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   4912篇
  免费   362篇
  国内免费   146篇
电工技术   56篇
综合类   172篇
化学工业   2575篇
金属工艺   556篇
机械仪表   263篇
建筑科学   119篇
矿业工程   28篇
能源动力   17篇
轻工业   293篇
水利工程   8篇
石油天然气   44篇
武器工业   21篇
无线电   279篇
一般工业技术   831篇
冶金工业   85篇
原子能技术   20篇
自动化技术   53篇
  2025年   1篇
  2024年   79篇
  2023年   104篇
  2022年   127篇
  2021年   198篇
  2020年   162篇
  2019年   158篇
  2018年   118篇
  2017年   151篇
  2016年   147篇
  2015年   163篇
  2014年   200篇
  2013年   774篇
  2012年   228篇
  2011年   290篇
  2010年   175篇
  2009年   191篇
  2008年   189篇
  2007年   240篇
  2006年   215篇
  2005年   183篇
  2004年   176篇
  2003年   124篇
  2002年   100篇
  2001年   101篇
  2000年   105篇
  1999年   81篇
  1998年   104篇
  1997年   81篇
  1996年   56篇
  1995年   86篇
  1994年   57篇
  1993年   40篇
  1992年   52篇
  1991年   29篇
  1990年   20篇
  1989年   22篇
  1988年   18篇
  1987年   14篇
  1986年   12篇
  1985年   16篇
  1984年   7篇
  1983年   10篇
  1982年   10篇
  1976年   4篇
  1974年   1篇
  1959年   1篇
排序方式: 共有5420条查询结果,搜索用时 15 毫秒
1.
2.
Glue-type bio-adhesives are in high demand for many applications, including hemostasis, wound closure, and integration of bioelectronic devices, due to their injectable ability and in situ adhesion. However, most glue-type bio-adhesives cannot be used for short-term tissue adhesion due to their weak instant cohesion. Here, we show a novel glue-type bio-adhesive based on the phase separation of proteins and polysaccharides by functionalizing polysaccharides with dopa. The bio-adhesive exhibits increased adhesion performance and enhanced phase separation behaviors. Because of the cohesion from phase separation and adhesion from dopa, the bio-adhesive shows excellent instant and long-term adhesion performance for both organic and inorganic substrates. The long-term adhesion strength of the bio-glue on wet tissues reached 1.48 MPa (shear strength), while the interfacial toughness reached ~880 J m−2. Due to the unique phase separation behaviors, the bio-glue can even work normally in aqueous environments. At last, the feasibility of this glue-type bio-adhesive in the adhesion of various visceral tissues in vitro was demonstrated to have excellent biocompatibility. Given the convenience of application, biocompatibility, and robust bio-adhesion, we anticipate the bio-glue may find broad biomedical and clinical applications.  相似文献   
3.
With the rapid development of wearable smart electronic products, high-performance wearable flexible strain sensors are urgently needed. In this paper, a flexible strain sensor device with Fe NWs/Graphene/PEDOT:PSS material added under a porous structure was designed and prepared. The effects of adding different sensing materials and a different number of dips with PEDOT:PSS on the device performance were investigated. The experiments show that the flexible strain sensor obtained by using Fe NWs, graphene, and PEDOT:PSS composite is dipped in polyurethane foam once and vacuum dried in turn with a local linearity of 98.8%, and the device was stable up to 3500 times at 80% strain. The high linearity and good stability are based on the three-dimensional network structure of polyurethane foam, combined with the excellent electrical conductivity of Fe NWs, the bridging and passivation effects of graphene, and the stabilization effect of PEDOT:PSS, which force the graphene-coated Fe NWs to adhere to the porous skeleton under the action of PEDOT:PSS to form a stable three-dimensional conductive network. Flexible strain sensor devices can be applied to smart robots and other fields and show broad application prospects in intelligent wearable devices.  相似文献   
4.
5.
为开发出高性能生物医用干式电极,提出了利用激光微铣-重铸加工方法,实现了表面具有微结构阵列特征的新型金属干式电极的制造成形。在分析电极表面微观形貌的基础上,研究了电极表面的润湿性能,并重点研究了扫描间距、扫描速度和扫描次数等加工参数对大肠杆菌粘附性能的影响规律。研究结果表明:在一定工艺参数条件下所加工出具有微结构阵列特征的电极的接触角可达150°以上,表现出超疏水的特性。在不同扫描间隙和扫描次数条件下加工出的电极对大肠杆菌的粘附性能具有较大影响,在选择0.1 mm扫描间隙时,电极表面粘附的大肠杆菌数量最少,适当增加扫描次数,也能够有效地减少电极表面大肠杆菌的粘结,从而发挥较好的抗菌效果。通过改变扫描速度加工出的电极则对大肠杆菌的粘附性能影响不大。  相似文献   
6.
室温固化耐高温耐水胶粘剂的研制   总被引:1,自引:0,他引:1  
采用酚醛环氧树脂F-51和环氧树脂CYD-128复合树脂、自制的羧基丁腈改性环氧树脂增韧剂和酚醛胺固化剂以及陶瓷耐热填充剂复配,研制出1种室温固化耐高温耐水胶粘剂。测试了不同固化剂,增韧剂,填充剂对胶粘剂粘接强度的影响并考察了胶粘剂的耐水性。结果表明,该胶A组分最佳配方为:CYD-12880g,F-5120g,羧基丁腈改性环氧树脂10g,轻质碳酸钙20g,陶瓷耐热填充剂1#40g,2#20g;B组分配方为:酚醛胺固化剂40g,轻质碳酸钙20g,陶瓷耐热填充剂1#35g,A与B质量比为2:1时,室温固化1d后的剪切强度达21.4MPa(室温),150℃剪切强度6.2MPa,水中浸泡30d后强度几乎无变化。该胶可长期在高温条件下使用,满足耐磨陶瓷粘接的技术要求。  相似文献   
7.
陶森 《电镀与涂饰》2007,26(3):29-30
介绍了氰化镀银配方及操作条件,给出了一种银上着色深的黑化剂配方及其后处理工艺。本工艺方便、快捷,成本低,膜层结合力好,符合欧盟环保法规要求。  相似文献   
8.
Focal adhesion kinase (FAK), a non-receptor tyrosine kinase, is overexpressed and activated in many cancer types. FAK regulates diverse cellular processes, including growth factor signaling, cell cycle progression, cell survival, cell motility, angiogenesis, and the establishment of immunosuppressive tumor microenvironments through kinase-dependent and kinase-independent scaffolding functions in the cytoplasm and nucleus. Mounting evidence has indicated that targeting FAK, either alone or in combination with other agents, may represent a promising therapeutic strategy for various cancers. In this review, we summarize the mechanisms underlying FAK-mediated signaling networks during tumor development. We also summarize the recent progress of FAK-targeted small-molecule compounds for anticancer activity from preclinical and clinical evidence.  相似文献   
9.
本文通过介绍了用漆包线弯曲盐水针孔试验法检验漆包线的漆膜连续性、附着性的理论基础及其应用前景。  相似文献   
10.
A vacuum impregnation procedure for examining the microstructure of thermal spray coatings has been evaluated using a low-viscosity fluorescent resin. The use of confocal laser scanning microscopy for examining the microstructure allows three-dimensional image reconstruction of the sample. Relationships between defects (i.e., porosity or micro/macrocracking) and coating properties can be established more accurately with the proposed methodology because it enables quantitative analysis.  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