全文获取类型
收费全文 | 55篇 |
免费 | 3篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 5篇 |
机械仪表 | 2篇 |
建筑科学 | 3篇 |
轻工业 | 9篇 |
水利工程 | 8篇 |
石油天然气 | 1篇 |
无线电 | 6篇 |
一般工业技术 | 11篇 |
冶金工业 | 5篇 |
原子能技术 | 1篇 |
自动化技术 | 6篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 5篇 |
2017年 | 1篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 11篇 |
2012年 | 3篇 |
2011年 | 5篇 |
2010年 | 6篇 |
2008年 | 2篇 |
2007年 | 2篇 |
2005年 | 1篇 |
2000年 | 1篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1993年 | 2篇 |
1976年 | 2篇 |
排序方式: 共有58条查询结果,搜索用时 31 毫秒
11.
12.
Reviews the literature on death anxiety as it relates to psychosocial care of the terminally ill. The literature strongly supports the need for caregivers to understand their own fears and feelings in order to deal with terminal patients. The negative potential consequences of misunderstood feelings about death are discussed as well as several major correlates (sex, socioeconomic status, occupation, general anxiety, and level of consciousness). Some results of groups emphasizing ventilation of fears about death are also reviewed briefly. Their positive effects on treatment suggest the value of gaining more accurate understanding of death anxiety through future research. (French abstract) (44 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
13.
Prem P. Jagabar Sathik Sivaraman P. Mathewsaran A. Shady H. E. Abdel Aleem 《中国工程学刊》2019,42(5):460-472
Multilevel inverters can synthesize a high-voltage staircase waveform with low- and medium-voltage components. A new multilevel inverter topology called Asymmetric Dual Source Multilevel Inverter (ADS-MLI) is proposed. When compared to the topologies found in the literature, it can produce multiple levels in the output voltage with fewer power switches. Most of the topologies found in the literature require cascading features to achieve asymmetric operation; but the ADS-MLI can operate without the need for cascading. A simulation prototype capable of synthesizing 13 levels is developed in MATLAB Simulink environment. Its performance is evaluated in the aspects of; number of switching components, efficiency, THD, switching voltage stress and common mode voltage. The simulated efficiency and power quality of the DS-MLI is validated using a 1 kW prototype fabricated using FGA25N120-ANTD controlled by FPGA-SPARTAN 6 processor. Further, the DS-MLI is field tested with a 1 kW solar PV unit and the results are presented. 相似文献
14.
Hsiao-Lan Chang Phillip Shady Wei-Heng Shih 《Journal of the American Ceramic Society》2000,83(8):2055-2061
Fine ZrO2 powders were synthesized by an aqueous precipitation method using zirconyl nitrate. By adding the precursor salt to NaOH, single-phase ZrO2 powders were formed, and the monoclinic phase did not appear upon heat treatment up to 1000°C. The samples were digested in NaOH for different amounts of time. Different levels of washing of digested samples produced surface area at 900°C for 4 h ranging from 8 to 100 m2 /g. It was found that the properties of the powders at elevated temperatures were sensitive to the sodium content. The surface area decreased while the crystallite size and pore size of the samples increased with increased sodium content. Our results indicated that sodium is detrimental to the stabilization of surface area at elevated temperatures. 相似文献
15.
Said H. Lubbad Shady N. Al-Batta 《The International journal of environmental studies》2020,77(3):382-397
ABSTRACT Lead poisoning, correlated to the high blood lead levels among the children of the Gaza Strip, is another severe problem for Palestinians. The paper reports a cost-effective and time-effective remediation by sphagnum moss, which can remove lead from aqueous solution through dispersive solid-phase extraction. The optimum conditions of adsorption such as equilibrium time, pH, adsorbate initial concentration and adsorbent mass were investigated. In conclusion, a cost-effective and ultrafast lead uptake of ~95% was established in 60 s as adsorption-equilibrium contact time. Thus, a design of flow-through remediation unit for lead removal from real-life contaminated water would provide healthy outflow water. Moreover, regeneration and reuse of sphagnum in lead removal is advantageous for less developed economies with a problem of lead pollution in their water. 相似文献
16.
