超声波辅助木片常压浸渍及其漂白

采用化学热磨机械浆（CTMP）工艺,以桉木与杨木2种木材为原料,初步研究了超声波辅助木片常压浸渍及其漂白效果。通过监测体系中的残余氢氧化钠的量来探究外部环境体系（温度、时间和用碱量）对超声波辅助木片常压浸渍的影响,结果表明：超声波辅助处理浸渍,桉木为温度75℃,时间30 min,用碱量6%;杨木为温度75℃,时间30 min,用碱量5%,此较优条件下,桉木白度提高2.83%（ISO）,残余过氧化氢质量分数提高了4.4个百分点,碱吸收量达41.5 kg/t,较未经超声波处理后的桉木的碱吸收量提高了5.06%;杨木白度无变化,而残余过氧化氢质量分数提高了2.73个百分点,碱吸收量达38.75 kg/t,较未经超声波处理的杨木碱吸收量提高了6.15%。     

木质纤维物料的爆炸冲击裂解预处理新方法

研究了一种新的天然木质纤维原料膨化裂解爆炸冲击预处理技术。结果表明，玉米芯等天然木质纤维试样处理后，纤维束长度变短、排列呈无序化，纤维生物组织形态和结构发生明显变化，呈膨化疏松状态；稀酸水解定量测定结果表明，处理后试样的总还原精得率获得大幅度提高。玉米芯试样的纤维素水解率达80％以上，水解率和水解速率成倍提高。     

搅拌方式对Ni-Fe合金镀层中铁的质量分数的影响

研究搅拌方式对Ni-Fe合金镀层显微组织形貌、铁的质量分数的影响,最终获得最佳工艺下的搅拌方式.采用扫描电子显微镜观察镀层微观形貌,X-ray衍射仪分析镀层相结构,能谱仪对镀层成分进行分析.结果表明:搅拌方式对镀层成分及显微形貌有较大影响.静止电沉积时镀层中铁的质量分数最低为38.82%;采用空气搅拌时铁的质量分数最高为55.06%,加强搅拌可增加镀层中铁的质量分数.无搅拌或搅拌不均匀时,镀层会出现针孔、裂纹、结晶不致密等疵病;搅拌均匀时,镀层细致,排列致密.     

彩色影像形态学的研究——染料云的形成过程与形态变化

在大颗粒(30—40μm)溴化银晶体上,使用高分散的油溶青成色剂,以CD-3为显影剂进行彩色显影,用显微摄影的方法,观察染料云在形成过程中的形态变化,并用显微密度计对图像进行了扫描。同时,研究了竞争成色剂和DIR成色剂对染料云形态的影响。     

网孔结构和可压缩材料抑制爆炸波的研究评述

对用网孔或可压缩材料抑制爆炸波的研究现状进行了评述 ,介绍了两种抑制爆炸波强度的理论和研究结果。指出了目前研究存在的问题 ,并对要解决的关键问题提出了见解     

高抗氧化铜银双金属粉的制备及性能研究

以铜粉为基体材料,在反应体系中加入铜离子掩蔽剂,采用化学置换法在铜粉表面多次包覆银及多次高温致密化处理,实现了银在铜粉表面的连续致密包覆。用X-射线衍射法、扫描电子显微镜、透射电子显微镜和热质量分析的方法对银包铜双金属粉进行了表征。结果表明,铜粉表面的银包覆层致密性好、包覆完全,在800℃以下的抗氧化性能良好。     

膨化聚四氟乙烯材料的制备与性能研究

采用在聚四氟乙烯中添加成孔剂的方法,制备了具有微孔结构的膨化聚四氟乙烯材料,研究了成孔剂处理对聚四氟乙烯压缩回复性能的影响。结果表明,随着成孔剂处理量的增加,膨化聚四氟乙烯密度减小,孔隙率增大,邵氏硬度减小;成孔剂种类不同,膨化聚四氟乙烯压缩回复性能也不同。     

荧光显微图像技术创新与推广

荧光显微图像技术是在荧光显微镜技术基础上结合扫描成像系统发展起来的,作为研究储集层中流体性质的一种技术手段,在大庆石油勘探开发领域已广泛应用。该文主要阐述通过对荧光显微图像摄像系统的改进,提高图像解释符合率及技术应用水平,使其在油水层识别、水淹层评价技术领域为油田勘探开发发挥更大作用。     

工艺参数对铝合金化学镀镍层微观形貌的影响

在铝合金表面制备化学镀镍层。利用扫描电子显微镜,讨论工艺参数对合金镀层微观形貌的影响。通过显微硬度计,确定不同合金镀层的显微硬度。结果表明:温度对合金镀层的微观形貌影响较大,在84℃下可获得均匀致密的合金镀层;光亮剂有较好的细化晶粒作用,添加光亮剂后镀层的平整度提高,晶粒更加均匀细致;合金镀层具有较高的显微硬度,最高可达5 620MPa。     

