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   164篇
  免费   7篇
电工技术   8篇
综合类   2篇
化学工业   40篇
金属工艺   11篇
机械仪表   1篇
建筑科学   2篇
能源动力   5篇
轻工业   12篇
水利工程   2篇
无线电   12篇
一般工业技术   58篇
冶金工业   2篇
自动化技术   16篇
  2023年   1篇
  2022年   9篇
  2021年   15篇
  2020年   7篇
  2019年   11篇
  2018年   6篇
  2017年   6篇
  2016年   9篇
  2015年   1篇
  2014年   18篇
  2013年   14篇
  2012年   16篇
  2011年   16篇
  2010年   11篇
  2009年   9篇
  2008年   9篇
  2007年   1篇
  2006年   4篇
  2005年   3篇
  2004年   1篇
  2003年   1篇
  2001年   1篇
  1993年   1篇
  1982年   1篇
排序方式: 共有171条查询结果,搜索用时 438 毫秒
101.
Akhtar  Faheem  Li  Jianqiang  Azeem  Muhammad  Chen  Shi  Pan  Hui  Wang  Qing  Yang  Ji-Jiang 《The Journal of supercomputing》2020,76(8):6219-6237
The Journal of Supercomputing - A newborn with a birth weight above the 90th percentile of same gestational age is termed as large for gestational age. Large for gestational age suffers from...  相似文献   
102.
The Journal of Supercomputing - The Internet of Things (IoT) has developed a well-defined infrastructure due to commercializing novel technologies. IoT networks enable smart devices to compile...  相似文献   
103.
Significant progress has been made in reducing the risk from exposure to radon and its progeny all over the world as a result of efforts made by different organisations which are working together to educate public about the harmful effects of radon. During the past several surveys, it was found that uneducated people were totally ignorant of radon in Pakistan. Even a large number of science graduates knew very little about radon and its hazards. Therefore, a nationwide survey was conducted to measure general awareness and factual knowledge about radon and its health hazards. In this regard, a questionnaire was prepared and distributed among different classes of the society including students, government employees and general public throughout the country. A total of 7000 people with different educational backgrounds participated in this survey, which includes uneducated people (1000), science and humanities graduates (2000 each) and under graduate (2000). Statistical analysis, excluding uneducated people, revealed that 30.4% of the total respondents were aware of radon and 69.6% had even not heard of radon. Only approximately 8.4% of the total respondents were knowledgeably aware of radon.  相似文献   
104.
The conservation and protection of historic monuments or culturally significant structures have recently attracted much attention from material scientists. This review is given of the various aspects of the monuments protection such as the main reasons of damaging and spoiling of the historical monuments, the factor of contact angle as one of the essential parameters in the selection of polymeric coatings, and some of usual types of polymeric materials used for monument protection. There has been growing interest in developing novel materials for using in protective fields. Nowadays, the polymeric coatings, especially those with high hydrophobicity, are widely used to decrease or even stop further deterioration of historical monument. This review presents some of the most well‐known polymers used as protective materials such as acrylics, alkoxysilanes, fluorinated polymers, and hybrid organic–inorganic coatings. Furthermore, hybrid organic–inorganic coatings as a new class of materials are increasingly interesting materials because of their extraordinary properties deriving from the combination of the different building blocks and it is attempted to focus on this materials. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   
105.
Here we report the synthesis of highly pure single crystalline tin selenide (SnSe) nanospheres by pretreatment of precursors with aqueous ammonia. In this work we have demonstrated that aqueous ammonia not only controls the preferred growth orientation but also controls the morphology of SnSe. Chemical vapor deposition technique was used for the growth of SnSe nanostructures. The optical properties were studied using UV–vis–NIR spectroscopy and Photoluminescence (PL) spectrum.  相似文献   
106.
107.
Chemically modified mesoporous carbon (CMMC) and chemically modified activated carbon (CMAC) were prepared by an acid surface modification method from mesoporous carbon (MC) and commercial activated carbon (AC) by wet impregnation method. The structural order and textural properties of the nanoporous materials were studied by XRD and nitrogen adsorption. The presence of carboxylic functional groups on the carbon surface was confirmed by FTIR analyses. Adsorption of 1-naphthol over various porous adsorbents such as CMMC, CMAC, MC and AC was studied. The adsorption isotherms of 1-naphthol were in agreement with a Langmuir model; moreover, the uptake capacity of 1-naphthol followed the order: CMMC>MC>CMAC>AC.  相似文献   
108.
109.
In this work, ZnO nanorod arrays were grown on glass substrate by the wet chemical method, and the effect of synthesis temperature on the properties was investigated. The grown nanorods were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Raman and Photoluminescence (PL) measurements. XRD pattern showed that nanorod prepared at 80 °C and 90 °C has high crystallinity with wurtzite structure and orientated along the c-axis. However, nanorods were not formed at 60 °C and 70 °C due to less energy supply for the growth of the ZnO. FE-SEM results showed that the morphology and the size of ZnO can be effectively controlled. In particular, as the temperature increased, diameter of the nanorod was increased while length decreased. Raman scattering spectra of ZnO nanorod arrays revealed the characteristic E2high mode that is related to the vibration of oxygen atoms in the wurtzite ZnO. Room-temperature PL spectra of the ZnO nanorods revealed a near-band-edge (NBE) emission peak. The NBE (UV light emission) band at ~383 nm might be attributed to the recombination of free exciton. The narrow full-width at half-maximum (FWHM) of the UV emission indicated that ZnO nanorods had high crystallinity.  相似文献   
110.
In this work, we report the fabrication of high quality single-crystalline ZnO nanorod arrays which were grown on the silicon (Si) substrate using a microwave assisted solution method. The as grown nanorods were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), photo-luminescence (PL) and magnetization measurements. The XRD results indicated that the ZnO nanorods are well oriented with the c-axis perpendicular to the substrate and have single phase nature with the wurtzite structure. FE-SEM results showed that the length and diameter of the well aligned rods is about ~ 1 μm and ~ 100 nm respectively, having aspect ratio of 20-30. Room-temperature PL spectrum of the as-grown ZnO nanorods reveals a near-band-edge (NBE) emission peak and defect induced green light emission. The green light emission band at ~ 583 nm might be attributed to surface oxygen vacancies or defects. Magnetization measurements show that the ZnO nanorods exhibit room temperature ferromagnetism which may result due to the presence of defects in the ZnO nanorods.  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