生物质复合材板坯内部孔隙形成的模拟与实验分析

应用计算机模拟的方法研究了生物质复合材板坯内部孔隙的形成。通过对板坯内孔隙体积比率与加工参数包括原料的几何形状、材料的公称密度之间的关系的考察结果表明,由模型得到的数据与由实验得到的数据的结果趋向一致。研究中通过在板材热压实验中测量板坯中心部位的温度和气体压力变化来说明孔隙对热和质传输的影响,实验和分析的结果也验证了该模型和模拟的方法对于研究生物质复合材板坯内孔隙具有一定的有效性。

多孔生物质基材用于城镇污水处理厂尾水深度净化的试验研究

为探讨城镇污水处理厂尾水的深度净化技术,以农林秸秆生物质发电后的废料制成的生物质基材为填料,考察填料对城镇污水处理厂尾水的处理效果,并借助Miseq高通量测序技术对移动床生物膜反应器(MBRR)中的悬浮填料,多孔生物质基材中生物膜的微生物群落组成和结构进行了解析。结果表明:多孔生物质基材能够深度净化市政污水处理厂尾水,对MBBR出水NH4+-N、TN、COD和TP的平均去除率分别提高了0.9%、19.0%、7.1%和10.5%。此外,由于多孔生物质基材的微生物物种丰度和多样性高于MBBR,其微生物群落结构中反硝化相关菌属占优势(24.2%),并含有一定比例的聚磷菌(4.6%)和自养硝化菌(1.3%),因此多孔生物质基材更利于脱氮除磷等功能菌群的富集和生长,可对污水的强化处理起关键作用。该结果可为城镇生活污水处理厂尾水深度净化过程中强化脱氮除磷的工程化应用提供依据和参数。

携菌新型生物质基材用于微污染水体治理

针对河道微污染水,以农林秸秆生物质发电后的废料制成的生物质基材为填料,将异养硝化菌Pseudomonas固定于其中,采用人工湿地模拟装置考察携菌生物质基材对微污染河道水体的处理效果,并与火山岩进行比较;借助高通量测序技术对生物膜的微生物群落进行解析,最后将携菌生物质基材应用于河道净化工程中。结果表明:携菌生物质基材对进水COD、NH_(4)^(+)-N、TP的去除率分别达到81.0%、98.2%、96.7%,其除污效果及稳定性均优于火山岩。生物质基材的微生物群落结构以Alphaproteobacteria菌属(36%)和Pseudomonas菌属(13%)为主,表明生物质基材携带增效菌种Pseudomonas后在脱氮方面有较大优势。将携菌生物质基材应用于处理量为150 m^(3)/d的城市内河点源污染治理工程,携菌生物质基材可进一步稳定去除传统AO装置尾水中的COD、NH_(4)^(+)-N和TP,出水水质可达到地表Ⅳ类水标准,且生物质基材所携带Pseudomonas仍占据一定比例(0.65%)。

Adsorption of Cu^(2+) from aqueous solution by modified biomass material

Cu2+ adsorption from simulated aqueous solution was investigated using a modified spent shiitake substrate (MSSS). The results showed that the MSSS has a high adsorption efficiency and removal performance. The Cu2+removal rate of the MSSS reached above 95%. Compared with spent shiitake substrate (SSS), the specific surface area, electronegativity and surface functional groups of the MSSS were all improved, resulting in a high adsorption capacity. The Cu2+ adsorption of MSSS reached equilibrium after 0.75 h and was an exothermic reaction. The SEM and EDS analyses of the MSSS before and after Cu2+ adsorption showed that the pores on the surface of the MSSS were occupied after adsorption and the Cu content increased but the Na content decreased.

Effects of Different Mulching Methods on Primary Substances and Secondary Substances of Lycium barbarum L.

[Objective] The aim was to provide certain theoretical basis for stuides on the high yield and high quality cultivation of Lycium barbarum L..[Method] Under yield conditions,the accumulation of primary substances and secondary substances of Lycium barbarum L.was studied under different mulching treatments.[Result] Different mulching methods all had a certain effects on the contents of main primary substances and main secondary substances in Lycium barbarum L.fruit.Among them,carbohydrates and flavonoids contents in Lycium barbarum L.were both obviously increased under straw-film mulching;carotenoid content was decreased relatively;hundred leaf weight,1 000-grain weight and yield of Lycium barbarum L.were increased to a certain extent,but there was no obvious effect on the shape of fruit.Besides,the yield of Lycium barbarum L.had no significant positive correlation with total carbohydrate and polysaccharide,almost had no correlation with flavonoids,and had no significant negative correlation with carotenoid.[Conclusion] The reasonable mulching could improve the yield and quality of Lycium barbarum L..

