全文获取类型
收费全文 | 585篇 |
免费 | 131篇 |
国内免费 | 105篇 |
专业分类
化学 | 395篇 |
晶体学 | 8篇 |
力学 | 60篇 |
综合类 | 8篇 |
数学 | 51篇 |
物理学 | 299篇 |
出版年
2024年 | 2篇 |
2023年 | 14篇 |
2022年 | 23篇 |
2021年 | 21篇 |
2020年 | 34篇 |
2019年 | 23篇 |
2018年 | 18篇 |
2017年 | 20篇 |
2016年 | 28篇 |
2015年 | 32篇 |
2014年 | 26篇 |
2013年 | 57篇 |
2012年 | 35篇 |
2011年 | 42篇 |
2010年 | 31篇 |
2009年 | 33篇 |
2008年 | 41篇 |
2007年 | 51篇 |
2006年 | 27篇 |
2005年 | 25篇 |
2004年 | 22篇 |
2003年 | 17篇 |
2002年 | 13篇 |
2001年 | 16篇 |
2000年 | 15篇 |
1999年 | 28篇 |
1998年 | 15篇 |
1997年 | 14篇 |
1996年 | 12篇 |
1995年 | 17篇 |
1994年 | 12篇 |
1993年 | 6篇 |
1992年 | 16篇 |
1991年 | 15篇 |
1990年 | 5篇 |
1989年 | 8篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有821条查询结果,搜索用时 31 毫秒
131.
132.
Zejing Xing Xiaodan Gou Prof. Dr. Li-Ping Jiang Prof. Dr. Jun-Jie Zhu Dr. Cheng Ma 《Angewandte Chemie (International ed. in English)》2023,62(39):e202308950
Protein coronas are present extensively at the bio-nano interface due to the natural adsorption of proteins onto nanomaterials in biological fluids. Aside from the robust property of nanoparticles, the dynamics of the protein corona shell largely define their chemical identity by altering interface properties. However, the soft coronas are normally complex and rapidly changing. To real-time monitor the entire formation, we report here a self-regulated electrochemiluminescence (ECL) microscopy based on the interaction of the Ru(bpy)33+ with the nanoparticle surface. Thus, the heterogeneity of the protein corona is in situ observed in single nanoparticle “cores” before and after loading drugs in nanomedicine carriers. The label-free, optical stable and dynamic ECL microscopy minimize misinterpretations caused by the variation of nanoparticle size and polydispersity. Accordingly, the synergetic actions of proteins and nanoparticles properties are uncovered by chemically engineered protein corona. After comparing the protein corona formation kinetics in different complex systems and different nanomedicine carriers, the universality and accuracy of this technique were well demonstrated via the protein corona formation kinetics curves regulated by competitive adsorption of Ru(bpy)33+ and multiple proteins on surface of various carriers. The work is of great significance for studying bio-nano interface in drug delivery and targeted cancer treatment. 相似文献
133.
Yang Zheng Dr. Junhua Chen Chunguo Duan Xinyue Zhang Dr. Xuefang Xu Dr. Qian Gou 《Chemphyschem》2023,24(7):e202200804
The pure rotational spectra of 1-phenylethanol and its monohydrate were measured by using a pulsed jet Fourier transform microwave spectrometer. One conformer of the 1-phenylethanol monomer with the trans form was observed in the pulsed jet. The experimental values of rotational constants of ten isotopologues, including eight mono-substituted 13C and one D isotopologues, allow an accurate structure determination of the skeleton of 1-phenylethanol. For its monohydrate, only one isomer has been observed, of which 1-phenylethanol adopts the trans form and binds with water through an O−H⋅⋅⋅Ow and an Ow−H⋅⋅⋅π hydrogen bond. Each rotational transition displays a doublet with a relative intensity ratio of 1 : 3, due to a hindered internal rotation of water around its C2 axis. This study provides the information on accurate geometry of 1-phenylethanol (PE) and large amplitude motion of water in the PE monohydrate. 相似文献
134.
135.
