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991.
D. Hong H. Rabat J. M. Bauchire M. B. Chang 《Plasma Chemistry and Plasma Processing》2014,34(4):887-897
Plasma actuators for flow control are intensively studied, but the production of ozone by the surface dielectric barrier discharge used in the actuators has never been quantified. Since ozone is harmful to human health, it is important to quantify its production for an application of this type of actuator on a land vehicle. This paper describes an experimental study to measure the concentration of ozone produced by an actuator with different parameters: amplitude and frequency of the applied high voltage, and the electrode configuration (shape, spacing and length). The results show that, under our experimental conditions, the production of ozone is directly proportional to the power dissipation. The production rate was measured at 21 g/kWh. Although the rate is much lower than that of an industrial ozonizer, it is still far from being negligible and should be taken into account for the future application of these actuators. 相似文献
992.
Seung Yoon Ryu Sung Hyun Kim Chang Su Kim Sungjin Jo Jun Yeob Lee 《Current Applied Physics》2012,12(5):1378-1380
Stacked organic light-emitting diodes (SOLEDs) with 30-nm nanoparticle (NP) interfacial layers were investigated. Zinc oxide (ZnO) was used as an interfacial layer between two green polymer (GP) layers. SOLEDs with NP interfacial layers had higher device efficiency than did a single-unit device due to the high probability of exciton recombination that originated from the Auger electron-assisted energy up-conversion process. Although the current density and luminance of SOLEDs with ZnO NP interfacial layers were smaller than those of the reference device, the efficiency was doubled because of the big band alignment difference and the large band gap between GP and ZnO NP interfacial layers, which induced more radiative-exciton recombination. 相似文献
993.
Experimental data from vented explosion tests using stoichiometric methane–air and 18% hydrogen–air mixtures in a 63.7 m3 chamber with a 2.7 or 5.4 m2 vent are presented. Results from experiments conducted using stoichiometric propane–air in 2.42 m3 vessel with a 0.26 m2 vent are also reported. The tests were focused on the effect of fuel, enclosure size, ignition location, vent size, and obstacles on the pressure development of a propagating flame in a vented enclosure. The dependence of the maximum pressure generated on the experimental parameters was analyzed. It was found that the pressure maxima may be caused by pressure transients controlled by the interplay of the maximum-flame area, the burning velocity, and the overpressure generated by an external explosion. A simple model was proposed to estimate the maximum pressure for each of the main pressure transients. The model was found to agree with the experimental data within the experimental uncertainty. 相似文献
994.
Dae Sung You Chang Su Kim Yong Jin KangKyounga Lim Sunghoon JungDo-Geun Kim Jong-Kuk KimSungjin Jo Joo Hyun Kim Jae-Wook Kang 《Current Applied Physics》2012,12(3):908-910
We report on the fabrication of efficient annealing-free organic solar cells using co-solvent solution considered as a promising method for low-cost and time-saving manufacturing. Higher device efficiency could be obtained compared to the pure solvent casted device, resulting from the improved crystallinity, optical absorption and transport properties. The power conversion efficiency of 2.8% was obtained, demonstrating the feasibility of achieving low-cost and high-efficiency organic solar cells without any additional treatment and processing additives. 相似文献
995.
Enantioselective Self‐Assembly of Triangular Dy3 Clusters with Single‐Molecule Magnet Behavior 下载免费PDF全文
Three pairs of enantiopure chiral triangular Ln3 clusters, [Ln3LRRRRRR/SSSSSS(μ3‐OH)2(H2O)2(SCN)4]?xCH3OH?yH2O ( R ‐Dy3 , Ln=Dy, x=6, y=0; S ‐Dy3 , Ln=Dy, x=6, y=1; R ‐Ho3 , Ln=Ho, x=6, y=1; S ‐Ho3 , Ln=Ho, x=6, y=1; R ‐Er3 , Ln=Er, x=6, y=0; S ‐Er3 , Ln=Er, x=6, y=1), have been successfully synthesized by a rational enantioselective synthetic strategy. The core of triangular Ln3 is bound in the central N6O3 of the macrocyclic ligand, and the coordination spheres of Ln ions are completed by four SCN? anions and two H2O molecules in axial positions of the macrocycle. The circular dichroism (CD) and vibrational circular dichroism (VCD) spectra of the enantiomers demonstrate that the chirality is successfully transferred from the ligands to the resulting Ln3 clusters. Ac susceptibility measurements reveal that single‐molecule magnet behavior occurs for both enantiopure clusters of R ‐Dy3 and S ‐Dy3 . This work is one of the few examples of the successful design of a pair of triangular Dy3 clusters showing simultaneously slow magnetic relaxation and optical activity, and this might open up new opportunities to develop novel multifunctional materials. 相似文献
996.
