum adsorption capacities of Pb²⁺ and Cd²⁺ were 94.79 and 24.47 mg/g, respectively, when the adsorption temperature was 25 ℃, pH value was 4, adsorption time was 960 min, and the mass concentrations of Pb²⁺ and Cd²⁺ were 429.24 and 280.34 mg/L. The removal process of lead and cadmium in water by biochar followed the pseudo-second-order kinetic equation and the Freundlich isotherm model. When the initial mass concentrations of lead and cadmium were all 150 mg/L, the obtained equilibrium adsorption capacities were 69.0 and 24.4 mg/g, respectively. Thermodynamic analysis showed that the process belongs to endothermic and entropy increasing. Additionally, Pb²⁺ could significantly antagonize the removal of Cd²⁺ in binary metal ion solution.The adsorption mechanism of corn straw biochar indicated that the removal of both metal ions was the combination of physical adsorption and chemical precipitation.

China was rich in biomass resources with various types, which could be directly used for combustion. With the proportion of installed biomass power generation capacity increasing year by year, environmental protection requirements were enhancing, and the flue gas emissions control of biomass power plants was more strictly. The inital nitrogen oxide emissions of biomass boiler fluctuated greatly, the alkali metal content of fly ash in flue gas was high, and the humidity was high. The biomass boilers denitration technology was facing major challenges. Based on the comparative analysis of the characteristics of biomass fuel combustion and flue gas emissions, the development status, advantages, and disadvantages of the widely used traditional denitrification technology and the new developing denitrification technology were analyzed. Traditional denitrification technologies included low nitrogen combustion technology, selective catalytic reduction technology, and selective non-catalytic reduction technology. New denitrification technologies included plasma denitrification technology, ozone oxidation denitrification technology, biomass activated carbon desulfurization and denitrification technology, ZYY dry desulfurization and denitrification technology, low temperature oxidation absorption synergistic semi-dry denitrification technology, liquid biological calcium denitrification technology, and solid polymer denitrification technology. Moreover, the technical problems, cost problems, and operation period of biomass boilers technology were also discussed.

Biochar had the advantages of environmental friendliness, wide sources, and low cost. It was widely used as catalyst and catalyst carrier in thermal conversion processes, while there were problems such as easy coking and inactivation and the unclear directional regulation mechanism of product. In this paper, the research progress on the application of biomass char-based catalysts for thermal conversion processes was reviewed, and the research status of preparation and modification(heteroatom doping and metal loading) schemes of biomass char-based catalysts were introduced. The application of char-based catalysts was discussed from five aspects: conventional catalytic pyrolysis, microwave-assisted pyrolysis, tar removal, esterification synthesis of transportation fuels, and hydrothermal liquefaction. Exploring the deep catalytic mechanism of catalysts and construct multistage char-based catalysts with multi-stage pore structure for targeted production of high-value chemicals were a future research direction as the future research directions.

In order to solve the low crosslinking activity resulted from protein denaturation of high-temperature soybean meal(HTSM), the thermal-alkali activation of HTSM was proposed, and the effects of sodium hydroxide(NaOH) dosage on the structure and properties of HTSM and HTSM-based adhesive were evaluated based on the FT-IR, XRD, XPS, TGA analysis and other traditional methods. The results revealed that thermal-alkali activation could not only unfold HTSM's globular structure to release the buried active group but also hydrolyze partial peptide into amino and carboxyl groups. Then, the crosslinking reactions between reactivated HTSM and crosslinking agent was increased, and the obtained soybean protein adhesive had equivalent thermal and water resistances with the adhesive prepared by low-temperature soybean meal due to the formation of sufficient crosslinked networks. The results of thermal-alkali activation showed that the most preferable NaOH dosage was 2%(mass fraction), and the acetaldehyde value of HTSM was 4.28 mg/g(reactivated HTSM). Correspondingly, the adhesive viscosity was 59.8 Pa·s, the soaked wet bonding strength was 1.48 MPa(63 ℃ for 3 h), the boiling-dry cycled wet bonding strength was 0.96 MPa, the boiling-water-insoluble content was 79.73%, the mass-residue ratio was 40.87%, and the temperature for maximal degradation rate was 306.1 ℃.

