机械制造迈向高技术未来第二部分:制造业走向高技术

新时期世界科学技术和产业发展一个新的特点和规律是学科间的交叉融合和产业技术间的结合互动。制造业和高技术相辅相成，新工艺和新装备集成创新，成为必然的潮流。     

可定制的网络课程系统研究

领域模型和学生模型是领域知识和学生已有知识、学习能力的表示,开发网络课程时需将领域模型和学生模型实例化;而教学模型和导航模型依赖于领域模型和学生模型,是实现个性化教学过程的关键,已做成系统的内置机制.该网络课程系统能提供学习者适合其特征和需要的学习方式、学习内容和导航帮助.     

基于特征性子离子和中性丢失快速筛查和识别食品中唑类和有机磷类农药

采用基于中性丢失和子离子的敞开式离子化技术,结合高分辨二级质谱,建立了一种快速、便捷地筛查和识别食品中唑类（三唑类、咪唑类、吡唑类）和有机磷类农药的分析方法。通过对待测物在质谱中产生的子离子和中性丢失行为进行归纳,建立了待测物的共性特征子离子和中性丢失库,以及辅助定性子离子和中性丢失库。配合适宜的制样方式、敞开式电离源和数据处理方式,可实现对唑类和有机磷类农药的筛查和识别。该方法快速准确,适用于多种类型食品中唑类和有机磷类农药的检测。     

石墨和二硫化钼填充氟橡胶的摩擦磨损特性研究

研究了石墨和二硫化钼填充量对氟橡胶(FKM)的摩擦磨损性能的影响, 并用扫描电子显微镜和热重分析仪分析了石墨和二硫化钼填充氟橡胶(FKM)的磨损表面和热稳定性.结果表明,石墨和二硫化钼的加入提高了FKM的摩擦磨损性能与热稳定性;随着石墨和二硫化钼用量的增大,复合材料的摩擦因数和磨损量先降后升;当石墨和二硫化钼质量分数分别为3%和5%时,复合材料的摩擦磨损性能最佳;当二硫化钼填充量为10%时,氟橡胶的热分解温度比未添加润滑剂的氟橡胶提高了7 ℃左右.     

火电厂继电保护故障诊断与处理技术研究

火电厂继电保护系统是保障电力系统安全和稳定运行的重要保障措施。然而,由于其复杂性和高度关键性,故障诊断和处理一直是一个重要的研究课题。本文基于对火电厂继电保护系统故障类型和原因分析的研究,阐述了基于数学模型、信号处理和人工智能的故障诊断方法,并探讨了常规处理、应急处理、预防性维护和智能化处理等故障处理技术的研究现状和发展方向,为提高火电厂继电保护系统的运行安全性和稳定性提供了一定的理论和技术支持。     

理顺和创造提升我国企业国际竞争力的政策制度环境

提升我国本土企业国际竞争力是“十二五”规划的重要任务.目前,影响我国企业竞争力和创新能力有三个关键因素：与企业制度和基础条件有关的企业和企业创业者;创新和成长激励;资源状况及配置方式.为提升我国企业竞争力目标应采取的主要政策分类明确不同产业的政策目标和重点支持部分大型国企和有基础的非公企业尽快提升国际竞争力;从企业制度、市场制度、资本制度、财税制度四方面推进改革和政策调整;制定和实施符合市场经济原则和功能导向型的产业政策;建立有效的支持服务和政策管理体系.     

基于图像增强直方图

图像增强是数字图像的预处理,对图像整体和局部特征都能有效地进行改善．文章主要研究比较了直方图的均衡化和规定化方法的图像增强的基本原理和算法,以及能改进灰度图像的对比度和灰度级动态范围的处理．为更好的快速掌握和应用直方图增强图像技术提供了好的指导和参考资料。     

数控机床典型制造工艺及装配工艺实例分析

机床设计的合理性决定它的使用寿命和在恶劣环境下能否表现出具有良好的稳定性和出色的操控性，对制造和装配工艺来讲，它是贯彻执行和实施设计师完成整个制造过程的一个系统工程，制造和装配的工艺决定着机床最终的静态几何精度和动态精度的好坏，对于数控机床这一环节来讲更为重要。     

虚拟环境下线缆和管路装配规划系统体系结构研究

首先分析了复杂产品中线缆和管路在设计和装配环节存在的问题,指出虚拟现实技术为解决线缆和管路的优化布局及可靠性装配提供了一种可行的技术途径,并分析了借助虚拟现实技术进行线缆和管路装配规划的优点.其后,分析了虚拟环境下线缆和管路装配规划的特点与内涵,提出了虚拟环境下线缆和管路装配规划系统的总体业务流程,并以功能模型和数据流模型进一步阐述了该业务流程.最后,提出了虚拟环境下线缆和管路装配规划系统的体系结构,原型系统的实现表明,该体系结构具有较好的开放性和可扩展性.     

