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51.
提出了两种适用于光突发交换网的可编程光缓存器结构:交叉型和多端口开关型.两种结构都能满足突发包缓存的超长性和可变性的要求,且结构简单紧凑,成本低,可扩展.交叉型缓存器通过指定信号在每个子缓存模块的光纤环中的循环次数即能实现可变时间的延迟.多端口开关型缓存器通过指定信号在两个多端口开关相应端口与所接光纤延迟线组成的光纤环中的循环次数实现可变时间的延迟.仿真结果表明,两种可编程光缓存器都能对光突发包实现ns级指定时间延迟,可用于解决光突发交换网突发包的冲突问题. 相似文献
52.
53.
Detoxification of Chemical Warfare Agents Using a Zr6‐Based Metal–Organic Framework/Polymer Mixture
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Dr. Su‐Young Moon Emmanuel Proussaloglou Gregory W. Peterson Dr. Jared B. DeCoste Morgan G. Hall Dr. Ashlee J. Howarth Prof. Joseph T. Hupp Prof. Omar K. Farha 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(42):14864-14868
Owing to their high surface area, periodic distribution of metal sites, and water stability, zirconium‐based metal–organic frameworks (Zr6‐MOFs) have shown promising activity for the hydrolysis of nerve agents GD and VX, as well as the simulant, dimethyl 4‐nitrophenylphosphate (DMNP), in buffered solutions. A hurdle to using MOFs for this application is the current need for a buffer solution. Here the destruction of the simulant DMNP, as well as the chemical warfare agents (GD and VX) through hydrolysis using a MOF catalyst mixed with a non‐volatile, water‐insoluble, heterogeneous buffer is reported. The hydrolysis of the simulant and nerve agents in the presence of the heterogeneous buffer was fast and effective. 相似文献
54.
Effect of double AlN buffer layer on the qualities of GaN films grown by radio-frequency molecular beam epitaxy
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This paper reports that the GaN thin films with Ga-polarity and high quality were grown by radio-frequency molecular beam epitaxy on sapphire (0001) substrate with a double A1N buffer layer. The buffer layer consists of a high-temperature (HT) A1N layer and a low-temperature (LT) A1N layer grown at 800℃ and 600℃, respectively. It is demonstrated that the HT-A1N layer can result in the growth of GaN epilayer in Ga-polarity and the LT-A1N layer is helpful for the improvement of the epilayer quality. It is observed that the carrier mobility of the GaN epilayer increases from 458 to 858cm^2/V.s at room temperature when the thickness of LT-A1N layer varies from 0 to 20nm. The full width at half maximum of x-ray rocking curves also demonstrates a substantial improvement in the quality of GaN epilavers by the utilization of LT-A1N layer. 相似文献
55.
Simulation optimization of buffer allocations in production lines with unreliable machines 总被引:3,自引:0,他引:3
Gül Gürkan 《Annals of Operations Research》2000,93(1-4):177-216
We use a recent simulationbased optimization method, sample path optimization, to find optimal buffer allocations in tandem production lines where machines are subject to random breakdowns and repairs, and the product is fluidtype. We explore some of the functional properties of throughput of such systems and exploit these properties to prove the almost sure convergence of our optimization technique, under a regularity condition on the steady state. Utilizing a generalized semiMarkov process (GSMP) representation of the system, we derive recursive expressions to compute onesided directional derivatives of throughput, from a single simulation run. Finally, we give computational results for lines with up to 50 machines. We also compare results for smaller lines with the results from a more conventional method, stochastic approximation, whenever applicable. In these numerical studies, our method performed quite well on problems that are considered difficult by current computational standards. 相似文献
56.
