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发展先进的制造工程技术,需要制造科学的支持。论述了当代制造工程技术的特点。探讨了世纪之交制造业内外正在发生的主要变化。阐述了今日制造工程学科面对的挑战。回顾了制造科学的历史发展。探讨了制造科学的研究现状。介绍了制造科学研究的两项成果。 相似文献
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云制造环境中的虚拟制造单元 总被引:1,自引:0,他引:1
为实现云制造环境下制造资源的灵活配置和制造能力的按需匹配,提出云制造环境中的虚拟制造单元(VMU-CM)和云制造环境中的虚拟制造中心(VMC-CM),基于VMC-CM给出了产品的制造过程。对云制造环境下制造资源、制造能力的特点进行分析,对制造资源和制造能力进行具体分类,给出了VMU-CM的结构和构造流程,根据制造任务设定VMU-CM的信息,构造从事各类制造活动的VMU-CM。通过生产过程、组织结构和对外服务信息,将各类VMU-CM整合起来构建VMC-CM。将VMC-CM的制造能力信息封装为制造服务接入制造服务中心,实现了"制造资源—制造能力—制造服务"的制造资源虚拟化过程。通过VMU-CM和VMC-CM的部分理论在面向集团企业的云制造平台的制造能力标准制定和制造服务中心构建中的应用,证明了所提理论的可行性。 相似文献
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微制造与数字制造——21世纪制造技术的重要发展方向 总被引:2,自引:0,他引:2
研究探讨了21世纪制造技术的两个重要发展方向--微制造技术和数字制造技术的基本概念、特征、研究内容和发展过程,提出了我们今后在微制造和数字制造技术方面重点研究内容。 相似文献
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制造业信息化技术的发展趋势 总被引:16,自引:0,他引:16
讨论了制造业信息化技术的发展趋势,指出集成制造技术、绿色制造技术、智能制造技术、网络化制造技术和大批量定制造技术等将对21世纪初期的制造业产生重大的影响,介绍了集成制造技术、绿色制造技术、智能造制技术、网络化制造技术和大批量定制技术的主要内容。 相似文献
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基于物理制造单元的网络化制造资源建模研究 总被引:1,自引:0,他引:1
面向未来数字化制造模式,提出对企业制造资源分三层进行管理,即物理制造单元层、工作中心层和物理设备层;针对生产制造过程中各个应用环节对制造资源的需求,利用面向对象方法对物理制造单元从基本信息、制造能力信息、物理构成、状态信息和工装信息等五方面进行了建模研究;对于物理制造单元的制造能力信息分别面向逻辑制造单元和物理制造单元可加工零件类别进行建模;最后将该模型应用在网络化协同工艺系统和可重构制造资源优化配置平台中,给出了具体的应用方案。 相似文献
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数字化制造是先进制造技术的核心技术 总被引:34,自引:1,他引:34
综观国内外先进制造技术的现状和发展,不难看出数字化制造技术实为先进制造技术的核心技术。阐述了数字化时代,数字化工程,数字化技术和数字化制造技术等的内涵,回顾了制造领域20年来发生的一些重要事件。列举了世纪之交制造业面临的挑战,讨论了数字化制造技术和我国制造业的振兴。最后,对数字化制造学科的发展作了展望,指出了开展制造科学研究的重要意义。 相似文献
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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. 相似文献
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Neu B Herrmuth H Ernst F Vaupel W Reindl W Hutzler P Atkinson MJ Classen M Schepp W 《Microscopy research and technique》2001,53(5):377-388
Apoptotic cell death is common in the inflamed gastric mucosa, but its role in the regulation of cell homeostasis in normal gastric mucosa is unknown. We investigated the expression of CD95, Bcl-2, and Bax and their roles in the regulation of apoptosis in normal rat gastric mucosa and in cultures of highly enriched rat chief and parietal cells by immunostaining, Western blotting, and FACS. In intact tissue CD95, Bcl-2, and Bax were localized predominantly in the glandular base region in chief cells. In freshly isolated cells, expression of CD95, Bcl-2, and Bax was much more pronounced in chief cells than in parietal cells. A lower intracellular Bcl-2/Bax ratio suggesting a higher susceptibility to apoptosis was noticed in chief rather than in parietal cells. In extended cultures of parietal and chief cells, Bax expression was upregulated and Bcl-2 expression was downregulated. These regulatory changes, presumably caused by in vitro effects, were not associated with an increase in spontaneous apoptosis. Treatment of chief and parietal cells with Fas-ligand induced apoptosis of all CD95 expressing cells. Expression of CD95, Bcl-2, and Bax predominantly in chief cells suggests that in this cell type regulation of apoptosis may differ from that in parietal cells. Binding of FasL with functionally active CD95 receptors on chief and parietal cells may be relevant for induction of apoptosis in inflamed gastric mucosa. 相似文献
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S. LIPOVEK DELAKORDA I. LETOFSKY-PAPST† T. NOVAK M. GIOVANNELLI‡ F. HOFER† & M.A. PABST§ 《Journal of microscopy》2008,231(1):38-46
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. 相似文献
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D'Angelo L De Girolamo P Cellerino A Tozzini ET Varricchio E Castaldo L Lucini C 《Microscopy research and technique》2012,75(4):441-447
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. 相似文献
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Gahr M 《Microscopy research and technique》2001,55(1):1-11
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. 相似文献
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Lozenka Ivanova Katerina Rebok Maja Jordanova Zrinka Dragun Vasil Kostov Sheriban Ramani Damir Vali Nesrete Krasnii Vlatka Filipovi Mariji Damir Kapetanovi 《Microscopy research and technique》2020,83(9):1141-1152
