全文获取类型
收费全文 | 400篇 |
免费 | 23篇 |
国内免费 | 50篇 |
专业分类
化学 | 358篇 |
晶体学 | 4篇 |
力学 | 9篇 |
综合类 | 1篇 |
数学 | 10篇 |
物理学 | 91篇 |
出版年
2023年 | 2篇 |
2022年 | 7篇 |
2021年 | 13篇 |
2020年 | 12篇 |
2019年 | 7篇 |
2018年 | 9篇 |
2017年 | 9篇 |
2016年 | 7篇 |
2015年 | 10篇 |
2014年 | 6篇 |
2013年 | 13篇 |
2012年 | 22篇 |
2011年 | 21篇 |
2010年 | 7篇 |
2009年 | 24篇 |
2008年 | 27篇 |
2007年 | 49篇 |
2006年 | 27篇 |
2005年 | 29篇 |
2004年 | 22篇 |
2003年 | 16篇 |
2002年 | 13篇 |
2001年 | 9篇 |
2000年 | 13篇 |
1999年 | 12篇 |
1998年 | 8篇 |
1997年 | 11篇 |
1996年 | 11篇 |
1995年 | 8篇 |
1994年 | 9篇 |
1993年 | 4篇 |
1992年 | 8篇 |
1991年 | 9篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1957年 | 1篇 |
排序方式: 共有473条查询结果,搜索用时 15 毫秒
1.
Yingjun Sun Dr. Yingjie Li Yingnan Qin Prof. Lei Wang Prof. Shaojun Guo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(18):4032-4038
Searching for new anti-poisoning Pt-based catalysts with enhanced activity for alcohol oxidation is the key in direct alcohol fuel cells (DAFCs). However, in the traditional strategy for designing bimetallic or multimetallic alloy is still difficult to achieve a satisfactory heterogeneous electrocatalyst because the activity often depends on only the surface atoms. Herein, we fabricate the multicomponent active sites by creating a sulfide structure on 1D PtNiCo trimetallic nanowires (NWs), to give a PtNiCo/NiCoS interface NWs (IFNWs). Owing to the presence of sulfide interfaces, the PtNiCo/NiCoS IFNWs enable an impressive methanol/ethanol oxidation reaction (MOR/EOR) performance and excellent anti-CO poisoning tolerance. They have the MOR and EOR mass activities of 2.25 Amg-1Pt and 1.62 Amg-1Pt, around 1.26, 3.21 and 1.46, 2.96 times higher than those of PtNiCo NWs and commercial Pt/C, respectively. CO-stripping and XPS measurements further demonstrate that the new interfacial structure and optimal bonding of Pt−CO can result in accelerating the removal of surface adsorbed carbonaceous intermediates. Moreover, such a unique structure has also demonstrated a much-improved ability for the electrochemical detection of some important molecules (H2O2 and NH2NH2). 相似文献
2.
Nanozymes are nanomaterials with enzyme-like catalytic activities. The unique features of nanozymes (such as high stability, low cost, large surface area for bioconjugation, ease of storage, and multi-functionalities) offer unprecedented opportunities for designing electrochemical biosensors. Recent years have witnessed the rapid development of nanozyme-based electrochemical biosensors. To highlight these achievements, this review first discusses the representative nanozymes including peroxidase mimics, oxidase mimics, hydrolase mimics, and superoxide dismutase mimics used in electrochemical biosensors. Then, it summarizes the bioanalytical applications for the detection of various analytes. Finally, current challenges and future research directions are summarized. 相似文献
3.
Yuan Wang Xuemei Liu Quyun Chen Tian C. Zhang Like Ouyang Shaojun Yuan 《Materials Today Chemistry》2022
Addressing arsenite pollution in groundwater has drawn great attention. It is attractive to pre-oxidize highly mobile As(III) to relatively low-toxic As(V) with a subsequent adsorption separation process. Herein, BiOI anchoring on γ-Fe2O3 is performed to synthesize BiOI/γ-Fe2O3 core–shell nanoparticles for efficient removal of As(III) via a simultaneous photocatalytic oxidization–adsorption process. The physical and chemical structures of BiOI/γ-Fe2O3 are investigated by transmission electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction measurements. The photoluminescence and electron spin resonance (ESR) characterization were employed to ascertain the possible reaction mechanism of visible-light-driven photocatalytic oxidation of As(III). Such BiOI/γ-Fe2O3 delivers a superior As(III) removal capability under visible light irradiation with an arsenic removal efficiency of 99.8% within 180 min, higher than those of BiOCl/γ-Fe2O3 (81.7%) and BiOBr/γ-Fe2O3 (98.9%). The optimal BiOI/γ-Fe2O3 (molar ratio of 2:1) is obtained by rationally adjusting the molar ratio of BiOI to γ-Fe2O3. The as-synthesized BiOI/γ-Fe2O3 performs well in a wide pH range of 2–8. Only coexisting PO43? anions have a significant effect on the As(III) removal. The free radical trapping experiment and ESR results demonstrate that the ?O2? and h+ are the main active substances for the photocatalytic oxidation of As(III) on BiOI/γ-Fe2O3. This work not only gives a novel magnetic core–shell nanoparticle photocatalyst for efficient photocatalytic oxidation and adsorption of As(III) but also offers a new strategy to rationally design BiOX for its related practical applications. 相似文献
4.