《压力容器》杂志征稿启事

1征稿内容1.1材料(1)压力容器和压力管道用新材料的研制和推广应用(2)压力容器和压力管道材料性能试验和测试方法的研究(3)特种金属材料、复合材料在压力容器中的开发应用(4)国外有关压力容器和压力管道用材的研究进展和动态     

Histochemical and ultrahistochemical localization of heavy metals in calf organs

Cadmium, zinc, selenium, and copper were administered, singly or in combination, orally or subcutaneously. Experiment I included 32 calves of both sexes; six received Cd (two groups), Zn, Cd, and Zn, and Cd and Se (two groups) and one group was a control. In Experiment II (21 bulls), three were given Cd, Cd, and Cu, and Cd and Zn, respectively, and one group was a control. For light microscopy, in Experiment I the highest amounts of silver granules were present in the samples of liver, small intestine, and vesicular gland of all the exposed groups; in Experiment II the most affected organs were liver, kidney, and small intestine. For electron microscopy, in Experiment I, after administration of Cd and Zn, the highest amounts of granules were seen in the cytoplasm of hepatocytes and cells of the proximal and distal renal tubules and the lowest amounts were found in glandular cells of the pancreas. Administration of Cd and Se resulted in the presence of large numbers of granules in the nuclei and nucleoli of spermatogonies. In Experiment II, ingestion of Cd and Zn in feed led to the appearance of highest amounts of granules in the nucleoli, nuclei, and cytoplasm of cells in testes, kidneys, and pancreas. Following Cd intake, the highest accumulation of granules was observed in the nucleoli of hepatocytes and cells of the proximal and distal renal tubules. Combined Cd and Cu produced the highest number of granules in cells of the proximal and distal renal tubules and in the nucleoli and nuclei of germinal epithelium.     

Sinusoidal endothelial cells of the liver: Fine structure and function in relation to age

Liver endothelial cells form a continuous lining of the liver capillaries, or sinusoids, separating parenchymal cells and fat-storing cells from sinusoidal blood. Liver sinusoidal endothelial cells differ in fine structure from endothelial cells lining larger blood vessels and from other capillary endothelia in that they lack a distinct basement membrane and also contain open pores, or fenestrae, in the thin cytoplasmic projections which constitute the sinusoidal wall. This distinctive morphology supports the protective role played by liver endothelium, the cells forming a general barrier against pathogenic agents and serving as a selective sieve for substances passing from the blood to parenchymal and fat-storing cells, and vice versa. Sinusoidal endothelial cells, furthermore, significantly participate in the metabolic and clearance functions of the liver. They have been shown to be involved in the endocytosis and metabolism of a wide range of macromolecules, including glycoproteins, lipoproteins, extracellular matrix components, and inert colloids, establishing endothelial cells as a vital link in the complex network of cellular interactions and cooperation in the liver. Fine structural studies in combination with the development of cell isolation and culture techniques from both experimental animal and human liver have greatly contributed to the elucidation of these endothelial cell functions. Morphological and biochemical investigations have both revealed little changes with age except for an accumulation of iron ferritin and a decrease in the activities of glucose-6-phosphatase, Mg-ATPase, and in glucagon-stimulated adenylcyclase. Future studies are likely to disclose more fully the role of sinusoidal endothelial cells in the regulation of liver hemodynamics, in liver metabolism and blood clearance, in the maintenance of hepatic structure, in the pathogenesis of various liver diseases, and in the aging process in the liver.     

中国部分典型地区气溶胶光学特性观测

利用DTF型太阳光度计在我国几个典型城市地区较长期观测得到的资料,分析了不同地区气溶胶光学厚度日变化和季节变化特征,得到了各地区观测期间日均值、月均值和季节值的变化.结果显示,观测期间丽江地区气溶胶光学厚度最小,大气较洁净,大气中以细粒子为主;其次是张北;喀什和合肥地区气溶胶光学厚度都较大,但喀什、张北多以粗粒子为主,合肥多以细粒子为主.各地区都在春季气溶胶光学厚度较大,冬季最小.喀什的气溶胶光学厚度值多集中在0.15到0.7之间,张北多集中在0.08到0.4之间,合肥多集中在0.2到0.75之间,丽江多集中在0.01到0.1之间.各地区气溶胶光学厚度和(A)ngstr(o)m波长指数频率分布基本呈高斯分布,气溶胶光学厚度峰值分布由高到低依次为合肥、喀什、张北、丽江,(A)ngstr(o)m波长指数由高到低依次为丽江、合肥、张北、喀什.     