Z. X. Li W. W. Zhao X. X. Gou X. H. Pu 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2016,90(5):1011-1014
The dissolution behavior of cis-diammineglycolatoplatinum (nedaplatin) in saline, water and glucose were studied by a microcalorimetric method. The integral heats and differential heats of the dissolution were measured to establish the equation for the solute and the heats. The corresponding half-life, kinetic and thermodynamic properties of the nedaplatin solutions were determined. The results show that hydrogen bonds could be generated and the dissolution entropy of nedaplatin in different solvents is negative during the dissolution process, so as to enhance the drug stability, but there is an obvious difference in stability in different solvents. 相似文献
136.
Xin Liu Qinglong Gou Layth Alwan Liang Liang 《The Journal of the Operational Research Society》2016,67(2):187-197
Owing to the limited service capacity of express delivery providers, most online retailers have to reject many orders during hot selling seasons. In this paper, we consider an express delivery service supply chain consisting of an express delivery provider and an online retailer whereby the selling season includes both regular periods and online sales periods. Utilizing a modified newsvendor model, we derive the express delivery provider’s optimal capacity decision and find that the overloading problem cannot be avoided because delivery service cannot be inventoried. To solve such a problem, we introduce an option contract to coordinate the supply chain. By allowing the online retailer to book the capacity, the express delivery provider can rent capacity from a third party in advance. Results show this approach can mitigate the problem significantly. We also extend our model to a supply chain consisting of a delivery provider and two retailers. 相似文献
137.
A series of novel triblock copolymers of poly(stearyl methacrylate)-b-poly(N-isopropylacrylamide)-b-poly(stearyl methacrylate) (PSMA-b-PNIPAAm-b-PSMA) with different molecular weights was synthesized through carboxyl-terminated trithiocarbonates as a highly efficient RAFT agent via reversible addition-fragmentation chain transfer (RAFT) polymerization. The resultant polymers were characterized by 1H NMR, FT-IR spectroscopy, and GPC. By varying the organic solvent used in the self-assembly procedure and adjusting the copolymer composition, multiple morphologies ranging from vesicles and core-shell spherical aggregates with different dimensions to pearl-necklace-like aggregates were obtained. The aggregates showed thermoresponsive and pH-responsive properties through the lower critical solution temperature (LCST) of PNIPAAm and the two carboxyl end groups of the copolymer. 相似文献
138.
A new self-assembled catalyst based on titanium complex has been developed for the effective enantioselective cyano-ethoxycarbonylation of aldehydes. The self-assembled catalyst was readily prepared from (R)-3,3′-bis((methyl((S)-1-phenylethyl)amino)methyl)-1,1′-binaphthyl-2,2′-diol (1h), N-((1S,2R)-2-hydroxy-1,2-diphenylethyl)acetamide (2b), and tetraisopropyl titanate (Ti(OiPr)4). A variety of aromatic aldehydes, aliphatic aldehydes, and α,β-unsaturated aldehydes were found to be suitable substrates in the presence of the self-assembled titanium catalyst (5 mol % 1h, 5 mol % 2b, and 5 mol % Ti(OiPr)4). The desired cyanohydrin ethyl carbonates were afforded with high isolated yields (up to 95%) and moderate to good enantioselectivities (up to 92% ee) under mild conditions (at −15 °C). A possible catalytic cycle based on the experimental observation was proposed. 相似文献
139.
Hydrostatic pressure sample injection method is able to minimize the number of electrodes needed for a microchip electrophoresis process; however, it neither can be applied for electrophoretic DNA sizing, nor can be implemented on the widely used single-cross microchip. This paper presents an injector design that makes the hydrostatic pressure sample injection method suitable for DNA sizing. By introducing an assistant channel into the normal double-cross injector, a rugged DNA sample plug suitable for sizing can be successfully formed within the cross area during the sample loading. This paper also demonstrates that the hydrostatic pressure sample injection can be performed in the single-cross microchip by controlling the radial position of the detection point in the separation channel. Rhodamine 123 and its derivative as model sample were successfully separated. 相似文献
140.