硝基芳烃化合物对大型蚤的联合毒性

分别测定了2，4-二硝基甲苯(2，4-DNT)与5种硝基芳烃化合物对大型蚤的单一毒性及二元混合物的联合毒性，采用毒性单位法评价了硝基芳烃化合物对大型蚤的联合毒性效应．结果表明，5种二元混合物的联合毒性以相加作用为主，说明此类化合物可能是以相似的方式作用于大型蚤．     

壳聚糖对作物的生理效应及其增产作用

本文综述了壳聚糖引起作物的生理效应，可提高作物的叶绿素含量。提高作物种子中的贮藏蛋白含量。提高作物产量、改善作物品质．壳聚糖还可诱导作物产生广谱抗逆性．它对作物的碳、氮代谢具有一定生物调节功能，作为一种天然生长调节剂在很多作物上具有广泛应用前景．     

大环二萜天然产物(±)-mayol的全合成

以香叶醇为起始原料,经多步反应完成了西松烷型大环二萜类天然产物(±)-mayol的全合成,关键步骤是二价铬诱导的烯丙基氯化物与醛的分子内加成环化;同时完成了直链二萜类天然产物16-羟基香叶基香叶醇12的合成.     

一种竹寄生真菌的分离鉴定及其有效成分发酵的初步研究

从乐山峨边县采集了一种竹寄生真菌，经过形态比较、菌丝特征的显微观察、组织切片和孢子的显微观察，以及其有效成分的比较，鉴定为竹黄（shiraiabambusicola）。其菌丝分离纯化后，以大米及马铃薯汁为基础培养基，分别研究了温度，pH值，碳源，氮源，水份等对该菌在固态条件下产Bei醌化合物的影响，并用正交实验选择了固态发酵的最佳培养条件：每kg基础培养基（大米）中添加硝酸铵20g、麦芽糖50g和马铃薯汁1200mL，温度26℃，自然pH值下，每克菌丝Bei醌类化合物的产量可达到2.4色价。     

16电子半夹心结构含硫碳硼烷钴配合物CptCoS2C2B10H10的合成以及结构表征

八羰基二钴Co2(CO)8与叔丁基取代的环戊二烯反应，可以得到半夹心结构的羰基钴化合物Cp^tCo(CO)2(2)(Cp^t=η^5-^tBuC5H4)，化合物(2)与元素碘进行反应可以被氧化成相应的钴的碘化产物Cp^tCo(CO)I2(3)，采用碳硼烷含硫锂化合物[(THF)3LiS2C2B10H10Li(THF)]2(1)与18电子半夹心结构羰基钴的碘化物Cp^tCo(CO)I2(3)反应得到16电子半夹心结构化合物Cp^tCoS2C2B10H10(4)，表征了化合物(2)，(3)和(4)，并解析了配合物(4)的X—衍射的单晶结构。     

TiAl自蔓延高温合成反应的机理

用燃烧波淬熄法研究了大颗粒Ti粉和Al粉制备TiAl金属间化合物的自蔓延高温合成反应机理.通过电镜观察和能谱分析发现:反应过程可用毛细铺展 界面反应机制解释.熔融的Al在整个反应过程中起着主要作用,首先熔融的Al液通过Ti粉间的毛细管作用以薄膜的形式铺展在Ti粉表面,并在接触面生成TiAl3.反应放出的热量有利于加速反应的进行,促使TiAl3与Ti进一步反应生成TiAl.但是生成的TiAl3层阻碍了Al液与Ti粉的接触,制约了反应的进行.最后,在试样中可以同时看到完全反应的Ti粉和未完全反应的Ti粉.     

甘南天然虫草与人工培养物化学成份比较研究

对从甘南州玛曲县所产的天然虫草与从中分离纯化的虫草头孢霉人工培养物进行化学成份对比分析，以进一步证实所分离苗种的可靠性。     

黄酮类化合物抗氧化性与其构效的关系

黄酮类化合物是一类在植物界广泛分布的酚性组分，目前已知的黄酮类化合物单体已达8000多种。众多研究表明黄酮类有抗突变、抗肿瘤、抗炎、治疗心血管疾病等广泛生物学活性，其中最为重要的是它减少自由基形成和清除自由基的抗氧化活性，而黄酮类化合物的抗氧化活性与其结构有着密切的关系。针对近几年在黄酮类物质抗氧化作用与其结构关系方面的研究作一综述，主要从黄酮类化合物中羟基的位置、数目及其不同取代等方面对黄酮类化合物抗氧化作用的影响，旨在为黄酮类化合物的研究、开发、应用提供参考。     

Cryptomelane（KxMn8-xO16）： Natural active octahedral molecular sieve（OMS-2）

The Xiangtan manganese deposit (XTM) used to be considered a supergene oxide manganese ore in South China. We reported a new identification of the naturally outcropping cryptomelane by examining the physical, chemical and structural features of the XTM supergene oxide manganese ore. The MnO2 content was over 90%, K2O more than 3%, and water from 2.2%-3.1% which is similar to one in zeolite. The cell parameters of the cryptomelane were given as a0 = 0.9974 nm, b0 = 0.2863 nm, c0 = 0.9693 nm and β= 91.47°. There was a larger pseduotetragonal tunnel in the natural cryptomelane that was formed by [MnO6] octahedral double chains with aperture of 0.462×0.466 nm2, filled with K cations resulting in some Mn3+ substituting for Mn4+ to balance the negative charges of structure. The finding is important not only for prospecting manganese resources in South China, but also in application of octahedral molecular sieve of natural cryptomelane as that developed in the tetragonal molecular sieve of natural zeolite o     

Inorganic chemical composition and source signature of PM2.5 in Beijing during ACE-Asia period

Aerosol samples for PM2.5 were collected in Beijing for 38 consecutive days from March to April 2001 using an IMPROVE Sampler. Concentrations of 20 elements in PM2.5 were determined using a PIXE method. Results show that the average mineral dust concentration of PM2.5 was 14.6 Ilg/m3 during the observation period. On the sand-dust event days of March 21 and April 10, dust PM2.5 mass concentrations were 62.4 and 54.1 μg/m^3, respectively.These demonstrate that fine particle pollution by dust event in Beijing was very severe. The enrichment factors of S and Cu reached minimums on the dusty days and were high on the non-dusty days. It is considered that enrichment factors of elements in PM2.5, which are associated with human activities, can probably provide an effective method to distinguish local sources from external sources of dust. Factor analysis on the chemical composition in PM2.5 shows that sources of crustal matters, anthropogenic emission, and oil combustion contributed to PM2.5 levels in air in the springtime of 2001 in Beijing.