Immunolocalization of S100-like protein in the brain of an emerging model organism: Nothobranchius furzeri

The S100 protein in nervous tissue appears to play important roles in regulating neuronal differentiation, glial proliferation, plasticity, development, axonal growth, and in neurogenetic processes. In fish, the adult neurogenic activity is much higher than in mammals. In this study, the localization of S100 protein was investigated in the brain of annual teleost fish, Nothobranchius furzeri, which is an emerging model organism for aging research. By immunohistochemical techniques, S100 immunoreactivity (IR) was detected in glial cells, small neurons, and fibers throughout all regions of central nervous system (CNS) with different pattern of distribution. In the telencephalon, S100 IR was seen in the olfactory bulbs and in different areas of the telencephalic hemispheres. In the diencephalon, S100 positivity was observed in the habenular nuclei of the epithalamus, in the cortical thalamic nucleus, in the dorsal, ventral and caudal portions, the latter with the posterior recessus nucleus, and in the diffuse inferior lobe of the hypothalamus, along the diencephalic ventricle and in the dorsal optic tract. In the mesencephalon, S100 IR was observed in the longitudinal tori, in the optic tectum, and along the mesencephalic ventricle. In the rhombencephalon, S100 IR was shown in valvula and body of the cerebellum, and in some nuclei of the medulla oblongata. The results suggest that S100 may play a key role in the maintenance of the CNS and in neurogenesis processes in the adulthood.     

TRPV4 in the sensory organs of adult zebrafish

TRPV4 is a nonselective cation channel that belongs to the vanilloid (V) subfamily of transient receptor potential (TRP) ion channels. While TRP channels have been found to be involved in sensing temperature, light, pressure, and chemical stimuli, TPRV4 is believed to be primarily a mechanosensor although it can also respond to warm temperatures, acidic pH, and several chemical compounds. In zebrafish, the expression of trpv4 has been studied during embryonic development, whereas its pattern of TPRV4 expression during the adult life has not been thoroughly analyzed. In this study, the occurrence of TRPV4 was addressed in the zebrafish sensory organs at the mRNA (RT-PCR) and protein (Westernblot) levels. Once the occurrence of TRPV4 was demonstrated, the TRPV4 positive cells were identified by using immunohistochemistry. TPRV4 was detected in mantle and sensory cells of neuromasts, in a subpopulation of hair sensory cells in the macula and in the cristae ampullaris of the inner ear, in sensory cells in the taste buds, in crypt neurons and ciliated sensory neurons of the olfactory epithelium, and in cells of the retina. These results demonstrate the presence of TRPV4 in all sensory organs of adult zebrafish and are consistent with the multiple physiological functions suspected for TRPV4 in mammals (mechanosensation, hearing, and temperature sensing), but furthermore suggest potential roles in olfaction and vision in zebrafish.     

Immunohistochemistry of neuronal nitric oxide synthase and protein nitration in the striatum of the aged rat

To ascertain the possible implications of the nitric oxide (NO*) producing system in striatal senescence, and by using immunohistochemistry and image-processing approaches, we describe the presence of the enzyme nitric oxide synthase (NOS), the NADPH-diaphorase (NADPH-d) histochemical marker, and nitrotyrosine-derived complexes (N-Tyr) in the striatum of adult and aged rats. The results showed neuronal NOS immunoreactive (nNOS-IR) aspiny medium-sized neurons and nervous fibres in both age groups, with no variation in the percentage of immunoreactive area but a significant decrease in the intensity and in the number of somata with age, which were not related to the observed increase with age of the striatal bundles of the white matter. In addition, NADPH-d activity was detected in neurons with morphology similar to that of the nNOS-IR cells; a decrease in the percentage of area per field and in the number of cells, but an increase in the intensity of staining for the NADPH-d histochemical marker, were detected with age. The number of neuronal NADPH-d somata was higher than for the nNOS-IR ones in both age groups. Moreover, N-Tyr-IR complexes were observed in cells (neurons and glia) and fibres, with a significant increase in the percentage of the area of immunoreaction, related to the increase of white matter, but a decrease in intensity for the aged group. On the other hand, we did not detect the inducible isoform (iNOS) either in adult or in aged rats. Taken together, these results support the contention that NADPH-d staining is not such an unambiguous marker for nNOS, and that increased protein nitration may participate in striatal aging.     

