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941.
为了易于模拟地形和地电体,有限单元被设计为三角单元,考虑到实际中岩石,矿物的物性参数均是变化的,单元内电导率被设计为双线性变化,导出一种点源二维地电断面电位计算的有限元方法,该法首先给出沿走向方向进行傅氏变换后的电位的变分问题,然后用有限元方法进行数值计算,最后通过傅氏反变换 ,求得空间域电场。 相似文献
942.
Sian Fang Yuhao Jiang Qianqian Gan Qing Ruan Di Xiao Junbo Zhang 《Molecules (Basel, Switzerland)》2020,25(24)
In order to seek novel technetium-99m bacterial infection imaging agents, a ciprofloxacin xanthate (CPF2XT) was synthesized and radiolabeled with [99mTcN]2+ core to obtain the 99mTcN-CPF2XT complex, which exhibited high radiochemical purity, hydrophilicity, and good stability in vitro. The bacteria binding assay indicated that 99mTcN-CPF2XT had specificity to bacteria. A study of biodistribution in mice showed that 99mTcN-CPF2XT had a higher uptake in bacterial infection tissues than in turpentine-induced abscesses, indicating that it could distinguish bacterial infection from sterile inflammation. Compared to 99mTcN-CPFXDTC, the abscess/blood and abscess/muscle ratios of 99mTcN-CPF2XT were higher and the uptakes of 99mTcN-CPF2XT in the liver and lung were obviously decreased. The results suggested that 99mTcN-CPF2XT would be a potential bacterial infection imaging agent. 相似文献
943.
We introduce W‐spin structures on a Riemann surface Σ and give a precise definition to the corresponding W‐spin equations for any quasi‐homogeneous polynomial W. Then we construct examples of nonzero solutions of spin equations in the presence of Ramond marked points. The main result of the paper is a compactness theorem for the moduli space of the solutions of W‐spin equations when W = W(x1, …, xt) is a nondegenerate, quasi‐homogeneous polynomial with fractional degrees (or weights) qi < ½ for all i. In particular, the compactness theorem holds for the superpotentials E6, E7, E8 or An ? 1, Dn + 1 for n ≥ 3. © 2008 Wiley Periodicals, Inc. 相似文献
944.
ZhiLin Yang QianHong Li FangXiong Ruan ZhiPeng Li Bin Ren HongXing Xu ZhongQun Tian 《科学通报(英文版)》2010,55(24):2635-2642
The exact electromagnetic enhancement mechanism behind SERS, TERS, HERS and SHINERS is one of the issues focused on in the study of enhanced Raman spectroscopy. The three dimensional finite difference time domain method (3D-FDTD), which is widely used in nanoplasmonic simulations, not only provides us with a powerful numerical tool for theoretical studies of the ERS electromagnetic enhancement mechanism, but also serves as a useful tool for the design of ERS-active systems with higher sensi-tivities and spectral spatial resolution. In this paper, we first introduce the fundamental principles of FDTD algorithms, and then the size-dependent dielectric function of dispersive metallic material is discussed. A comparative study of FDTD and rigorous Mie evaluations of electromagnetic fields in the vicinity of a system of self-similar nanospheres shows an excellent correlation between the two computational methods, directly confirming the validity and accuracy of 3D-FDTD simulations in ERS calculations. Finally, we demonstrate, using a TERS calculation as an example, that the non-uniform mesh method can be more computationally efficient without loss of accuracy if it is applied correctly. 相似文献
945.
946.
Nuclear safeguards evaluation (NSE) is to verify that a State is living up to its international undertakings not to use nuclear
programs for nuclear weapons purposes. The main issue in NSE is on the aggregation of expert evaluations for numerous indicators
to make a final decision about the State’s nuclear activity. Fuzzy multiple attribute decision making (FMADM) methods are
capable of dealing with such an issue. In this study, we propose a new FMADM methodology to solve the NSE problem. To this
end, we investigate the applicability of four basic FMADM methods, namely a simple additive weighting method, a TOPSIS method,
a linguistic method, and a non-compensatory method, to the NSE issue. As a result of the assessment of the basic methods,
we propose a new FMADM methodology based on a new aggregation operator in which a cumulative belief structure is used to represent
the expert evaluations. The basic methods and the proposed method as well are applied to an example from the literature for
illustration purposes. 相似文献
947.
