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1.
本文主要分析了我国目前数控机械产品的研发的状况;并且有针对性的提出了关于我国数控机械产品的开发的方向和研制的路线和技术问题;提出了具体的对数控机械设备的进行开发的内容和策略;并且提出了在引进国外先进的技术的数控技术的同时,用该开发出具有我国特色的数控机械的产品,并且指明了数控机械产品的发展的大方向;并提出了我国数控机械产品的售后服务的模式。本文主要是针对数控土木机械的发展方向进行讨论的。  相似文献   

2.
张驰 《中国机械》2014,(10):192-192
随着时代的进步和高速的发展,各国的能源问题也被逐渐的提上日程。本文就世界能源的现状还有内燃机的发展进行相应的论述,提出相应的看法和亟待解决的措施。对中国的能源发展提出相应的看法,希望能走出一个适合中国国情的一条特色的道路。  相似文献   

3.
面向工程的优化算法性能实验研究   总被引:1,自引:1,他引:1       下载免费PDF全文
韩明红  邓家禔 《中国机械工程》2007,18(12):1460-1464
针对10种工程常用的优化算法进行实验研究,选取12个优化算法Benchmark测试函数进行算法评价,包括连续的和不连续的、凸的和非凸的、单峰的和多峰的、二次的和非二次的、低维的和高维的、有约束的和无约束的测试函数。对实验结果进行分析,从解空间的角度对算法的特性进行分析总结,给出了算法选取的准则。  相似文献   

4.
在现在的发展中,各项工作都需要在先进的科学技术的支持下更好的开展相关的工作计量质量检验检测工作的进行对我们的工作有很大的帮助,面向未来,就要求我们在先进的技术的指导下更好的开展相关的工作。我们自身的发展还不够完善,根据实际的发展需求不断地做好相关的工作,这样才能达到更高的发展水平,随着现代化进程的加快,我们就更需要做好自己的工作,达到发展的目标。  相似文献   

5.
锅炉在工业生产还有日常生活中有着重要的作用,现阶段我国的锅炉的使用的效率,还有非常大的改进空间。因此对于锅炉进行检验还有对于锅炉的能量的消耗进行分析对于提高锅炉的使用的效率热能产生的效率的提升都有重要的作用。  相似文献   

6.
从古至今,我国的农业取得很大的发展,已基本实现自动化,作为其中最重要的经济作物之一的玉米,在其中的地位非常重要。玉米在一定程度上不但为我国的经济发展做出了相应的贡献,另外在人们的日常饮食以及生产当中的作用也十分巨大,因此将玉米高产栽培技术的推广工作做好具有非常深远的意义。然而通过对广大玉米产地进行的实际调查研究发现,在具体的推广高产栽培技术的的时候,依然有许多问题对提高玉米的生产效益造成了很大的困扰。下面我们就将对此进行简单的分析,并有针对性的提出相应的解决措施,希望能够对我国农业的发展起到借鉴和参考的作用。  相似文献   

7.
预应力混凝土管桩的生产过程,其中预应力是对管桩抗弯性能的一个最重要的参数,预应力的施加是由一台张拉机的设备来控制,以前采用传统的标尺来控制管桩长度的拉伸量,员工观看标尺刻度到达规定的标准值时,人手控制停止的方式来决定一条管桩的预应力,这样对操作员工的要求较高(不同管桩的长度的拉伸值要相应的改变),控制产品的精度差,产品的质量得不到保证。针对生产现场的实际情况,合理设计张拉机的全自动控制系统,对员工操作的要求降低,全自动控制系统精度得到保证,从而保证产品质量的稳定,提高公司的生产效益。  相似文献   

8.
殷东岳  孔栋  王晨 《中国机械》2014,(17):144-145
在基建矿井的设备管理当中,很好的针对设备的实际状况,并且进行相应的改进以及技术方面的提升,对于维持企业的经济效益、不断的增强企业的竞争力来讲,有着积极的作业和意义。文章将针对这一方面的内容展开论述,详细的分析如何改进设备管理之中存在的问题和不足,并且提出相应的措施方案,力求加强实际当中的操作和应用,更好的为相关工作的进行作出积极贡献。  相似文献   

9.
提出了一种将模糊控制、滑模控制与自适应控制三者有机的整合的模糊滑模自适应控制的算法,并以虚拟轴机床的单通道的阀控非对称液压缸作为研究的对象。仿真实验表明,该算法可以使得系统输出渐进地收敛于参考的输入信号,且可以很快地对变化的信号进行有效地跟踪,对参数的摄动与有界的干扰具有不变性。提出的方法与传统的PID控制比较,更加的适用于较强的干扰的复杂系统、高阶的非线性,将方法应用于虚拟轴机床的液压的控制系统可以获得较高的控制精度、较好的机床动态性能与较小的稳态误差。  相似文献   