视频显示显微分析仪研制

一台自制的热显微分析仪，由小型实验电炉及升降台，温度控制器，光学显微镜头，CCD红外摄象头及视频显示器组成，用于直接观察在加热过程中材料的物理化学变化，并可实现计算机图像处理。     

加压热水预处理温度对毛白杨木材结构及酶解效果的影响

采用加压热水对毛白杨进行预处理,利用扫描电镜（SEM）、X射线衍射仪（XRD）、傅里叶变换红外光谱（FT-IR）等研究了预处理温度对毛白杨木材及其酶解材微结构的影响,并考察了预处理温度对还原糖得率的影响。结果表明：毛白杨木材经加压热水处理后结构松散,纤维形态和表面结构发生了改变;加压热水处理温度超过180 ℃以后,酶解前后物料的结晶度降低明显,酶解后的降幅最大可达74%。随着预处理温度的增加,木材酶解还原糖得率先增加后减小,其中预处理温度为200 ℃时还原糖得率最大可达38.3%。     

Change of pyrolysis characteristics and structure of woody biomass due to steam explosion pretreatment

Steam explosion (SE) pretreatment has been implemented for the production of wood pellet. This paper investigated changes in biomass structure due to implication of steam explosion process by its pyrolysis behavior/characteristics. Salix wood chip was treated by SE at different pretreatment conditions, and then pyrolysis characteristic was examined by thermogravimetric analyzer (TGA) at heating rate of 10 K/min. Both pyrolysis characteristics and structure of biomass were altered due to SE pretreatment. Hemicellulose decomposition region shifted to low temperature range due to the depolymerization caused by SE pretreatment. The peak intensities of cellulose decreased at mild pretreatment condition while they increased at severe conditions. Lignin reactivity also increased due to SE pretreatment. However, severe pretreatment condition resulted in reduction of lignin reactivity due to condensation and re-polymerization reaction. In summary, higher pretreatment temperature provided more active biomass compared with milder pretreatment conditions.     

爆破处理对赤桉板材干燥速度的影响

对赤桉板材在压力为0.8MPa,温度为95℃的条件下进行爆破预处理,并与未处理板材的干燥速度作对比研究。爆破处理后赤桉板材含水率有所下降,与未爆破的赤桉板材相比,渗透性和干燥速度有明显的提高。当含水率在50%～30%时,爆破处理过的赤桉板材和未爆破处理过的赤桉板材的含水率降低速度最快;当含水率在纤维饱和点以下时,爆破处理对赤桉板材干燥速度的改善效果不显著。同时在该试验压力下,赤桉板材的力学强度没有降低,说明爆破预处理没有影响赤桉板材的宏观结构,具有一定的可行性。     

Mechanism for De-aspirating Pits in Subalpine Fir by Steam Explosion Prior to Drying

Subalpine fir with wet wood (wet pocket wood) is regarded as a species that is difficult to dry. Aspirated pits are one of the principal reasons to block water paths up in wood tracheids. Steam explosion is a technology to improve the dryability of subalpine fir by creating water paths in some aspirated pits.

In this study, green subalpine fir lumber was treated with steam explosion. Samples taken from the lumber before and after the treatment were observed with a scanning electron microscope (SEM). Amechanism for de-aspirating pits during the process of steam explosion was proposed based on the understanding of wood anatomy. A series of observations with the SEM verified the mechanism for de-aspiration. The observations also discovered that the fractures in the pits between ray parenchyma cells and earlywood tracheids occurred during the process of steam explosion.     

Long‐term lime pretreatment of poplar wood

Long‐term lime pretreatment has proven to increase digestibility of many herbaceous lignocellulose sources; but until this work, its effects had not been evaluated on wood, whose lignin content is higher, and therefore, more recalcitrant to enzymatic hydrolysis. In this study, the mild conditions of long‐term lime pretreatment (1‐atm pressure, temperatures ranging from 25 to 75°C, and reaction times between 1 and 12 weeks, with and without air) were systematically applied to poplar wood available in two batches with different lignin contents. These batches were designated as low‐lignin biomass (LLB) with lignin content of 21.4% and high‐lignin biomass (HLB) with lignin content of 29.1%. Full factorial designs resulted in 79 samples of pretreated poplar that were analyzed for lignin and carbohydrates pretreatment yields, and enzymatic digestibility (15 FPU/g glucan in raw biomass cellulose loading). After aerated lime pretreatment at 65°C for 4 weeks, and subsequent enzymatic hydrolysis, an overall yield of 0.76 g glucan + xylan recovered per gram glucan + xylan in raw biomass was obtained. This is equivalent to an increased poplar wood digestibility of 7.5‐fold compared with untreated biomass. Different batches of the feedstock resulted in different lignin and carbohydrates pretreatment yields; however, overall yields of carbohydrates (combining pretreatment and enzymatic hydrolysis) were similar. © 2010 American Institute of Chemical Engineers AIChE J, 2011     

