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   490篇
  免费   59篇
  国内免费   6篇
电工技术   5篇
化学工业   121篇
金属工艺   12篇
机械仪表   5篇
建筑科学   8篇
矿业工程   1篇
能源动力   12篇
轻工业   17篇
水利工程   7篇
无线电   97篇
一般工业技术   111篇
冶金工业   29篇
原子能技术   4篇
自动化技术   126篇
  2024年   1篇
  2023年   16篇
  2022年   21篇
  2021年   40篇
  2020年   29篇
  2019年   24篇
  2018年   28篇
  2017年   30篇
  2016年   32篇
  2015年   24篇
  2014年   34篇
  2013年   36篇
  2012年   30篇
  2011年   29篇
  2010年   26篇
  2009年   15篇
  2008年   18篇
  2007年   25篇
  2006年   15篇
  2005年   7篇
  2004年   5篇
  2003年   5篇
  2002年   8篇
  2001年   3篇
  2000年   3篇
  1999年   6篇
  1998年   8篇
  1997年   6篇
  1996年   3篇
  1995年   2篇
  1994年   4篇
  1993年   2篇
  1992年   1篇
  1991年   1篇
  1990年   3篇
  1984年   1篇
  1983年   1篇
  1981年   1篇
  1980年   3篇
  1979年   2篇
  1978年   2篇
  1977年   1篇
  1976年   2篇
  1975年   1篇
  1974年   1篇
排序方式: 共有555条查询结果,搜索用时 31 毫秒
431.
Precise control of the microstructure in organic semiconductors (OSCs) is essential for developing high-performance organic electronic devices. Here, a comprehensive charge transport characterization of two recently reported rigid-rod conjugated polymers that do not contain single bonds in the main chain is reported. It is demonstrated that the molecular design of the polymer makes it possible to achieve an extended linear backbone structure, which can be directly visualized by high-resolution scanning tunneling microscopy (STM). The rigid structure of the polymers allows the formation of thin films with uniaxially aligned polymer chains by using a simple one-step solution-shear/bar coating technique. These aligned films show a high optical anisotropy with a dichroic ratio of up to a factor of 6. Transport measurements performed using top-gate bottom-contact field-effect transistors exhibit a high saturation electron mobility of 0.2 cm2 V−1 s−1 along the alignment direction, which is more than six times higher than the value reported in the previous work. This work demonstrates that this new class of polymers is able to achieve mobility values comparable to state-of-the-art n-type polymers and identifies an effective processing strategy for this class of rigid-rod polymer system to optimize their charge transport properties.  相似文献   
432.
Journal of Mechanical Science and Technology - Six-legged hexapod walking robots are well-known for their intrinsic stability during navigation and 6-DoF object manipulation. The robot must be...  相似文献   
433.
Forschung im Ingenieurwesen - Electrification and automation are attracting interest from the public-transportation sector for their potential to improve energy efficiency, cost efficiency, and...  相似文献   
434.
Multimedia Tools and Applications - This paper presents a new composite scheme to tackle the non-uniform blurring that arises because of image up-scaling. The image up-scaling results in...  相似文献   
435.

Breast cancer is a common cancer in women. Early detection of breast cancer in particular and cancer, in general, can considerably increase the survival rate of women, and it can be much more effective. This paper mainly focuses on the transfer learning process to detect breast cancer. Modified VGG (MVGG) is proposed and implemented on datasets of 2D and 3D images of mammograms. Experimental results showed that the proposed hybrid transfer learning model (a fusion of MVGG and ImageNet) provides an accuracy of 94.3%. On the other hand, only the proposed MVGG architecture provides an accuracy of 89.8%. So, it is precisely stated that the proposed hybrid pre-trained network outperforms other compared Convolutional Neural Networks. The proposed architecture can be considered as an effective tool for radiologists to decrease the false negative and false positive rates. Therefore, the efficiency of mammography analysis will be improved.

  相似文献   
436.
Metallurgical and Materials Transactions A - The spatial variation of thermokinetic parameters has a significant influence on solidification and microstructural aspects such as grain orientation,...  相似文献   
437.
Spectroscopic methods play an instrumental role in the implementation of the U.S. Food and Drug Administration outlined process analytical technology for biopharmaceutical manufacturing. Industrial spectroscopic calibration models are typically developed in an offline setting using traditional methods, such as partial least squares and principal component regression. Apart from the limiting performances of these conventional models under time-varying operating conditions, these methods require access to extensive historical data, which are seldom available in biopharmaceutical manufacturing. In this article, we propose a novel spatiotemporal just-in-time learning (ST-JITL) based spectroscopic model calibration platform for automatic training and maintenance of calibration models using routine batch data. The proposed ST-JITL framework uses Gaussian processes (GPs) for local model calibration. A GP model not only exhibits superior performance over traditional methods but also provides credibility intervals around the model predictions. The efficacy of the ST-JITL based model calibration platform is demonstrated in predicting the critical performance parameters of an industrial cell culture process.  相似文献   
438.
With the burgeoning interest in hyaluronic acid (HA) in recent years, hyaluronidases (HYALs) have come to light for their role in regulating catabolism of HA and its molecular weight (MW) distribution in various tissues. Of the six hyaluronidase-like gene sequences in the human genome, HYALs 1 and 2 are of particular significance because they are the primary hyaluronidases active in human somatic tissue. Perhaps more importantly, for the sake of this review, they cleave anti-inflammatory and anti-fibrotic high-molecular-weight HA into pro-inflammatory and pro-fibrotic oligosaccharides. With this, HYALs regulate HA degradation and thus the development and progression of various diseases. Given the dearth of literature focusing specifically on HYALs in the past decade, this review seeks to expound their role in human diseases of the skin, heart, kidneys, and more. The review will delve into the molecular mechanisms and pathways of HYALs and discuss current and potential future therapeutic benefits of HYALs as a clinical treatment.  相似文献   
439.
440.
Most chemical transport models treat the partitioning of semi-volatile organic compounds (SVOCs) with the assumption of instantaneous thermodynamic equilibrium. However, the mass accommodation coefficients, α, of biomass-burning organic aerosol (BBOA) are largely unconstrained. During the FLAME-IV campaign, we thermally perturbed aged and fresh BBOA with a variable residence time thermodenuder and measured the resulting change in particle mass concentration to restore equilibrium. We used this equilibration profile to retrieve an effective α for components of BBOA that dictated this profile and found that the mass accommodation coefficients lie within the range 0.1 ? α ? 1. A simple plume dilution model shows a maximum of only a 7% difference between a dynamical and an instantaneous equilibrium partitioning model using our best-estimate value for α. This supports continued use of the equilibrium assumption to treat partitioning of biomass-burning emissions in chemical-transport models.

Copyright © 2018 American Association for Aerosol Research  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