苏云金杆菌晶体蛋白不同给药途径对小鼠体内日本血吸虫的作用

将小鼠人工感染日本血吸虫尾蚴 40条 /只 ,30 d后将苏云金杆菌伴胞晶体蛋白以不同的给药方式 (静脉注射、肌肉注射、灌胃、腹腔注射 )给药 ,用药后 15 d剖检查虫。结果发现 ,各种给药方式对小鼠体内的日本血吸虫成虫均有一定的效果 ,但以静脉注射效果最好 ,肌肉注射次之 ,灌胃和腹腔注射效果较差。这表明苏云金杆菌制剂作用于小鼠体内的日本血吸虫时 ,静脉注射是最佳给药途径。     

对双轴晶体的双折射现象的电磁理论解释

自然界的晶体多是双轴的,与单轴晶体一样,一束入射光在双轴晶体中一般也分成两束折射光,其振动面互相垂直,但这两束光都不遵从折射定律,且传播速度都随方向而变,一般不在入射面内,只有在晶体中的两个方向上,无论光的振动面有怎样的取向,它们的传播速度都相同,入射光不再分为两束,此即双轴晶体名称的由来。长期以来,一般书籍很少系统的讨论这一问题。本文应用电磁理论,从特殊情形出发来分析研究双轴晶体的双折射现象,这对于双轴晶体的理论研究具有一定的意义。     

Synthesis, crystal structure and biological activity of aryl [(N,N'-diacyl-N'-tert-butylhydrazino)thio]methylcarbamates

A series of novel aryl [(N,N'-diacyl-N'-tert-butylhydrazino)thio]methylcarbamates were synthesized by the reaction of aryl (chlorothio)methylcarbamates with N,N'-diacyl-N-tert-butylhydrazines in the presence of sodium hydride. X-Ray single crystal diffraction of 2-isobutylphenyl [(N,N'-dibenzoyl-N'-tert-butylhydrazino)thio]methylcarbamate demonstrated the presence of N-S-N bonding. All of the compounds exhibited excellent larvicidal activities. Toxicity assays indicated that the products had knockdown activities of aryl methylcarbamates at higher concentrations and insect growth regulator activities of diacylhydrazines at lower concentrations.     

Synthesis, crystal structure and herbicidal activity of mimics of intermediates of the KARI reaction

Two mimics of the intermediate in the reaction catalyzed by ketol-acid reductoisomerase (KARI) were synthesized. Their structures were established on the basis of elemental analyses, IR, 1H NMR and GC/mass detector. The crystal structure of compound 2 was found to be a substituted dioxane, formed by the condensation of two molecules. The two compounds showed some herbicidal activity on the basis of tests using rape root and barnyard grass growth inhibition. However, the herbicidal effect was weaker in greenhouse tests.     

Laboratory and field tests of spray-dried and granular formulations of a Bacillus thuringiensis strain with insecticidal activity against the sugarcane borer

Formulations of Bacillus thuringiensis Berliner (Bt) with insecticidal activity against the sugarcane borer, Diatraea saccharalis Fabricius (Lepidoptera: Pyralidae), were developed and tested under laboratory and field conditions. The formulations were prepared using biodegradable polymers such as modified corn starch as an encapsulating agent, gelatin as an adherent, powdered sugarcane as a feeding stimulant and a Bt var. kurstaki GM-34 strain from a non-sugarcane region as the active ingredient. The spore-crystal complex of this strain was mixed at three different concentrations (30, 70 and 100 g kg(-1)) with the other ingredients. The blends were prepared as spray-dried and granular formulations, and then submitted to laboratory tests with two day old larvae of D. saccharalis and field tests in sugarcane crops with natural sugarcane borer infestation. Spray-dried formulations in laboratory bioassays caused mortality near 100% with all three concentrations, and granular formulations caused mortality around 84%. The field tests showed that spray-dried formulations at 70 and 100 g kg(-1) concentrations were as effective as a commercial bioinsectide (Lepinox), while granular formulations were ineffective.     