Decorated wood fiber/high density polyethylene composites with thermoplastic film as adhesives

It is difficult for wood fibers/high density polyethylene (WF/HDPE) composites to laminate with poplar (Populus tomentosa) wood veneer due to its nonpolar and imporous surface. In present study, four types of thermoplastic films, include two sorts of chlorinated polypropylene (CPP32 and CPP22) film and a mixture film of maleic anhydride grafted polyethylene (MAPE) and HDPE, were developed to glue poplar wood veneer onto WF/HDPE composite board under heat-pressing. The intermediate layer has well water resistance when used aforementioned films. Optical microscopy and scanning electron microscopy (SEM) results show that CPP32 with higher melt flow rate had the higher permeability into poplar wood and fitness with WF/HDPE surface than CPP22; accordingly, the bonding strength of CPP32 was higher than CPP22. MAPE/HDPE film formed the strongest bonding layer for the high compatibility with the WF/HDPE surface which confirmed using SEM, and the covalent bonding between the poplar veneer and MAPE were confirmed using fourier transform infrared (FTIR). Compared to the high heat-press temperature of MAPE/HDPE, CPP32 has the lower processing temperature and acceptable bonding strength. CPP32 and MAPE/HDPE film both suited as the bonding intermediary to substitute traditional adhesive to manufacture veneered wood-plastic composite boards.     

云芝(Coriolus versicolor)高木质素降解活性菌株筛选的研究

从自然界中分离了32个云芝菌株，比较了它们在含愈创木酚的土豆培养基中的变色反应和对杨木粉的降解能力，表明不同的菌株对木材的降解能力和降解方式有很大的差异，但都有一定的选择性，从中筛选出了木质素降解能力较强（30天内，40％左右klason木素），选择性较高的菌株。和Phanerochaetechrysosporium相比，它们的木质素降解率提高近一倍，而综纤维素降解率则有不同程度的减少。     

Effect of the Loosening of Wood Texture on the Mercerization of Cellulose in Wood

When wood was treated with 23% aqueous sodium hydroxide followed by washing with water and drying, no lattice conversion of cellulose was observed under the experimental conditions employed. On the other hand, wood subjected to a pretreatment that results in the loosening of its morphological texture, upon mercerization, showed a varying degree of lattice conversion. The explosion process and the TFA (trifluoroacetic acid) treatment were used to achieve the loosening of wood texture. The lattice conversion of cellulose was studied by X-ray diffractograms. The extent of lattice conversion was found to depend on the conditions of the pretreatment used to achieve the loosening of wood texture. The extent of lattice conversion increased with an increase in the explosion temperature and the time at temperature, within the range of these experiments. Increased duration of TFA pretreatment, at a particular temperature, resulted in a higher degree of lattice conversion. These observed facts have been ascribed to the extent of loosening of the morphological texture of wood, which allows comparatively free swelling of cellulose in alkali.     

Surface properties of methyl methacrylate hardened hybrid poplar wood

The surface properties of fast‐growing poplar clones and their methyl methacrylate (MMA)‐hardened wood related to potential end uses were investigated. Samples from 24 trees of six hybrid poplar clones in one plantation in Quebec were hardened with MMA. The effects of MMA hardening on the density and surface properties were studied. Scanning electron microscopy and Fourier transform infrared analysis showed that filling the voids in the wood structure was the main hardening mechanism. The incorporation of the polymer increased the density of all of the poplar clones by 120–160%. The Janka hardness was found to be 2.5–4 times higher in the treated poplar wood than in the untreated poplar wood. The treated wood also exhibited superior abrasion resistance compared to the controls. The results indicate that hardening with MMA improved the surface properties and that the MMA‐hardened wood was comparable to natural hardwoods. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

不同预处理对剑麻纤维组分和结构的影响

采用机械破碎、酸法蒸煮、氢氧化钠溶液碱法蒸煮、氨水处理和蒸汽爆破等五种不同物理和化学方法对剑麻纤维进行处理。通过化学分析、扫描电镜(SEM)及红外光谱(IR)等手段表征了处理前后剑麻纤维组分和结构的变化。结果表明,不同预处理方法均使剑麻纤维组分分离,杂质含量降低,纤维素含量提高。其表面形态和聚集态结构根据不同的处理方法而发生不同变化。在五种方法中以碱煮和蒸汽爆破处理效果较佳。