全文获取类型
收费全文 | 107篇 |
免费 | 7篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 1篇 |
综合类 | 1篇 |
化学工业 | 30篇 |
机械仪表 | 1篇 |
建筑科学 | 2篇 |
轻工业 | 14篇 |
无线电 | 41篇 |
一般工业技术 | 12篇 |
冶金工业 | 8篇 |
自动化技术 | 5篇 |
出版年
2023年 | 3篇 |
2022年 | 9篇 |
2021年 | 6篇 |
2019年 | 2篇 |
2018年 | 4篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2015年 | 1篇 |
2014年 | 4篇 |
2013年 | 3篇 |
2012年 | 2篇 |
2011年 | 2篇 |
2010年 | 3篇 |
2009年 | 7篇 |
2008年 | 3篇 |
2007年 | 4篇 |
2006年 | 2篇 |
2005年 | 3篇 |
2004年 | 4篇 |
2002年 | 1篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1998年 | 5篇 |
1997年 | 3篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 5篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1988年 | 2篇 |
1985年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 4篇 |
排序方式: 共有115条查询结果,搜索用时 15 毫秒
1.
The key synchronization aspects in the system design of a QQPSK (quadrature-quadrature phase-shift-keying) modem are addressed. The sensitivity of the data demodulator to synchronization errors is discussed, and contextually the performances of some IF and baseband carrier phase and symbol timing recovery schemes are evaluated both theoretically and by computer simulations. In particular, a fourth-power IF carrier/clock regenerator and two baseband clock recovery schemes, with and without the aid of data decisions, respectively, are taken into account. The analysis shows on the one hand the substantial robustness of QQPSK to carrier phase errors and the adequacy of the examined carrier extraction scheme. On the other hand, the remarkable sensitivity of QQPSK to symbol timing inaccuracy is stressed and the need to resort to the newly proposed decision-aided baseband clock recovery scheme is pointed out 相似文献
2.
Alonzo Gonzlez-Gonzlez Oscar Snchez-Snchez R. Luise Krauth-Siegel Maria Laura Bolognesi Rogelio Gmez-Escobedo Benjamín Nogueda-Torres Lenci K. Vzquez-Jimnez Emma Saavedra Rusely Encalada Jos Carlos Espinoza-Hicks Alma D. Paz-Gonzlez Gildardo Rivera 《International journal of molecular sciences》2022,23(21)
American trypanosomiasis is a worldwide health problem that requires attention due to ineffective treatment options. We evaluated n-butyl and isobutyl quinoxaline-7-carboxylate 1,4-di-N-oxide derivatives against trypomastigotes of the Trypanosoma cruzi strains NINOA and INC-5. An in silico analysis of the interactions of 1,4-di-N-oxide on the active site of trypanothione reductase (TR) and an enzyme inhibition study was carried out. The n-butyl series compound identified as T-150 had the best trypanocidal activity against T. cruzi trypomastigotes, with a 13% TR inhibition at 44 μM. The derivative T-147 behaved as a mixed inhibitor with Ki and Ki’ inhibition constants of 11.4 and 60.8 µM, respectively. This finding is comparable to the TR inhibitor mepacrine (Ki = 19 µM). 相似文献
3.
Prerna Arora Lu Zhang Cheila Rocha Luise Graichen Inga Nehlmeier Amy Kempf Anne Cossmann Gema Morillas Ramos Eva Baier Bjrn Tampe Onnen Moerer Steffen Dickel Martin S. Winkler Georg M. N. Behrens Stefan Phlmann Markus Hoffmann 《International journal of molecular sciences》2022,23(22)
Recently, a recombinant SARS-CoV-2 lineage, XD, emerged that harbors a spike gene that is largely derived from the Omicron variant BA.1 in the genetic background of the Delta variant. This finding raised concerns that the recombinant virus might exhibit altered biological properties as compared to the parental viruses and might pose an elevated threat to human health. Here, using pseudotyped particles, we show that ACE2 binding and cell tropism of XD mimics that of BA.1. Further, XD and BA.1 displayed comparable sensitivity to neutralization by antibodies induced upon vaccination with BNT162b2/Comirnaty (BNT) or BNT vaccination followed by breakthrough infection. Our findings reveal important biological commonalities between XD and Omicron BA.1 host cell entry and its inhibition by antibodies. 相似文献
4.
Resident democracy as a special form of participatory democratic set-up is fundamental in the understanding, and self-understanding, of the non-profit housing sector in Denmark. Through a case study, the paper explores how resident democracy is perceived and narrated between residents and employees at a housing association. The study indicates that the meta-story of democracy is disconnected from practice and the lived lives of residents. Three analytical tensions structure the analysis, which relate to the conditions for realizing the democratic ideal embedded in the structure of the sector. The tensions are related to representative versus participatory democracy; collectivity versus individuality; and service versus welfare. The tensions elucidate how resident democracy is squeezed between different logics, which result in an ambiguous setting for practising democracy. Based on the results, the article discusses conditions for prospective democracy in the Danish non-profit housing sector. 相似文献
5.
