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   51篇
  免费   10篇
综合类   1篇
化学工业   13篇
金属工艺   4篇
机械仪表   2篇
建筑科学   5篇
矿业工程   2篇
轻工业   1篇
水利工程   6篇
无线电   11篇
一般工业技术   13篇
冶金工业   1篇
原子能技术   1篇
自动化技术   1篇
  2023年   1篇
  2022年   3篇
  2021年   2篇
  2019年   1篇
  2018年   1篇
  2017年   4篇
  2016年   1篇
  2014年   6篇
  2012年   5篇
  2011年   17篇
  2010年   2篇
  2009年   1篇
  2008年   1篇
  2007年   2篇
  2006年   1篇
  2003年   1篇
  2001年   1篇
  2000年   2篇
  1999年   2篇
  1998年   1篇
  1996年   2篇
  1995年   2篇
  1994年   1篇
  1993年   1篇
排序方式: 共有61条查询结果,搜索用时 625 毫秒
1.
介绍消失模工艺生产Dg75闸阀阀体铸件的铸造工艺,生产过程中铸件重要装配尺寸精度的保证,铸件表面粗糙度、铸件表面碳夹杂缺陷及表面皱皮现象控制等试验情况。通过模具结构设计、成型工艺及参数的调整、浇注工艺的调整、陶瓷成型浇道的应用等措施,使铸件表面质量及尺寸精度符合客户验收标准。同时使铸件表面因轻微缺陷的返修率由试验初期的90%下降到10%以内,产品合格率达到99%。  相似文献   
2.
介绍了一种用于评价耐水型室内腻子的耐水渗透性测定方法,通过测量浸入水中的腻子层在一定时间内渗透的距离反映出腻子的耐水渗透性能.该方法与JG/T 298-2010《建筑室内用腻子》方法中耐水型腻子的耐水性和粘结强度有规律的数据变化关联性,腻子的耐水渗透性越差对应的耐水性和粘结强度也越差.该方法能量值化的测出耐水型腻子的耐水渗透性,避免JG/T 298-2010中耐水性测试的外观评价中的主观影响以及粘结强度测试的不确定度来源多的问题.  相似文献   
3.
4.
Co-functionalized titanate nanotubes (Co-Ti-NTs) were successfully synthesized by means of an ion-exchange reaction. In contrast to the pristine titanate nanotubes (Ti-NTs), Co-Ti-NTs retained rich porous channels and owned even larger specific surface area and better electronic conductivity, which rendered electrons and OH? ions easily contact the Co species uniformly distributed on their surfaces for energy storage at high rates. The Co-Ti-NTs delivered a specific capacitance (SC) of 124 F g?1 at 0.4 A g?1, and a SC degradation of ca. 7% after 1500 continuous cycling at 3 A g?1, indicating that the Co-Ti-NTs were good candidates and/or even good supports for other electroactive materials for supercapacitors application.  相似文献   
5.
6.
Magneto-opticCurrentSensorBasedonTotalReflectionsinaQuadrangularBulkGlass¥CHENXikun;QIUJinghe;ZHUQibiao;DAILaifa(ShanghaiUniv...  相似文献   
7.
Lithium ion capacitors are new energy storage devices combining the complementary features of both electric double‐layer capacitors and lithium ion batteries. A key limitation to this technology is the kinetic imbalance between the Faradaic insertion electrode and capacitive electrode. Here, we demonstrate that the Li3VO4 with low Li‐ion insertion voltage and fast kinetics can be favorably used for lithium ion capacitors. N‐doped carbon‐encapsulated Li3VO4 nanowires are synthesized through a morphology‐inheritance route, displaying a low insertion voltage between 0.2 and 1.0 V, a high reversible capacity of ≈400 mAh g?1 at 0.1 A g?1, excellent rate capability, and long‐term cycling stability. Benefiting from the small nanoparticles, low energy diffusion barrier and highly localized charge‐transfer, the Li3VO4/N‐doped carbon nanowires exhibit a high‐rate pseudocapacitive behavior. A lithium ion capacitor device based on these Li3VO4/N‐doped carbon nanowires delivers a high energy density of 136.4 Wh kg?1 at a power density of 532 W kg?1, revealing the potential for application in high‐performance and long life energy storage devices.  相似文献   
8.
有效运用多媒体远程教育现代化的教学手段,关键是要设计和制作出大量符合教学要求、丰富多样、引人入胜且符合国际通用标准的多媒体网络课件。将Articulate这个简单专业的软件与易用的PowerPoint相结合,必将对教育培训的发展产生积极影响。  相似文献   
9.
A facile one‐step hydrothermal method is developed for large‐scale production of well‐designed flexible and free‐standing Co3O4/reduced graphene oxide (rGO)/carbon nanotubes (CNTs) hybrid paper as an electrode for electrochemical capacitors. Densely packed unique Co3O4 monolayer microsphere arrays uniformly cover the surface of the rGO/CNTs film. The alkaline hydrothermal treatment leads to not only the deposition of Co3O4 microspheres array, but also the reduction of the GO sheets at the same time. The unique hybrid paper is evaluated as an electrode for electrochemical capacitors without any ancillary materials. It is found that the obtained hybrid flexible paper, composed of Co3O4 microsphere array anchored to the underling conductive rGO/CNTs substrate with robust adhesion, is able to deliver high specific capacitance with excellent electrochemical stability even at high current densities, suggesting its promising application as an efficient electrode material for electrochemical capacitors.  相似文献   
10.
A film composed of graphene (GN) sheets, polyaniline (PANI) and carbon nanotubes (CNTs) has been fabricated by reducing a graphite oxide (GO)/PANI/CNT precursor prepared by flow-directed assembly from a complex dispersion of GO and PANI/CNT, followed by reoxidation and redoping of the reduced PANI in the composite to restore the conducting PANI structure. Scanning electron microscope images indicate that the ternary composite film is a layered structure with coaxial PANI/CNT nanocables uniformly sandwiched between the GN sheets. Such novel hierarchical structure with high electrical conductivity perfectly facilitates contact between electrolyte ions and PANI for faradaic energy storage and efficiently utilizes the double-layer capacitance at the electrode–electrolyte interfaces. The specific capacitance of the GN/PANI/CNT estimated by galvanostatic charge/discharge measurement is 569 F g−1 (or 188 F cm−3 for volumetric capacitance) at a current density of 0.1 A g−1. In addition, the GN/PANI/CNT exhibits good rate capability (60% capacity retention at 10 A g−1) and superior cycling stability (4% fade after 5000 continuous charge/discharge cycles).  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