全数字晶闸管变流器在高炉料钟上的应用

介绍了西门子ＳＩＭＯＲＥＧ Ｋ ６ＲＡ２４全数学字直流调速装置控制系统在鞍钢炼铁厂３号高炉料钟系统上的应用,对老设备控制系统的改造具有现实意义。     

技术信息

技术信息包钢４号高炉建成投产Ｎｏ．４ＢＦＡＴＢＡＯＴＯＵＩＲＯＮ＆ＳＴＥＥＬＡＮＤＲＡＲＥＥＡＲＴＨＣＯＭＰＡＮＹＰＵＴＩＮＴＯＯＰＥＲＡＴＩＯＮ￥内容积２２００ｍ~３的包钢４号高炉已建成投产。该炉采用节能高产的矮胖式炉型，自立式炉壳，富氧喷煤，炉前?..     

石钢300m^3高炉计算机人工智能炉况预报系统简介

石钢３００ｍ~３高炉计算机人工智能炉况预报系统简介ＩＮＴＲＯＤＵＣＴＩＯＮＡＢＯＵＴＣＯＭＰＵＴＥＲＡＩ－ＦＵＲＮＡＣＥＣＯＮＤＩＴＩＯＮＰＲＥＤＩＣＴＩＮＧＳＹＳＴＥＭＯＦ３００ｍ~３ＢＦＯＦＳＨＩＪＩＡＺＨＵＡＮＧＩＲＯＮＡＮＤＳＴＥＥＬＰＬＡＮＴ...     

高炉监控计算机信息系统

目前电子计算机不仅作为数据处理，而且更广泛地应用于生产的实时监控。武钢５号高炉自动化成套设备是从国外引进，上位机是用法国布尔公司ＳＯＬＡＲＳＰＳ５／７０小型计算，下位机是用西门子Ｓ５系列的ＰＬＣ和美国霍尼韦尔的ＴＤＣ－３０００组成，本文就武钢５号高炉监控计算机信息系统作出介绍和分析。     

新型优质耐火材料在首钢高炉上的应用

从１９００年起,首钢４座高炉相继进行了重大技术改造,在高炉不同部位分别采用了Ｓｉ３Ｎ４－ＳｉＣ砖,热压小块炭砖,组合砖等新型耐火材料以及“陶瓷杯”技术。其中２号,３号,４号高炉采和了炭砖－高铝砖综合炉底,将ＮＭＡ砖砌筑在炉底炉缸交界处“蒜头状”侵蚀区。２号高炉凤产后炉底温度一直维持在１００－２００℃范围。１号高炉采用了“陶瓷杯”和热压炭块相互补充的炉衬结构。     

新型优质耐火材料在首钢高炉上的应用

从１９９０年起，首钢４座高炉相继进行了重大技术改造。在高炉不同部分别采用了Ｓｉ３Ｎ４－ＳｉＣ砖，热压小块岩砖，组合砖等新型耐火材料以及“陶瓷杯”技术。其中２，３，４号高炉采用了炭砖－高铝砖综合炉底，将ＮＭＡ砖砌筑在炉底炉缸交界处“蒜头状”侵蚀区。２号高炉投产后炉底温度－直维持在１００－２００℃之间。１号高炉采用了“陶瓷杯”和热压炭块相互补充的炉衬结构。     

新钢铁合金厂3#高炉上料控制系统

新钢铁合金厂３ #高炉是容积为３００ｍ３的锰铁炉。１９９９年８月开始大修 ,扩容为３８０ｍ３,改炼生铁 ,１个月后投产。该高炉上料系统为有料钟、双料车 ,有１８个料仓及４个集中称量漏斗。控制系统由西门子的Ｓ５ １１５Ｕ和工业微机组成。在该系统中 ,所有输出（除模拟屏部分状态显示外）都采用中间继电器隔离 ,强、弱电分开 ,使系统更加安全可靠。上位机与ＰＬＣ之间采用串行通信完成数据交换 ,通信协议为ＳＩＭＡＴＩＣ ３９６４Ｒ主从式网络通信协议 ,通信速率为９６００ｂ／ｓ。在该系统设计中 ,采用灵活的手动 /自动切换功能。系…     

