基于ARM7与FPGA组成的可编程控制器

本文以32位嵌入式微处理器S3C44BOX(ARM7)为控制核心,以CAN为现场总线设计可编程控制器.描述了系统的工作原理及PLC主机各功能模块与嵌入式微处理器S3C44BOX的接口电路原理.采用FPGA扩展可编程控制器所需要的I/O口及A/D、D/A的扩展电路;并用另一块FPGA嵌入智能控制算法.由于系统采用了集成众多功能的嵌入式微处理器S3C44BOX,从而简化了电路的设计,提高了系统的可靠性.     

聚丙烯纤维混凝土的工程特性

介绍了聚丙烯纤维混凝土的工程性能.聚丙烯纤维的加入能减少和防止混凝土塑性裂缝的产生,提高混凝土的抗渗性、抗冻性、抗冲击性能和耐磨损性能.强调了施工中应注意的问题.     

Ba_（1-x）Bi_x（Ti_（0.9）Zr_（0.1））O_3陶瓷的介电弛豫特征

采用固相反应法制备了Ba1-xBix（Ti0.9Zr0.1）O3（x=0.01,0.02,0.03,0.04）陶瓷,X射线衍射分析表明所有样品均是四方晶体结构,3%mol的Bi3＋能够完全溶入钙钛矿晶格中。不同频率下Ba1-xBix（Ti0.9Zr0.1）O3陶瓷的介电温谱显示所有样品均表现出弥散相变的特征,在x≥0.02的三组样品又表现出弛豫铁电体的特征。通过纳米极性微区和畴壁探讨了弛豫现象产生的机理。     

浅粉红色—粉红色绿柱石的宝石学特征

以前珠宝市场上粉色系列绿柱石并不常见,近期发现粉色绿柱石数量增加,笔者对彩宝市场上的浅粉红色—粉红色绿柱石进行了宝石学特征研究。浅粉红色—粉红色这一系列的绿柱石与以前研究较多的祖母绿、海蓝宝石相比,颜色明显不同,在折射率、密度等方面也存在一定的差别。通过常规宝石仪器,红外光谱仪,X射线荧光能谱仪对这一系列绿柱石进行测试分析,对比发现其与常见的海蓝宝石存在一些差异;本文按照粉色绿柱石测试的折射率的结果分为A、B、C 3组,将同时检测的黄绿色绿柱石和常见的海蓝宝石分成2组,发现浅粉红色—粉红色绿柱石的折射率与密度存在正相关性,而且随着Cs元素替代的增加,Rb元素替代的减少,折射率与密度升高,粉红色绿柱石的折射率可高达1.61。     

The effect of local chemical sympathectomy of the rat uterus on its sensitivity to sex hormones

Chemical sympathectomy of the rat uterus did not alter the main metabolic processes maintaining the uterus weight even though it changed its response to sex steroids. Sensitivity of endo- and myometrium to progesterone significantly decreased thus inducing a relative increase in the estradiol action.     

Mucin-like glycoprotein genes are closely linked to members of the trans-sialidase super-family at multiple sites in the Trypanosoma cruzi genome

In Trypanosoma cruzi a cell surface enzyme with trans-sialidase (TS) activity has been implicated as an important factor in establishing infection. The enzyme is encoded by genes belonging to a large super-family which on the basis of sequence has been subdivided into 4 groups. TS mediates the transfer of sialic acid residues from host glycoconjugates to acceptor molecules on the parasite surface. To study the organisation of the TS genes we isolated several distinct cosmids from a library constructed with DNA from the T. cruzi X10.6 clone. In these cosmids, the TS genes (group I) were present either as single copies or as a direct tandem repeat. A common feature of the cosmids was the presence of a related group III gene located 10-12kb downstream of the TS gene(s) and arranged in the same orientation. In several of the cosmids we also identified a mucin-like glycoprotein gene located between the group I and group III genes. The mucin-like genes are part of a large polymorphic family and contour clamped homogeneous electric field electrophoresis (CHEFE) analysis showed that they were linked to members of the TS super-family at multiple sites in the X10.6 genome. Screening of a second cosmid library made with DNA from the CL-Brener clone confirmed this multiple linkage suggesting that it is a common feature of the species. This genetic organisation may have important functional significance since the mucin-like glycoproteins are the major cell surface acceptors of sialic acid.     

Glycosaminoglycans in intervertebral disc amyloid deposits

Intervertebral discs are a common site of localized articular and some forms of systemic articular amyloid deposition. Whether there is an intrinsic matrix factor that favours amyloid deposition in intervertebral disc connective tissues is uncertain, but it is known that small localized deposits of amyloid in intervertebral discs are largely age related. As the glycosaminoglycans (GAGs) composition of the intervertebral disc is known to change with age, and as some forms of systemic amyloid deposition have been shown to be associated with particular highly sulphated GAGs, we examined the GAGs profile of amyloid deposits in intervertebral discs using mucin histochemistry (Alcian blue: MgCl2 critical electrolyte concentration) and immunohistochemistry. We found strong staining for very highly sulphated GAGs (0.9 M and 1 M MgCl2) and confirmed the presence of keratan sulphate in both localized and systemic, dialysis-associated beta 2-microglobulin amyloid deposits within disc fibrocartilage. These findings suggest that qualitative and quantitative changes in matrix GAGs, particularly strongly sulphated GAGs such as keratan sulphate, may play a role in the pathogenesis of localized and systemic amyloid deposition in intervertebral discs.     

The creatine kinase activity of chick myoblasts and neuroblasts in primary culture after intensive laser irradiation

The influence of green-yellow light of copper laser (mean power of impulse-periodic emanation 3 W, working density of power in experiment is 200 mW/cm2) on biochemical indices of chick embryo myoblasts and neuroblasts in primary culture was studied. The content of water extracted protein was found to increase progressively, the total and specific activities of creatine kinase elevated considerably in both the cell cultures under irradiation with the total doses equal to 3 and 15 J. However, with dose of 30 J these parameters corresponded to the level characteristic of nonirradiated cultures. Mechanisms of stimulating action of highly intensive laser emanation on cell functions are discussed.