全文获取类型
收费全文 | 1013篇 |
免费 | 181篇 |
国内免费 | 97篇 |
专业分类
化学 | 698篇 |
晶体学 | 5篇 |
力学 | 85篇 |
综合类 | 2篇 |
数学 | 80篇 |
物理学 | 421篇 |
出版年
2023年 | 22篇 |
2022年 | 17篇 |
2021年 | 28篇 |
2020年 | 39篇 |
2019年 | 52篇 |
2018年 | 31篇 |
2017年 | 26篇 |
2016年 | 50篇 |
2015年 | 40篇 |
2014年 | 39篇 |
2013年 | 68篇 |
2012年 | 109篇 |
2011年 | 115篇 |
2010年 | 75篇 |
2009年 | 61篇 |
2008年 | 64篇 |
2007年 | 49篇 |
2006年 | 46篇 |
2005年 | 39篇 |
2004年 | 45篇 |
2003年 | 23篇 |
2002年 | 22篇 |
2001年 | 16篇 |
2000年 | 25篇 |
1999年 | 29篇 |
1998年 | 21篇 |
1997年 | 16篇 |
1996年 | 25篇 |
1995年 | 21篇 |
1994年 | 8篇 |
1993年 | 13篇 |
1992年 | 10篇 |
1991年 | 12篇 |
1990年 | 11篇 |
1989年 | 6篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1981年 | 1篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有1291条查询结果,搜索用时 15 毫秒
1.
We theoretically study complementarity between micro-micro and micro-macro entanglement in a Bose–Einstein condensate with two Rydberg impurities. We investigate quantum dynamics of micro-micro and micro-macro entanglement in the micro-macro system. It is found that strong micro-macro entanglement between Rydberg impurities and the BEC can be generated by the use of initial micro-micro entanglement between two Rydberg impurities, which acts as the seed entanglement to create micro-macro entanglement. We demonstrate a curious complementarity relation between micro-micro and micro-macro entanglement, and find that the complementarity property can be sustained to some extent even though in the presence of the BEC decoherence. 相似文献
2.
Meiru Lu Dr. Xiaoling Wu Dr. Changlong Hao Prof. Chuanlai Xu Prof. Hua Kuang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(28):7023-7030
Nonylphenols (NPNs) are persistent endocrine disruptors and their release into the environment is causing increasing concern about their impact on human health. Herein, an ultrasensitive electrochemical immunosensor was developed for the detection of NPNs in the leachates from 61 instant noodle containers (INCs) from 8 countries across Southeast Asia. Gold nanoclusters (AuNCs) were self-assembled with reduced graphene oxide (rGO; polyethylenimine–rGO) and used to modify a glassy carbon electrode (GCE), which showed excellent electrical conductivity. An anti-NPN antibody was then immobilized on the AuNCs and, if it specifically bound NPN, the reduction in conductivity of the GCE was remarkable. The designed immunosensor has a low detection limit (5.25 ng L−1) and high sensitivity for NPNs in the leachates of INCs. Remarkably, the leaching of estrogen-like compounds from different plastics of INCs and the correlation between NPN content and total estrogenic activity were thoroughly investigated. High temperatures caused polyethylene and polystyrene INCs to release more estrogen-like compounds than that of polypropylene INCs; this increased release of NPNs was associated with higher estrogen activity in living cells. These data fill the gap in human and environmental exposure to estrogen-like compounds through INCs. 相似文献
3.
Yaqin Wang Xibo Zhang Kuan Chang Zhiying Zhao Jiayu Huang Prof. Qin Kuang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(16):e202104514
Exploring new catalytic strategies for achieving efficient CO2 hydrogenation under mild conditions is of great significance for environmental remediation. Herein, a composite photocatalyst Zr-based MOF encapsulated plasmonic AuPt alloy nanoparticles (AuPt@UiO-66-NH2) was successfully constructed for the efficient photothermal catalysis of CO2 hydrogenation. Under light irradiation at 150 °C, AuPt@UiO-66-NH2 achieved a CO production rate of 1451 μmol gmetal−1 h−1 with 91 % selectivity, which far exceeded those obtained by Au@Pt@UiO-66-NH2 with Pt shell on Au (599 μmol gmetal−1 h−1) and Au@UiO-66-NH2 (218 μmol gmetal−1 h−1). The outstanding performances of AuPt@UiO-66-NH2 were attributed to the synergetic effect originating from the plasmonic metal Au, doped active metal Pt, and encapsulation structure of UiO-66-NH2 shell. This work provides a new way for photothermal catalysis of CO2 and a reference for the design of high-performance plasmonic catalysts. 相似文献
4.