We study a delayed non-autonomous Schoener model with feedback control, which was proposed by Qiming Liu, Rui Xu and Pinghua Yang [8]. By applying a differential inequality and some analysis technique, we show that under some suitable assumptions, the feedback control variable has no influence on the persistent property of the system. Our result improves the existing ones. 相似文献
948.
949.
Liang Wang Yingkuan Wang Paul Chen Roger Ruan 《Applied biochemistry and biotechnology》2010,162(8):2324-2332
The present study, based on a previous batch-wise experiment, investigated a lab-scale semi-continuous cultivation of green
microalgae Chlorella vulgaris (UTEX 2714), as a useful means for nutrient reduction as well as production of algal biomass which can be used as potential
feedstock for the production of biofuel and other commodities, on 20× diluted dairy manures. Both undigested and digested
samples were applied in parallel experiments for comparison regarding the requirements of hydraulic retention times (HRTs),
removal efficiencies of nitrogen, phosphorus, and chemical oxygen demand (COD), biomass productivities, and CO2 sequestration abilities. It was demonstrated that algae grown in undigested dairy manure achieved removal rates of 99.7%,
89.5%, 92.0%, and 75.5% for NH4+–N, TN, TP, and COD, respectively, under a 5-day HRT, while the HRT had to extend to 20 days in order to achieve 100.0% removal
of NH4+–N in digested one with simultaneous removals of 93.6% of TN, 89.2% of TP, and 55.4% of COD. The higher organic carbon contained
in undigested dairy manure helped boost the growth of mixotrophic Chlorella, thus resulting in a much shorter HRT needed for complete removal of NH4+–N. Moreover, algae grown in digested dairy manure provided more penitential than those grown in undigested one in CO2 sequestration per milligram of harvested dried biomass (1.68 mg CO2/mg dry weight (DW) vs 0.99 mg CO2/mg DW), but did not surpass in total the amount of CO2 sequestered on a 15-day period basis because of the better productivity gained in undigested dairy manure. 相似文献
950.
Zhen Wang Xiaochen Ma Wenguang Zhou Min Min Yanling Cheng Paul Chen Jian Shi Qin Wang Yuhuan Liu Roger Ruan 《Applied biochemistry and biotechnology》2013,171(3):689-703
The aim of this study was to evaluate the use of hydrolysates from acid hydrolysis of four different oil crop biomass residues (OCBR) as low cost culture media for algae growth. The one-factor-at-a-time method was used to design a series of experiments to optimize the acid hydrolysis conditions through examining the total nitrogen, total phosphorus, chemical oxygen demand, and ammonia nitrogen in the hydrolysates. The optimal conditions were found to be using 3 % sulfuric acid and hydrolyzing residues at 90 °C for 20 h. The hydrolysates (OCBR media) produced under the optimal conditions were used to cultivate the two algae strains, namely UM258 and UM268. The results from 5 days of cultivation showed that the OCBR media supported faster algae growth with maximal algal biomass yield of 2.7 and 3 g/L, respectively. Moreover, the total lipids for UM258 and UM268 were 54 and 35 %, respectively, after 5 days of cultivation, which suggested that the OCBR media allowed the algae strains to accumulate higher lipids probably due to high C/N ratio. Furthermore, over 3 % of omega-3 fatty acid (EPA) was produced for the two algae strains. In conclusion, OCBR media are excellent alternative for algae growth and have a great potential for large-scale production of algae-based ingredients for biodiesel as well as high-value food and pharmaceutical products. 相似文献