全文获取类型
收费全文 | 198篇 |
免费 | 6篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 2篇 |
综合类 | 5篇 |
化学工业 | 55篇 |
金属工艺 | 43篇 |
机械仪表 | 24篇 |
建筑科学 | 1篇 |
矿业工程 | 4篇 |
能源动力 | 2篇 |
轻工业 | 12篇 |
石油天然气 | 1篇 |
武器工业 | 2篇 |
无线电 | 8篇 |
一般工业技术 | 26篇 |
冶金工业 | 19篇 |
原子能技术 | 1篇 |
自动化技术 | 2篇 |
出版年
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 5篇 |
2019年 | 3篇 |
2018年 | 8篇 |
2017年 | 2篇 |
2016年 | 6篇 |
2015年 | 5篇 |
2014年 | 9篇 |
2013年 | 11篇 |
2012年 | 11篇 |
2011年 | 7篇 |
2010年 | 13篇 |
2009年 | 9篇 |
2008年 | 11篇 |
2007年 | 17篇 |
2006年 | 13篇 |
2005年 | 14篇 |
2004年 | 10篇 |
2003年 | 10篇 |
2002年 | 9篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 7篇 |
1998年 | 4篇 |
1997年 | 4篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1989年 | 1篇 |
排序方式: 共有207条查询结果,搜索用时 15 毫秒
1.
2.
3.
聚四氟乙烯烧结成型的制备工艺 总被引:6,自引:0,他引:6
对聚四氟乙烯(PTFE)进行了压制试验和烧结试验,讨论了成型压力与试件的致密度、压缩强度以及压缩模量之间的关系,且对不同烧结工艺下试件的压缩强度进行了分析,得到较合适的成型压力和烧结工艺。结果表明:咖材料的压缩强度随压制压力的升高而减小,压缩模量随压制压力的升高而增加;闻的成型压力为27.5MPa,烧结温度380℃,保温时间4h。 相似文献
4.
C.M. Wichern B.C. De Cooman C.J. Van Tyne 《Journal of Materials Processing Technology》2005,160(3):278-288
A hot-dipped galvanized zinc-coated sheet steel was deformed with three different laboratory test systems: a Marciniak punch system, a flat-die friction test system, and a cupping system. These systems were able to impose various combinations of deformation modes to the sheet. The deformation modes include: (1) strain without die contact, (2) sliding, (3) pressing, and (4) bending. Strain measurements from the electrolitically gridded specimens were made at the same locations as surface profilometry measurements, allowing a direct correspondence of surface roughness with strain. Quantification of the roughening as a function of strain, sliding and bending was determined. The roughening rate depends upon the strain level as well as the strain path. Increased strain without die contact causes an increase in the surface roughness with strain paths close to plane strain exhibiting the highest roughening rate. The deformation modes of sliding, pressing, and bending cause a decrease in the surface roughness (i.e. smoothing) to occur. A first-order model is proposed to account for the surface roughness as a function of these deformation modes. 相似文献
5.
水下夹桩器是一种广泛应用于海洋石油平台建设的液压夹具。基于扩展的拉格朗日算法,使用ANSYS软件对钢桩和夹桩器压块齿的接触问题进行了数值模拟受力分析,获得压块齿实际工况下的接触压力及其挤压变形等结果。并将该结果与理论计算结果进行了比较,计算结果满足工程要求。分析结果显示,将有限元接触分析技术应用于水下夹桩器压块齿的设计是一种有效的方法,为水下夹桩器压块齿结构进一步改进,提供了理论依据。 相似文献
6.
《粉末冶金学》2013,56(4):259-264
In this study, the Selective Laser Melting (SLM) technology was used to manufacture flat specimens from Inconel 718 powder. The SLM process parameters have a major impact on the microstructure as well as on the mechanical properties of the fabricated specimens. Despite using optimized processing parameters, defects like pores cannot be completely avoided. These pores act as stress raisers and lead to premature crack initiation under cyclic loading, eventually reducing the fatigue strength of the material. Hot Isostatic Pressing (HIP) offers the possibility to eliminate the porosity and thus to increase the fatigue performance of the material. HIP combines high pressure and high temperature to produce materials with superior properties. Unfortunately, open porosity, i.e. open pores on the surface, can prevent full densification. In the present work, SLM flat specimens were encapsulated by means of Cathodic Arc Deposition (Arc-PVD) and High Velocity Oxygen Fuel Spraying (HVOF) to seal open pores. For this purpose, different encapsulation materials were investigated with a focus on materials offering additional functions such as an improved high temperature corrosion resistance or applicability as a bond coat for thermal barrier coatings. 相似文献
7.
