油菜体内铜和锌的化学形态与分配特征研究

采用连续浸提法研究油菜体内铜和锌的化学形态。在幼苗期,各种化学形态的铜和锌主要在地下部积累,向地上部的转运相对较少。铜在幼苗体内以活性较强的水溶态和醇溶态为主,锌在幼苗体内以活性较低的酸溶态和残留态为主。在成熟期,锌仍然是以活性较低的酸溶态和残留态含量相对较高,在植株体内的相互转运较弱。根和种子中各种化学形态的铜和锌的含量高于叶和荚壳,说明在成熟期,铜和锌均向油菜籽实中积累     

铜对鲤鱼损害的电镜X射线显微分析

用电镜X射线显微分析法,研究铜在鲤（Cyprinus carpio）肝细胞和肾细胞中的分布和相对含量,从细胞水平探讨鲤的铜中毒机理。结果表明,铜进入鲤体内后,在肝细胞、肾细胞的溶酶体中分布最多,溶酶体旁、细胞核次之,细胞质内最少,中毒组与正常组差异显著。鲤中毒后肝细胞核膜扩张、线粒体呈空泡状,溶酶体数量增多、体积增大;肾小管上皮细胞核膜扩张,线粒体肿胀,嵴断裂。     

我院英专口语测试系统的质量分析和完善对策

援引测试学的有关理论．分析我院英语专业英语口语测试系统存在的一些关于效度、信度和反拨效应的质量问题．并就此提出相应的完善目前英专口语测试系统的对策。     

铜对青菜光合色素的影响及其在体内的分布

用溶液培养的方法研究了铜对青菜幼苗叶绿体色素含量的影响,以及铜在青菜体内的积累、分布情况.结果表明:5μmol/L Cu2 处理时,青菜幼苗叶片的叶绿素和类胡萝卜素含量明显降低,10μmol/LCu2 处理下,与对照相比,叶绿素a、b的含量分别减少了45.24%和50.69%;青菜根系铜含量远大于地上部,随着Cu2 处理浓度的增加,根系和地上部的铜含量均显著升高,而地上部铜的增加量低于根系,所占植株总铜量的百分比下降.     

吡啶硫酮铜悬浮剂的研制及其防霉效果

通过吡啶硫酮铜悬浮剂的研制,进行室内木材防霉试验,探究吡啶硫酮铜悬浮剂对常见木腐菌的防治效果。结果表明:20%吡啶硫酮铜悬浮剂较好的润湿、分散剂为602#、33#、500#,产品的各项指标都能够达到悬浮剂的要求。防霉试验结果表明:吡啶硫酮铜浓度为1%左右时对3种霉菌(烟曲霉、可可球二孢、产紫青霉)具有比较好的防治效力。     

The effects of plastic slatted floor or straw bedding on performance, liver weight and liver copper concentrations in intensively reared lambs

One hundred and eight Texel sired lambs were weaned at 37 days old and allocated three days later to one of two treatments, using two pens per treatment, in order to evaluate lamb hepatic copper (Cu) values. In Treatment 1 (T1) the lambs were confined to pens having recycled plastic slatted flooring, while in Treatment 2 (T2) the lambs were confined to pens having straw bedded floors, with fresh straw added on alternate days. The lambs had ad libitum access to a coarse lamb concentrate. The crude protein (g/kg DM), crude fibre (g/kg DM), total zinc (mg/kg) and background levels of copper (Cu) (mg/kg) and molybdenum (Mo) (mg/kg) of the diet were 17.2, 10.9, 152, 9.7 and 0.92, respectively. The lambs were slaughtered when they reached about 39 kg live weight. Following slaughter, the liver was removed and weighed and the caudal lobe frozen for subsequent Cu analysis. The livers of lambs on the plastic floor treatment had higher liver weights (843 vs. 804 g, S.E.M. 11.0; P < 0.05) and higher hepatic copper (396 vs. 315 mg/kg DM, S.E.M. 18.2; P < 0.05) than those from lambs that were bedded with straw. The Cu accumulation per kg of liver DM per week was estimated to be 8.4 and 13.7 mg for lambs on the straw bedding and plastic slated treatments, respectively. It is concluded that when lambs are housed on plastic slatted flooring, relative to straw bedding, there is a higher accumulation of hepatic copper levels likely to result in a greater risk of Cu toxicity when lambs are reared on all concentrate diets.     

