KOH微波活化法处理竹炭的研究

研究了以自制的快速裂解产物竹炭为原料,采用KOH-微波辐射活化法制备竹质活性炭.利用正交试验探讨了不同因素对竹质活性炭性质的影响.最佳工艺条件为KOH质量分数 25 %,浸渍时间 24 h,微波功率 800 W,活化时间 7 min,所制备的活性炭产品的碘吸附值为 1 239.08 mg/g,亚甲基蓝吸附值为 274.95 mg/g,比表面积为 1 394.16 m2/g,亚甲基蓝吸附值为国家一级品标准(GB/T 13803.2-1999)的2.04倍,同时测定了活化前后竹炭的红外光谱.结果表明,活化后竹炭表面结构有了较大的修饰,增加了较多的表面化学官能团,从而提高了竹炭的比表面积和吸附性能.     

萃取蔗皮二十八烷醇工艺

以果蔗皮为试验原料,采用响应曲面分析法（RSM）优化超临界CO2萃取蔗皮二十八烷醇的工艺条件。在单因素试验的基础上,选取萃取压力、温度和时间为影响因子,应用Box-Behnken中心组合进行了3因素3水平的试验设计。验证了二次多项数学模型的有效性,并探讨了萃取压力、温度、时间对二十八烷醇萃取物产率的作用规律。统计分析表明压力、温度以及压力和时间的交互作用对二十八烷醇的提取量有显著影响。根据该模型进行了工艺参数的优选,试验所得二十八烷醇超临界CO2萃取的优化工艺条件为：压力31．2MPa,温度44．8℃,时间226．17min,该条件下提取量高达7．5855mg／g。     

响应面法优化超声波辅助提取黑木耳多糖的工艺研究

黑木耳是我国重要的药食兼用真菌,采用超声波辅助提取黑木耳多糖的方法,改进了传统的浸提工艺。研究超声功率、超声时间、液料比及水浴浸提时间等因素对黑木耳多糖提取效果的影响,在单因素基础上,进行响应面分析实验,结果表明,超声波辅助提取黑木耳多糖的最佳工艺条件为：超声功率520W,超声时间13min,液料比132,水浴浸提时间3.1h,黑木耳多糖得率可达16.59%。     

Key rock strata effecting analysis on surface boreholeshear deformation fracture

A good method for creating a surface borehole for withdrawing coal strata methane is to build before excavation and use during the whole process. But the excavation greatly affects the overlying rock strata, and when the excavation face passes through the     

磁性高分子微球及其在食品工业中的应用

磁性高分子微球是指通过适当的方法使有机高分子与无机磁性物质结合起来形成的具有一定磁性及特殊结构的微球。与传统的固定化技术相比,磁性高分子微球易于修饰、分离,目前主要应用在生物医学和生物工程学领域。重点介绍磁性高分子微球在食品工业中的应用,介绍了磁性高分子微球的制备、性质和表面修饰方法。     

响应面法优化超声波提取核桃油工艺的研究

应用超声波法辅助浸提核桃油,在单因素实验的基础上,通过Box-Benhnken中心组合实验,确定超声波辅助提取核桃油的最佳工艺条件为:正己烷作提取溶剂,液料比为7(mL∶g),提取温度53℃,超声时间48 min,超声波功率120 W,核桃油提取率达到61.91%。     

Relationships of culm surface area to other culm dimensions for bamboo, Phyllostachys pubescens

We determine the relationships of culm surface area to other culm dimensions for one of the largest bamboo species, Phyllostachys pubescens Mazel ex Houzeau de Lehaie. A total number of 150 sample culms were collected from a stand of P. pubescens in Mt. Toshima, Kumamoto Prefecture, western Japan. The culm surface area for each sample was calculated, and then the relationships of the culm surface area to basal area and product of diameter at breast height (dbh) and culm height were analyzed. The relationship between culm surface area and basal area could be described successfully by the power equation, whereas there was a linear relationship of culm surface area to product of dbh and height. Although the regression equations determined here would be useful in estimating culm surface area of P. pubescens, it is necessary to select an appropriate equation depending on the purpose and available time and labor.     

西藏林芝地区森林防火阻隔带作用研究

介绍西藏林芝地区森林火灾情况,分析森林火灾多发原因．以1999～2006年在察隅、波密、林芝3县收集的8次森林火警与火灾阻隔带数据及灾后调查数据为依据,以防火阻隔带烧损程度划分地表火行为等级,共划分为4级．防火阻隔带对中等强度以下的森林地表火能起到有效的阻隔作用．提出建设防火阻隔带要根据森林分布特点科学区划,统筹安排．     

Effects of preferential flow on soil-water and surface runoff in a forested watershed in China

Preferential flow is a runoff mechanism intermediate between matrix flow and surface flow, transmitting water at high velocity through the subsurface zone. To assess the effect of preferential flow on soil-water flow and surface runoff in a forested watershed, precipitation and volumes of preferential flow, matrix flow and surface runoff were measured over a period of four years in a forested watershed in the Three Gorges area of southern China. Results show that preferential-flow hydrographs have gentler rises and steeper recessions than those for matrix flow and surface runoff. Preferential flow as a percentage of soil-water flow ranged from 2.40% to 8.72% and the maximum preferential-flow velocity exceeded as much as 5600 times that of matrix flow. This shows that preferential flow plays an important role in the movement of soil water. Preferential flow has a significant effect on peak surface runoff by increasing the surface runoff rate and accelerating the appearance of peak surface runoff. Preferential flow can also prolong the duration of surface runoff. Surface runoff was observed to be positively correlated with preferential flow. The greater the sum of rainfall amount and antecedent precipitation is, the greater the effect of preferential flow on surface runoff is.     

东亚钳蝎神经毒素BmK CT三维结构分子建模及晶体生长条件的初步筛选

东亚钳蝎是一类广泛分布于我国且具有重要药用价值的野生资源.其氯离子通道神经毒素(BmK CT)对人脑神经胶质瘤细胞具有靶向特异性的抑制作用.利用SWISS-MODEL服务器对BmK CT进行蛋白质原子结构的同源建模,利用Insight II软件包对建模结果做能量最小化和分子动力学优化,获得最佳候选模型.三维结构对比分析表明,BmK CT与以色列蝎氯通道毒素(Cltx)三维结构极为相似,均由一个α-helix和两个反向平行的β-sheet构成,但BmK CT属于βαβ型,而Cltx属于αββ型.表面静电势分析表明,BmK CT和Cltx分子表面分布着大量正电势,暗示两分子功能相似,且其中的碱性氨基酸及产生的正电势对其与受体结合起决定作用.采用晶体生长试剂盒(Crystal Screening Kit)中的51个缓冲液配方筛选BmK CT的结晶条件,在7号配方(1.4 mol/L 乙酸钠,0.1 mol/L 甲次砷酸钠,pH 6.51中筛选到柱状六边形晶体.