Effect of Enzyme Pre-treatments on Bioactive Compounds in Extracted Tiger Nut Oil and Sugars in Residual Meals 下载免费PDF全文
Onyinye Ezeh Keshavan Niranjan Michael H. Gordon 《Journal of the American Oil Chemists' Society》2016,93(11):1541-1549
Tiger nut oil is a novel oil that requires more research data on its characteristics. In this study, the oil was extracted using both enzyme‐aided pressing (EAP) and aqueous enzymatic extraction (AEE) methods. Using enzymes as a pre‐treatment prior to mechanical pressing increased the concentration of some phenolic acids and tocopherols present in extracted oils compared to controls. High pressure processing as a pre‐treatment before aqueous enzymatic extraction also enhanced tocopherols and total polyphenolic content in oils. The percentage free fatty acid and peroxide values indicated that under the initial extraction parameters, the oils were stable and they all met the standards for virgin olive oil set by the International Olive Oil Council. Residual meals from both extraction processes contained low protein contents ranging from 2.4 to 4.6 %. Additionally, EAP and AEE meals contained low DP (degree of polymerisation) sugars that appeared as 1‐kestose (DP3) and nystose (DP4). EAP had the highest total DP3 and DP4 sugar content of 82.5 mg/g. These sugars would need further assessment to verify their identity and determine their suitability as a potential food. 相似文献
8.
水轮机转轮叶片模压成型技术 总被引:4,自引:0,他引:4
介绍了水轮机转轮叶片模压制造所涉及的叶片展平方法、压模设计制造、叶片模压成型工艺及热处理等技术,并对今后制造模压叶片提出了一些改进措施。 相似文献
9.
通常情况下,复杂断块油气田中的细小断层十分发育,单井单块的情况在一些油田经常遇到。那么在一定的地质条件下,能否在生产过程中通过压裂改造的方式,打破断层限制、完善注采井网,实现区块的整体注采开发呢?通过一个典型的生产实例,从油井见效原因、生产动态情况及地质构造等方面进行了阐述,并提出了具体建议,对压穿断层注水开发的可行性进行探讨。 相似文献
10.
Differentiation of Mechanically and Chemically Extracted Hazelnut Oils Based on their Sterol and Wax Profiles 下载免费PDF全文
Cansu Ekin Gumus Asli Yorulmaz Aziz Tekin 《Journal of the American Oil Chemists' Society》2016,93(12):1625-1635
The sterol and wax content of solvent extracted (SEHO) and cold pressed hazelnut oils (CPHO) were compared. A total of 48 samples from 19 hazelnut varieties were collected for two successive crop years from four different geographical districts in Turkey. Hazelnuts were processed to oil with a laboratory scale press, than the remaining oil in cake was extracted with n‐hexane. CPHO and SEHO were evaluated for their wax, sterol and squalene contents. Results showed that sterol, squalene and wax contents of all individual cultivars were higher in SEHO than those of CPHO, indicating the higher solubility of these compounds in solvent. Total sterol contents ranged between 1088.56 (Kargalak)—1609.39 mg/kg (Mincane) for CPHO and 1590.86 (Çak?ldak)—2897.26 mg/kg (Mincane) for SEHO. Hazelnut oils were found to be richer of C36‐38 esters than C40‐46 group. Total wax content was between 24.19 (Kargalak)—94.58 mg/kg (Ku?) for CPHO and 81.46 (Kargalak)—160.92 mg/kg (Akçakoca) for SEHO. The squalene amounts of the samples obtained by hexane extraction were between 499.75 (Allahverdi)—885.36 mg/kg (Cavcava), while it varied between 288.55 (Kargalak)—647.68 mg/kg (Mincane) in cold pressed oils. Significant and obvious variations between SEHO and CPHO were verified by principal component and hierarchical cluster analysis. Geographical discrimination was also achieved by discriminant analysis. 相似文献