全文获取类型
收费全文 | 916篇 |
免费 | 47篇 |
国内免费 | 2篇 |
学科分类
工业技术 | 965篇 |
出版年
2023年 | 20篇 |
2022年 | 49篇 |
2021年 | 91篇 |
2020年 | 35篇 |
2019年 | 47篇 |
2018年 | 50篇 |
2017年 | 44篇 |
2016年 | 32篇 |
2015年 | 30篇 |
2014年 | 37篇 |
2013年 | 87篇 |
2012年 | 37篇 |
2011年 | 42篇 |
2010年 | 40篇 |
2009年 | 42篇 |
2008年 | 36篇 |
2007年 | 29篇 |
2006年 | 25篇 |
2005年 | 19篇 |
2004年 | 19篇 |
2003年 | 22篇 |
2002年 | 16篇 |
2001年 | 9篇 |
2000年 | 6篇 |
1999年 | 9篇 |
1998年 | 8篇 |
1997年 | 9篇 |
1996年 | 10篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 9篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1985年 | 4篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1966年 | 2篇 |
1963年 | 1篇 |
排序方式: 共有965条查询结果,搜索用时 31 毫秒
1.
Bukhari Muhammad Adnan Ahmad Zahoor Ashraf M. Yasin Afzal Muhammad Nawaz Fahim Nafees Muhammad Jatoi Wajid Nasim Malghani Naveed Aslam Shah Adnan Noor Manan Abdul 《SILICON》2021,13(12):4757-4772
Silicon - Feeling prone to stress differs with plant production stage, water scarcity near commencement of grain filling phase has a significant reduced grain yield through fewer endosperm and sink... 相似文献
2.
Wireless Networks - This paper introduces a distributed and energy-aware algorithm, called Minimum Drone Placement (MDP) algorithm, to determine the minimum number of base stations mounted on... 相似文献
3.
In this report, praseodymium hydroxide Pr(OH)3 nanowires with different aspect ratios (length to diameter ratios) were synthesized by a facile hydrothermal approach. The variations in alkali concentration during synthesis are found to form different aspect ratios of nanowires. The X-ray diffraction and Raman spectroscopy analysis demonstrate the absence of any impurity phases in as-prepared materials. Subsequently, photocatalytic activities of as-prepared nanowires were evaluated by the degradation of methyl orange (MO). Our findings reveal that the nanowires with larger aspect ratios have higher photocatalytic efficiency than the smaller aspect ratio samples. X-ray photospectroscopy investigations reveal that the samples with higher aspect ratio are found to exhibit more oxygen vacancies as compared to lower aspect ratio samples. The enhanced photocatalytic activities can be attributed to the presence of higher percentage of active crystal facet (100), higher concentration of defects densities and narrower band gap. Thus, Pr(OH)3 nanowires can be considered as a potential candidate for the application of wastewater treatment and related technologies. 相似文献
4.
Shahid M. Ramay Asif Mahmood Hamid M. Ghaithan Nasser S. Al-Zayed Adnan Aslam Abdullah Murtaza Nisar Ahmad Saadat A. Siddiqi Murtaza Saleem 《中国稀土学报(英文版)》2019,37(9):989-994
Dy_2O_3 is a rare earth oxide having a number of advanced applications in various fields including protective or antireflective coatings, Main objective of this novel research work is to check the effect of Cr and Cu addition on different properties of Dy_2O_3 and achievement of antireflective thin films with enhanced abso rption. Thin films of these materials we re deposited using DC magnetron with reactive cosputtering. XRD studies reveals the crystalline nature of thin films having Dy_2O_3(222) reflection in all samples with Cr_2O_3(116) and CuO(111) reflections in Cr and Cu containing compositions. Field emission scanning electron microscopy demonstrates the homogeneous deposition of thin films with uniform shape, size and distribution of grains. Refractive index, extinction coefficient and absorption coefficient significantly increase while optical reflectance decreases with Cr and Cu mediation corroborating an improved antireflective mechanism. The imaginary part of dielectric constant is found to increase slightly with low tangent loss for Cr containing composition co nsidered favorable for energy storage applications. 相似文献
5.
Hanane Laouira Fateh Mebarek‐Oudina Ahmed K. Hussein Lioua Kolsi Amine Merah Obai Younis 《亚洲传热研究》2020,49(1):406-423
The heat transfer phenomena inside a horizontal channel with an open trapezoidal enclosure subjected to a heat source of different lengths was investigated numerically in the present work. The heat source is considered as a local heating element of varying length, which is embedded at the bottom wall of the enclosure and maintained at a constant temperature. The air flow enters the channel horizontally at a constant cold temperature and a fixed velocity. The other walls of the enclosure and the channel are kept thermally insulated. The flow is assumed laminar, incompressible, and two‐dimensional, whereas the fluid is considered Newtonian. The results are presented in the form of the contours of velocity, isotherms, and Nusselt numbers profiles for various values of the dimensionless heat source lengths (0.16 ≤ ε ≤ 1). while, both Prandtl and Reynolds numbers are kept constant at (Pr = 0.71) and (Re = 100), respectively. The results indicated that the distribution of the isotherms depends significantly on the length of the heat source. Also, it was noted that both the local and the average Nusselt numbers increase as the local heat source length increases. Moreover, the maximum temperature is located near the heat source location. 相似文献
6.
7.
Predicting catastrophic temperature changes based on past events via a CNN-LSTM regression mechanism
Yusuf Syed Adnan Alshdadi Abdulrahman A. Alassafi Madini O. AlGhamdi Rayed Samad Abdul 《Neural computing & applications》2021,33(15):9775-9790
Neural Computing and Applications - The modelling and prediction of extreme temperature changes in enclosed compartments is a domain with applications ranging from residential fire alarms,... 相似文献
8.
Muhammad Zafar Mushtaq Ahmad Shazia Sultana Lubna Adnan Amin Hafiz Muhammad Naseer Zafar Jamal Sheikh Zain Ul Abidin Sajid Mehmood Amir Shehzad Khan 《Microscopy research and technique》2019,82(5):550-557
The use of quality control tool for authentication of Jadwar (Delphinium denudatum Wall. ex Hook.f. & Thomson), a folk herbal drug used for the treatment of different ailments, was studied. People face problems of adulteration for this drug at global, regional, national and local levels. Two different plant species are commercially marketed in the Indo‐Pak Subcontinent under the same trade name of Jadwar. One is D. denudatum Wall. ex Hook.f. & Thomson and the other is Aconitum heterophyllum Wall. ex Royle. To focus on this problem, a marketable available drug sample of Jadwar was authenticated by using basic microscopy tools (LM) and advanced chemo‐taxonomic markers. Authentication, quality and standardization of this drug was achieved using morphology, organoleptography, UV and IR analyses, scanning electron microscopy of pollen and anatomical investigations. The techniques used for authentication marked the clear difference between the studied plants. Microscopic studies, chemotaxonomic investigation and other techniques used in this project provided the basis for the authentication of this species. 相似文献
9.
10.