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991.
Zhengchun Xu Yueguang Jiao Shien-Kuei Liaw Fu-Chun Hung TAO Qin Hanyi Zhang Yili Guo Xiaoping Zheng 《光学学报》2003,23(Z1)
Two array waveguide grating (AWGs) based fiber ring lasers are experimentally demonstrated. Either of them achieves wavelength discrete tuning of 32 nm, or yields simultaneously lasing up to four channels with -7 dBm output power for each channel. 相似文献
992.
Jih‐Jung Chen Chang‐Yih Duh Hung‐Yi Huang Ih‐Sheng Chen 《Helvetica chimica acta》2003,86(6):2058-2064
A new pyridone alkaloid, 5,6‐dihydro‐5‐hydroxy‐1H‐pyridin‐2‐one ( 1 ), and a new ester, sintenin (=3‐(3,4‐dimethoxyphenyl)propyl 3‐(3,4‐dimethoxyphenyl)propanoate 2 ), together with three known compounds, 5,6‐dihydro‐1H‐pyridin‐2‐one ( 3 ), d‐sesamin (=5,5′‐(3a,4,6,6a‐tetrahydro‐1H,3H‐furo[3,4‐c]furan‐1,4‐diyl)bis[1,3‐benzodioxole]; 4 ), and (E)‐phytol (=3,7,11,15‐tetramethylhexadec‐2‐en‐1‐ol; 5 ) have been isolated from the whole plant of Piper sintenense. The structures of the two new compounds were determined through spectral analyses. Among twenty isolates obtained so far, four compounds exhibited effective cytotoxicities against P‐388, HT‐29, or A549 cell lines in vitro. 相似文献
993.
Y. Y. Hung 《Optics and Lasers in Engineering》1997,26(4-5)
This paper reviews and compares two major optical methods for non-destructive evaluation: digital shearography and TV-holography. Digital shearography measures surface displacement gradients whereas TV-holography measures surface displacements. Both methods reveal flaws by looking for flaw-induced deformation anomolies. While both methods enjoy the advantages of being full-field and non-contacting, digital shearography has been proven to be more practical than TV-holography because it employs a simpler set-up and does not require special vibration isolation. 相似文献
994.
995.
This paper considers the partitioning of all transportation problem instances into a finite number of equivalent classes. Combinatoric properties of each class, in both primal and dual spaces, are investigated. The problem instances are partitioned into convex regions by degeneracy hyperplanes. Properties of adjacent regions are fully developed. It turns out that adjacency relations are much more complex in the primal space than in the dual space. Finally, algorithms based on the simplex method are classified according to how they behave in each class. 相似文献
996.
Breast cancer is one of the most important medical problems. In this paper, we report the results of using neural networks for breast cancer diagnosis. The theoretical advantage is that posterior probabilities of malignancy can be estimated directly, and coupled with resampling techniques such as the bootstrap, distributions of the probabilities can also be obtained. These allow a researcher much more insight into the variability of estimated probabilities. Another contribution is that we present an integrative approach to building neural network models. The issues of model selection, feature selection, and function approximation are discussed in some detail and illustrated with the application to breast cancer diagnosis. 相似文献
997.
Hsu CH Hung SC Wu CY Wong CH 《Angewandte Chemie (International ed. in English)》2011,50(50):11872-11923
Carbohydrates have been shown to play important roles in biological processes. The pace of development in carbohydrate research is, however, relatively slow due to the problems associated with the complexity of carbohydrate structures and the lack of general synthetic methods and tools available for the study of this class of biomolecules. Recent advances in synthesis have demonstrated that many of these problems can be circumvented. In this Review, we describe the methods developed to tackle the problems of carbohydrate-mediated biological processes, with particular focus on the issue related to the development of the automated synthesis of oligosaccharides. Further applications of carbohydrate microarrays and vaccines to human diseases are also highlighted. 相似文献
998.
An intramolecular aza-Michael reaction with a Cbz carbamate and an enone is reported to result in 3,5-disubstituted nitrogen-containing heterocycles. Either cis or trans isomers were obtained selectively using chiral substrates and an achiral Pd(II) complex or strong Br?nsted acid catalysis. A range of substrates undergoes these selective transformations. Functionalization of the resulting products yielding bicyclic heterocycles is also demonstrated. 相似文献
999.
Tsai IL Liu HY Kuo PH Wang JY Shen LJ Kuo CH 《Analytical and bioanalytical chemistry》2011,401(7):2205-2214
Tuberculosis (TB), an infectious disease caused by Mycobacterium tuberculosis, infects approximately one third of the current world population. Isoniazid is one of the most frequently used first-line
anti-TB drugs. In this study, we developed a sensitive cation-selective exhaustive injection–sweeping–micellar electrokinetic
chromatography method (CSEI-Sweep-MEKC) for analyzing isoniazid in human plasma. Parameters including acetonitrile (ACN) percentage
in the separation buffer; the injection time, and concentration of the high-conductivity buffer; sodium dodecyl sulfate (SDS)
concentration; phosphate concentration in the sample matrix; and the sample injection time were all optimized to obtain the
best analytical performance. The optimal background electrolyte comprised 50 mM phosphate buffer, 100 mM SDS, and 15% ACN.
Non-micelle background electrolyte, containing 75 mM phosphate buffer and 15% ACN, was first injected into the capillary,
followed by a short plug of 200 mM phosphate (high-conductivity buffer). Run-to-run repeatability (n = 3) and intermediate precision (n = 3) of peak area ratios were found to be lower than 8.7% and 11.4% RSD, respectively. The accuracy of the method was within
98.1–106.9%. The limit of detection of isoniazod in human plasma was 9 ng mL−1. Compared with conventional MEKC, the enhancement factor of the CSEI-Sweep-MEKC method was 85 in plasma samples. The developed
method was successfully used to determine isoniazid concentration in patient plasma. The results demonstrated that CSEI-Sweep-MEKC
has the potential to analyze isoniazid in human plasma for therapeutic drug monitoring and clinical research. 相似文献
1000.
Tang KC Chang MJ Lin TY Pan HA Fang TC Chen KY Hung WY Hsu YH Chou PT 《Journal of the American Chemical Society》2011,133(44):17738-17745
Using 7-hydroxy-1-indanone as a prototype (I), which exhibits excited-state intramolecular proton transfer (ESIPT), chemical modification has been performed at C(2)-C(3) positions by fusing benzene (molecule II) and naphthalene rings, (molecule III). I undergoes an ultrafast rate of ESIPT, resulting in a unique tautomer emission (λ(max) ~530 nm), whereas excited-state equilibrium is established for both II and III, as supported by the dual emission and the associated relaxation dynamics. The forward ESIPT (normal to proton-transfer tautomer species) rates for II and III are deduced to be (30 ps)(-1) and (22 ps)(-1), respectively, while the backward ESIPT rates are (11 ps)(-1) and (48 ps)(-1). The ESIPT equilibrium constants are thus calculated to be 0.37 and 2.2 for II and III, respectively, giving a corresponding free energy change of 0.59 and -0.47 kcal/mol between normal and tautomer species. For III, normal and tautomer emissions in solid are maximized at 435 and 580 nm, respectively, achieving a white light generation with Commission Internationale de l'Eclairage (CIE) (0.30, 0.27). An organic light-emitting diode based on III is also successfully fabricated with maximum brightness of 665 cd m(-2) at 20 V (885 mA cm(-2)) and the CIE coordinates of (0.26, 0.35). The results provide the proof of concept that the white light generation can be achieved in a single ESIPT system. 相似文献