全文获取类型
收费全文 | 381篇 |
免费 | 22篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 4篇 |
综合类 | 2篇 |
化学工业 | 61篇 |
金属工艺 | 10篇 |
机械仪表 | 16篇 |
建筑科学 | 3篇 |
能源动力 | 44篇 |
轻工业 | 20篇 |
水利工程 | 2篇 |
无线电 | 47篇 |
一般工业技术 | 91篇 |
冶金工业 | 12篇 |
原子能技术 | 7篇 |
自动化技术 | 86篇 |
出版年
2024年 | 1篇 |
2023年 | 9篇 |
2022年 | 32篇 |
2021年 | 29篇 |
2020年 | 23篇 |
2019年 | 19篇 |
2018年 | 19篇 |
2017年 | 17篇 |
2016年 | 17篇 |
2015年 | 20篇 |
2014年 | 24篇 |
2013年 | 43篇 |
2012年 | 26篇 |
2011年 | 16篇 |
2010年 | 19篇 |
2009年 | 18篇 |
2008年 | 12篇 |
2007年 | 12篇 |
2006年 | 6篇 |
2005年 | 7篇 |
2004年 | 4篇 |
2003年 | 1篇 |
2002年 | 8篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1989年 | 2篇 |
1981年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有405条查询结果,搜索用时 93 毫秒
11.
Abd Elnaby Kabeel Yazan Taamneh Ravishankar Sathyamurthy Padmanabhan Naveen Kumar Athikesavan Muthu Manokar Thirugnanasambantham Arunkumar 《亚洲传热研究》2019,48(1):100-114
This study primarily focuses on comparative experimental analysis on standalone conventional solar still (CSS), inclined solar still (ISS), and integrated conventional and inclined solar still (CSS‐ISS) for different parameters that affect the freshwater yield. For enhancing the freshwater yield only a few studies are available on still‐still integration. The present novel study provides a greater improvement in improving the freshwater yield by integrating ISS with CSS. This experimental work mainly concentrates on the importance of water depth (d w) and mass flow rate of water ( m w) in the solar still. Water depth inside the conventional still varied from 0.02 to 0.06 m whereas, water is constantly flown with a mass flow rate of 8.33 kg/hour in an ISS with baffles. The experimental result shows that the accumulated freshwater yield from CSS‐ISS, ISS, and CSS were 6.2, 5.04, and 4.24 kg, respectively. CSS‐ISS and ISS produced 46.23% and 18.87% higher productivity than the CSS. From the experimental investigation, it is also identified that the water temperature is significantly improved by 20% using integration as compared with CSS without integration under the same water depth of d w = 0.02 m. The overall improvement in yield was higher in the case of CSS‐ISS. The deviations between experimental and theoretical values of yield from the conventional and modified solar still were in the range of ±7%. 相似文献
12.
13.
14.
Optimization and Engineering - Aircraft ejection systems are lifesaving devices used, in case of emergencies for military pilots. As per current literature the success rate of ejections happening... 相似文献
15.
Wireless Networks - One of the biggest challenges in political mayhem is visible during the election process where no stone is kept unturned in order to gain the power. Further, due to poll... 相似文献
16.
One of the advances in biotechnology has been the development of the capability to produce large quantities of highly purified polypeptides and proteins. Unfortunately, the circulatory half-lives of many of these agents are short, usually of the order of minutes and the time required for a response in tissues is usually long compared to the half-life. Hence, there is always demand for polymeric systems which can deliver the proteins for prolonged period and also to protect the molecules from degradation. The present work was attempted to develop heparin-functionalized gelatin microspheres (HMS) to deliver heparin-binding growth factors particularly for wound-healing applications. The heparin conjugation was carried out using EDC/NHS coupling protocol. Heparin-binding EGF-like growth factor (HB-EGF) was loaded in HMS and its in vitro release behaviour in an environment with or without proteases was studied. The bioactivity of the HB-EGF released from the microspheres was assessed using NIH 3T3 mouse embryonic fibroblast culture. The extent of heparin modification was found to be 1.97 μmol/g of HMS and demonstrated significant protection against enzymatic degradation and sustained release of HB-EGF for more than 10 days. The bioactivity of HB-EGF released from the HMS was retained during the observed release period. The HMS was also found to be non-toxic as determined by calcein AM fluorescent staining. The overall study suggests that the HMS could be used as a growth factor’s delivery component in tissue engineering scaffolds particularly for wound-healing applications. 相似文献
17.
Naveen Chella 《Drug development and industrial pharmacy》2015,41(6):888-897
Solid dispersion (SD) technique is a promising strategy to improve the solubility and dissolution of BCS class II drugs. However, only few products are marketed till today based on SD technology due to poor flow properties and stability. The present work was intended to solve these problems by using combination approach, melt dispersion and surface adsorption technologies. The main aim of the present work is to improve the absorption in the stomach (at lower pH) where the absorption window exists for the drug by improving the dissolution, resulting in the enhancement of oral bioavailability of poorly soluble, weakly acidic drug with pH dependant solubility, i.e. valsartan. Melt dispersion granules were prepared in different ratios using different carriers (Gelucire 50/13, PEG 8000 and Pluronic F-68) and lactose as an adsorbent. Similarly, physical mixtures were also prepared at corresponding ratios. The prepared dispersion granules and physical mixtures were characterized by FTIR, DSC and in vitro dissolution studies. DSC studies revealed reduction in the crystallinity with a possibility of presence of amorphous character of drug in the dispersion granules. From dissolution studies, valsartan Gelucire dispersion (GSD4; 1:4 ratio) showed complete drug release in 30?min against the plain drug which showed only 11.31% of drug release in 30?min. Pharmacokinetic studies of optimized formulation in male Wistar rats showed 2.65-fold higher bioavailability and 1.47-fold higher Cmax compared to pure drug. The melt dispersion technology has the potential to improve dissolution and the bioavailability of BCS class II drugs. 相似文献
18.
Naveen Kumar Chenna Pablo Piovano Christian Järnefelt Tapani Vuorinen 《木材化学与工艺学杂志》2016,36(5):318-328
An oxygen delignified eucalyptus kraft pulp was bleached by applying a catalytic amount of a tertiary amine, 1,4-diazabicyclo[2,2,2]octane, and hypochlorous acid at varying pH, temperature, and time. The bleaching filtrate was analyzed for chloroform and AOX and the pulp for residual lignin, hexenuronic acid, and OX. In comparison with chlorine dioxide bleaching, the novel catalytic bleaching (pH < 6) generated only traces of chloroform and low contents of AOX and OX. Separate catalytic oxidations of authentic hexenuronic acid showed that it was a major precursor of chloroform. The results demonstrate a practical way to reduce organochlorine formation in pulp bleaching and provide new understanding on the reaction pathways that yield chloroform. 相似文献
19.
Wighmal Kosheen Peddi Giridhar Apoorva Kumar Naveen Amin S. Intekhab Anand Sunny 《SILICON》2022,14(11):5951-5959
Silicon - Through this paper, we discuss how Tunnel Field Effect Transistors can be utilized for the detection of biomaterials hence acting as a biosensor. The device proposed is a 3-D Doping less... 相似文献
20.
Powder Metallurgy and Metal Ceramics - Powder compaction is the most crucial process in powder metallurgy since almost all the desired properties of a material, such as a shape, size, density,... 相似文献