Shu‐Ting Wu Zhen‐Wen Cai Qiao‐Yan Ye Chen‐Hao Weng Xi‐He Huang Xiao‐Lin Hu Chang‐Cang Huang Nai‐Feng Zhuang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(47):13074-13078
Circular dichroism is known to be the feature of a chiral agent which has inspired scientist to study the interesting phenomena of circularly polarized light (CPL) modulated molecular chirality. Although several organic molecules or assemblies have been found to be CPL‐responsive, the influence of CPL on the assembly of chiral coordination compounds remains unknown. Herein, a chiral coordination polymer, which is constructed from achiral agents, was used to study the CPL‐induced enantioselective synthesis. By irradiation with either left‐handed or right‐handed CPL during the reaction and crystallization, enantiomeric excesses of the crystalline product were obtained. Left‐handed CPL resulted in crystals with a left‐handed helical structure, and right‐handed CPL led to crystals with a right‐handed helical structure. It is exciting that the absolute asymmetric synthesis of a chiral coordination polymer could be enantioselective when using CPL, and provides a strategy for the control of the chirality of chiral coordination polymers. 相似文献
997.
Jinping Song Hui Li Jianbin Chao Chuan Dong Shaomin Shuang 《Journal of inclusion phenomena and macrocyclic chemistry》2012,72(3-4):389-395
The formation of the inclusion complex of p-sulfonatocalix[6]arene (SCX6) with different forms of vitamin B6 (VB6) was studied by using fluorescence spectroscopy. VB6 can exist in one of three forms (the acidic form, neutral zwitterionic form and basic form) depending on pH. The fluorescence intensities of acidic and basic forms of VB6 remarkably decreased in presence of SCX6. SCX6 preferred to form 1:1 inclusion complexes with acidic and basic forms of VB6 but hardly form inclusion complex with neutral zwitterionic form. According to the nonlinear curve fitting method, the inclusion constant (K) for the formation of inclusion complexes of acidic and basic forms of VB6 with SCX6 were evaluated to be 1.4?×?104 and 9?×?103 L/mol, respectively. The binding affinity of SCX6 towards acidic form is attributed to hydrogen bonds and hydrophobic interaction, furthermore, additional electrostatic interaction also plays a crucial role. The possible inclusion mode was given by 1H NMR technique. 相似文献
998.
The cyclopalladated ferrocenylimine adducts Ia , Ib , Ic were evaluated in the Suzuki cross‐coupling reaction of benzyl halides with arylboronic acids. The tricyclohexylphosphine adduct Ia exhibited highly catalytic activity for the coupling of aryl and heteroaryl boronic acids containing various functional groups with benzylic bromides and chlorides (up to 99% yield), furnishing diarylmethane derivatives with low catalyst loading (1 mol%). It is worth noting that catalyst Ia can be reused eight times without losing its catalytic activity. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
999.
锶原子单态和三重态间的互组跃迁(5s2)1S0-(5s5p)3P1辐射率远小于一般的电偶极跃迁,共振跃迁荧光信号微弱。介绍了一种应用于探测该互组跃迁荧光谱的直流偏置探测器。该探测器选用极低输入偏置电流运算放大器作为前置放大,具有信噪比高、增益高、偏置可调等优点。此探测器探测增益为106 V/W量级,-3dB带宽为1MHz。实验中利用该探测器对锶原子互组跃迁(5s2)1S0-(5s5p)3P1微弱共振荧光进行探测,获得信噪比很好的共振荧光谱,且无直流偏置,并由此获得高信噪比的鉴频曲线。应用该探测器观测到了饱和荧光谱线以及对应的鉴频曲线,可用于689nm激光锁频,应用于锶光钟系统。 相似文献
1000.