全文获取类型
收费全文 | 491篇 |
免费 | 36篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 15篇 |
综合类 | 1篇 |
化学工业 | 135篇 |
金属工艺 | 17篇 |
机械仪表 | 9篇 |
建筑科学 | 16篇 |
矿业工程 | 1篇 |
能源动力 | 26篇 |
轻工业 | 47篇 |
水利工程 | 9篇 |
石油天然气 | 4篇 |
无线电 | 67篇 |
一般工业技术 | 65篇 |
冶金工业 | 26篇 |
原子能技术 | 7篇 |
自动化技术 | 84篇 |
出版年
2024年 | 2篇 |
2023年 | 5篇 |
2022年 | 14篇 |
2021年 | 31篇 |
2020年 | 26篇 |
2019年 | 32篇 |
2018年 | 28篇 |
2017年 | 37篇 |
2016年 | 28篇 |
2015年 | 11篇 |
2014年 | 41篇 |
2013年 | 49篇 |
2012年 | 31篇 |
2011年 | 22篇 |
2010年 | 34篇 |
2009年 | 20篇 |
2008年 | 22篇 |
2007年 | 12篇 |
2006年 | 9篇 |
2005年 | 9篇 |
2004年 | 6篇 |
2003年 | 3篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1973年 | 2篇 |
排序方式: 共有529条查询结果,搜索用时 11 毫秒
51.
Mathematical Modeling of a Simulated Moving‐Bed Adsorption Process: Parex™ Technology as a Case Study
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)
Mahdi Rezazadeh Mohammad Seifi Esfahani Amir Rahimi Mohammad Reza Ehsani 《化学工程与技术》2015,38(5):759-768
A simplified dynamic mathematical model for a simulated moving‐bed adsorption process is presented. The model is adopted to simulate the separation process of p‐xylene from the other 8‐carbon aromatics by means of the Parex? technology. Operating conditions and the moving‐bed structure for a commercial plant were used and the performance of the unit was simulated. The model results are in good agreement with the findings of similar existing studies. Comparison of the results of this simplified model with those obtained by other researches indicates a considerable decrease in central processing unit (CPU) time. 相似文献
52.
Gut microbiota is well known as playing a critical role in inflammation and asthma development. The very low-calorie ketogenic diet (VLCKD) is suggested to affect gut microbiota; however, the effects of VLCKD during pregnancy and lactation on the infant gut microbiota are unclear. The VLCKD appears to be more effective than caloric/energy restriction diets for the treatment of several diseases, such as obesity and diabetes. However, whether adherence to VLCKD affects the infant gut microbiota and the protective effects thereof on asthma remains uncertain. The exact mechanisms underlying this process, and in particular the potential role of short chain fatty acids (SCFAs), are still to be unravelled. Thus, the aim of this review is to identify the potential role of SCFAs that underlie the effects of VLCKD during pregnancy and lactation on the infant gut microbiota, and explore whether it incurs significant implications for reducing asthma. 相似文献
53.
Ashraf Mahmoud Ahmad Abo Naser Marwan Abu‐Amara Tarek Sheltami Nidal Nasser 《International Journal of Communication Systems》2018,31(1)
The evolved packet core (EPC) network is the mobile network standardized by the 3rd Generation Partnership Project and represents the recent evolution of mobile networks providing high‐speed data rates and on‐demand connectivity services. Software‐defined networking (SDN) is recently gaining momentum in network research as a new generation networking technique. An SDN‐based EPC is expected to introduce gains to the EPC control plane architecture in terms of simplified, and perhaps even software‐based, vendor independent infrastructure nodes. In this paper, we propose a novel SDN‐based EPC architecture along with the protocol‐level detailed implementation and provide a mechanism for identifying information fields exchanged between SDN‐EPC entities that maintains correct functionality with minimal impact on the conventional design. Furthermore, we present the first comprehensive network performance evaluation for the SDN‐based EPC versus the conventional EPC and provide a comparative analysis of 2 networks performances identifying potential bottlenecks and performance issues. The evaluation focuses on 2 network control operations, namely, the S1‐handover and registration operations, taking into account several factors, and assessing performance metrics such as end‐to‐end delay (E2ED) for completion of the respective control operation, and EPC nodes utilization figures. 相似文献
54.
Wireless Networks - In a wireless sensor network, one of the most important constraints on sensor nodes is their power source, which is a battery. Sensor nodes carry a limited and generally... 相似文献
55.