斯洛伐克总理菲佐出席中国林科院与斯洛伐克国家林业中心合作协议签字仪式

2月6日,中国林业科学研究院与斯洛伐克国家林业中心合作协议签字仪式在北京保利大厦举行。我院院长张守攻和斯洛伐克驻华大使贝尔托克分别代表双方在合作协议上签字。斯洛伐克总理菲佐、经济部长Peter Ziga、农林部长Miroslav Jurena,中国商务部副部长姜增伟、驻斯洛伐克大使黄忠坡出席签字仪式。国家林业局国际合作司副司长章红燕、我院副院长刘世荣和院办公室、国际合作处有关人员也出席了签字仪式。签字仪式后,张守攻院长、章红燕副司长等还出席了斯洛伐克——中国商务论坛开幕式。

Experimental investigation of performance properties and agglomeration behavior of fly ash from gasification of corncobs

The gasification industries make use of biomass residue as feedstock to produce synthesis gas,but the gasification of this waste biomass generates tons of ash everyday.Performance properties and agglomeration behavior of corncob ash(CCA) collected from the gasification of corncobs in a pilot-scale gasification station were investigated by using some experimental methods.Based on the chemical composition results,the agglomeration tendency of CCA from combustion and gasification process was also analyzed.Chemical analysis shows that the fly ash is mainly composed of inorganic matters formed by K,Mg,Ca,Na,Fe,Al,S,etc.The agglomeration characteristics indicate that the slagging degree increases with the increase of ashing temperature,and the slagging tendency of these CCA samples from gasification or combustion is different with various slagging indices.All CCA samples from combustion or gasification can cause slagging/fouling problems in thermal conversion systems.The applications of CCA are closely related to its performances,and CCA has the potential to be used in various fields,for example,as a material for ceramic products and activated carbon,as an adsorbent,as a crude fertilizer,and as a structural material.

Regenerative Engineering for Knee Osteoarthritis Treatment： Biomaterials and Cell-Based Technologies

Knee osteoarthritis （OA） is the most common form of arthritis worldwide. The incidence of this disease is rising and its treatment poses an economic burden. Two early targets of knee OA treatment include the predominant symptom of pain, and cartilage damage in the knee joint. Current treatments have been beneficial in treating the disease but none is as effective as total knee arthroplasty （TKA）. However, while TKA is an end-stage solution of the disease, it is an invasive and expensive procedure, Therefore, innovative regenerative engineering strategies should be established as these could defer or annul the need for a TKA. Several biomaterial and cell-based therapies are currently in development and have shown early promise in both preclinical and clinical studies. The use of advanced biomaterials and stem cells independently or in conjunction to treat knee OA could potentially reduce pain and regenerate fo- cal articular cartilage damage. In this review, we discuss the pathogenesis of pain and cartilage damage in knee OA and explore novel treatment options currently being studied, along with some of their limitations.

Potential of Forest Wood Biomass in Bulgaria, Market and Possibilities for Its Utilization

The total annual increment in forests in Bulgaria is about 14.5 Mio m^3 of the growing stock, of which the harvesting amounts at 5-6 Mio m^3 of fallen wood. An increase of the actually harvested quantities of wood is possible and it may rise up to 8-10 Mio m^3. The volume of forestry waste is 1,066,900 m^3, incl. economically accessible forestry waste are 373,400 m^3. Every year, there are about 3.0 Mio m^3 of wood which are obtained by the wood category, being 2.5 Mio m^3 of that same one used by the population as fire wood for stoves about 40% efficiency. In that connection, a map has been elaborated of the economically accessible forest-wood waste from the wood harvesting. Taking into account the data on the share of that wood, is considered capable for energy production, as well as the fact that a part of fire wood shall not be used in the conventional way but shall be processed, instead, that is to say, transformed into chips, pellets and briquettes, a map of category of woods has been made for the purposes and needs of this elaboration. There are some reserves as regards to thinning operations where small- and medium-sized wood is harvested and from temporarily inaccessible forest exploitation basins or the so called ＂closed basins＂ should arrive to. This paper proposes the most promising technologies for waste processing and transformation into chips, which could be applicable in Bulgaria and in some other countries as well.

