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131.
王玉英 《天津理工大学学报》2002,18(3):84-86
为了解决供热企业收费难的问题 ,市政府要求在 3年内基本实现供热计量 ,从而进行供热收费机制的改革 ,实现供热计量后 ,室内采暖系统是一个变流量系统时 ,它必然反映到热网及热源 ,为适应热网的变流量 ,热源、热网、换热站 ,要具有必要的自控调节措施 .本文以热源热网间接连接系统作为研究对象探讨供热系统的调节问题 ,采用在热源处集中调节和在热力站局部调节来实现统一的调节 .从而达到节能 1 5 %~ 2 5 % . 相似文献
132.
本文根据电动大门对速度的要求,给出了由8031单片机、变频器电路及其驱动电路等组成的电动大门控制系统.本控制系统的特点是硬件线路比较简单.所设计的软件只用一个定时器即可产生频率变化的SPWM信号.采用本控制系统可比较经济地使电动大门按给定的速度曲线运动.因此可解决现有电动大门所普遍存在的,由于速度单一而带来的各种问题. 相似文献
133.
章兢 《湖南大学学报(自然科学版)》1993,20(6):93-99,112
本文针对常规模糊控制系统存在的稳态误差,对设定值的跟踪性能差等缺陷,提出一种参数自调整Fuzzy+I调节器,用智能积分器来消除稳态误差,在线自调整调节器参数以改善动态特性。计算机仿真表明这种调节器有良好的动态特性,静态特性与很强的鲁棒性。 相似文献
134.
M.-C. Broillet 《Cellular and molecular life sciences : CMLS》1999,55(8-9):1036-1042
The transfer of a nitric oxide group to cysteine sulfhydryls on proteins, known as S-nitrosylation, is increasingly becoming
recognized as a ubiquitous regulatory reaction comparable to phosphorylation. It represents a form of redox modulation in
diverse tissues, including the brain. An increasing number of proteins have been found to undergo S-nitrosylation in vivo.
These proteins are called S-nitrosothiols, and may play an important role in many processes ranging from signal transduction,
DNA repair, host defense, and blood pressure control to ion channel regulation and neurotransmission. This review focuses
on the importance of the S-nitrosylation reaction and describes some recently identified S-nitrosothiols in various fields
of research. 相似文献
135.
L. A. García-Alonso 《Cellular and molecular life sciences : CMLS》1999,55(11):1386-1398
The peripheral sensory system of the Drosophila adult has been used for the genetic analysis of axon guidance because of its accessibility for experimental manipulation
and mutant screens. Wing, leg, antenna, or eye sensory axons are able to pathfind normally under different perturbations,
indicating that sensory axon guidance is a highly canalized process. Similarly to other model systems, sensory growth cones
seem to use multiple, simultaneous cues for guidance. In addition, sensory axons from peripheral structures seem to be capable
of using alternative substrates for pathfinding. Developmental regulation could account for the high stability of axon guidance
under experimental and natural perturbation conditions. Despite this flexibility, functional characterization of genes involved
in sensory axon guidance is being carried out in situations where there appears to be less system redundancy. 相似文献
136.
胡丹丹 《大理学院学报:综合版》2006,5(3):45-47
宏观调控主体是宏观调控法中的重要范畴,对其的法律规制,能够使主体的行为制度化、规范化.保障宏观调控权的实现,从而进一步完善宏观调控。 相似文献
137.
138.
The means by which oxygen intervenes in gene expression has been examined in considerable detail in the metabolically versatile bacterium Rhodobacter sphaeroides. Three regulatory systems are now known in this organism, which are used singly and in combination to modulate genes in response to changing oxygen availability. The outcome of these regulatory events is that the molecular machinery is present for the cell to obtain energy by means that are best suited to prevailing conditions, while at the same time maintaining cellular redox balance. Here, we explore the dangers associated with molecular oxygen relative to the various metabolisms used by R. sphaeroides, and then present the most recent findings regarding the features and operation of each of the three regulatory systems which collectively mediate oxygen control in this organism.Received 26 June 2003; received after revision 30 July 2003; accepted 8 August 2003 相似文献
139.
140.
Profiling of the secreted proteins during 3T3-L1 adipocyte differentiation leads to the identification of novel adipokines 总被引:3,自引:0,他引:3
Wang P Mariman E Keijer J Bouwman F Noben JP Robben J Renes J 《Cellular and molecular life sciences : CMLS》2004,61(18):2405-2417
Adipose tissue is an endocrine organ capable of secreting a number of adipokines with a role in the regulation of
adipose tissue and whole-body metabolism. We used two-dimensional gel electrophoresis combined with mass spectrometry to
profile the secreted proteins from (pre)adipocytes. The culture medium of 3T3-L1 cells during adipocyte differentiation
was screened, and 41 proteins that responded to blocking of secretion by 20°C treatment and/or brefeldin A treatment
were identified. Prohibitin, stress-70 protein, and adhesion-regulating molecule 1 are reported for the first time as
secreted proteins. In addition, procollagen C-proteinase enhancer protein, galectin-1, cyclophilin A and C, and SF20/IL-25
are newly identified as adipocyte secreted factors. Secretion profiles indicated a dynamic environment including an
actively remodeling extracellular matrix and several factors involved in growth regulation.Received 15 June 2004; received after revision 26 July 2004; accepted 2 August 2004 相似文献