In the present study, the potential of aqueous leaf extract of Nigella arevensis for biosynthesis of silver nanoparticles (AgNPs) was evaluated. The formation of AgNPs was confirmed by color changes and UV–visible spectroscopy, which showed absorbance maxima peak at 416?nm. The transmission electron microscope (TEM) image showed the AgNPs to be anisotropic and mostly spherical with sizes in the range of 5–100?nm. Fourier transform infrared (FTIR) analysis indicated that the flavonoids, alkaloids and phenolic groups present in leaf extract were involved in the reduction and capping of phytogenic AgNPs. These nanoparticles showed the cytotoxic effects against H1229 and MCF-7 cancer cell lines with an IC50 value of 10?μg/mL. AgNPs showed insignificant antioxidant properties compared to the crude extract, and it was effective against clinical isolated bacterial strains. Furthermore, the bioderived AgNPs displayed significant catalytic activity against methylene blue. These results confirmed the advantages and applications of these phytogenic AgNPs using the green method in various fields. 相似文献
56.
Moharramnejad Mojtaba Ehsani Ali Malekshah Rahime Eshaghi Shahi Mehrnaz Bavandpour Razieh Rajabi Hamidreza Mojab Seyyed Mohammadreza 《Journal of Materials Science: Materials in Electronics》2022,33(25):19693-19710
Journal of Materials Science: Materials in Electronics - This review gives an overview of the synthesis, surface, and electrochemical investigations over Mn-based compounds in the development of... 相似文献
57.
Wireless Personal Communications - Benefiting from unlimited power supply, vehicular ad hoc networks (VANETs), in a 5G platform, can deal superiorly with the challenges of providing high... 相似文献
58.
Rad Abdolvahab Ehsani Rahim Mohd Shafry Mohd Kolivand Hoshang Norouzi Alireza 《Multimedia Tools and Applications》2018,77(21):28843-28862
Multimedia Tools and Applications - Dental diseases have high risk of affection across the globe and mostly in adult population. The analysis of dental X-ray images has some difficulties in... 相似文献
59.
Alejandro J. Paredes Peter E. McKenna Inken K. Ramöller Yara A. Naser Fabiana Volpe-Zanutto Mingshan Li M. T. A. Abbate Li Zhao Chunyang Zhang Juhaina M. Abu-Ershaid Xianbing Dai Ryan F. Donnelly 《Advanced functional materials》2021,31(1):2005792
Poorly soluble drugs constitute more than 60% of currently marketed pharmaceuticals with over two-thirds of promising new chemical entities failing to enter a clinical setting due to solubility issues. Although oral formulations have made some impact, alternative enhancement strategies for administration of such molecules are actively sought. Over the last decade, innovation on a global scale has enabled the expansion of the frontiers of microarray patches (MAPs) further than ever before. Initially designed to load low doses of hydrophilic and potent therapeutic agents, MAPs are now becoming a viable strategy for the immediate and long-acting delivery of poorly soluble drugs through the skin. This together with the advantages of transdermal administration over the oral and parenteral routes, make of MAPs an appealing platform for the development of products with increased patient compliance. Undoubtedly, MAPs will soon become a readily available therapeutic alternative, and experts from academia, industry and regulatory bodies are working together aiming to facilitate the progression of MAPs toward safe and effective clinical use. This review aims to highlight the ability of MAPs to deliver poorly soluble actives, discuss the mechanisms behind in-skin drug absorption, and evaluate the future direction of the field. 相似文献
60.
The spun tapes of synthesized PAN, its copolymer with 1 wt% itaconic acid, and doped version with 1 wt% sodium dodecyl sulfate (SDS) all showed stripy, even, and compact cross-sections as the hallmark of gel forming products. PAN doping with SDS and acrylonitrile copolymerization with itaconic acid reduced its dimethylformamide (DMF) solution structural viscosity index (Δη) by 50% and 30%, respectively, at 675 s??1. In addition, the modification of synthesized PAN through doping and acrylonitrile copolymerization with itaconic acid led to severe and mild gelation temperature decrease, respectively. The stabilization peak of the synthesized PAN tape was enhanced as much as 25 °C by 900% hot drawing, decreased by about 10 °C through copolymerization, while experienced small temperature changes through doping. The second derivative of Fourier transform infrared and Gaussian fitting was used to analyze the tapes cyclization due to stabilization treatment through introducing Isd index. 10 min Isd index was raised as much as 430% and 800% in comparison with the synthesized PAN through its doping or acrylonitrile copolymerization with itaconic acid, respectively. Further 180 min of Isd index, however, showed the same proportional increase as toughness of the drawn tapes versus their heat of stabilization through their physical and chemical modifications. 相似文献