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31.
用微滤技术/紫外线(MF/UV)辅助催化臭氧氧化组合工艺进行洗车废水处理回用的中试研究,结果表明操作压力≤20 kPa时,膜通量长期稳定.膜滤对COD、TN、TP和SS的去除率分别达到69.74%、40.12%、37.81%和100.00%,但膜滤对阴离子表面活性剂(LAS)基本没有去除效果.UV辅助催化臭氧氧化对膜滤出水进一步降解,系统出水水质良好,符合生活杂用水水质标准(CJ/T48-1999).  相似文献   
32.
Si3N4/SiC纳米复合材料由于具有优良的力学和热性能,广泛应用于涡轮发动机、热交换器和其他复杂情况中。然而,不添加添加剂很难制备出Si3N4/SiC复合材料。添加剂在烧结过程形成液相从而促进复合材料的致密化。然而,添加剂的存在降低了复合材料的高温力学性能。通常在不添加添加剂的情况下,采用电场辅助烧结,利用聚合物前体路线制备Si3N4/SiC复合材料。本研究中,在无添加剂、温度1700°C、真空50MPa条件下,热压烧结2h,利用非晶前体路线成功制备了六方-BN致密化的Si3N4/SiC复合材料。聚合物前驱体和BN的作用减少了的SiC含量。并对相变、致密化、微观组织和力学性能进行了讨论。  相似文献   
33.
The characteristic evaluation of aluminum oxide (Al2O3)/carbon nanotubes (CNTs) hybrid composites for micro-electrical discharge machining (EDM) was described. Alumina matrix composites reinforced with CNTs were fabricated by a catalytic chemical vapor deposition method. Al2O3 composites with different CNT concentrations were synthesized. The electrical characteristic of Al2O3/CNTs composites was examined. These composites were machined by the EDM process according to the various EDM parameters, and the cha...  相似文献   
34.
The grain growth behaviors of nanocrystalline aluminum, alloy and composite are compared. First, nanocrystalline aluminum is fabricated by consolidation of ball-milled powder. Second, nanocrystalline aluminum alloy is designed to have elements such as Mn, Zr, and Misch metals, which can form thermally stable second phases at grain boundaries and also drag the movement of grain boundaries. Third, nanocrystalline aluminum-based composites containing multi-walled carbon nanotubes (MWCNTs) are also prepared because MWCNTs are expected to be located at grain boundaries and to suppress the grain growth of nanocrystalline aluminum. These three types of samples are annealed at 550 °C for up to 5 d and the effect of annealing time on Vickers hardness of the samples is compared. As a result, MWCNTs are found to be most effective to impede grain growth of nanocrystalline aluminum.  相似文献   
35.
This paper presents a new approach to the segmentation of fluorescence in situ hybridization images. First, to segment the cell nuclei from the background, a threshold is estimated using a Gaussian mixture model and maximizing the likelihood function of the grey values for the cell images. After the nuclei segmentation, the overlapping and isolated nuclei are classified to facilitate a more accurate nuclei analysis. To do this, the morphological features of the nuclei, such their compactness, smoothness and moments, are extracted from training data to generate three probability distribution functions that are then applied to a Bayesian network as evidence. Following the nuclei classification, the overlapping nuclei are segmented into isolated nuclei using an intensity gradient transform and watershed algorithm. A new stepwise merging strategy is also proposed to merge fragments into a major nucleus. Experimental results using fluorescence in situ hybridization images confirm that the proposed system produced better segmentation results when compared to previous methods, because of the nuclei classification before separating the overlapping nuclei.  相似文献   
36.
Thermal spray coating presents a sacrificial-anode cathodic protection method since differences between the potentials of materials are employed. If a base metal is exposed to seawater, due to defect in the thermal spray coating, the metal is protected by the sacrificial anodic characteristics of the coating layer because micro-cells formed by the base metal and the thermal spray coating act as cathodes and anodes, respectively. The coating thickness has little effect on the surface morphology of the coating. However, the electrochemical properties with the increasing of coating thickness present good results.  相似文献   
37.
TiO2 nanotube layers can be formed with titanium in the electrolytes containing fluoride by electrochemical method. The role of fluoride ion, the crystallinity of the anodic oxide, and the chemical state were investigated. The results show the anodic film is composed of oxide and a little amount of hydroxide. The presence of F ions leads to chemical dissolution of Ti oxide layer and prevents hydroxide precipitation. Consequently, chemical dissolution rate increases with increasing the fluoride content in the range of 0–2% (in mass fraction) because F ions in electrolyte attack the interface and allow the ions of the electrolyte to easily penetrate into the interface. The as-anodized TiO2 nanotubes exhibit an amorphous structure. Thermally treated nanotubes are composed of mixtures of the anatase and rutile phases.  相似文献   
38.
Erratum to:J.Cent.South Univ.(2014)21:3811-3820DOI:10.1007/s11771-014-2366-9The original version of this article unfortunately contained three mistakes.The mistakes are corrected as follows:1)The spelling of third author is incorrect.The correct name is Jae-Young PYUN.2)The information of corresponding author is incorrect.The correct information should be Goo-Rak KWON,Professor,PhD;Tel/Fax:+98-711-7264102;E-mail:grkwon@chosun.ac.kr  相似文献   
39.
Thermolabile (TL) and thermostable (TS) pectinesterases (PE) were extracted from the pulp of fresh Valencia oranges by enzyme hydrolysis using a native pH and high ionic strength buffer system. Each form was separated individually by CM-Sephadex C-50, Phenyl Sepharose CL-4B and CM-Bio-Gel A chromatography. TLPE and TSPE exist as multiple forms which were shown to differ in their stability and effects on cloud loss in single strength orange juice.  相似文献   
40.
The evolution of crystallization and porosity changes with firing temperature were studied in ZnO–B2O3–SiO2–MgO glasses. Those glasses presintered at 610 °C to a low porosity were crystallized in the temperature range of 690–870 °C. The glasses were crystallized by a surface crystallization mechanism. The porosity increased with the crystallization temperature. In the temperature range of 710–790 °C, several crystalline phases, such as 3ZnO–B2O3, willemite (2ZnO–SiO2), 5ZnO–2B2O3, and another form of zinc silicate (2ZnO–SiO2), produced at relatively low temperatures, were produced, while above 800 °C only the 2ZnO–SiO2 phase co-existed with a glass phase. Only an observed density difference between the glass and the crystallized glass cannot be attributed to the void formation during the crystallization reaction. Due to the crystallization the composition of the remaining glass around the crystalline phases is expected to change. The depletion of a certain component in the remaining glass, probably the SiO2 due to the production of the 2ZnO–SiO2 phase, might result in the increase in the vapour pressure of the remaining glass and lead to the observed increase in porosity. Below 800 °C, at which temperature the crystallization rate is fast and only a small amount of the glass phase remained, the porosity remained constant after the completion of the crystallization. Contrarily at 860 °C the porosity continuously increased with firing time. This revised version was published online in November 2006 with corrections to the Cover Date.  相似文献   
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