Pigmented macrophage aggregates (MAs) are known to change under influence of various factors, such as aging, season, starvation, and/or pollution. In this study, changes in the pigment content of the MAs in the spleen of Vardar chub (Squalius vardarensis, Karaman) (n = 129) collected in spring and autumn, from three rivers with different pollution impact was examined: Zletovska River (metals), Kriva River (metals and municipal wastewater), and Bregalnica River (municipal wastewater). Collected data revealed increased relative volume and number of MAs containing hemosiderin under the influence of metals, significant in autumn (p < .05). In chub exposed to metals combined with municipal wastewater, significant increase of lipochrome accumulation in MAs in autumn, melanin in MAs in fish captured in the spring season, and number of splenic MAs containing combination of melanin and lipochrome was noted. Volumes and number of MAs containing combination of hemosiderin and lipochrome increased in spleen of fish captured in autumn from both Zletovska River and Kriva River, most likely due to the contribution of hemosiderin and lipochrome, respectively. Values measured for the various pigments in splenic MAs in fish captured from Bregalnica River, were overall closer to the values measured for fish captured from Kriva River. Notably, melanin and lipochrome are more likely to be found in fish from waters influenced by municipal wastewater (organic pollution) and hemosiderin in fish spleen from water influenced by mining activity (heavy metals pollution). 相似文献
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Del Moral ML Esteban FJ Hernández R Blanco S Molina FJ Martínez-Lara E Siles E Viedma G Ruiz A Pedrosa JA Peinado MA 《Microscopy research and technique》2004,64(4):304-311
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. 相似文献
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A considerable momentum has recently been gained by in vitro and in vivo studies of interactions of trace elements in biomolecules due to advances in inductively coupled plasma mass spectrometry (ICP MS) used as a detector in chromatography and capillary and planar electrophoresis. The multi-isotopic (including non-metals such as S, P, or Se) detection capability, high sensitivity, tolerance to matrix, and large linearity range regardless of the chemical environment of an analyte make ICP MS a valuable complementary technique to electrospray MS and MALDI MS. This review covers different facets of the recent progress in metal speciation in biochemistry, including probing in vitro interactions between metals and biomolecules, detection, determination, and structural characterization of heteroatom-containing molecules in biological tissues, and protein monitoring and quantification via a heteroelement (S, Se, or P) signal. The application areas include environmental chemistry, plant and animal biochemistry, nutrition, and medicine. 相似文献
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F. Parillo G. Catone M. Maranesi A. Gobbetti B. Gasparrini M. Russo C. Boiti M. Zerani 《Microscopy research and technique》2012,75(12):1682-1690
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Pyza E 《Microscopy research and technique》2002,58(4):335-344
The visual system of insects provides an excellent model to study processes of transduction and transmission of photic information, synaptogenesis, synaptic plasticity, and wiring between photoreceptors and their visual interneurons in the optic lobe. This review describes synaptic contacts between photoreceptors and other neurons in the visual system of insects, especially in the fly's first optic neuropile (the lamina), and summarizes changes observed in the synapses of visual cells that have been reported both in phylogeny and ontogeny, and also examples of synaptic plasticity in adult insects that have been evoked by intrinsic and extrinsic factors. Plasticity observed in synapses of the insect's visual system seems to exemplify not only synaptic contacts in insects but, given that similar examples of plasticity have been found in other animal groups, may also be a general phenomenon in the nervous system. 相似文献