首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   649篇
  免费   31篇
  国内免费   56篇
综合类   60篇
化学工业   10篇
金属工艺   470篇
机械仪表   13篇
矿业工程   8篇
能源动力   2篇
轻工业   18篇
石油天然气   2篇
武器工业   12篇
无线电   1篇
一般工业技术   88篇
冶金工业   52篇
  2024年   3篇
  2023年   2篇
  2022年   14篇
  2021年   14篇
  2020年   20篇
  2019年   5篇
  2018年   12篇
  2017年   11篇
  2016年   13篇
  2015年   9篇
  2014年   20篇
  2013年   20篇
  2012年   38篇
  2011年   42篇
  2010年   67篇
  2009年   45篇
  2008年   33篇
  2007年   45篇
  2006年   92篇
  2005年   67篇
  2004年   46篇
  2003年   43篇
  2002年   29篇
  2001年   18篇
  2000年   9篇
  1999年   9篇
  1998年   4篇
  1997年   1篇
  1996年   1篇
  1994年   1篇
  1993年   1篇
  1992年   1篇
  1989年   1篇
排序方式: 共有736条查询结果,搜索用时 0 毫秒
81.
As texture properties in novel food categories have a crucial role in consumer acceptance, mouthfeel profile of different plant-based yogurt-like semi-solid products were studied and compared to dairy yogurts. Mouthfeel properties of five plant-based yogurt-like products and two dairy yogurts were analyzed using temporal dominance of sensations (TDS) with consumers (n = 87). The attributes evaluated were thick, thin, creamy, watery, sticky, and foamy. Following TDS, overall liking and mouthfeel liking were evaluated using a 7-point hedonic scale. Temporal drivers of mouthfeel liking were studied using correspondence analysis and penalty-lift analysis with different time points during mastication. For penalty-lift analysis TDS data was analyzed as check-all-that-apply (CATA) data. Results from the present work show that mouthfeel perception in non-dairy yogurt alternatives is a dynamic process. Attributes typically used to describe dairy yogurts are also relevant for describing non-dairy yogurt alternatives. Yogurt alternatives and dairy yogurts can be similar and equally liked by their mouthfeel profile. Temporal drivers of liking in plant-based products are thickness and creaminess and temporal drivers of disliking are thinness and wateriness. In this study, the first dominant attributes were found to have a stronger impact on mouthfeel liking than the dominant attributes perceived later during mastication.  相似文献   
82.
ZL201铝合金的触变锻造组织与性能   总被引:4,自引:0,他引:4  
利用自行设计的模具,采用半固态触变锻造的方法,研究近液相线铸造法制备的ZL201铝合金半固态坯料触变成形件的组织和性能.结果表明,半固态闭模锻造成形后的成形件组织均匀、致密.合金在525℃~530℃固溶12h、155℃时效20h后,强化相充分溶解,均匀析出,合金的维氏硬度可达129.8HV.半固态触变锻造可以获得理想的成形件.  相似文献   
83.
In this study, oilfield wastewater (OWW) was used to prepare coal–oilfield wastewater–slurry (COWS), and the apparent viscosity, solid concentration, and rheological curve were studied. Compared with original coal–water–slurry (CWS), the maximum solid concentration of COWS increased, and the viscosity decreased; therefore, the slurrying ability of the coal slurry was improved with the use of OWW. However, although the oil in OWW promoted the slurrying ability of the coal slurry, its effectiveness was insufficient, and a chemical additive was still needed to obtain a coal slurry with enhanced slurrying ability. Both COWS and CWS exhibited shear-thinning behavior, and the rheological index value of COWS was lower, which indicated that pseudoplasticity of COWS was more obvious, and OWW improved the rheological properties of coal slurry.  相似文献   
84.
85.
The relationship between structure morphology of semi-solid aluminum alloy die-casting sample and filling condition was studied. By systematical structure analysis and computer simulation of the filling process, the quantitative relationship between microscopic morphology (such as solid fraction, grain size and shape) and formation state was studied. The results showed that the billet microstructure must have fine and round grains for the die-casting of complex shapes. It is necessary to optimize injection speeds to escape the non-uniform distribution of the solid fraction in complex and changeable mold cavity.  相似文献   
86.
