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   2521篇
  免费   292篇
  国内免费   3篇
电工技术   15篇
综合类   4篇
化学工业   830篇
金属工艺   64篇
机械仪表   85篇
建筑科学   34篇
矿业工程   1篇
能源动力   70篇
轻工业   466篇
水利工程   6篇
石油天然气   9篇
无线电   307篇
一般工业技术   529篇
冶金工业   175篇
原子能技术   28篇
自动化技术   193篇
  2024年   4篇
  2023年   46篇
  2022年   87篇
  2021年   153篇
  2020年   82篇
  2019年   89篇
  2018年   109篇
  2017年   119篇
  2016年   133篇
  2015年   115篇
  2014年   162篇
  2013年   161篇
  2012年   189篇
  2011年   224篇
  2010年   163篇
  2009年   137篇
  2008年   121篇
  2007年   93篇
  2006年   75篇
  2005年   78篇
  2004年   71篇
  2003年   42篇
  2002年   42篇
  2001年   21篇
  2000年   30篇
  1999年   20篇
  1998年   56篇
  1997年   48篇
  1996年   28篇
  1995年   23篇
  1994年   17篇
  1993年   13篇
  1992年   10篇
  1991年   7篇
  1990年   3篇
  1989年   3篇
  1988年   2篇
  1987年   3篇
  1986年   5篇
  1985年   3篇
  1984年   3篇
  1981年   1篇
  1980年   1篇
  1979年   2篇
  1977年   3篇
  1976年   10篇
  1975年   4篇
  1974年   1篇
  1970年   1篇
  1965年   2篇
排序方式: 共有2816条查询结果,搜索用时 31 毫秒
81.
Advances in material science and nanotechnology have fostered the miniaturization of devices. Over the past two decades, the form-factor of these devices has evolved from 3D rigid, volumetric devices through 2D film-based flexible electronics, finally to 1D fiber electronics (fibertronics). In this regard, fibertronic strategies toward wearable applications (e.g., electronic textiles (e-textiles)) have attracted considerable attention thanks to their capability to impart various functions into textiles with retaining textiles' intrinsic properties as well as imperceptible irritation by foreign matters. In recent years, extensive research has been carried out to develop various functional devices in the fiber form. Among various features, lighting and display features are the highly desirable functions in wearable electronics. This article discusses the recent progress of materials, architectural designs, and new fabrication technologies of fiber-shaped lighting devices and the current challenges corresponding to each device's operating mechanism. Moreover, opportunities and applications that the revolutionary convergence between the state-of-the-art fibertronic technology and age-long textile industry will bring in the future are also discussed.  相似文献   
82.
83.
In addition to two well‐recognized proteasome subtypes—constitutive proteasomes and immunoproteasomes—mounting evidence also suggests the existence of intermediate proteasome subtypes containing unconventional mixtures of catalytic subunits. Although they appear to play unique biological roles, the lack of practical methods for detecting distinct proteasome subtypes has limited functional investigations. Here, we report the development of activity‐based probes that crosslink two catalytic subunits within intact proteasome complexes. Identification of the crosslinked subunit pairs provides direct evidence of the catalytic subunit composition of proteasomes. Using these probes, we found that U266 multiple myeloma cells contain intermediate proteasomes comprising both β1i and β2, but not β1 and β2i, consistent with previous findings with other cell types. Our bifunctional probes can be utilized in functional investigations of distinct proteasome subtypes in various biological settings.  相似文献   
84.
The present work involved the application of a two-step sintering (TSS) technique for typical Ce0.9Gd0.1O2?δ–La0.6Sr0.4Co0.2Fe0.8O3–δ (GDC–LSCF) composites and its effect on the microstructure and resultantly mechanical and O2-permeating properties. The samples obtained by conventional sintering (CS) performed at 1100, 1250, and 1400 °C for 3 h exhibited maximum flexural strength and hardness values of 142 MPa and 8.71 GPa, respectively. However, the application of a TSS procedure produced fine-grained microstructures with improved mechanical properties. In particular, with the use of a typical 1250/1200 TSS protocol, increases of approximately 31 % and 7% in the flexural strength and hardness values, respectively, were observed compared to those obtained using the CS method. Moreover, thick-film (~ 60 μm) GDC–LSCF membrane prepared by tape casting and the TSS technique showed remarkably 1.5–2 times higher oxygen permeation flux than membrane sintered by CS method. The results are discussed and explained in detail.  相似文献   
85.
Regulations, such as the Health Insurance Portability and Accountability Act (HIPAA), establish standards to protect patients' medical records from security breaches. Insiders' prosocial misbehaviour within healthcare organisations can cause significant damage to relevant stakeholders. Such behaviour without malicious intention needs to be better understood and carefully managed from the perspective of prosocial behaviour. For this study, a research model was developed that includes the factors influencing student nurses' intention to disclose patient health information. The model was empirically tested with nursing students in South Korea with a scenario-based experiment. We find that both altruistic (impact on others) and egoistic (impact on the self) motivations are significantly important in raising situational empathy. On the other hand, an egoistic motivation (impact on the self) significantly affects people's perception of their responsibility, which mediates the relationship between situational empathy and prosocial intention to disclose. The implications of our findings are discussed.  相似文献   
86.
Food Science and Biotechnology - As storage temperature impacts frozen meat quality, we evaluated the ideal freezing and storage temperatures for pork loin, and effects of long-term storage...  相似文献   
87.
Food Science and Biotechnology - In this study, we investigated the multi-functionality of bioactive peptides derived from fermented skate (Raja kenojei) skin gelatin hydrolysates. The extracted...  相似文献   
88.
89.
A significant change in the UV-vis absorption of TiO2 nanorods (NRs) was induced by changing electrondonating stabilizer from oleic acid (OA) to acrylic acid (AcA). When TiO2 NRs with an average size of 2.5 nm in diameter and 30 nm in length were dispersed in an aqueous AcA solution, a red shift in the optical absorption (0.73 eV at the band edge and 0.55 eV at the onset) was observed. The red shift was attributed to an increase in the electron density inside the TiO2 NRs. The applicability of the AcA-exchanged TiO2 NRs for the photocatalyst as well as a UV sensor was evaluated. The AcA-exchanged TiO2 NRs showed significant photocatalytic activity on the degradation of toluene in the visible light region. Moreover, thin film of the AcA-exchanged TiO2 NRs on a quartz plate was tested as a UV sensor and it exhibited a good response to a wide range of the UV light.  相似文献   
90.
Journal of Mechanical Science and Technology - The cervical intervertebral disc has a unique feature in that a fissure or cleft runs along the uncinate process toward the nucleus pulposus called...  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