纳米纤维素制备优化及其形貌表征

通过硫酸水解微晶纤维素制备纳米纤维素,分析硫酸浓度、反应温度和水解时间对纳米纤维素得率的影响,采用正交实验优化了实验参数。用场发射环境扫描电镜(ESEM-FEG)和透射电镜(HR-TEM)表征了微晶纤维素与纳米纤维素的形貌,并对其尺寸分布进行了分析。结果表明,当硫酸浓度为56%,反应温度40℃,水解时间90min时,纳米纤维素得率最高,达55.40%;电镜观察纳米纤维素呈棒状,其尺寸较微晶纤维素明显减小,直径2-24nm,长度为50-450nm。     

微型热光电系统中一维光子晶体过滤器改进设计

为进一步提高微型热光电系统的能量转化效率,在系统中设置了一维Si/SiO2光子晶体过滤器,以实现对长波辐射能的回收利用。根据光学薄膜设计理论以及传输矩阵的方法,获取了过滤器的基本结构及光学特性,并针对其第一反射带宽度过窄的缺点,采用多层膜叠加的方法,获得了一个改进结构的过滤器[1.10(L/2HL/2)](L/2HL/2)3[1.10(L/2HL/2)] [0.95(L/2HL/2)](L/2HL/2)3[0.95(L/2HL/2)],其第一反射带宽度被拓展至2~4μm,同时在通带内也具有0.95的透射率。利用完善后的系统能量转换计算模型进行了相关对比分析,其结果表明,过滤器可在有效缓解电池冷却负荷的同时,通过提高辐射壁面的温度达到提升系统输出性能的效果,在1500mL/min的总流量下,采用改进结构过滤器的系统输出功率达到了5.46W,效率为2.6%,比采用基本结构过滤器提高了5.7%。     

石英晶体微天平传感器检测香蕉成熟度的试验

为了对采后香蕉的成熟度进行无损检测,提高货架品质和减少过熟造成的损失,以巴西香蕉为研究对象,以1,2-二油锡甘油-3-磷-L-丝氨酸、半乳糖神经酰胺、纤维素乙酯、乙基纤维素做为敏感材料,采用滴涂法修饰了4个石英晶体微天平(quartz crystal microbalance,QCM),测试了1~7级成熟度的香蕉的挥发性有机化合物的响应特性,并用主成分分析法和线性判别分析法对响应结果做了分析。试验表明,在4种敏感膜中纤维素乙酯对香蕉的7个成熟阶段的挥发性气体的响应最明显,响应值先随香蕉成熟度增加而增加,在4级成熟阶段时最大,随后降低。用主成分分析法对7个成熟阶段香蕉的挥发物的响应值聚类分析,97%能够正确聚类;用线性判别分析法可获得100%的识别率。据此,4种材料修饰的石英晶体微天平传感器可以用于香蕉成熟度的识别。该研究结论对香蕉成熟度自动化分级研究有一定实用价值。     

植物草酸钙晶体的研究进展

畜牧业养殖作为农业发展的重要分支,对社会经济发展、人民生活水平的提高起着至关重要的作用。中国盐碱地分布广泛,东北、西北、华北等地区均有分布,且次生盐碱化日益加剧,严重影响牧草产量,限制了畜牧业养殖的可持续发展。发展新型畜牧业养殖,改造治理、充分利用不适宜放牧的盐碱地等闲置土地资源,不仅可以发展新型畜牧业养殖,同时对农业可持续发展、推动区域经济、促进生态环境的可持续发展具有重要意义。新近有研究表明草酸钙晶体与植物抗盐碱具有密切联系,并且对其合成与调控机制已经展开了一些研究。虽然其合成与降解机制尚不完全清楚,但已有研究表明草酸钙晶体在钙调节,植物保护、防御、结石病防治、离子平衡、食品安全、植物病虫防治、缓解逆境胁迫等方面具有重要作用。本研究通过梳理相关文献,对植物草酸钙晶体的分布特征,研究方法、合成机制、降解机制、生物功能等方面进行综述,以期对其潜在的应用价值提供理论基础。     

简单离子晶体离子半径比的计算

介绍了关于简单离子晶体中离子半径比的计算方法,给出了一个适用于各种类型简单离子晶体的一般公式,具有简便直观,易掌握之优点.