Rajat Kumar Singh Rajiv Srivastava Yatindra Nath Singh 《Optical and Quantum Electronics》2007,39(14):1153-1165
Optical packet switching provides high speed, data rate/format transparency, efficient use of bandwidth and flexibility. The
major problem in the implementation of “all-optical” switching is contention which occurs when two or more packets arrive
at the same time for the same destination. To resolve the contention, we have proposed an optical packet switch architecture
based on WDM loop buffer memory in the feedback configuration. In that architecture, the contending packets are stored in
a loop buffer module, and routed in the free time slots. The buffering duration in the recirculating loop is limited by a
circulation limit. The analysis was been done to obtain the maximum number of allowed circulations. This paper proposes improved
version of that optical packet switch architecture, to increase the number of maximum allowed circulations. The modification
is done either by adding an extra erbium doped fiber amplifier (EDFA) in the original switch or by replacing the core space
switch with arrayed waveguide grating (AWG). The performance analysis has been done by the simulations. 相似文献
57.
Wang-bing Zhang Xin-an Yang Yuan-yuan Ma Hai-xia Zhu Shang-bing Wang 《Microchemical Journal》2011,97(2):201-206
The determination of trace concentrations of Hg in water samples by the use of electrolytic cold vapor generation (ECVG) system and AFS was studied. Several buffer solutions were used and the detection limits with these systems were found to be by a factor of 1–2 lower than in the conventional electrolytic cold vapor generation system. Comparing with the traditional inorganic acid, phosphate buffer solution (PBS) increased the signal intensity of Hg vapor from electrolytic generation on Pt cathode and reduced the impact of cathode erosion on the stability of signal intensity. Moreover, buffer solution has better interference tolerance. The effects of the electrolytic conditions and interference ions on the ECVG have been studied. Under optimized conditions and with PBS as catholyte the detection limit for Hg was found to be 0.27 ng L−1. The relative standard deviation was 2.8% for 11 consecutive measurements of 1 μg L−1 Hg. This method has been applied in the determination of inorganic Hg in Yangtze River water. 相似文献
58.
The rates of hydrolysis of some pyridilmonoimines have been investigated in aqueous methanol medium of acetate buffer. The hydrolysis of the studied bases found to be slower than that of benzylideneaniline. It is evident from the dependent of the rate constants upon the buffer concentration that the rate equation has the form of special and general acid catalysis. From the results it is suggested that the rate-determining step appears to be the protonation of the nitrogen atom of the imino group of the monoamines at the employed pH. 相似文献
59.
Zhi Zeng Marina Hincapie Brian B. Haab Samir Hanash Sharon J. Pitteri Steven Kluck Jason M. Hogan Jacob Kennedy William S. Hancock 《Journal of chromatography. A》2010,1217(19):3307-3315
Protein glycosylation represents one of the major post-translational modifications and can have significant effects on protein function. Moreover, changes in the carbohydrate structure are increasingly being recognized as an important modification associated with cancer etiology. In this report, we describe the development of a proteomics approach to identify breast cancer related changes in either concentration and/or the carbohydrate structures of glycoprotein(s) present in blood samples. Diseased and healthy serum samples were processed by an optimized sample preparation protocol using multiple lectin affinity chromatography (M-LAC) that partitions serum proteins based on glycan characteristics. Subsequently, three separate procedures, 1D SDS-PAGE, isoelectric focusing and an antibody microarray, were applied to identify potential candidate markers for future study. The combination of these three platforms is illustrated in this report with the analysis of control and cancer glycoproteomic fractions. Firstly, a molecular weight based separation of glycoproteins by 1D SDS-PAGE was performed, followed by protein, glycoprotein staining, lectin blotting and LC–MS analysis. To refine or confirm the list of interesting glycoproteins, isoelectric focusing (targeting sialic acid changes) and an antibody microarray (used to detect neutral glycan shifts) were selected as the orthogonal methods. As a result, several glycoproteins including alpha-1B-glycoprotein, complement C3, alpha-1-antitrypsin and transferrin were identified as potential candidates for further study. 相似文献
60.
A fluid queue with ON periods arriving according to a Poisson process and having a long-tailed distribution has long range
dependence. As a result, its performance deteriorates. The extent of this performance deterioration depends on a quantity
determined by the average values of the system parameters. In the case when the the performance deterioration is the most
extreme, we quantify it by studying the time until the amount of work in the system causes an overflow of a large buffer.
This turns out to be strongly related to the tail behavior of the increase in the buffer content during a busy period of the
M/G/∞ queue feeding the buffer. A large deviation approach provides a powerful method of studying such tail behavior.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献