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991.
The liquid‐solid flotation separation behaviors of Cd2+ in ammonium sulfate‐potassium iodide‐cetylpyridine chloride‐water system and the conditions for the separation of Cd2+ from other metal ions were studied. The results showed that in the presence of 1.0 g (NH4)2SO4 and when the dosage of 0.1 M potassium iodide was 2.0 mL and 0.01 M cetylpyridine chloride (CPC) solution was 1.0 mL respectively, the formed water‐insoluble ternary association complex of KI‐CPC‐Cd floated above water phase and liquid‐solid phases were formed with clear interface. In this condition, Zn2+, Mn2+, Fe2+, Co2+, Ni2+ and Al3+ could not be floated and Cd2+ was floated quantitatively at pH 5.0. Therefore, the quantitative separation of Cd2+ from the above metal ions could be achieved. The quantitative flotation separation determination of Cd2+ in the sample of synthetic water and industrial waster water was performed, and the results agreed well with those by AAS method. The recoveries were 97.2%~102.4%, and the RSD was 1.8%. 相似文献
992.
Establishment of the Model CD40 Cell Membrane Chromatography and Its Chromatographic Characteristics
Guangde Yang Rong Lin Zhen Hu Jiye Zhang Chunjie Han Langchong He Weirong Wang 《Chromatographia》2008,67(9-10):829-831
A new model of atherosclerosis cell membrane chromatography has been established by using a CD40 cell membrane stationary phase (CD40 CMSP) prepared by immobilizing the CD40 cell membrane onto the surface of a silica carrier. The surface and chromatographic characteristics of CD40 CMSP were studied. The retention characteristics of anti-CD40 antibody and statins (lovastatin, simvastatin and pravastatin) were also investigated using this model. Affinities of the anti-CD40 antibody and statins toward CD40 cell membrane and receptors were based on the determination of log k′ values (the logarithm of capacity factor of a solute). There was a significant correlation between the affinity in the CD40–CMC and the effect in vitro for the pharmacological effect. 相似文献
993.
Zhong‐Quan Zhang Jian‐Chao Chen Xian‐Ming Zhang Zhong‐Rong Li Ming‐Hua Qiu 《Helvetica chimica acta》2008,91(8):1494-1499
Two new spirostanol saponins, (1β,3β,5β,25S)‐spirostan‐1,3‐diol 1‐(β‐D ‐xylopyranoside) ( 1 ) and (1β,3β,5β,25S)‐spirostan‐1,3‐diol 1‐[α‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐fucopyranoside] ( 2 ), along with two known compounds, (1β,3β,5β,25S)‐spirostan‐1,3‐diol 1‐[α‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐xylopyranoside] ( 3 ) and (1β,3β,4β,5β,25S)‐spirostan‐1,3,4,5‐tetrol 5‐(β‐D ‐glucopyranoside) ( 4 ) were isolated from the whole plant of Reineckia carnea. The structures of the new steroids were determined by detailed analysis of their 1D‐ and 2D‐NMR spectra and chemical methods, and by comparison with spectral data of known compounds. Compounds 3 and 4 were isolated from the genus Reineckia for the first time. 相似文献
994.
Shu‐Wei Tang Ying‐Fei Chang Li‐Li Sun Hao Sun Zhong‐Min Su Rong‐Shun Wang 《International journal of quantum chemistry》2008,108(8):1391-1399
ABSTRACT: Stability and electronic property calculations are performed systematically based on density functional theory at the B3LYP/6‐31G(d) level for Td C28 fullerene and exohedral fluorine and trifluoromethyl derivatives C28F4–n(CF3)n (n = 0,1,2,3,4). All the exohedral derivatives that are on the potential energy surfaces are kinetically stable with large HOMO‐LUMO gaps. Further investigations show that binding energies of C28F4–n(CF3)n (n = 0,1,2,3,4) molecules are positive, suggesting they are thermodynamically stable. An analysis of the π‐orbital axis vector indicates the high strain in Td C28 cage could be greatly released by fluorine and trifluoromethyl decorations. Mulliken charge analysis reveals that adding different electron groups to the Td C28 cage can cause remarkably different charge populations. In addition, from the ionization potential and electron affinity investigations, the C28F4–n(CF3)n (n = 0,1,2,3,4) molecules manifest weak redox properties. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008 相似文献
995.
996.