Potential Energy of Crops

This work consists of estimating the energy achieved from all land and water-based vegetations. This real potential is determined by identifying 10 biomass samples taken from vegetable resources which are favored by their aptitude of adaptation to the conditions of Iran. The net energy values of the 10 biomass samples change in the range of 13.65-18.00 MJ/kg using bomb calorimeter. By means of least squarere regression method all correlations were found. The results of 10 different biomass materials have been used to develop a linear equation correlation.

The Effect of Bioceramic Composite Extracellular Matrixes Used to Repair Bone Deficiency on Relevant Blood Biochemical Indices

At the base of experimental animal model construction of bone defect in New Zealand rabbit, the promoting repair effect of bioactive ceramics on bone defect as well as its machanism was studied through testing body mineral elements, enzymes related to bone morphogenetic proteins and some biochemical indexes. Refering to some documents, materials of TCP, CHA and HA were combined and TCP/BMP/ TCP-β1 and CHA/BMP/ TCP-β1,HA/BMP/ TCP-β1 composite materials were made. All kinds of them were implanted into the radial defect site of rabbit, respectively. The chosen blood indexes (Ca, P, ALP, GGT, AST, ALT, TPA, BUN and Cr) were tested by colorimetry, speed rate and bromocresol green testing methods. No abnormal effects were found in any animal after operation. Serum concentrations of Ca, P and ALP were increased with the length of time in all groups of the three kinds of composite material, mixed material and pure materials. The increases in composite material groups were more significant (P<0.05). Comparison of the three kinds of material showed TCP>CHA>HA. There was a tendency of increased TPA and decreased BUN with the length of time. There was no significant difference between the composite material groups and pure material group (P>0.05). The three kinds of bioactive ceramics composed of extracellular matrix could increase the serum concentrations of Ca and P and activity of ALP after being implanted into defect bone and showed some repairing capacity. This provided a new area of machanism study of bone defect repair by biomaterials.

Interface and Surface Properties of Nano-hydroxyapatite /Poly (1,4-PhenyleneSulfide)-Poly(2,4-Phenylene Sulfide Acid) Copolymer Composite

The interface and surface properties of nano-hydroxyapatite(n-HA) and poly( 1, 4-phenylene sulfide)-poly (2,4-phenylene sulfide acid)(PPS-PPSA) copolymer composite were investigated. The results show that there are some strong interface combinations of calcium ion (Ca2+ ), car-boxyl (-COO- ) and phosphate radicle ion (PO_4~3- ) between copolymer and n-HA in the composite. The presence of the 2,4-phenylene sulfide acid in copolymer can increase the affinity to n-HA, which causes the formation of chemical bindings between the PPS-PPSA copolymer and n-HA. XRD analysis and IR surface analysis indicate that n-HA is not encapsulated by copolymer but exposed on the surface of the composite, and has same structure and properties with the origi-nal n-HA. The presence of the interface chemical bindings between the PPS-PPSA copolymer and n-HA can increase the content of n-HA in composite but does not cause the decrease of the composite mechanical strength.

Ethanol Production Process by Lignocellulosic Material Fermentation from Water Hyacinth Biomass

In order to take advantage of the lignocellulosic material in water hyacinth （Eichhornia crassipes）, dehydration pretreatment in the first step and then sodium hydroxide and hydrogen peroxide pretreatment was performed. The microorganism used for the fermentation process was Zimomonas mobilis. Batch fermentation experiments were carried out with four tests using 22 factorial design with two levels leadings to evaluate the effect of NaOH concentration, conditioning salts as independent variables and ethanol produced as a dependent variable. The optimum condition with higher amount of glucose hydrolyzed and ethanol was： substrate conditioning cellulases, it was pretreated 10% NaOH, with 92.38% conversion of glucose to ethanol and yield of 0.47 g ethanol per g of glucose and 0.018 g ethanol per g of biomass.