Dr. Hui Zhang Chuqi Wang Hongxia Luo Junliang Chen Prof. Min Kuang Prof. Jianping Yang 《Angewandte Chemie (International ed. in English)》2023,62(5):e202217071
The electrochemical nitrate reduction reaction (NO3RR) is an appealing technology for regulating the nitrogen cycle. Metallic iron is one of the well-known electrocatalysts for NO3RR, but it suffers from poor durability due to leaching and oxidation of iron during the electrocatalytic process. In this work, a graphene-nanochainmail-protected iron nanoparticle (Fe@Gnc) electrocatalyst is reported. It displays superior nitrate removal efficiency and high nitrogen selectivity. Notably, the catalyst delivers exceptional stability and durability, with the nitrate removal rate and nitrogen selectivity remained ≈96 % of that of the first time after up to 40 cycles (24 h for one cycle). As expected, the conductive graphene nanochainmail provides robust protection for the internal iron active sites, allowing Fe@Gnc to maintain its long-lasting electrochemical nitrate catalytic activity. This research proposes a workable solution for the scientific challenge of poor lasting ability of iron-based electrocatalysts in large-scale industrialization. 相似文献
5.
Tuoya Naren Gui-Chao Kuang Ruheng Jiang Piao Qing Hao Yang Jialin Lin Yuejiao Chen Weifeng Wei Xiaobo Ji Libao Chen 《Angewandte Chemie (International ed. in English)》2023,62(26):e202305287
Lithium (Li) metal anodes have the highest theoretical capacity and lowest electrochemical potential making them ideal for Li metal batteries (LMBs). However, Li dendrite formation on the anode impedes the proper discharge capacity and practical cycle life of LMBs, particularly in carbonate electrolytes. Herein, we developed a reactive alternative polymer named P(St-MaI) containing carboxylic acid and cyclic ether moieties which would in situ form artificial polymeric solid electrolyte interface (SEI) with Li. This SEI can accommodate volume changes and maintain good interfacial contact. The presence of carboxylic acid and cyclic ether pendant groups greatly contribute to the induction of uniform Li ion deposition. In addition, the presence of benzyl rings makes the polymer have a certain mechanical strength and plays a key role in inhibiting the growth of Li dendrites. As a result, the symmetric Li||Li cell with P(St-MaI)@Li layer can stably cycle for over 900 h under 1 mA cm−2 without polarization voltage increasing, while their Li||LiFePO4 full batteries maintain high capacity retention of 96 % after 930 cycles at 1C in carbonate electrolytes. The innovative strategy of artificial SEI is broadly applicable in designing new materials to inhibit Li dendrite growth on Li metal anodes. 相似文献
6.
ZnO‐Coated Carbon Nanotubes: Inter‐Diffusion of Carboxyl Groups and Enhanced Photocurrent Generation 下载免费PDF全文
Chia‐I Hung Dr. Hua‐Chiang Wen Yao‐Cheng Lai Dr. Shih‐Hsin Chang Prof. Dr. Wu‐Ching Chou Prof. Dr. Wen‐Kuang Hsu 《Chemphyschem》2015,16(4):812-816
ZnO is a defect‐governed oxide and emits light at both visible and UV regimes. This work employs atomic layer deposition to produce oxide particles on oxygenated carbon nanotubes, and the composites only show emission profiles at short wavelengths. The quenching of defect‐related emissions at long wavelengths is verified, owing to carboxyl diffusion into oxygen vacancies, and doping is supported by ZnCO3 formation in oxide lattice. Fully coated tubes display an increased photocurrent and the quantum efficiency increases by 22 % relative to the bare nanotubes. 相似文献
7.
