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101.
《Electroanalysis》2005,17(17):1540-1546
The accumulation voltammetry of mercury(II) was investigated at a carbon paste electrode chemically modified with silica gel functionalized with 2,5‐dimercapto‐1,3,4‐thiadiazole (DTTPSG‐CPE). The repetitive cyclic voltammogram of mercury(II) solution in the potential range ?0.2 to +0.8 V (vs. Ag/AgCl), (0.02 mol L?1 KNO3 ; v=20 mV s?1) show two peaks one at about 0.0 V and other at 0.31 V. However, the cathodic wave peak, around 0.0 V, is irregular and changes its form in each cycle. This peak at about 0.0 V is the reduction current for mercury(II) accumulated in the DTTPSG‐CPE. The anodic wave peak at 0.31 V is well‐defined and does not change during the cycles. The resultant material was characterized by cyclic and differential pulse anodic stripping voltammetry performed with the electrode in differents supporting electrolytes. The mercury response was evaluated with respect to pH, electrode composition, preconcentration time, mercury concentration, “cleaning” solution, possible interferences and other variables. The precision for six determinations (n=6) of 0.05 and 0.20 mg L?1 Hg(II) was 2.8 and 2.2% (relative standard deviation), respectively. The method was satisfactory and used to determine the concentration of mercury(II) in natural waters contaminated by this metal. 相似文献
102.
A new mercury(II) complex of 1,2‐bis(4‐pyridyle)ethene (bpe) with anionic acetate and thiocyanate ligands has been synthesized and characterized by elemental analysis, IR, 1H NMR and 13C NMR spectroscopy. The single crystal X‐ray analysis shows that the complex is a two‐dimensional polymer with simultaneously bridging 1,2‐bis(4‐pyridyle)ethane, acetate and thiocyanate ligands and basic repeating dimeric [Hg2(μ‐bpe)(μ‐OAc)2(μ‐SCN)2] units. The two‐dimensional system forms a three‐dimensional network by packing via π‐π stacking interactions. 相似文献
103.
In the work the procedure of chromium(VI) determination by catalytic adsorptive stripping voltammetry (CAdSV) with application of fumed silica, is presented. Two variants of the method are proposed: in the first fumed silica is put directly to the electrolytic cell containing tested solution, in the second the silica is shaken with the sample and next centrifuged. The effectiveness of many surface‐active substances removal from synthetic solutions as well as natural water samples, is studied. In the experiments the fumed silica (Sigma‐Aldrich) of the specific surface area in the range 200–390 m2 g?1 was used. Two types of the working electrodes were applied, i.e., hanging mercury drop electrode (HMDE) and cyclic renewable mercury film electrode (Hg(Ag)FE). In the silica presence i) the relative standard deviation (RSD) for 0.1 μg L?1 Cr(VI) is <2% (HMDE) and <5% (Hg(Ag)FE), n=7, ii) the detection limits estimated deposition time 20 s were respectively 14 ng L?1 (HMDE) and 22 ng L?1 (Hg(Ag)FE). The accuracy of the method was tested by studying the recovery of Cr(VI) from spiked natural water samples. 相似文献
104.
本文研究了饱和硫化钠溶液对土壤样品中硫化汞的浸取效率(其加标回收率达100%),以及用硝酸和硫化钠溶液对样品中汞的选择性浸取并研究了土壤中硫化汞垂直分布。提出了利用硝酸、饱和硫化钠溶液浸取,由冷原子荧光法选择性测定土壤及河流沉积物中硫化汞的新方法。用该方法对同一样品进行8次测定,其相对标准偏差为7.1%。 相似文献
105.
N. M. Bogdanovich V. P. Gorelov V. B. Balakireva T. A. Demyanenko 《Russian Journal of Electrochemistry》2005,41(5):576-581
The phase composition and electroconduction in air of solid electrolytes (Ce0.8Sm0.2)1 − x
CuxO2 − δ (CSCu), where x = 0, 2, 5, 10, and 20 mol % and which are synthesized using the ceramic technology, are studied. Adding an additive of CuO lowers the CSCu sintering temperature by 100– 200°C and leads to the formation of single-phase solid solutions of a fluorite type up to x = 10 mol %. The electroconductivity of the CSCu electrolytes remains practically invariant upon adding up to 5 mol % Cu and equals 0.089–0.095 and 0.017–0.021 S cm−1 at 800 and 600°C. The sintering, adhesion, and electroconductance of composite cathodes based on La0.8Sr0.2MnO3 with 40% CSCu and their electrochemical behavior in air in the temperature interval 900–1000°C on carrying electrolyte Zr0.9Y0.1O1.95 with a CSCu sublayer containing 2 mol % Cu are studied.__________Translated from Elektrokhimiya, Vol. 41, No. 5, 2005, pp. 656–661.Original Russian Text Copyright © 2005 by Bogdanovich, Gorelov, Balakireva, Dem’yanenko. 相似文献
106.