Alkali lignin(AL) was separated and purified from papermaking black liquor by acidic precipitation. Then, quaternary ammonium lignin(QAL) was obtained by modifying AL with 3-chloro-2-hydroxypropyl trimethyl ammonium chloride. Using cellulose hydrogel(CEH) as matrix, antibacterial silver nanoparticles-quaternary ammonium lignin-cellulose hydrogel(Ag NPs-QAL-CEH) was prepared by impregnating with QAL and silver nitrate solutions. The structures of AL and QAL were characterized by Fourier transform infrared spectroscopy and the results showed that QAL was successfully prepared. The results of elemental analysis showed that the content of nitrogen increased from 0.6% to 5.9%. Ag NPs-QAL-CEH was characterized by X-ray diffraction and scanning electron microscopy. The results indicated that Ag NPs were obtained by reducing Ag⁺ with QAL, and Ag NPs-QAL was uniformly dispersed in the three-dimensional network structure of CEH. The antibacterial performance of the hydrogel showed that Ag NPs-QAL-CEH formed obvious inhibition zone against S. aureus and E. coli. Furthermore, with the increase of AgNO₃ dosage, the diameters of antibacterial circle increased from 14.2 mm to 20.1 mm and 16.1 mm to 18.1 mm, respectively. When the mass concentration of AgNO₃ was 7.87 g/L in 50 mL QAL solution(including 2.5 g QAL), the obtained Ag NPS-6-QAL-CEH had the best bacteriostatic effect, and the inhibitory rates against S. aureus and E. coli could reach more than 99.5%.

In this paper, the heterogeneous catalytic conversions of lignocellulose to high value-added platform compounds of levulinic acid and esters were studied. The research progress and trend of the direct conversion of lignocellulose to levulinic acid and esters using sulfate as catalytic system at home and abroad were reviewed. Firstly, the basic information of levulinic acid/esters and their application in industrial production were summarized. The preparation process of levulinic acid/esters using different sulfate catalysts was compared, and the law of the conversion of lignocellulose to levulinic acid/esters under the synergy effects of different solvent systems was deeply analyzed. And, the mechanism of direct conversion of lignocellulose catalyzed by sulfate catalysts was also summarized. Finally, the problems of existing process were discussed, and the development direction of this research field was prospected.

Tobacco in Sichuan, Guizhou, and Fujian was selected as raw materials, and the essential oil of tobacco was extracted by distillation in water. Gas chromatography-mass spectrometry(GC-MS) was used to analyze the composition and content of tobacco essential oil from different production areas, and the influences of different production areas on the yield and composition of the product were compared. The results showed that the average yields of tobacco from Fujian, Sichuan, and Guizhou were 0.139 1%, 0.085 1%, and 0.107 5%, respectively, and the corresponding contents of neophytadiene were 39.86%, 36.12%, and 44.88%, respectively. According to the comparison analysis, the tobacco produced in Fujian had the highest oil yield and moderate characteristic aroma; the tobacco essential oil produced in Guizhou had moderate oil yield, prominent tobacco aroma, and obvious licorice aroma; the tobacco essential oil produced in Sichuan had the highest oil yield, and weaker aroma.

Furfural is the bridge connecting raw biomass to the biorefinery industry. The reductive transformations of furfural in aqueous medium is an important way to prepare a wide variety of fine chemicals. Plenty of downstream products can be obtained by heterogeneous catalyst, such as(tetrahydro) furfuryl alcohol, 2-methyl(tetrahydro) furan, lactone, levulinate, cyclopentanone, cyclopentanol, and so on. The activity of catalyst mainly depends on the properties of metal and support, as well as reaction conditions, such as temperature, time, solvent, and pressure and so on. The research progress of furfural hydrogenation for preparing cyclopentanone and cyclopentanol using different non-noble metal(Cu, Ni, and Co) and precious metals(Pd, Ru, Pt, and Au) based catalyst were summarized. It was found that Ru, Pd, Au, and Cu-based catalysts have higher selectivity than other catalysts, and Cu-Ni bimetallic catalysts have excellent catalytic activity and selectivity, while their stability needs to be improved. The mechanism of the hydrogenation reaction on the metal surface was discussed, and the results showed that the aqueous medium and weaker Lewis acid sites play an important role in the reaction of ring rearrangement. Meanwhile, the future research direction of the hydrogenation reaction of furfural in aqueous medium is proposed.

