企业家的经济贡献

主要从企业家对企业主体地位的实现 ,对企业资源的优化配置 ,对企业利润目标的实现 ,对现代企业制度的建立和企业产业升级五个方面分析了企业家对企业的经济贡献     

氮氧化物储存还原反应中还原时间的控制方法

使用H_2作为还原剂,采用NO_x存储还原循环的试验方法,在石英反应器上研究了还原时间、反应温度和还原剂体积分数对NO_x存储还原(NSR)催化剂Pt/Ba/Ce/γ-Al_2O_3存储还原特性的影响.结果表明:存在一个最佳还原时间,在此处可取得最高的循环转化率;最佳还原时间与反应温度和还原剂体积分数相关,提高反应温度或者降低还原剂体积分数,最佳还原时间延长.     

机械手模型的PLC控制系统设计

利用S7--300系列PLC对机械手进行控制，详细阐述了系统的主回路和控制回路工作原理以及接线图。     

关于五年一贯制模式培养农村小学教师的思考

农村小学教育师资在总体上数量不足、素质偏低、知识陈旧、年龄老化,使农村小学教育的质量受到严重影响,城乡教育差距不断拉大。利用五年一贯制的培养模式,直接招收初中毕业生进行全面、系统的小学教育专科学历教育,对建设一支数量适当、素质良好、结构合理、相对稳定、适应基础教育发展的全科型农村小学教师有重大意义。     

High-affinity binding of beta-alanine to cerebral synaptosomes might involve glycine-receptors.

High-affinity, Na+-independent binding of beta-alanine to a synaptosomal fraction of rat brain was potently inhibited by glycine and by some other alpha-amino acids, but not by taurine or GABA. This binding mechanism, which was also sensitive to both bicuculline and strychnine, might involve synaptic receptors for both beta-alanine and glycine.     

Cholinergic and adrenergic innervation of the penis artery of the bull: transmitter concentrations and synaptic vesicles.

The penile artery of the bull contained significant amounts of acetylcholine, noradrenaline and dopamine, and its axon profiles contained either numerous small granular or agranular vesicles, as well as some large granular vesicles. In the dorsal metatarsal artery, only noradrenaline and dopamine were detectable, and the axon profiles observed contained numerous small granular vesicles. In the penile artery, the axons with small agranular vesicles, probably cholinergic axons, were in close contact with axons containing small granular vesicles. It is suggested that, in the penile artery of the bull, one of the functions of the cholinergic nerves is suppression of excitatory adrenergic neurotransmission.     

Species-dependent stereospecific serum protein binding of the oral anticoagulant drug phenprocoumon.

13 mammalian species are classified into 3 clearcut groups with respect to the stereospecific serum protein-binding of phenprocoumon: 2 groups showing opposed stereospecific binding characteristics and a 3rd group exhibiting no stereospecific binding. Structural differences in the albumin molecule account for these stereospecific differences in serum protein-binding.     

Lipoperoxidation rates and drug-oxidizing enzyme activities in the liver and placenta of some mammal species during the perinatal period.

Lipoperoxidation and drug-metabolizing enzymes were measured in livers and placentas of different mammal species during the perinatal perios. In placentas and fetal livers of rat, rabbit and guinea-pig, cofactor-supported lipoperoxidation was negligible, as were the activities of drug-oxidizing enzymes. Human fetal liver contained an intact drug-oxidizing electron transport chain, and lipoperoxidation activity was accordingly abserved. It is suggested that lesions mediated by lipoperoxidation may be possible in human fetus, but they are less probable in animal fetuses.