廊坊市冶炼厂二十年来锰铁高炉的技术进步

廊坊市冶炼厂二十年来锰铁高炉的技术进步田征文（廊坊市冶炼厂）ＴＥＣＨＮＩＣＡＬＰＲＯＧＲＥＳＳＯＦＦｅＭｎＢＬＡＳＴＦＵＲＮＡＣＥＩＮＬＡＮＧＦＡＮＧＳＭＥＬＴＩＮＧＰＬＡＮＴＦＯＲ２０ＹＥＡＲＳ￥ＴｉａｎＺｈｅｎｇｗｅｎ（ＬａｎｇｆａｎｇＳｍｅｌｔ...     

梅山3^#高炉自动化控制系统

介绍了上海梅山冶金公司３＾＃高炉的工艺特点，采用ＳＩＭＡＴＩＣＳ５ＰＬＣ组成的全ＰＬＣ高炉自动化控制系统的功能特点，系统独特的网络结构以及现场应用的经验。     

徐钢采用聚能爆破高炉炉瘤获成功

徐钢采用聚能爆破高炉炉瘤获成功ＴＥＣＨＮＩＱＵＥＯＦＥＮＥＲＧＹ－ＡＧＧＲＥＧＡＴＥＤＥＸＰＬＯＳＩＯＮＷＡＳＳＵＣＣＥＳＳＦＵＬＬＹＵＳＥＤＴＯＲＥＭＯＶＥＡＣＣＲＥＴＩＯＮＯＦＢ．Ｆ．ＩＮＸＵＺＨＯＵＩＲＯＮＡＮＤＳＴＥＥＬＧＥＮＥＲＡＬＰＬＡＮ...     

Complex formation between RAS and RAF and other protein kinases

We used a Saccharomyces cerevisiae genetic system to detect the physical interaction of RAS and RAF oncoproteins. We also observed interaction between RAS and byr2, a protein kinase implicated as a mediator of the Schizosaccharomyces pombe ras1 protein. Interaction with RAS required only the N-terminal domains of RAF or byr2 and was disrupted by mutations in either the guanine nucleotide-binding or effector-loop domains of RAS. We observed interaction between MEK (a kinase that phosphorylates mitogen-activated protein kinases) and the catalytic domain of RAF. RAS and MEK also interacted but only when RAF was overexpressed.     

The ovarian renin-angiotensin system in reproductive physiology

The identification of the presence of prorenin, renin, angiotensinogen, angiotensin-converting enzyme, angiotensin II (Ang II), and Ang II receptors in the ovary suggests that there is a functional ovarian renin-angiotensin system (RAS). It could play a significant role in such areas of ovarian physiology as follicular development, steroidogenesis, oocyte maturation, ovulation, and follicle atresia. Expression of the ovarian RAS is regulated by gonadotropins. Ang II, a bioactive octapeptide of RAS, has important effects as a paracrine/autocrine regulator at different stages of the reproductive cycle. Ang II modulates ovarian steroidogenesis and formation of the corpus luteum and also stimulates oocyte maturation and ovulation via Ang II receptors on granulosa cells. In addition, increasing evidence demonstrates that Ang II is a major factor in regulating the function of atretic follicles. In any physiologic system, aberrations result in the development of pathologic states. Disturbances in the ovarian RAS can be the cause or the result of such reproductive disorders as polycystic ovary syndrome, ovarian hyperstimulation syndrome, ovarian tumors, and ectopic pregnancy. Data support the concept of an active and regulated RAS in ovarian follicles. Species differences observed in the expression of ovarian RAS suggest varying functional roles among species with respect to ovarian physiology.     