Lutz Prager Luise WennrichWolfgang Knolle Sergej NaumovAndrea Prager 《Materials Chemistry and Physics》2012
A simple but reliable method was developed for the determination of wavelength-dependent absorption coefficients in the vacuum-UV (VUV) spectral range 160 nm < λ < 195 nm. 相似文献
6.
Identification and Structure–Activity Relationship Studies of Small‐Molecule Inhibitors of the Methyllysine Reader Protein Spindlin1
下载免费PDF全文
![点击此处可从《ChemMedChem》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. Dina Robaa Dr. Tobias Wagner Chiara Luise Dr. Luca Carlino Joel McMillan Dr. Ralf Flaig Prof. Dr. Roland Schüle Prof. Dr. Manfred Jung Prof. Dr. Wolfgang Sippl 《ChemMedChem》2016,11(20):2327-2338
The methyllysine reader protein Spindlin1 has been implicated in the tumorigenesis of several types of cancer and may be an attractive novel therapeutic target. Small‐molecule inhibitors of Spindlin1 should be valuable as chemical probes as well as potential new therapeutics. We applied an iterative virtual screening campaign, encompassing structure‐ and ligand‐based approaches, to identify potential Spindlin1 inhibitors from databases of commercially available compounds. Our in silico studies coupled with in vitro testing were successful in identifying novel Spindlin1 inhibitors. Several 4‐aminoquinazoline and quinazolinethione derivatives were among the active hit compounds, which indicated that these scaffolds represent promising lead structures for the development of Spindlin1 inhibitors. Subsequent lead optimization studies were hence carried out, and numerous derivatives of both lead scaffolds were synthesized. This resulted in the discovery of novel inhibitors of Spindlin1 and helped explore the structure–activity relationships of these inhibitor series. 相似文献
7.
This paper introduces a new methodology to measure the elastic constants of transversely isotropic rocks from a single uniaxial compression test. We first give the mathematical proof that a uniaxial compression test provides only four independent strain equations. As a result, the exact determination of all five independent elastic constants from only one test is not possible. An approximate determination of the Young's moduli and the Poisson's ratios is however practical and efficient when adding the Saint–Venant relation as the fifth equation. Explicit formulae are then developed to calculate both secant and tangent definitions of the five elastic constants from a minimum of four strain measurements. The results of this new methodology applied on three granitic samples demonstrate a significant stress-induced nonlinear behavior, where the tangent moduli increase by a factor of three to four when the rock is loaded up to 20 MPa. The static elastic constants obtained from the uniaxial compression test are also found to be significantly smaller than the dynamic ones obtained from the ultrasonic measurements. 相似文献
8.
9.
Cavallini A. Giannetti F. Luise M. Reggiannini R. 《Communications, IEEE Transactions on》1997,45(4):456-463
This paper is concerned with the design and performance evaluation of a direct-sequence spread-spectrum transmission and signal-detection technique for application to code-division multiple-access mobile radio networks. Unlike the conventional differential encoding/detection of data symbols, such a technique envisages differential encoding/detection of the spreading code chips to counteract the fast time-selective fading encountered in mobile radio transmissions. Binary PSK modulation on a Rician frequency-flat-fading channel is assumed, with Gaussian and Rayleigh channels as particular cases. The bit-error rate performance of the receiver is analytically evaluated as a function of the relevant system parameters, and the impact on the receiver performance of a carrier frequency offset is also investigated 相似文献
10.
Functionally Graded Ceramics Fabricated with Side‐by‐Side Tape Casting for Use in Magnetic Refrigeration
下载免费PDF全文
![点击此处可从《International Journal of Applied Ceramic Technology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Regina Bulatova Christian Bahl Kjeld Andersen Luise Theil Kuhn Nini Pryds 《International Journal of Applied Ceramic Technology》2015,12(4):891-898
Functionally graded ceramic tapes have been fabricated by a side‐by‐side tape casting technique. This study shows the possibility and describes the main principles of adjacent coflow of slurries resulting in formation of thin plates of graded ceramic material. Results showed that the small variations of solvent and binder system concentrations have a substantial effect on slurry viscosity. Varying these parameters showed that side‐by‐side tape casting with a well‐defined interface area is possible for slurries with viscosities above 3500 mPa s at a casting shear rate of 3.3 s?1. As it was expected, the choice of de‐bindering and sintering regimes significantly influences crack formation, and a three‐step heating programme was found to result in tapes of the highest quality. The interface regions of green graded tapes were investigated structurally by scanning electron microscopy; for a distinct identification of the interface region and analysing the degree of cross‐interface diffusion, the isothermal entropy change was measured by a vibrating sample magnetometer as the magnetic transition temperature (Curie temperature) is very sensitive to the dopant level in ceramics. Also the purpose of developing this graded ceramic tape casting was applications of these specific magnetocaloric properties within the magnetic refrigeration technology. 相似文献