以应用广泛的弹簧钢(60Si2Mn)为研究对象,利用Gleeble-1500试验机进行了单向压缩实验,对其在半固态下压缩变形过程中的力学特性及组织演变规律进行了观察及分析.实验结果表明:在液-固两相区间半固态坯料的流变应力很低,只有10MPa左右;流变应力随变形量的增加而出现应变软化现象,变形速率对其影响比较复杂.在压缩变形过程中,半固态坯料固-液两相参与塑性变形的方式是不同的,其组织形貌与变形温度、变形量和变形速率都有直接的关系.  相似文献   
87.
利用自行设计的半固态钢铁材料直接轧制系统对弹簧钢(60Si2Mn)与奥氏体不锈钢(1Cr18Ni9Ti)进行了半固态浆料直接轧制试验.结果表明:半固态浆料在轧制过程中,液固相会产生分离,导致液固相偏析,影响轧制产品的组织及性能;只有当固相率达到一定数值时,固相颗粒才会发生塑性变形;仅经过一道次轧制,但轧件的力学性能已相当高.同时发现,浆料与轧辊温差等因素将导致轧件产生表面裂纹;若轧件宽向上没有约束,一定会产生边裂.  相似文献   
88.
由于节能环保以及轻量化的要求,Cu/Al异种金属复合管件被广泛应用于各工业领域,为此探索一种Cu/Al管件间高效可靠的连接技术具有较大应用价值和研究意义。为了探究Cu/Al管半固态钎焊连接机理并优化相关工艺参数,基于新提出的磁脉冲-半固态复合辅助钎焊方法制备了Cu/Al异种金属管件钎焊接头,利用LS-DYNA分析了半固态钎料不同表观粘度参数下外管内壁的受力情况,采用材料力学拉伸试验机,能谱仪和电子探针显微分析仪研究了半固态Zn-Al系钎料固相率及组分对焊接接头质量的影响。结果表明:外管内壁所受压力幅值随着表观粘度的增大而减小,剪切应力随着表观粘度的增大而增大;半固态钎料固相率为0.8时钎料与母材间没有良好冶金结合,固相率为0.4时会导致钎料填充不足的缺陷。在二次放电电压7 kV,半固态Zn-Al钎料固相率为0.6的条件下,磁脉冲-半固态复合辅助钎焊工艺能够实现Cu/Al管的无钎剂有效连接;与Zn-3Al和Zn-22Al相比,Zn-15Al钎料制得的接头综合性能更好,是较为合适的Cu/Al管磁脉冲辅助半固态钎焊用Zn-Al钎料。  相似文献   
89.
研究了传统液态挤压铸造与半固态挤压铸造成形ZL104铝合金连杆的充填状态、微观组织及力学性能。结果表明:传统液态挤压铸造成形连杆充填饱满,但其抗拉强度及伸长率低于半固态挤压铸造成形连杆。对于半固态挤压铸造成形,浇注温度高于565℃时,铸件充填性能良好;平均晶粒尺寸及形状因子随浇注温度的升高而逐渐增大;连杆抗拉强度及伸长率先增加后减小。挤压压力高于25MPa时,铸件均充填饱满;挤压压力升高,平均晶粒尺寸不断减小且形状因子不断增大,连杆机械性能不断提高。模具预热温度升高,平均晶粒尺寸和形状因子不断增大,连杆机械性能逐渐提高。但当模具预热温度超过300℃时,平均晶粒尺寸进一步增大而其形状因子减小,导致连杆的机械性能下降。  相似文献   
90.
The hot cracking tendency of 7075 semi-solid alloy under different conditions was studied by critical diameter method. The experiment and simulation results show that the dendrite arms of the rod grow from the edge to the center. The smaller the diameter of the rod is, the more obvious the directional growth of dendrite is, and the greater the tendency of hot cracking is. Compared with ordinary melt, for semi-solid slurry, increasing mould temperature or decreasing pouring temperature can significantly decrease hot cracking tendency of 7075 alloy, decreasing hot cracking grade from 256 to 100 mm2. Furthermore, based on the RDG criterion, the effects of solidification conditions on the hot cracking tendency were discussed combined with simulation. At the same time, the application and development of RDG criterion were also researched.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号