平面有界三次系统有限奇点分布举例

通过构造有界的平面三次系统,证实了（1）其有限奇点的5－4（5个奇点指标为＋1,另4个奇点指标为－1）,3－2,2－1,＋1四种分布均可实现;（2）仅有一个指标为＋1的有限奇点的有界三次系统至少有11种类型;（3）赤道附近轨线拓扑结构相同的有界三次系统它们有限奇点的分布可以有不同类型。     

分布式电网中四线制变流器的性能对比分析

在我国现行的低电压配电网络中一般采用TT、TN配电方式,即三相四线制配电,为了使分布式发电机组与四线制低压电网相连接,需要选择一个合适的变流器拓扑结构。同时为了提高电网中的电能质量,分布式发电机组需要添加有源电力滤波器(APF)后再接入四线制低压电网中。本篇论文主要进行两种四线制拓扑结构——非分裂链路式四桥臂变流器和分裂链路式三桥臂变流器拓扑结构的性能进行对比分析。主要在控制的难易程度、电磁兼容性(EMC)、中点控制、直流侧母线电压利用率和电路复杂性等方面进行对比分析。本篇论文总结出分裂链路式三桥臂拓扑结构变流器主要性能要优于非分裂链路式四桥臂变流器,主要体现于在相同电路复杂性和直流母线利用率的参照标准下,分裂链路式三桥臂拓扑结构的变流器在电流控制方面更加简单,同时有较小的电磁兼容性问题。     

Construction of the glucose isomerase deficient strain ofStreptomyces M1033 by homologous recombination

After the establishment of the transformation conditions ofStreptomyces diastaticus No.7 Strain M1033, the integration plasmid pXW for homologous recombination, which contains a 600 bp fragment of incompleteGI (G138P. G247D) gene, has been constructed in order to realize the stable overexpression of theGI (G138P. G247D) which is valuable for large-scale industrial production. The Gigene’s disruption has been realized by pXW’s integration into M1033 chromosomes via homologous recombination andGI deficient strain ofStreptomyces M1033 has been obtained. The reliability of introduction of mutation has been proved by analysis of recombinant fragment and affirmance of existence of the mutation, as well as detection of the stability of the deficient strain.     

Mechanism for chronic pain generation

Neuropathic pain and the other abnormalities of sensation induced by axon injury or by peripheral nerve inflammation should result from functional compensations of the injured neurons during their regeneration. Ectopic distribution of proteins related to Na⁺, K⁺ and Ca²⁺ channels as well as of receptors on both membranes of injured axon and its cell body becomes a main pacemaker from which spontaneous ectopic afferent of primary sensatory neurons and crosstalk between neurons occur. Abnormal ectopic afferent activities lead to disorders of the sensation, such as hyperalgesia, allodynia, spontaneous pain and paraesthesia. Administration of some ion channel agents and/or α2-adrenergic blockers has shown efficiency in preventing neuropathic pain development and in relieving neuropathic pain.     

Analysis on the types of chemokines expressed by the murine thymic epithelial cell line MTEC1

Six kinds of chemokines including SDF-1α, IP-10, KC, RANTES, MCP-1 and Lymphotactin have been amplified using the primers designed by ourselves with RT-PCR from the total RNA of a medullary-type murine thymic epithelial cell line MTEC1 cells. The amplified cDNA fragments of the chemokines have been identified by nucleotide sequencing and Northern blot analysis. The results demonstrate that there are two different splicing forms of SDF-1 mRNA existing in MTEC1. The concentrated culture supernatant of MTEC1 shows an intermediate level of chemotaxis to CD4⁻CD8⁻ thymocytes, which conforms to the biological function of SDF-1.     

Studies on kinetics of reactions between phycobiliproteins and hydroxyl radicals by a pulse radiolytic technique

Scavenging of hydroxyl radical (· OH) by phycobiliproteins (C-phycocyanin, Allophycocyanin and R-phycoerythrin) was studied by competitive kinetics methods. Hydroxyl radicals were generated from pulse radiolysis of aqueous systems saturated with nitrous oxide (N₂O). The experimental results indicated that the three types of phycobiliproteins are all strong scavengers of · OH, the rate constants are around (2.8-5.6)×10⁹ L · mol^-1 · s^-1.     

The electron-beam (EB) irradiation and grafting of acrylic monomers onto EPDM copolymer

Radiation techniques (electron-beam, γ-ray, etc.) are usually used for improving the compatibility between polymer and ingredients in composite materials. Electron-beam pre-irradiation has been used for the first time to enhance the flame retardance of EVA copolymer. Efforts are being made to decline the flammability for EPDM copolymer by EB technique and remarkable reduction has been attained through a series of treatments: pre-irradiation, grafting and saponification.     

基于单片机的电力通信规约转换器的设计与应用

结合工程实例设计出一种基于单片机的电力系统通信规约转换器, 它能够实现主站、RTU以及IEDs设备之间不同通信规约的转换,其工程化应用可为中小型变电所综合自动化系统的改造减少一大笔资金投入.     

高浓度甲基橙低压湿式催化氧化及动力学研究

采用低压湿式催化氧化法（ＬＰＷＣＯ）处理高浓度模拟偶氮染料甲基橙溶液,考察了温度、Ｈ２Ｏ２浓度、Ｆｅ＾２＋浓度等因素对去除效果的影响,结果表明,ＬＰＷＣＯ法能有效云除废水颜色,同时用一级反应模型拟合了甲基橙溶液脱色的ＬＰＷＣＯ反应,由实验数据确定了反应速率方程。     

Bi(Ⅲ)──硫氰酸盐──罗丹明B──阿拉伯树胶体系光度法测铋的研究

研究在表面活性剂阿拉伯树胶存在时,铋（Ⅲ）－ＳＣＮ－一罗丹明Ｂ高灵敏显色体系．缔合物λmax=580nm,ε580=2. 84×105L·mol-1· cm-1.铋在0μg/25 mL～8μg/25mL范围内服从比耳定律．