10.
随着时代的发展,经济的增长,社会的进步,我国的综合国力逐渐提高,科学技术不断的改良、创新、进步,而这些改变随之而来的是我国的工业发展越来越迅速,以往的封建的旧的思想以及旧的技术、产品已近满足不了这个时代的需求,人们的生活水平不断提高,对于新兴的产品以及技术的需求越来越高,超声振动辅助钻削钛合金技术的发展就是其中之一。  相似文献   

11.
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   

12.
智能机床成为机床装备发展的趋势。在介绍国内外智能机床的研究现状的基础上,分析目前智能机床技术研究的三个问题,提出智能机床的狭义和广义定义;给出智能机床的包括人计机的协同性、整体与局部的协调性、智能的恰当性与无止性、自学习及其能力持续提高性、自治与集中的统一性、结构的开放性和可扩展性、制造和加工的绿色性、智能的贯穿性八个智能技术特征;阐述包括以人为中心的人计机动态交互功能、三个基本功能——执行智能功能、准备智能功能、维护智能功能的智能功能特征,以及功能之间的相互关系;建立八个理论与技术的智能机床技术理论框架,包括人计机一体化融合理论与技术、多源信息的感知理论与技术、智能决策理论与技术、智能执行理论与技术、智能维护理论与技术、智能机床综合能力评价理论与技术、智能机床标准化技术、智能机床支撑技术等,形成了智能机床的技术体系框架,同时指出上述内容将随着技术的进步和应用的深入不断充实和丰富。  相似文献   

13.
Xiuchun ZHANG 《Biocell》2019,43(4):313-319
To investigate the effects of polydatin on the proliferation, migration, and invasion of ovarian cancer, the change of proliferative ability, migration ability, and invasive ability of human ovarian cancer cell OVCAR-3, A2780, and HO-8910 was detected by using polydatin and up-regulating PI3K. The anticancer activity and mechanism of polydatin in ovarian cancer were analyzed. Polydatin could effectively inhibit the proliferation, migration, and invasion of OVCAR-3, A2780, and HO-8910, and inhibit the expression of PI3K protein. After the expression level of PI3K protein was up-regulated, the inhibitory effect of polydatin on the proliferative ability, migration ability, and invasive ability of OVCAR-3, A2780, and HO-8910 significantly decreased, suggesting that PI3K was the target of polydatin. Therefore, we concluded that polydatin could inhibit the proliferation, migration, and invasion of ovarian cancer cells by inhibiting the expression of PI3K protein, which provides an experimental basis for polydatin in the treatment of ovarian cancer.  相似文献   

14.
Semiautomated methods are used to measure elongated, curved and complex branching profiles and isolated perimeter segments in monochrome video images with a general-purpose analysis system. These methods are used to make the major primary measurements of bone histomorphometry. Accuracy and reproducibility of the image acquisition, processing and measurement system is documented by measuring a semicircular standard of known dimensions. Semiautomated applications of the Ar/Le method for measuring areas and perimeters, and calculating lengths and widths of osteoid seams, lengths of mineralization labels and mineral apposition rate, wall width, indirect measurements of eroded, osteoclastic and osteoblastic perimeters without tracing, and measurement of mineralized or total cancellous bone area and perimeter gave values comparable to measurements of the same parameters by tracing or grid counting techniques with equal or better reproducibility and much greater efficiency. Intraindividual variation in measuring multiple bone biopsies was comparable to that reported with current standard methods. Major sources of variability for semiautomated methods were image magnification and selection of profile edges by thresholding, and sources of variability for manual methods are image magnification, numbers of orthogonal intercepts, tracing speed and accuracy of the algorithm used to measure traced pixels. Semiautomated methods are accurate, reproducible and rapid methods suitable for bone histomorphometry.  相似文献   

15.
In recent years, microbial metabolomics, a new field that has attracted wide attention, provides a map of metabolic pathways and clarifies the interaction mechanism between microorganisms and hosts. Many microorganisms are found in the human intestine, oral cavity, vagina, etc. Probiotics could maintain the good health of the host, while pathogens and an imbalance of bacterial flora lead to a series of diseases of the body and mind. Metabolomics is a science for qualitative and quantitative analysis of all metabolites in an organism or biological system, which could provide key information to understand the related metabolic pathways and associated changes. This approach analyzes the final products of cellular regulatory processes, the level of which can be regarded as the ultimate response of the biological system to genetic or environmental changes. Microbial metabolomics has been widely used in different research fields, such as microbial phenotypic classification, mutant screening, metabolic pathways, microbial metabolic engineering, fermentation engineering monitoring and optimization, microbial environmental pollution, and so on. However, there are only a few reviews on microbial metabolomics of probiotics and pathogens. This review summarizes the main methodologies, including sample preparation, identification of metabolites, data processing, and analysis. Recent applications in microbial metabolomics of probiotics and pathogens are also described. This paper first summarized the research progress and application of microbial metabolomics from two aspects: probiotics and pathogenic bacteria. Probiotics and pathogenic bacteria do not exist independently most of the time; hence, these were reviewed in the research field of coexistence of probiotics and pathogenic bacteria, which was subdivided into important microbial research fields closely related to human health, including the human gut, oral cavity, food, and nutrition-related microorganisms. Then, the main problems and trends associated with microbial metabolomics are discussed.  相似文献   