Local stress, not systemic factors, regulate gene expression of the cardiac renin-angiotensin system in vivo: a comprehensive study of all its components in the dog

Cardiac hypertrophy is associated with altered expression of the components of the cardiac renin-angiotensin system (RAS). While in vitro data suggest that local mechanical stimuli serve as important regulatory modulators of cardiac RAS activity, no in vivo studies have so far corroborated these observations. The aims of this study were to (i) examine the respective influence of local, mechanical versus systemic, soluble factors on the modulation of cardiac RAS gene expression in vivo; (ii) measure gene expression of all known components of the RAS simultaneously; and (iii) establish sequence information and an assay system for the RAS of the dog, one of the most important model organisms in cardiovascular research. We therefore examined a canine model of right ventricular hypertrophy and failure (RVHF) in which the right ventricle (RV) is hemodynamically loaded, the left ventricle (LV) is hemodynamically unloaded, while both are exposed to the same circulating milieu of soluble factors. Using specific competitive PCR assays, we found that RVHF was associated with significant increases in RV mRNA levels of angiotensin converting enzyme and angiotensin II type 2 receptor, and with significant decreases of RV expression of chymase and the angiotensin II type 1 receptor, while RV angiotensinogen and renin remained unchanged. All components remained unchanged in the LV. We conclude that (i) dissociated regional regulation of RAS components in RV and LV indicates modulation by local, mechanical, not soluble, systemic stimuli; (ii) components of the cardiac RAS are independently and differentially regulated; and (iii) opposite changes in the expression of angiotensin converting enzyme and chymase, and of angiotensin II type I and angiotensin II type 2 receptors, may indicate different physiological roles of these RAS components in RVHF.     

Angiotensin II: a reproductive hormone too?

It has long been known that angiotensin II (Ang II) can affect reproductive tissues such as the uterus. However, the existence of a local renin-angiotensin system (RAS) in female as well as male reproductive tissues is a relatively recent observation. Of great interest is the discovery that all components of the RAS are present in the ovary, that the ovary secretes components of the RAS into the bloodstream, and that the ovary itself is responsive to Ang II. Recent studies suggest that the primary role of Ang II in the ovary is to cause atresia in non-ovulatory follicles; however, there is also compelling data to suggest that Ang II facilitates ovulation. Male reproductive structures also contain all of the components of the RAS, gonadotropins regulate the activity of these components, and these tissues have Ang II receptors. Of great interest is the expression of testis-specific angiotensin-converting enzyme (ACE), which is located on germ cells. Recent studies using gene knock-out techniques indicate that testis ACE plays an important role in male fertility. However, the overall significance of the RAS for normal reproductive function remains questionable. There is now a body of evidence implicating the RAS in pathophysiologies associated with reproductive function, which gives rise to the possibility that drugs acting on the RAS might ameliorate some of these disorders. Considerable work remains to determine the role of Ang II in reproductive functions.     

Effects of transplantation on the renin angiotensin system (RAS)

Hypertension in organ transplant recipients is associated with several functional modifications of the renin angiotensin system (RAS), which varies according to the type of transplanted organs (kidney, heart, liver or bone marrow) and the immunosuppressive regimen. Before transplantation, chronic organ failure is associated with direct and indirect stimulation of both systemic and local RASs. After transplantation, cyclosporin per se is the major determinant of hypertension. It induces stimulation of both systemic and local RAS via direct and indirect effects within the kidney and peripheral vessels. In kidney transplant recipients, ischaemia from the native kidneys and from the graft, due to acute or chronic rejection, also contributes to RAS stimulation. In cardiac transplant recipients, several haemodynamic parameters, abnormal cardiorenal neuroendocrine reflex mechanism and other hormonal systems (ANF, AVP, catecholamines) stimulate the RAS.     