Ibraheem Shady M. Bedawy Walid Saad Waleed Shokair Mona 《Wireless Personal Communications》2022,123(1):727-744
Wireless Personal Communications - Existing security approaches for safeguarding data exchange among the sensor nodes are investigated in presence of apriori information of an adversary in... 相似文献
17.
A systematic approach to designing a wide‐current range,MOS capacitor‐based switched‐capacitor DC‐DC converter with an augmenting LDO
下载免费PDF全文
![点击此处可从《International Journal of Circuit Theory and Applications》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Hakan Dogan Shady A. El‐Sayed Mohammed 《International Journal of Circuit Theory and Applications》2018,46(3):468-482
Switched‐capacitor DC‐DC converters (SC DC‐DC) are analyzed for loss sources, voltage regulation integrity, start‐up latency, and ripple size, while the trade‐offs between these metrics are derived. These analyses are used to design a SC DC‐DC that achieves high efficiency in a wide load current range. Four‐way interleaving was employed to reduce the output ripple and efficiency loss due to this ripple. The design can be reconfigured to achieve gains of 1/3 and 2/5 for inputs ranging between 1.4 and 3.6 V to generate output voltage range of 0.4 to 1.27 V and can supply peak load current of 22 mA. It uses thin‐oxide MOS capacitors for their high density and achieves 75.4% peak efficiency with an input frequency of 100 MHz and a load capacitor of 10 nF. An augmenting LDO that only regulates during sudden load transients helps the converter respond fast to these transients. The chip was implemented using a 65‐nm standard CMOS process. 相似文献
18.
This paper is considered as an application of a centralized control non orthogonal multiple access (NOMA) based cognitive radio network. Here, a base station (BS) sends simultaneously two information signals by employing the superposition coding scheme to two different types of users, i.e., group of near users and one far user. The near users, namely, the secondary users, exchange cooperatively their own received information among themselves ensuring the realization of maximal diversity gain. Besides, they are responsible for relaying information to the far user, namely, the primary user. One potential secondary user is selected to decode and forward the BS information signal to the primary user and the rest of the secondary users to reinforce the reliability, as well as, mitigate the non-decodable messages. Two equivalent cases of a relay (secondary user) selection scheme are proposed. In the first case, the selection aims at maximizing the minimum of the joint secondary to secondary (S to S) and secondary to primary (S to P) channels’ coefficients under a certain limit of interference condition. In the second case, the selection aims at maximizing the minimum of the BS to S and S to S paths while a certain quality of service of the primary user is strictly guaranteed. Assuming Rayleigh fading channels, new closed form expressions are derived for the achievable capacity associated with the two information signals. Simulation results reveal the advantage of our proposed schemes over the conventional orthogonal max–min approach and confirm the validity of our analysis. 相似文献
19.
Most of text categorization techniques are based on word and/or phrase analysis of the text. Statistical analysis of a term frequency captures the importance of the term within a document only. However, two terms can have the same frequency in there documents, but one term contributes more to the meaning of its sentences than the other term. Thus, the underlying model should identify terms that capture the semantics of text. In this case, the model can capture terms that present the concepts of the sentence, which leads to discovering the topic of the document. A new concept‐based model that analyzes terms on the sentence, document, and corpus levels rather than the traditional analysis of document only is introduced. The concept‐based model can effectively discriminate between nonimportant terms with respect to sentence semantics and terms which hold the concepts that represent the sentence meaning. A set of experiments using the proposed concept‐based model on different datasets in text categorization is conducted in comparison with the traditional models. The results demonstrate the substantial enhancement of the categorization quality using the sentence‐based, document‐based and corpus‐based concept analysis. 相似文献
20.
A maximum length sequence (MLS) is used to perform broadband impedance spectroscopy on a dielectric sample. The method has a number of advantages over other pulse-based or frequency sweep techniques. It requires the application of a very short sequence of voltage steps in the microsecond range and therefore allows the measurement of time-dependent impedance of a sample with high temporal resolution over a large bandwidth. The technique is demonstrated using a time-invariant passive RC network. The impedance of single biological cell flowing in a microfluidic channel is also measured, showing that MLS is an ideal method for high speed impedance analysis. 相似文献