果蔬农产品质量安全影响因素的研究

本文在对我国果蔬农产品质量安全现状分析的基础上,结合大量文献和理论知识,提出了影响果蔬质量安全的因素,并通过大量调查问卷验证了假设的可信度和有效性。旨在为科学的评价和保障果蔬的质量安全提供一种有效的方法和理论支持。     

A single application of Cu to field soil has long-term effects on bacterial community structure, diversity, and soil processes

Long-term diversity-disturbance responses of soil bacterial communities to copper were determined from field-soils (Spalding; South Australia) exposed to Cu in doses ranging from 0 through to 4012 mg Cu kg⁻¹ soil. Nearly 6 years after application of Cu, the structure of the total bacterial community showed change over the Cu gradient (PCR-DGGE profiling). 16S rRNA clone libraries, generated from unexposed and exposed (1003 mg Cu added kg⁻¹ soil) treatments, had significantly different taxa composition. In particular, Acidobacteria were abundant in unexposed soil but were nearly absent from the Cu-exposed sample (P<0.05), which was dominated by Firmicute bacteria (P<0.05). Analysis of community profiles of Acidobacteria, Bacillus, Pseudomonas and Sphingomonas showed significant changes in structural composition with increasing soil Cu. The diversity (Simpsons index) of the Acidobacteria community was more sensitive to increasing concentrations of CaCl-extractable soil Cu (Cu_Ext) than other groups, with decline in diversity occurring at 0.13 Cu_Ext mg kg⁻¹ soil. In contrast, diversity in the Bacillus community increased until 10.4 Cu_Ext mg kg⁻¹ soil, showing that this group was 2 orders of magnitude more resistant to Cu than Acidobacteria. Sphingomonas was the most resistant to Cu; however, this group along with Pseudomonas represented only a small percentage of total soil bacteria. Changes in bacterial community structure, but not diversity, were concomitant with a decrease in catabolic function (BioLog). Reduction in function followed a dose-response pattern with Cu_Ext levels (R²=0.86). The EC₅₀ for functional loss was 0.21 Cu_Ext mg kg⁻¹ soil, which coincided with loss of Acidobacteria diversity. The microbial responses were confirmed as being due to Cu and not shifts in soil pH (from use of CuSO₄) as parallel Zn-based field plots (ZnSO₄) were dissimilar. Changes in the diversity of most bacterial groups with soil Cu followed a unimodal response - i.e. diversity initially increased with Cu addition until a critical value was reached, whereupon it sharply decreased. These responses are indicative of the intermediate-disturbance-hypothesis, a macroecological theory that has not been widely tested in environmental microbial ecosystems.     

根际铁膜对铜胁迫下水稻叶片叶绿素及MDA质量摩尔浓度的影响

采用盆栽和水培试验,在添加氧化铁及人工制备植物根系铁膜条件下,以水稻叶片叶绿素和MDA质量摩尔浓度为指标,探讨铁膜对重金属Cu胁迫的响应。结果表明,在铜污染条件下添加氧化铁对维持植株中叶绿素含量具有显著作用,但增加土壤中氧化铁的含量对水稻幼苗生长也会产生不利影响;在水培条件下,水稻幼苗对Cu胁迫十分敏感,培养液中铜质量浓度达到1 mg/L时对叶绿素含量就有显著的抑制效应,但随着Cu质量浓度的增加（1~15 mg/L）,铜胁迫对叶绿素的抑制强度变化并不剧烈,反映出铁膜对铜胁迫的抵御功效。     

对合法性与公允性关系的认识——兼议二者的优先性

由于会计准则本身的不完善性,使得企业财务报表编制者和独立审计师不可避免地会遇到会计准则规定与企业交易事项的经济实质不一致的情况,这直接导致会计核算及财务报告表述的“合法性”和“公允性”的冲突问题。本文讨论了导致冲突的两方面原因及理论界关于合法性与公允性关系的认识,并分析了我国对于该问题的会计政策现状。因为会计报袁不能总做到既合法又公允,注册会计师发表审计意见往往处于两难境地,所以确定二者的优先性对于明确我国的审计目标是至关重要的。