Application of elemental microanalysis to elucidate the role of spherites in the digestive gland of the helicid snail Chilostoma lefeburiana

In this case study we present an application of different analytical electron microscopic methods in biology, to elucidate their usefulness in such investigations. Using analytical electron microscopy, spherites in the digestive gland cells of the helicid snail Chilostoma lefeburiana were examined at three stages: just before the non-feeding period of over-wintering in November, in the middle of over-wintering in February and at its end in March. A detailed characterization of changes in the elemental composition of the spherites was characterized by a combination of transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy (EDXS), electron energy-loss spectroscopy (EELS) and energy filtering TEM (EFTEM). During over-wintering, the spherites passed the following changes. Before over-wintering in November, they consisted of striking concentric layers of electron-dense and electron-lucent zones, while in February and March they showed clear empty zones between materials of different electron density. In November spherites, C, O, Ca, P, Cl, Fe, Si, Na, K, Mg and S were detected, whereas in February ones C, O, N, Cl, Si and S were found and only C, O, N, Si and Cl were detected in March spherites. It is suggested that the elements missing in February and March were used in different physiological processes during over-wintering, like (1) the maintenance of the appropriate elemental composition of the internal environment, (2) accumulation of non-toxic waste materials that cannot be metabolized and (3) avoiding potential intoxication by contamination with toxic metals.     

Distribution of sex steroid hormone receptors in the avian brain: functional implications for neural sex differences and sexual behaviors

Developmental and seasonal changes in the production of androgens, estrogens, and progestins seem to control sex-specific differentiation and seasonal changes in appetitive and consummatory sexual behaviors of birds. This results in profound sex differences in the quality (sex-specific) or quantity (sex-typical) of behaviors such as courtship, territoriality, or copulation. Steroids affect the brain by binding to intracellularly located receptors. The same brain areas express androgen, estrogen, and progesterone receptors in male and female brains. Sex differences in these genetically determined patterns occur in the size of neuron populations that intrinsically express sex steroid receptors. Further permanent sex differences are subsequent to degenerative fates of receptor expressing neuron populations during ontogeny. Transient sex differences in receptor expression appear to be due to area-specific up- and down-regulation of receptor levels, reflecting transient changes in the level of circulating steroids, changes in environmental conditions, or in the physiological status of the individuals. In particular, intrinsic sex differences in the expression pattern of sex steroid receptors and steroid-independent regulation of the expression level of these receptors in the brain are limiting mechanisms for gonad-dependent sexual development and activities.     

原子吸收分光光度法在环境分析领域中的应用

原子吸收分光光度法是国内外环境分析中最常见的方法之一,本文介绍了原子吸收分光光度法在环境分析中的应用,对美国ＥＰＡ、日本ＪＩＳ和我国现行的标准法系列和统一方法进行了比较,还报道了ＧＦＡＡＳ测定的样品消解中,可能由于用水及酸类引起的沾污问题,同时对国外ＧＦＡＳＳ法直接测定固体环境试样进行了报道,环境形态分析是ＡＡＳ法的主要应用领域,且该技术在国内外发展很快,以Ａｓ、Ｐｂ、Ｓｎ的形态分析为重点,介绍了ＧＣ－ＡＡＳ、ＨＰＬＣ－ＡＡＳ、ＩＣ－ＡＥＳ在形态分析中的应用,同时,对于使用不同的固体样品处理方法,使用ＡＡＳ测定定重金属也进行了介绍,本文引用至１９９９年国内外文献４４篇。     

Early changes induced by short-term low-dose cadmium exposure in rat ventral and dorsolateral prostates

Prostate cancer (PCa) is the most commonly diagnosed cancer in men. The etiology of PCa in humans is multifactorial and includes age, ethnicity, environmental factors, and other unknown causes. Epidemiological and experimental evidence has shown that cadmium is associated with PCa both in humans and rodents. This metal can act as an endocrine disruptor during prostate development, and it induces prostate lesions late in life. In this study, we investigated the effects of low-dose cadmium on rat prostate morphology during puberty. Two-month-old male Wistar rats were randomized into two experimental groups: cadmium-treated and control. The ventral and dorsolateral prostates were dissected, weighed, and immunohistochemically stained with specific antibodies against Ki-67 and the androgen receptor (AR). The concentration of cadmium was measured in the blood and prostate, and testosterone concentration was measured from the plasma. Our results show that cadmium concentration was increased in both the blood and the prostate of cadmium-treated rats, but there were no changes in the prostatic weight, epithelial cell height, or testosterone levels. However, AR immunostaining and epithelial cell proliferation (Ki-67 index) were increased in both prostates with an increase in apoptosis only in the dorsal lobe. Furthermore, atypical hyperplasic proliferative lesions were found in the dorsolateral lobe after cadmium exposure. Cadmium treatment reduced collagen fiber absolute volume in both prostates. Thus, low-doses of cadmium, even for a short period of time, can interfere with prostate epithelium-stroma homeostasis, and this disruption might be an important factor in the onset of prostate lesions late in life.