全文获取类型
收费全文 | 725篇 |
免费 | 65篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 8篇 |
综合类 | 1篇 |
化学工业 | 206篇 |
金属工艺 | 5篇 |
机械仪表 | 23篇 |
建筑科学 | 12篇 |
能源动力 | 47篇 |
轻工业 | 123篇 |
水利工程 | 3篇 |
石油天然气 | 4篇 |
无线电 | 66篇 |
一般工业技术 | 165篇 |
冶金工业 | 16篇 |
原子能技术 | 8篇 |
自动化技术 | 108篇 |
出版年
2024年 | 5篇 |
2023年 | 26篇 |
2022年 | 70篇 |
2021年 | 105篇 |
2020年 | 70篇 |
2019年 | 53篇 |
2018年 | 52篇 |
2017年 | 59篇 |
2016年 | 51篇 |
2015年 | 32篇 |
2014年 | 38篇 |
2013年 | 44篇 |
2012年 | 27篇 |
2011年 | 33篇 |
2010年 | 27篇 |
2009年 | 16篇 |
2008年 | 19篇 |
2007年 | 14篇 |
2006年 | 8篇 |
2005年 | 1篇 |
2004年 | 1篇 |
2003年 | 3篇 |
2001年 | 2篇 |
1999年 | 4篇 |
1998年 | 7篇 |
1997年 | 4篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1990年 | 3篇 |
1988年 | 4篇 |
1987年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 2篇 |
排序方式: 共有795条查询结果,搜索用时 15 毫秒
81.
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
82.
Ali Farman Ali Zulfiqar Li Bing-Zhao Qamar Sadia Nazeer Amna Riaz Saba Khan Muhammad Asif Fayyaz Rabia Nawaz Abbasi Javeria 《Water Resources Management》2022,36(9):2989-3005
Water Resources Management - Drought is recurrently occurring in many parts of the globe. In contrast to other natural hazards, drought has complex climatic characteristics. Several environmental... 相似文献
83.
84.
85.
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
86.
Production of Synthesis Gas via Dry Reforming of Methane over Co‐Based Catalysts: Effect on H2/CO Ratio and Carbon Deposition
下载免费PDF全文
![点击此处可从《化学工程与技术》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Ahmed A. Ibrahim Muhammad Awais Naeem Anis H. Fakeeha Wasim Ullah Khan Ahmed S. Al‐Fatesh Ahmed E. Abasaeed 《化学工程与技术》2015,38(8):1397-1405
The effect of support type on synthesis gas production using Co‐based catalysts supported over TiO2‐P25, Al2O3, SiO2, and CeO2 was investigated. The catalysts were prepared by the incipient wet impregnation method and characterized by various techniques for comparison. Experiments were performed in a micro tubular reactor. The results revealed that all Co‐supported catalysts produced synthesis gas ratios of 1 and below and, thus, proved to be well‐suited for methanol and Fischer‐Tropsch syntheses. Co catalysts supported over TiO2‐P25 and Al2O3 provided better synthesis gas ratios and stability performances. The promotion of a Co/TiO2‐P25 catalyst with Ce had a substantial influence on its catalytic activity and the amount of carbon deposit. A Ce‐promoted catalyst diminished markedly the extent of carbon deposition and thus boosted the performance towards better activity and stability. 相似文献
87.
Tanoli Shujaat Ali Khan Mustafa Ali Nawaz Faiza Khan Imran Usman Muhammad Khan Zuhaib Ashfaq 《Wireless Networks》2019,25(8):5045-5056
Wireless Networks - This research article presents an innovative approach based on analog network coding (ANC) in conjunction with space time block coding (STBC) which is termed as space time... 相似文献
88.
Nawaz M. Saqib Fournier-Viger Philippe Shojaee Abbas Fujita Hamido 《Applied Intelligence》2021,51(5):3086-3103
Applied Intelligence - The genome of the novel coronavirus (COVID-19) disease was first sequenced in January 2020, approximately a month after its emergence in Wuhan, capital of Hubei province,... 相似文献
89.
Mohamed Janshir Bin Gulam Mohamed Hafiz Abdul Mannan Rizwan Nasir Dzeti Farhah Mohshim Hilmi Mukhtar Aymn Abdulrahman Anas Ahmed 《应用聚合物科学杂志》2020,137(12):48476
Membrane technology has been considered a key factor for sustainable growth in high-efficiency gas separation. Current mixed matrix membranes (MMMs) technology is rising, but these membranes in the dense structure are having difficulties in operating at high pressures and scale up for commercialization. The purpose of this research is to synthesize composite MMMs (CMMMs) consisting of polyethersulfone (PES), carbon molecular sieve (CMS 1–5 wt %), and Novatex 2471 nonwoven fabric (support layer). The membranes' physical, chemical, and thermal properties were evaluated by different analytical equipment. The morphology of both PES and PES-CMS composite membranes had a porous and asymmetric structure, in which CMS was uniformly distributed in the polymer matrix. The thermal properties showed that the membranes were stable up to 350 °C with a single glass transition temperature. The functional groups in the membrane were confirmed by spectral analysis. The gas performance results showed that carbon dioxide permeance increased with increased CMS concentration and methane permeance decreased due to the hindering effect of CMS under similar operating conditions. The highest selectivity achieved was 12.774 using CMMM of 5 wt % of CMS at 10 bar, which on average was 137.80%, improved selectivity compared to pure PES membrane. The support layer was able to withstand high operating pressures and showed the ability to scale up. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48476. 相似文献
90.