Local renin-angiotensin system: especially in coagulating glands of mice

It is well known that the renin-angiotensin system (RAS) is involved in the control of blood pressure. Recently, all or part of the components concerning the RAS have been reported to be synthesized and secreted outside of classical organs or tissues, at sites including the brain, pituitary and pineal glands, eye, heart, adrenal gland, testes, ovary, placenta, and coagulating glands. The functions and roles of these local RAS are not well known. In the present review, the author explains the history of the RAS, the circulating RAS and the existence of local RAS in multiple organs and tissues, discussing especially the function of coagulating gland renin. Renin protein, the triggering enzyme of the RAS, is distributed generally in certain fixed cells of several organs and tissues, exemplified by the gonadotrops in the pituitary glands and Leydig cells in the testis. Renin mRNA and its expressing cells can also be detected from the above cells as a whole. In some tissues, angiotensinogen-containing cells do not, however, correspond to its mRNA-expressing cells and potent activator angiotensin II-containing cells, as, for example, in the brain. These cases are explained by constitutive pathways of angiotensinogen processing. Coagulating gland renin, which the author is investigating vigorously, is the most recently discovered local renin, and represents significant subject for investigations. It is suggested that coagulating gland renin may play an unique function for sexual organs by exocrine mechanism.     

Structure of the renin-angiotensin system and its significance in the body

Renin-angiotensin system (RAS) is a methabolic pathway producing octapeptid angiotensin II (AII) with vasoconstrictive effects, which is also involved in the regulation of water homeostasis and electrolyte balance in the organism. Genes encoding individual components of the RAS can be considered as "candidate genes" for some cardiovascular diseases e.g. hypertension or myocardial infarction. Besides the circulating RAS, also local tissue systems exist. Local RASs are involved in various physiological functions e.g. regulation of growth and proliferation, apoptosis or signal transmission where AII serves as the neurotransmitter.     

The human placental renin-angiotensin system

The human placenta and related tissues are considered to be examples of the recently accepted local renin-angiotensin systems (RAS). The brain is another example of a system that is thought to be regulated independently of the kidney and the role of angiotensin within the CNS as a neural mediator has drawn considerable attention. It has been known for a long time that many of the neuroendocrine mediators and receptors are expressed in the placenta and it has been suggested that there are many parallels between the classical neuroendocrine system and the placental one. The present review summarizes information that components of the RAS are expressed in uteroplacental tissues, are regulated by endogenous substances, and have important biological functions within this reproductive system. A comparison of similarities and differences between the classical and the placental RAS may provide clues to functions in other endocrine and neuroendocrine systems. The major components of the placental RAS that are considered are renin, prorenin, angiotensin I, angiotensin II, angiotensin converting enzyme (ACE), angiotensin receptors, and angiotensinogen (renin substrate). The factors that regulate these components at the cellular and the nuclear level are described. It is concluded that prorenin via angiotensin-dependent and angiotensin-independent mechanisms influences functions within uteroplacental tissues. Some of these actions are direct and others are mediated by the release of different signalling molecules. These features are similar to many neuroendocrine systems and utilize some of the same messengers.     

Role of cardiac renin-angiotensin system in swimming induced physiological myocardial hypertrophy

To determine the contribution of cardiac renin-angiotensin system (RAS) to the physiological myocardial hypertrophy induced by swimming training and the relationship between locally produced and circulating RAS, both ventricular and plasma angiotensin (Ang) I and II contents, ventricular angiotensin converting enzyme (ACE) and plasma renin activity (PRA) were detected by means of radioimmunoassay and biochemical method. It was shown that after 5 weeks of swimming, the ventricular wet weight to body weight ratio (V/Bwt) and Ang II in both left and right ventricles and ACE activity increased markedly as compared with the controls (P < 0.05). Furthermore, significantly positive correlation was found between the ventricular Ang II and V/Bwt (r = 0.7721, P < 0.001), while the plasma Ang I and II and PRA remained at the control level. No correlation was found between plasma Ang II and V/Bwt. These above findings suggest that cardiac RAS may play an important role in physiological myocardial hypertrophy and to a large extent is in dependent on circulating RAS.