The effects of torrefaction pretreatment on the preparation and properties of activated carbon by phosphoric acid using corn straw as the raw materials were studied. The results showed that the contents of carbon and fixed carbon were increased and the volatile content was reduced using torrefaction pretreatment which increased the quality of pyrolytic carbon. The effect of torrefaction temperature was stronger than that of torrefaction time. By torrefaction pretreatment, the specific surface area of activated carbon increased firstly and then decreased, the total pore volume and the mesoporosity decreased, while the microporosity increased significantly. The adsorption performance of activated carbon could be improved by torrefaction pretreatment. As 100 g corn straw with the particle size of 154-450 μm were pretreated under the torrefaction temperature of 240 ℃ and torrefaction time of 60 min, the pretreated corn straw contained carbon, fixed carbon, and ash with the mass fractions of 51.32%, 27.64% and 4.72%, respectively. The activated carbon was prepared from the pretreated corn straw under the impregnation ratio of 1∶4(i.e., the mass ratio of the pretreated corn straw and 55% phosphate acid), dipping temperature of 140 ℃, dipping time of 90 min, activated temperature of 400 ℃, activated time of 60 min, the specific surface area of the obtained activated carbon reached 1 317.05 m²/g, and the values of iodine adsorption, methylene blue adsorption, and caramel decolorization were 876 mg/g, 210 mg/g and 100%, respectively.

Lignin amine(AL) was prepared by modifying corn cob via Mannich reaction, and then AL was mixed with water-based polyamide(PAE) and polyethylene glycol diglycidyl ether(PEGDE). Soybean meal was used as raw material to prepare soybean gum with high solid content by AL/PAE/PEGDE modification. The properties of soybean gum were characterized and tested, and the FT-IR results showed that the absorption peak of amide Ⅰ of the soybean meal adhesive modified with AL, PAE, and PEGDE after curing shifted from 1632 cm^-1 to 1640 cm^-1, and amide Ⅱ shifted from 1533 cm^-1 to 1538 cm^-1. And the shift suggested that the cured adhesive possessed a dense and cross-linking structure. The TGA results also showed that the network structure between PAE, PEGDE, AL, and protein molecules was more compact, and the rheological behavior analysis showed that the cured soybean meal adhesive had the characteristics of pseudoplastic fluid. The solid content in the modified adhesive was as high as 42.5%, while the apparent viscosity was simply 3 746 mPa·s, which was suitable for application in plywood industry. The wet bonding strength of the prepared plywood reached 0.86 MPa and the pass rate was 100%, which meet the national standard for type II plywood(bonding strength≥0.70 MPa, and the pass rate≥90%).

Our country has the most abundant genera and species of Pinaceae plant in the world, including ten genera: Pinus, Picea, Cathaya, Pseudotsuga, Larix, Pseudolarix, Cedrus, Tsuga, Keteleeria and Abies. The liposoluble substance in pine needles from Pinaceae plant contain some compound with novel structure and significant bioactivity. In this paper, the domestic and foreign research progress on extraction method, chemical constituents, biological activity, and its application in biomedical and agricultural field of liposoluble substance from pine needles are reviewed. It mainly includes acidic materials and neutral materials. The main extraction solvents were petroleum ether, dichloromethane, and n-hexane. The application of liposoluble substance from pine needles in the development of drugs, green ecological and safe feed additives, plant protection agents, veterinary drugs, and plant growth promoters were also introduced. Suggestions for future study on protection and utilization of pine needles resources from Pinaceae plant, as well as research and development of liposoluble substance from pine needles are proposed.

To study the effects of mixing ratio on the co-pyrolysis thermal behavior and kinetic parameters of Camellia oleifera shell(CS) and polypropylene(PP), CS and PP were mixed at different mass ratios(3∶7, 5∶5 and 7∶3) to carry out thermogravimetric experiment and kinetic analysis from 50 to 800 ℃ with the heating rates of 5, 10, 15 and 20 ℃/min. The result of thermogravimetric experiment indicated that the co-pyrolysis of mixed samples could be divided into two stages. When the temperature was lower than 352 ℃, the pyrolysis of CS played a leading role in the pyrolysis of mixed samples and PP promoted the pyrolysis of CS. When the temperature was higher than 352 ℃, the pyrolysis of PP dominated the pyrolysis of mixed samples and the pyrolysis of CS played an inhibitory role. The results of kinetic analysis showed that the FWO method was suitable for the kinetic analysis of pyrolysis and co-pyrolysis of CS and PP, and the average apparent activation energy of the mixed samples with a mass ratio of 3∶7 between CS and PP was the lowest(217.04 kJ/mol), which was 54.3% lower than that of CS pyrolysis alone(474.94 kJ/mol).