Microbial fuel cells (MFCs) have been extensively studied as self-powered toxicity biosensors; however, their applications are limited by the relatively poor toxicity responses. The toxicity responses are known to be related to the factors such as the resistance of species to toxicants, the bioavailability of toxicants and the type of sensing elements. Accordingly, some strategies have already been proposed to enhance the toxicity responses in the past several years, including the external resistance tuning, quorum sensing effect, shear stress control, nutrient level control, electrode material choice, sensing element choice, and cell configuration design. This work introduces and discusses these strategies, and the suggestion for future work is also provided finally. 相似文献
5.
Antibiotics, once being released into the environment, become recalcitrant organic pollutants, which pose a potential risk to ecological balance and human health. In this study, a Z-scheme heterojunction of bismuth oxyiodide (BiOI)/exfoliated g-C3N4 (BiOI/ECN hereafter) was synthesized by the combination of thermal exfoliation of g-C3N4 and chemical precipitation of BiOI for efficient photocatalytic degradation of tetracycline in aqueous solutions under visible light irradiation. The optimized BiOI/ECN delivered an outstanding degradation rate at circa 0.0705 min?1, which was 10 times higher than that of the bulk g-C3N4. The photocatalytic degradation efficiency of tetracycline remained almost unchanged in a pH range of 3–11, and the BiOI/ECN displayed an excellent photostability upon recycled usage. The photocatalytic mechanism of tetracycline was ascribed to the main reactive oxidation species of photogenerated holes and superoxide radicals. In addition, the possible degradation pathways of tetracycline were investigated by HPLC-MS to identify intermediates. The toxicity of photocatalytic-generated intermediates of tetracycline was found significantly alleviated according to the calculation of quantitative structure–activity relationship prediction. This work not only provides an attractive photocatalyst for the removal of tetracycline but also opens a new avenue for rational design of Z-scheme heterojunction composites for tetracycline degradation. 相似文献
6.
Xia Peng Shaojun Wang Xiaomin Zhang You Shu Shengpei Su Jin Zhu 《Cellulose (London, England)》2017,24(11):4683-4689
In this work, cellulose–Ag@AgCl composite films have been fabricated directly through a one-step coagulation of a cellulose/1-butyl-3-methylimidazolium chloride (BmimCl) solution with AgNO3 and PVP. The AgCl was formed upon the addition of AgNO3 to a cellulose/BmimCl solution, and underwent further reaction with excess Cl?, leading to the complete dissolution of AgCl. The AgCl crystals were regenerated on the cellulose matrix during the coagulation process. The AgCl was partial decomposed to Ag0 and formed Ag@AgCl under visible light irradiation. The morphology of Ag@AgCl in the cellulose matrix was controlled by varying the concentration of PVP. The addition of PVP enabled the formation of stable cellulose films embedded with Ag@AgCl. The composite film demonstrated efficient photodegradation of methyl orange, which was retained upon recycling. This work thus provides a simple pathway for the preparation of Ag@AgCl embedded on a polymer support via one-step coagulation. 相似文献
7.
In situ synthesis of CdS/ZnS composite nanoparticles from ZIF-8 for visible light disposal of Cr(VI)
Bai Lei Ge Lili Gu Junjiu Fang Lu Li Shaojun 《Journal of Sol-Gel Science and Technology》2021,99(1):211-219
Journal of Sol-Gel Science and Technology - Zeolitic Imidazolate Framework (ZIF-8) micropolyhedra were employed as a raw material for the synthesis of fine cadmium sulfide/zinc sulfide (CdS/ZnS)... 相似文献
8.
Gao Mingming Wang Jinling Fang Shaojun Nan Jingchang Daming Li 《International Journal of Theoretical Physics》2021,60(7):2358-2367
International Journal of Theoretical Physics - Quantum-dot is the result of elastic relaxation which has a straight relationship with the optical and electronic aspects of the quantum-dot-based... 相似文献
9.
10.