Execution of Measurements for Determining the Parameters Affecting the Thermochemical Treatment of Brine Treated Biomass and the Adsorption of Dyes

Brine is a solution of salt （usually sodium chloride） in water. In different contexts, brine may refer to salt solutions ranging from about 3.5% （a typical concentration of seawater, or the lower end of solutions used for brining foods） up to about 26% （a typical saturated solution, depending on temperature）. Adsorption onto activated carbon is the most widespread technology for the removal of pollutants from water and wastewaters. In this study, continuous fixed-bed-column systems were investigated. The adsorbents which authors use are： spruce （Picea abies） untreated, spruce modified by autohydrolysis. The column systems were filed with biomass at various initial dye concentrations, flow rates and bed-depths. The column kinetics of MB （Methylene Blue） adsorption on spruce （Picea abies） untreated, spruce modified by autohydrolysis was simulated. Economies arise when the facility that can use such adsorption materials is near a source of a lignocellulosic waste as agricultural residues, thus saving transportation cost and contributing to industrial ecology at local level.

Life cycle assessment of alkali-activated materials:a systematic literature review

The physical-mechanical,chemical,and durability characteristics of alkali-activated materials(AAMs)have been widely investigated.However,a critical gap in the literature is the lack of a comprehensive overview of recently published literature regarding the life cycle assessment(LCA)of these binders.This study aims to fill that gap by conducting a systematic literature review of globally published literature on the topic.This paper consolidates knowledge by searching different databases,focusing on LCA studies that used AAMs as pastes,mortars,concretes,bricks,and rammed earth/soil blocks.The selected articles were reviewed and categorized based on precursors,alkaline activators,functional units,system boundaries,life cycle inventory databases,allocation,impact methodologies,and software used.Additionally,this paper also critically analyzes the key challenges of LCA for AAMs.The major challenges were identified as selecting a functional unit,subjectivity in boundary systems,and data interpretation.This work concludes that AAMs show substantial advantages in global warming potential compared to ordinary Portland cement-based materials;however,the average of other categories such as marine ecotoxicity and ozone layer depletion has been reported to be higher than for the reference samples.

Advanced carbon materials for flexible and wearable sensors

Flexible and wearable sensors have drawn ex-tensive concern due to their wide potential applications inwearable electronics and intelligent robots. Flexible sensorswith high sensRivity, good flexibility, and excellent stabilityare highly desirable for monitoring human biomedical signals,movements and the environment. The active materials and thedevice structures are the keys to achieve high performance.Carbon nanomaterials, including carbon nanotubes （CNTs）,graphene, carbon black and carbon nanofibers, are one of themost commonly used active materials for the fabrication ofhigh-performance flexible sensors due to their superiorproperties. Especially, CNTs and graphene can be assembledinto various multi-scaled macroscopic structures, includingone dimensional fibers, two dimensional films and three di-mensional architectures, endowing the facile design of flexiblesensors for wide practical applications. In addition, the hybridstructured carbon materials derived from natural bio-mate-rials also showed a bright prospect for applications in flexiblesensors. This review provides a comprehensive presentation offlexible and wearable sensors based on the above variouscarbon materials. Following a brief introduction of flexiblesensors and carbon materials, the fundamentals of typicalflexible sensors, such as strain sensors, pressure sensors,temperature sensors and humidity sensors, are presented.Then, the latest progress of flexible sensors based on carbonmaterials, including the fabrication processes, performanceand applications, are summarized. Finally, the remainingmajor challenges of carbon-based flexible electronics are dis-cussed and the future research directions are proposed.

Converting biomass into efficient oxygen reduction reaction catalysts for proton exchange membrane fuel cells

It is urgent to develop low-cost but efficient oxygen reduction reaction(ORR)catalysts for the emerging clean energy devices of fuel cells based on proton exchange membrane.Herein,we report a facile method to covert the biomass of black fungus into an efficient ORR catalyst.The black fungus undergoes hydrothermal and pyrolysis processes to transform into carbon-based materials.The as-obtained BF-N-950 catalyst shows prominent ORR catalytic activities in both acidic and alkaline electrolytes with a half-wave potential reaching 0.77 and 0.91 V,respectively.A membrane electrolyte assembly was fabricated with the as-obtained BF-N-950 as the cathode catalyst which shows a high peak power density of255 mW cm^-2.The study shows the potential of converting conventional biomass into low-cost ORR catalyst,which is promising for the fuel cell technology.