The method of water bath oscillation assisted with ethanol extraction was used to optimize the extraction process of polyphenols from Malus asiatica Nakai, and the composition of polyphenols was analyzed. The optimal extraction conditions of unripe M. asiatica were the volume fraction of ethanol 50%, solid-liquid ratio of 1∶25(g∶mL), water bath oscillation time with 50 min, and water bath oscillation temperature of 30 ℃ via the orthogonal experiment. Under these conditions, the polyphenol yield could reach(7.875±0.008) mg/g. Similarly, the optimal extraction conditions of ripe M. asiatica were the volume fraction of ethanol 60%, solid-liquid ratio of 1∶25(g∶mL), water bath oscillation time with 30 min, and water bath oscillation temperature at 40 ℃, correspondingly, the polyphenol yield could reach(10.259±0.020) mg/g. The results of liquid chromatography showed that there were four kinds of polyphenols in the unripe M. asiatica, including chlorogenic acid(22.03%), proanthocyanidin B₂(8.875%), epicatechin(5.95%), and phloperidin(1.259%). These four kinds of polyphenols accounted for 38.117% of the total polyphenols. Meanwhile, the above four kinds of polyphenols in the ripe M.asiatica were 41.075%, 5.641 3%, 8.325 2%, and 0.499 8%, respectively. In addition, (+)-catechtin was also found with the fraction of 7.244 4%, and the above five kinds of polyphenols accounted for 62.786 5% of the toal polyphenols in the ripe M. asiatica. However most unknow polyphenols were not detected in the ripe M. asiatica. The ripe fruit had more polyphenol and nutrition than that in the unripe one.

The corn stalks were expanded by means of single-screw steam explosion to obtain different types of puffed corn straws, which were compounded with polypropylene resin(PP) to prepare a straw composite board. The changes of fiber before and after the explosion were investigated by scanning electron microscopy(SEM), reflected infrared(ART-FTIR), thermogravimetric analysis(TGA), differential scanning calorimetry(DSC), and Bauer fiber screening tests. The SEM results showed that corn stalks could effectively carry out the "three elements separation" through steam explosion, so that the surface structure of the stalks changed from smooth and regular to fibrous and powdery fragments. Meanwhile, the TGA, DSC and ATR-FTIR results showed that there was no obvious change in the fiber structure during the puffing process, while the hemicellulose and lignin were partially thermally decomposed. The mechanical properties of the straw composite board prepared by expanded corn stalks and PP were tested. Comparing with the board prepared by unexpaned corn stalks as the raw material, the impact resistance and tensile strength of steam expanded corn stalks increased by 15.69% and 17.24%, respectively.Similarly, the impact strength of boards prepared by expanded corn stalks modified by acrylates compolymer and ethylene-vinyl acetate copolymer increased by 156.74% and 100.98%, respectively, and the tensile strength increased by 83.42% and 12.03%, respectively.

Sugarcane bagasse(SCB) was pretreated by hydrogen peroxide-acetic acid(HPAC). The pretreated SCB was used as raw material for enzymatic hydrolysis, and then the hydrolysate was fermented for ethanol. The effects of pretreatment on enzymatic hydrolysis and fermentation of SCB were discussed. The results showed that HPAC pretreatment removed 88.85% lignin and retained 90.10% cellulose in the substrate when 20 g SCB was added with 150 mL aqueous hydrogen peroxide(i.e., 75 mL hydrogen peroxide(30%) and 75 mL water) and 150 mL acetic acid(99%), the amount of sulfuric acid was 0.5% of the HPAC solution volume, and the reaction was preformed at 70 ℃ for 2 h. The enzyme accessibility of substrate was 80.30 mg/g, which increased by 38.26% and 31.08% compared with those of hydrogen peroxide pretreatment (HP/70-SCB) and acetic acid pretreatment(AC/70-SCB) under the same conditions, respectively, and the surface coverage of lignin decreased from 0.66 to 0.22. After hydrolysis with enzyme dosage of 5 FPIU/g(substrate), the yield of glucose was 87.63%, which was 6.89 and 20.62 times than those of HP/70-SCB and AC/70-SCB, respectively. The mass concentration of ethanol produced by fermentation was 7.57 g/L, which was 7.65 and 22.94 times than those of HP/70-SCB and AC/70-SCB, respectively.