Spevácková V Korunová V Cejchanová M Vobecký M 《Analytical and bioanalytical chemistry》2004,380(2):346-350
A sampling procedure appropriate for the determination of mercury in whole blood was tested by using both inactive controls and a 197Hg mercury radio-indicator. To exclude the influence of the instrumental device (an AMA 254 single-purpose mercury atomic absorption spectrometer) on the determination of mercury in whole blood, the function of the instrument was checked by using rat blood with metabolised 197Hg. The measurement procedure was found to be free of errors. However, the study showed that the material used for the sampling vessels is a crucial parameter for obtaining accurate analytical results. The stability of solutions and samples was tested towards polyethylene (PE) and polypropylene (PP) vessels. PE displayed a time-dependent increase in the mercury content both in the samples and in the blood control material. The probable cause of this increase was direct contamination from the material of the vessel and/or diffusion of mercury from the environment through the vessel walls related to a strong complexing affinity of the sample matrix. This assumption was confirmed by supplying the vessels with the complexing agent Na2EDTA (0.05 mol L–1). Commercial PP vessels for blood sampling (Sarstedt S-Monovette Metall Analytik) did not give rise to statistically significant variations in mercury content in the samples and blood control material over a 30-day period. 相似文献
107.
On Coinage Metal Mercury Chalcogenide Halides. IV Hydrothermal Synthesis and Crystal Structure of CuHgSI and CuHg2S2I The hydrothermal reaction of CuI with α‐HgS in diluted aqueous HI‐solution as solvent at 180 °C yields dark red crystals of CuHgSI. The compound crystallizes orthorhombic in the space group Pna21 with a = 718.3(1) pm, b = 834.3(2) pm and c = 698.9(1) pm and Z = 4. CuHg2S2I was obtained by the hydrothermal reaction of CuI with α‐HgS in diluted HI‐solution at 300 °C as black crystals. The compound crystallizes orthorhombic in the space group Cmc21 with a = 1261.8(3) pm, b = 722.4(1) pm and c = 693.7(1) pm and Z = 4. Both crystal structures could be explained as distorted version of the Wurtzite structure type in which two different types of anion‐lattices are built up. 相似文献
108.
Poly(vinyl chloride) (PVC)-based membrane of pentathia-15-crown-5 exhibits good potentiometric response for Hg2+ over a wide concentration range (2.51 × 10−5 to 1.00 × 10−1 mol dm−3) with a slope of 32.1 mV per decade of Hg2+ concentration. The response time of the sensor is as fast as 20 s. The electrode has been used for a period of six weeks and exhibits fairly good discriminating ability towards Hg2+ in comparison to alkali, alkaline and some heavy metal ions. The electrode can be used in the pH range from 2.7 to 5.0. 相似文献
109.
The temperature-composition phase diagram of the HgTe?HgI2 pseudobinary system on the HgTe rich side
The temperature-composition phase diagram of the HgTe? HgI2 system was determined from 0 to 45 Mol-% HgI2 between 25 and 670°C using Debye-Scherrer powder X-ray diffraction techniques and differential thermal analysis. Solid solutions of HgTe and HgI2 with the cubic, zinc blende-type structure exist above 300°C, having a maximum solubility of 11.7 ± 0.8 Mol-% HgI2 in HgTe at 501 ± 5°C. The known monoclinic compound Hg3Te2I2 is formed by a peritectic reaction upon cooling at 501 ± 5°C, with the peritectic point at approximately 37 ± 4 Mol-% HgI2. 相似文献
110.
Sheng Yang Antonio Gaetano Ricciardulli Dr. Shaohua Liu Dr. Renhao Dong Dr. Martin R. Lohe Alfons Becker Marco A. Squillaci Prof. Paolo Samorì Prof. Klaus Müllen Prof. Xinliang Feng 《Angewandte Chemie (International ed. in English)》2017,56(23):6669-6675
To bridge the gap between laboratory-scale studies and commercial applications, mass production of high quality graphene is essential. A scalable exfoliation strategy towards the production of graphene sheets is presented that has excellent yield (ca. 75 %, 1–3 layers), low defect density (a C/O ratio of 21.2), great solution-processability, and outstanding electronic properties (a hole mobility of 430 cm2 V−1 s−1). By applying alternating currents, dual exfoliation at both graphite electrodes enables a high production rate exceeding 20 g h−1 in laboratory tests. As a cathode material for lithium storage, graphene-wrapped LiFePO4 particles deliver a high capacity of 167 mAh g−1 at 1 C rate after 500 cycles. 相似文献