CSP分析方法在简化燃烧化学反应系统中的应用 总被引:2,自引:0,他引:2
基于计算奇异摄动(CSP)思想, 对甲烷/空气预混燃烧系统进行分析. CSP将反应空间分裂, 消除刚性; 将单点分析和全局分析相结合, 合理选择主要组分和稳态物质, 使用CSP的特征指数简化方程. 构建了针对甲烷/空气预混燃烧系统的总包15步反应机理, 并利用Sandia实验室的PREMIX软件包对该系统进行分析, 验证了简化机理的准确性, 证实了CSP分析方法在燃烧系统中应用的可靠性和优越性, 并为研究简化燃烧系统的分析提供了一种新的思路. 相似文献
997.
一维链状锰配位聚合物的合成、晶体结构及热稳定性研究 总被引:1,自引:0,他引:1
A manganese coordination polymer, [Mn(C7H2I3O2)2(CH3OH)2]n was synthesized and characterized by the element analysis, IR, TG and single crystal X-ray diffraction structure analysis. The title complex crystallizes in monoclinic system with space group P21/c, a=0.461 66(9) nm, b=1.716 6(3) nm, c=1.647 5(3) nm, β=91.84(3)°, and V=1.305 2(4) nm3, Z=2, R=0.026 2, wR=0.063 4. Each manganese(Ⅱ) ion exists in an octahedral geometry with four O atoms from three different triiodobenzoate groups and two O atoms from two methanol molecules. Two adjacent manganese(Ⅱ) atoms are bridged by two triiodobenzoate groups in bis-monodentate mode, constructing a one-dimensional chain structure along a axis, with the adjacent Mn…Mn distance being 0.461 7(5) nm. Moreover, the weak interactions between the iodine atoms lead to a three-dimensional supramolecular network. CCDC: 666558. 相似文献
998.
Uniform hollow Au@TiO2 core shell spheres with moveable Au nanoparticles were synthesized based on templating against Au@carbon spheres. The diameter of the shell of the Au@TiO2 spheres could be controlled by adjusting the Ti(OC4H9)4 hydrolyzing reaction time or the ratio of Ti(OC4H9)4 to Au@carbon spheres, and the shell thickness of the core-shell spheres can be varied from 25 nm to 40 nm. As prepared hollow Au@TiO2 core-shell spheres display enhanced photocatalytic activity in the initial stage of photocatalytic degradation of methylene blue compared with pure hollow TiO2 spheres and the commercial photocatalyst TiO2(P-25). 相似文献
999.
A facile method for the copper-catalyzed synthesis of N-benzyl-N-phenyl-2-benzothiazolamines was explored. In the presence of CuI, N-phenylbenzothiazolamines was in situ generated from substituted 1-(2-iodophenyl)-3-phenylthioureas, which susequently underwent coupling with benzyl/allyl halides to give the desired N-benzyl/allyl-N-phenyl-2-benzothiazolamines fluently in a one-pot manner. The protocol features easy performance, easily available materials, good yield and broad substrates scope, showing potential synthetic value for the preparation of a variety of biologically or pharmaceutically active compounds. 相似文献
1000.
Hui Xu Dr. Shengbo Zhang Xinyuan Zhang Min Xu Dr. Miaomiao Han Prof. Li Rong Zheng Prof. Yunxia Zhang Prof. Guozhong Wang Prof. Haimin Zhang Prof. Huijun Zhao 《Angewandte Chemie (International ed. in English)》2023,62(52):e202314414
The integration of highly active single atoms (SAs) and atom clusters (ACs) into an electrocatalyst is critically important for high-efficiency two-electron oxygen reduction reaction (2e− ORR) to hydrogen peroxide (H2O2). Here we report a tandem impregnation-pyrolysis-etching strategy to fabricate the oxygen-coordinated Fe SAs and ACs anchored on bacterial cellulose-derived carbon (BCC) (FeSAs/ACs-BCC). As the electrocatalyst, FeSAs/ACs-BCC exhibits superior electrocatalytic activity and selectivity toward 2e− ORR, affording an onset potential of 0.78 V (vs. RHE) and a high H2O2 selectivity of 96.5 % in 0.1 M KOH. In a flow cell reactor, the FeSAs/ACs-BCC also achieves high-efficiency H2O2 production with a yield rate of 12.51±0.18 mol gcat−1 h−1 and a faradaic efficiency of 89.4 %±1.3 % at 150 mA cm−2. Additionally, the feasibility of coupling the produced H2O2 and electro-Fenton process for the valorization of ethylene glycol was explored in detail. The theoretical calculations uncover that the oxygen-coordinated Fe SAs effectively regulate the electronic structure of Fe ACs which are the 2e− ORR active sites, resulting in the optimal binding strength of *OOH intermediate for high-efficiency H2O2 production. 相似文献