全文获取类型
收费全文 | 676篇 |
免费 | 62篇 |
国内免费 | 12篇 |
专业分类
电工技术 | 13篇 |
综合类 | 2篇 |
化学工业 | 159篇 |
金属工艺 | 19篇 |
机械仪表 | 24篇 |
建筑科学 | 11篇 |
能源动力 | 41篇 |
轻工业 | 128篇 |
水利工程 | 8篇 |
石油天然气 | 4篇 |
无线电 | 47篇 |
一般工业技术 | 180篇 |
冶金工业 | 14篇 |
原子能技术 | 9篇 |
自动化技术 | 91篇 |
出版年
2024年 | 1篇 |
2023年 | 17篇 |
2022年 | 47篇 |
2021年 | 82篇 |
2020年 | 49篇 |
2019年 | 54篇 |
2018年 | 50篇 |
2017年 | 45篇 |
2016年 | 57篇 |
2015年 | 28篇 |
2014年 | 50篇 |
2013年 | 64篇 |
2012年 | 43篇 |
2011年 | 25篇 |
2010年 | 21篇 |
2009年 | 6篇 |
2008年 | 12篇 |
2007年 | 11篇 |
2006年 | 7篇 |
2005年 | 4篇 |
2004年 | 2篇 |
2003年 | 7篇 |
2002年 | 3篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1998年 | 5篇 |
1997年 | 5篇 |
1996年 | 6篇 |
1995年 | 5篇 |
1994年 | 4篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 4篇 |
1977年 | 1篇 |
1976年 | 2篇 |
排序方式: 共有750条查询结果,搜索用时 15 毫秒
1.
2.
3.
Muhammad Zia ul Mustafa Hilmi bin Mukhtar Nik Abdul Hadi Md Nordin Hafiz Abdul Mannan Rizwan Nasir Nabilah Fazil 《化学工程与技术》2019,42(12):2580-2593
Flue gas emissions and the harmful effects of these gases urge to separate and capture these unwanted gases. Ionic liquids due to negligible vapor pressure, thermal stability, and wide electrochemical stability have expanded its application in gas separations. A comprehensive overview of the recent developments and applications of ionic liquid membranes (ILMs) for gas separation is given. The three general classifications of ILMs, such as supported ionic liquid membranes (SILMs), ionic liquid polymeric membranes (ILPMs), and ionic liquid mixed‐matrix membranes (ILMMMs) along with their applications, for the separation of various mixed gases systems is discussed in detail. Furthermore, issues, challenges, computational study, and future perspectives for ILMs are also considered. 相似文献
4.
M. Imran Saira Riaz Ifra Sanaullah Usman Khan Anjum N. Sabri Shahzad Naseem 《Ceramics International》2019,45(8):10106-10113
Composites play important role in dental filling by controlling shrinkage along with correction in teeth's shape and position. Rehabilitation of severely worn dentition can be achieved using mechanically strong composites. This study aims to synthesize zirconia-based composites to be used as dental fillers. Effect of microwave powers (100–900?W) along with Fe3O4 doping are studied on the structural, mechanical and magnetic properties of stabilized zirconia. SEM and TEM reveal formation of spherical nanoparticles with diameter of ~30?nm. XRD results shows phase pure tetragonal zirconia (t-ZrO2) at microwave power of 500?W without any post heat treatment. Crystallite size calculated from XRD data (~23?nm) matches well with the previously reported value for stabilization of t-ZrO2. Microwave energy dissipation results in stresses causing volume shrinkage leading to monoclinic to tetragonal phase transformation with higher X-ray density and hardness of ~1347HV. VSM results show ferromagnetic response with low coercivity (600Oe) value and saturation magnetization (~2emu/g). It is worth mentioning here that this is one of its kind study reporting synthesis of room temperature stabilized Fe3O4 doped zirconia composites at microwave power of 500?W. Antibacterial studies reveal inhibition zone of ~32?mm against bacillus bacteria suggesting their potential use as dental filler. 相似文献
5.
Mohamed Abdin Yahya Saud Hamed Hafiz Muhammad Saleem Akhtar Dan Chen Shanza Mukhtar Peng Wan Asad Riaz Xiaoxiong Zeng 《International Journal of Food Science & Technology》2019,54(6):2084-2093
The objectives of this study were to determine the optimal extraction conditions of polyphenols from Syzygium cumini seeds by response surface methodology and investigate their antioxidant activity and inhibition on α-amylase and pancreatic lipase. As results, the optimal extraction conditions in the ultrasonic extraction process which maximised total polyphenols content, minimised the IC50 values of α-amylase and pancreatic lipase were determined as follows: extraction time 60 min, ethanol concentration 63% and solvent/solid ratio 44 mL g−1. The main phenolic compounds in partially purified fraction of Syzygium cumini seeds were catechin, epicatechin, kaempferol, gallic, 5-caffeoylquinic, caffeic and ferulic acids. In addition, the partially purified fraction inhibited 87.66 ± 5.55 and 86.61 ± 3.15% of α-amylase and pancreatic lipase, respectively. The results suggested that Syzygium cumini seeds could be explored as a natural antioxidant and could be used as a source of highly antidiabetic and anti-obesity bioactive compounds. 相似文献
6.
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
7.
Telecommunication Systems - This paper proposes two algorithms for hybrid (Analog–Digital) beamforming in a single-user millimeter-wave (mm-wave) multi-input multi-output (MIMO) systems under... 相似文献
8.
Mobile Networks and Applications - An effective measure of Key Performance Indicators (KPIs) is of great significance to enhance the capabilities of a decision support system (DSS) of any... 相似文献
9.
Fidelis Azi Chuanhai Tu Hafiz Abdul Rasheed Mingsheng Dong 《International Journal of Food Science & Technology》2020,55(4):1689-1697
Water kefir microbiota was used to develop novel soy whey-based beverages that have antioxidant activity. In the present study, comparative phenolics, antioxidant and metagenomic composition of the soy whey beverages fermented using three different water kefir microbiota, named WKFS-A, WKFS-B and WKFS-C were investigated. WKFS-B beverage had the highest concentrations of isoflavone aglycones (208.73 ± 2.78 mg L−1) and phenolic acids (132.33 ± 3.41 mg L−1) compared with WKFS-A (193.88 ± 1.15 mg L−1) and (91.73 ± 2.34 mg L−1) and WKFS-C (160.63 ± 1.76 mg L−1) and (97.13 ± 2.63 mg L−1), respectively. The WKFS-B also showed higher DPPH and ABTS radical scavenging activity and ferric reducing antioxidant power compared with WKFS-A and WKFS-C beverages. Microbial species diversity index analysis showed that a higher concentration of isoflavone aglycones, phenolic acids and increased antioxidant activity in the WKFS-B beverage correlates with the higher relative abundance of Lactobacillus genus. This study thus revealed that Lactobacillus dominated water kefir microbiota produces soy whey beverages with high phenolic acids, isoflavone aglycones and antioxidant activity. 相似文献
10.