现场总线在陶瓷梭式窑控制系统中的应用

该文论述了CAN现场总线在工业控制系统——陶瓷梭式窑控制系统中的应用。分析了陶瓷梭式窑控制特点,就炉膛内的温度以及气氛的控制设置两个控制主回路。组成CAN总线通信系统,设计EPP-CAN接口模块和以89C52单片机为核心的各种底层接口模块,为网络控制系统提供底层通信网络,保证数据通信的实时性与可靠性。取得预定的控制结果。     

A study of electron-shuttle mechanism in <Emphasis Type="Italic">Klebsiella pneumoniae</Emphasis> based-microbial fuel cells

In microbial fuel cell (MFC), the rate of electron transfer to anode electrode is a key intrinsic limiting factor on the power output of MFCs. Using Klebsiella pneumoniae (K. pneumoniae) strain L17 as biocatalyst, we studied the mechanism of electron shuttle via self-producing mediator in a cubic air-chamber MFC. To eliminate the influence of biofilm mechanism, the anode electrode was coated with microfiltration membrane (0.22 μm). Data showed that the microfiltration membrane coated and uncoated MFCs achie...     

梭形翻板太阳直射辐射传输计算模型及实现

首先,取相邻2块遮阳翻板为研究对象,采用解析法建立直射辐射直接透过部分的计算模型,采用光线追踪法得到的反射次数和方向建立直射镜面反射部分的计算模型,采用净辐射法建立直射漫反射部分的计算模型;其次,在模型分析基础上,用MATLAB软件编制了能描述翻板形状、尺寸、倾角、表面光学特性的梭形翻板直射辐射传输计算程序;最后,分析了传统计算方法对梭形翻板进行平板假设所带来的误差,认为用"平板假设"模型的计算结果偏大,特别是在翻板开口朝向正对太阳光线入射方向时误差值最大,其余情况相对误差都在5%以上.     

Stress and putative endogenous ligands for benzodiazepine receptors: The importance of characteristics of the aversive situation and of differential emotionality in experimental animals

The relationships between anxiety/stress, possible endogenous ligands for benzodiazepine receptors and the behavioral modification by drugs are discussed in this short review, including the specific characteristics of elements involved in those interactions, e.g. ones concerning the aversiveness of the stressful situation and the nature of the organism under investigation. These are important factors when considering aversive tasks, insofar as they may involve stressful conditions which differ in intensity and in the degree of control afforded the subject. These characteristics may well lead to differing functional effects on GABA-gated chloride channels or, in other words, to an incongruous balance between endogenous benzodiazepine receptor agonist and inverse agonist activity. This is not surprising, as it is well known that different forms of stressors often actually produce divergent behavioral, physiological and biochemical effects. This review also illustrates the necessity of taking into account the variable effects of stressors and/or drugs on animals differing in reactivity or emotionality, even in the case of non-selected stocks. The implication is made that, by genetic and/or environmental manipulation of the emotional state of the animals used, it will be possible to obtain more clearly definable results in neuropharmacological and psychopharmacological studies.     

三种新的穿梭质粒pCC10、pCCT7和pST16的构建和性质研究

利用大肠杆菌质粒pUC18、pTG206和金黄色葡萄球菌质粒pC194在体外构建3个嵌合质粒pCC10、pCCT7和pST16.3个新质粒均是大肠杆菌和枯草杆菌的穿梭质粒。它们在大肠杆菌中呈Ap~rCm~r型,在枯草杆菌中则为Cm~rAp~5型。其中pCCT7和pST16含有xylE基因,可作为启动子探测质粒。所有的新质粒都具有来自pUC18的多酶克隆位点,适合于在大肠杆菌和枯草杆菌中重组外源DNA以及比较它们的表达情况。     

深粒高产、优质、多抗、紧凑型玉米杂交种正红6号的选育研究

以美国玉米带杂交种3163为基础材料,利用南北穿梭同步定向育种新方法,用自交系698 3作测验种在S1和S3早期分离世代连续进行早代测定和定向选育,5年内同步育成玉米新自交系K169及其杂交种正红6号(K169×698 3).该杂交种是四川省"十五"期间育成的第一个比对照种增产15%以上的玉米突破性杂交种,并具有籽粒深,综合品质优,抗病、抗倒、耐旱力强,株型紧凑和适应性广等优点,为紧凑型玉米提供了理想的接班品种.     

低温菌穿梭质粒的构建及转化方法研究

 由于低温微生物在细胞结构上的特殊性,使得对它们进行遗传操作受到很大的限制.以分离自冻土的低温菌Acinetobacter sp.DWC6为宿主菌,构建了一套外源DNA导入系统.通过在质粒pBR322和pUC118中插入一段Acinetobacter属特异性的Ori片段,成功构建了一系列穿梭质粒,并建立了稳定的转化方法,所有重组质粒均可在Escherichia coli和Acinetobacter sp.DWC6中正常复制.通过优化转化方法,使质粒在低温菌Acinetobacter sp.DWC6中的转化率达3×10⁶转化子/μg DNA.     

弹性蛋白酶保护因子--Elafin结构基因腺病毒载体穿梭质粒的构建、鉴定及表达

构建能表达弹性蛋白酶保护因子———elafin基因腺病毒表达载体的穿梭质粒,为进一步包装能高效表达结构蛋白的腺病毒载体做准备.以含有elafin基因的真核质粒pEGFP-N1-Elafin为模板,PCR扩增elafin基因,PCR产物以SalⅠ、EcoRⅤ双酶切,定向插入到腺病毒穿梭质粒pAdTrack-CMV中CMV启动子下游SalⅠ与EcoRⅤ位点之间,获得重组腺病毒穿梭质粒pAdTrack-CMV-Elafin,通过SalⅠ及EcoRⅤ双酶切、PCR及插入片段序列测定对该质粒进行鉴定,将pAdTrack-CMV-Elafin转染293细胞,以RT-PCR及Western-Blot检测其在293细胞中的瞬时表达.结果表明:双酶切、PCR及测序鉴定证实,pAdTrack-CMV-Elafin穿梭质粒的插入片段为elafin基因,用pAdTrack-CMV-Elafin穿梭质粒转染293细胞后可见绿色荧光蛋白的表达,RT-PCR和Western-blotting表明其可在293细胞中瞬时表达.     

Extracellular electron transfer

Results from several laboratories indicate that extracellular electron transfer may be a general mechanism whereby microoorganisms generate energy for cell growth and/or maintenance. Specifically, bacteria can use redox-active organic small molecules, generated outside or inside the cells, to shuttle electrons between reduced and oxidized compounds. Electron shuttling has now been reported for several different bacterial species, and exchanges of shuttling compounds may even syntrophically link diverse organisms in nature. Biofilm systems in both geological and clinical settings are likely to be important environments for metabolisms that employ extracellular electron transfer. Both structural and functional analyses suggest that electron shuttles and some virulence factors may be related to one another. Received 21 March 2001; received after revision 10 May 2001; accepted 11 May 2001