Production and closed-loop recycling of biomass-based malleable materials

The search of biomass-based substitutes for fossil-based plastics has become a pressing task due to the severe long-term threats of plastic wastes to the ecosystem.However,the development in this area is strongly impeded by the high cost of biomass separation and the poor processability of unseparated biomass.Herein,we demonstrate,for the first time,an efficient and scalable method to generate greener plastics by directly integrating unseparated biomass waste(i.e.,wood powder)with crosslinked covalent adaptable networks.Through a simple compression molding process,the wood biomass and polymer particles can be fused together to form a continuous material,which is endowed with repairability,reprocessibility,and closed-loop full recyclability.The method demonstrated in this work paves the way for largescale industrial production of environmentally friendly biomass-based plastics.

Treatment of osteonecrosis of femoral head with BMSCsseeded bio-derived bone materials combined with rhBMP-2 in rabbits

Objective： To evaluate the effect of autologous bone marrow mesenchymal stem cells （BMSCs） seeded bio-derived bone materials （BBM） combined with recombinant human bone morphogenetic protein-2 （rhBMP-2） in repairing defect of osteonecrosis of femoral head （ONFH）. Methods： Early-stage osteonecrosis in the left hip was induced in 36 adult New Zealand white rabbits （provided by the Animal Center of Guangxi Medical University, Nanning, China） after core decompression and delivery of liquid nitrogen into the femoral head. Then the animals were divided into three groups according to the type of implants for bone repair： 12 rabbits with nothing （Group Ⅰ, the blank control group）, 12 with BBM combined with rhBMP-2 （Group Ⅱ）, and 12 with BMSCs-seeded BBM combined with rhBMP-2 （Group Ⅲ）. At 4, 8, and 12 weeks after surgery, X-ray of the femoral head of every 4 rabbits in each group was taken, and then they were killed and the femoral heads were collected at each time point, respectively. Gross observation was made on the femoral heads. After hematoxylin and eosin staining, Lane-sandhu scores of X-ray and bone densitometry were calculated and the histomorphometric measurements were made for the new bone trabeculae. Results： At 12 weeks after surgery, two femoral heads collapsed in Group Ⅰ, but none in Group Ⅱ or Group Ⅲ. X-ray examination showed that the femoral heads in Group I had defect shadow or collapsed while those in Group II had a low density and those in Group III presented with a normal density. Histologically, the defects of femoral heads were primarily filled with no new bone but fibrous tissues in Group Ⅰ. In contrast, new bone regeneration and fibrous tissues occurred in Group II and only new bone regeneration occurrd in Group Ⅲ. Lane-sandhu scores of X-ray, bone mineral density and rate of new bone in trabecular area in Group Ⅲ were higher significantly than those of the other two groups. Conclusions： Our findings indicate a superior choice of repairing the experimental defect of OFH with BMSCsseeded BBM combined with rhBMP-2.

Bacterial cellulose-regulated synthesis of metallic Ni catalysts for high-efficiency electrosynthesis of hydrogen peroxide

The decentralized production of H_(2)O_(2) via a twoelectron oxygen reduction reaction(2e^(-)ORR)has emerged as a promising alternative to the energy-intensive anthraquinone(AQ)process.However,its practical application requires 2eORR electrocatalysts with high activity and selectivity.Herein,we report the synthesis of metallic Ni nanoparticles anchored on bacterial cellulose-derived carbon fibers(Ni-NPs/BCCF)via a facile impregnation-pyrolysis method as efficient electrocatalysts for 2 e-ORR to H_(2)O_(2).By tuning the amount of Ni precursor,the best electrocatalytic performance toward 2 eORR was achieved for Ni-NPs/BCCF-20.7,affording a high H_(2)O_(2) selectivity of ~90% and an onset potential of 0.75 V vs.reversible hydrogen electrode(RHE)in an alkaline electrolyte.Ni-NPs/BCCF-20.7 achieved the largest H_(2)O_(2) yield rate of 162.7±13.7 mmol gcat^(-1)h^(-1) and the highest Faradaic efficiency of 93.9%±4.2% at 0.2 and 0.5 V vs.RHE from the bulk ORR system,respectively.Theoretical calculations revealed the more favorable"end-on"adsorption configuration of molecular oxygen on the exposed Ni(111)plane,which can effectively suppress the O-O bond dissociation,resulting in high selectivity for H_(2)O_(2) generation.