Kuang X.-Y. Jin S.-Q. Cao Y.-H. Zhang Y.-M. Dong S.-G. Zhu L.-H. Lin L.-W. Lin C.-J. 《电化学》2021,(6):624-636
The ordinary organic coatings on aluminum alloy usually encounter a problem of low adhesion to the substrate, which results in destruction and failure of the long-term protective performance of the anticorrosion systems. The surface modification of aluminum alloy is able to enhance the adhesion of organic coating on aluminum alloys, and to improve their protective performance. In this work, a combined surface modification of anodic oxidation and mussel adhesion protein/CeO2/3-aminopropyltriethoxysilane composite film (MCA) was developed on the aluminum alloy. The adhesion of modified polyurethane coated on the treated aluminum alloy and its corrosion protective performance were evaluated comprehensively by using contact angle, adhesion strength, electrochemical impedance spectroscopy (EIS), and scanning reference electrode technique (SRET). The measurements of EIS and SRET demonstrated that the MCA composite film on anodic oxidized Al possessed self-healing function and provided effective protection against early corrosion of aluminum alloy. The pull-off test showed that both anodic oxidation treatment and MCA composite film modification were able to increase the adhesion of modified polyurethane coating on aluminum alloy, and their combined action were supposed to remarkably enhance the adhesion strength up to 17.1 MPa. The reason for the improvement of adhesion was that the anodic oxidation treatment and MCA composite film modification could improve the surface roughness of aluminum alloy, and enhance the surface wettability and surface polarity, which is beneficent to enhance the bonding of the modified polyurethane coating to aluminum alloy surface. The EIS results showed that no any corrosion occurred for the modified polyurethane coating on the treated aluminum alloy during 65 d immersion in 3.5wt.% NaCl solution. The impedance value in low frequency range of the modified polyurethane coating always maintained at a high order of magnitude on the aluminum alloy treated by anodic oxidation and MCA composite film modification, showing an excellent protective performance of the coating system. The evaluation of Neutral Salt Spray (NSS) indicated that the modified polyurethane coating on the treated aluminum alloy owned superior corrosion protection performance, and the adhesion strength remained 13.1 MPa and no any corrosion was found at the scratch locations even after 1200 h of salt spray testing. It was concluded that combination of anodic oxidation and MCA composite film were capable of significantly improving the adhesion of modified polyurethane coating on aluminum alloy and providing long-term effective corrosion protection for aluminum alloy. © 2021 Authors. All rights reserved. 相似文献
8.
The g factors for Cu2+ in meta-zeunerite (Cu(UO2)2(AsO4)2·3H2O), kroehnkite (Na2Cu(SO4)2·2H2O), copper benzoate (Cu(PhCO2)2·3H2O) and diaboleite (Pb2Cu(OH)4Cl2) of the tetragonal phase are uniformly treated by high order perturbation formulas for 3d 9 ions in tetragonally elongated octahedra. The calculation results are in good agreement with the observed values and systematically analyzed in view of the local structures around Cu2+. The g anisotropies Δg (= g ‖?g ⊥) are largely ascribed to the local tetragonal elongations of the Cu2+ sites, characterized by the relative elongation ratios (R ‖?R ⊥)/R? ≈ 19%, 21%, 27% and 30% for metazeunertie, kroehnkite, copper benzoate and diaboletie, respectively. The anomalous valley (minimum) of relative g anisotropy for copper benzoate is attributed to the modification of the Cu2+ electronic states due to the phenyl ring. The ligand orbital contributions are found to be significant due to covalency, and should be taken into account. The present study would be helpful to the unified investigations of structures and properties of the copper oxygen compounds. 相似文献
9.
Dan Liu Chaopeng Fu Ningshuang Zhang Yanling Li Haihui Zhou Yafei Kuang 《Journal of Solid State Electrochemistry》2017,21(3):759-766
Porous nitrogen-doped graphene (PNG) has been prepared via simple thermal treatment of graphene oxide and urea, and the morphology and structure of the PNG have been characterized by using a range of electron microscopy, X-ray photoelectron spectroscopy, and other techniques. The electrochemical performances of the PNG have been investigated in an ionic liquid electrolyte by cyclic voltammetry and galvanostatic charge-discharge via both three-electrode and two-electrode configurations. The PNG electrode delivers a specific capacitance of 310 F g?1 at 1 A g?1 with good cycling stability over 4000 cycles. The high electrochemical performance is ascribed to the porous structure and nitrogen-doping in the PNG. The porous structure enables high specific surface area and rapid ion mobility, contributing to double layer capacitance, while the N-doping enhances electrochemical activity and electric conductivity, contributing to pseudocapacitance. Meanwhile, the ionic liquid electrolyte enables a very wide working voltage of 3 V, leading to a high energy density up to 163.8 W h kg?1. The fabricated supercapacitor can light up a LED for a long while with low self-discharge, showing good potential for practical application. 相似文献
10.
Two kinds of 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) dyads BDP-OH containing 4-hydroxystyrene groups and BDP-PY bearing pyridinyl units were prepared. In addition, a naphthalene derivative NAP-PY modified by pyridinyl moieties substituent was made. The above three dyads could be used to construct white-light emission (WLE) material by a supramolecular engineering strategy due to their three primary colors of blue, green and red. The supramolecular correlations between the hydroxyl group of BDP-OH and the pyridinyl groups of NAP-PY and BDP-PY were confirmed by 1H NMR titration, 2D NOESY and FTIR. A fluorescence monitor application was carried out based on the realization of WLE. This work might be useful for designing other WLE supramolecular systems and image display. 相似文献