16.
在长期进化过程中,自然界中的多种动物、植物形成了独特的轻质、高强结构,以此来抵抗外界的复杂冲击载荷,保护自身完整,满足生存需要。生物轻质高强结构的优越性,启发了科研和工程人员采用结构仿生学的方法来对管状和板状两大类吸能结构进行设计优化和改进。对竹子、茎秆/树干、羽轴、骨骼四类管状生物结构和甲虫鞘翅、贝壳、柚子皮、龟壳四类板状生物结构进行综述,阐述了分层、多孔、螺旋、中空等多种结构与轻质高强特性之间的关系。在此基础上,对比和分析了相应的结构元素在单胞管、多胞管、嵌套管、波纹管等管状吸能结构和蜂窝夹芯板、复合材料板、混合结构板等板状吸能机构中起到的作用。进一步对当前仿生吸能领域存在的结构复杂、质量大、缺乏普适性的机理和过渡“桥梁”等问题做出了分析;最后对仿生吸能技术的形式简单化、结构轻量化、理论通用化、“形神兼备”化发展趋势做出展望。  相似文献   

17.
介绍了应用OCS控制器实现压力仪表的计量采集和系统授权管理,压力仪表具有4 mA~20mA、RS485、HART及RJ45等多种电气接口,工业一体化PLC控制器OCS自身具备多种IO端口,可以直接应用OCS采集压力仪表的实时数据和配置参数。同时,设计出一套授权模型以满足设备用户进行权限授权和商务追款的技术需求,依次通过授权码合法性判断、操作时效性限制、授权时效性约束等实现压力计量授权系统的授权管理。经测试验证,所设计的压力计量仪表授权系统可以较稳定高效地实现压力仪表数据采集和设备授权管理,达到了预期的设计效果。  相似文献   

18.
The present study was conducted on characterization of morpho‐anatomical, phytochemical, and bio‐elemental analysis of root, stem, and leaf of Verbascum thapsus. Morphologically Verbascum is a biennial plant that flowers for a month and a half in mid‐ to late summer. Various organoleptic features of root, leaf, and stem were recorded. Anatomically the T. S of the root, stem, and leaf showed a typical dicot histological differentiation. Leaf possessed anomocytic stomata, crescent shape vascular bundles, and covered with long and stellate type trichomes while, stem contained collateral type of vascular bundles and a well‐developed pith to store phytochemicals responsible for various pharmacological activities. The powder drug study through scanning electron microscopy revealed the presence of various types of tissues. Branched, tree like and stellate trichomes in root and leaf help in absorption and reduce loss of water. These anatomical features are responsible for the survival of the plant as biennial. Four macro elements (Na, K, Ca, and Mg) and seven microelements (Cr, Cu, Fe, Mn, Ni, Zn, and Cd) and their concentrations in ppm were also studied using Atomic Absorption Spectroscopy. Phytochemical screening of methanolic extract showed existence of various secondary metabolites, while mucilage and anthraquinones was not detected. The present study helps to understand the taxonomic identification of the plant based on morpho‐anatomical features and throws the attention of the researchers to carry out the work for developing its various formulations, which can ultimately be beneficial for the human beings as well as animals.  相似文献   

19.
In order to investigate the mode of existence of the sarcoglycan complex, neuronal nitric oxide synthase (nNOS), beta-dystroglycan, and dystrophin in the normal skeletal myofiber, we examined the ultrastructural localization and mutual spatial relationship of nNOS, beta-dystroglycan, dystrophin, and the individual components of the sarcoglycan complex by using triple immunogold labeling electron microscopy. Each molecule of alpha-, beta-, gamma- and delta-sarcoglycans is located intracellularly or extracellularly near the muscle plasma membrane mostly in accordance with the sarcoglycan antigenic sites against which the antibodies were generated. The association of different two and/or three sarcoglycan molecules out of alpha-, beta-, gamma- and delta-sarcoglycan molecules was frequently observed. Each molecule of nNOS, beta-dystroglycan, and dystrophin was ultrastructurally noted along the cell surface of normal skeletal myofibers. Moreover, the close relation of a sarcoglycan molecule with beta-dystroglycan and dystrophin, and the association of nNOS with dystrophin were also confirmed ultrastructurally. Thus, this study demonstrated that the constituting molecules of the sarcoglycan complex, nNOS, beta-dystroglycan, and dystrophin existed in the form of a cluster at the normal muscle plasma membrane. The association of nNOS with dystrophin and its associated glycoproteins may form a macromolecular signaling complex at the muscle plasma membrane.  相似文献   

20.
A small, economic, test rig to evaluate friction materials and fluids for wet clutch applications has been designed, built and commissioned. In this paper, the construction, operation and performance of the machine are described, and results are presented, for two sets of typical tests. The system is capable of recording data, and torque test track, coefficients of friction, and oil temperature rise, are given.  相似文献   

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