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971.
In this article, in the setting of connected DG-modules, we prove that, for any A ∞-algebra (M, {m i } i≥1), there is a chain contraction from a DG-algebra A M onto the DG-module M such that the A ∞-algebra structure induced by perturbation theory on M is precisely the original one. In fact, the mentioned DG-algebra can be considered a rectification of the A ∞-algebra in the sense of (Boardman and Vogt, 1973). Appropiate dual results are given for A ∞-coalgebras. 相似文献
972.
A basic geometric question is to determine when a given framework G(p) is globally rigid in Euclidean space Rd, where G is a finite graph and p is a configuration of points corresponding to the vertices of G . G(p) is globally rigid in Rd if for any other configuration q for G such that the edge lengths of G(q) are the same as the corresponding edge lengths of G(p), then p is congruent to q. A framework G(p) is redundantly rigid, if it is rigid and it remains rigid after the removal of any edge of G. 相似文献
973.
Christelle Lemaitre-Guillier Christelle Dufresne Agns Chartier Stphanie Cluzet Josep Valls Lucile Jacquens Antonin Douillet Nicolas Aveline Marielle Adrian Xavier Daire 《Molecules (Basel, Switzerland)》2021,26(14)
Grapevine is susceptible to fungal diseases generally controlled by numerous chemical fungicides. Elicitors of plant defence are a way of reducing the use of these chemicals, but still provide inconsistent efficiency. Easy-to-analyse markers of grapevine responses to elicitors are needed to determine the best conditions for their efficiency and position them in protection strategies. We previously reported that the elicitor sulphated laminarin induced the emission of volatile organic compounds (VOCs) by grapevine leaves. The present study was conducted to characterise and compare VOC emissions in response to other elicitors. Bastid® was first used to test the conditions of VOC collection and analysis. Using SBSE-GC-MS, we detected several VOCs, including the sesquiterpene α-farnesene, in a time-dependent manner. This was correlated with the induction of farnesene synthase gene expression, in parallel with stilbene synthesis (another defence response), and associated to resistance against downy mildew. The other elicitors (Redeli®, Romeo®, Bion®, chitosan, and an oligogalacturonide) induced VOC emission, but with qualitative and quantitative differences. VOC emission thus constitutes a response of grapevine to elicitors of various chemical structures. Therefore, VOC analysis is relevant for studying the impact of environmental factors on grapevine defence responses and optimising the performance of elicitors in vineyards. 相似文献
974.
Timo Rabe Erik Svensson Grape Dr. Tobias A. Engesser Dr. A. Ken Inge Jonas Ströh Gitta Kohlmeyer-Yilmaz Dr. Mohammad Wahiduzzaman Prof. Dr. Guillaume Maurin Prof. Dr. Frank D. Sönnichsen Prof. Dr. Norbert Stock 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(28):7696-7703
The reaction of the V-shaped linker molecule 5-hydroxyisophthalic acid (H2L0), with Al or Ga nitrate under almost identical reaction conditions leads to the nitration of the linker and subsequent formation of metal–organic frameworks (MOFs) with CAU-10 or MIL-53 type structure of composition [Al(OH)(L)], denoted as Al-CAU-10-L0, 2, 4, 6 or [Ga(OH)(L)], denoted as Ga-MIL-53-L2. The Al-MOF contains the original linker L0 as well as three different nitration products (L2, L4 and L4/6), whereas the Ga-MOF mainly incorporates the linker L2. The compositions were deduced by 1H NMR spectroscopy and confirmed by Rietveld refinement. In situ and ex situ studies were carried out to follow the nitration and crystallization, as well as the composition of the MOFs. The crystal structures were refined against powder X-ray diffraction (PXRD) data. As anticipated, the use of the V-shaped linker results in the formation of the CAU-10 type structure in the Al-MOF. Unexpectedly, the Ga-MOF crystallizes in a MIL-53 type structure, which is usually observed with linear or slightly bent linker molecules. To study the structure directing effect of the in situ nitrated linker, pure 2-nitrobenzene-1,3-dicarboxylic acid (m-H2BDC-NO2) was employed which exclusively led to the formation of [Ga(OH)(C8H3NO6)] (Ga-MIL-53-m-BDC-NO2), which is isoreticular to Ga-MIL-53-L2. Density Functional Theory (DFT) calculations confirmed the higher stability of Ga-MIL-53-L2 compared to Ga-CAU-10-L2 and grand canonical Monte Carlo simulations (GCMC) are in agreement with the observed water adsorption isotherms of Ga-MIL-53-L2. 相似文献
975.
Heungju Ahn 《Mathematische Nachrichten》2007,280(4):343-350
We introduce a notion of q ‐pseudoconvex domain of new type for a bounded domain of ?n and prove that for given a ‐closed (p, r)‐form, r ≥ q, that is smooth up to the boundary, there exists a (p, r – 1)‐form smooth up to the boundary which is a solution of ‐equation on a bounded q ‐pseudoconvex domain. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
976.
Schroeter TS Schwaighofer A Mika S Ter Laak A Suelzle D Ganzer U Heinrich N Müller KR 《Journal of computer-aided molecular design》2007,21(12):651-664
We investigate the use of different Machine Learning methods to construct models for aqueous solubility. Models are based on about 4000 compounds, including an in-house set of 632 drug discovery molecules of Bayer Schering Pharma. For each method, we also consider an appropriate method to obtain error bars, in order to estimate the domain of applicability (DOA) for each model. Here, we investigate error bars from a Bayesian model (Gaussian Process (GP)), an ensemble based approach (Random Forest), and approaches based on the Mahalanobis distance to training data (for Support Vector Machine and Ridge Regression models). We evaluate all approaches in terms of their prediction accuracy (in cross-validation, and on an external validation set of 536 molecules) and in how far the individual error bars can faithfully represent the actual prediction error. 相似文献
977.
某PBX炸药的动态力学性能研究 总被引:1,自引:0,他引:1
PBX炸药作为现代武器的主装药,它的力学行为决定着武器的生存能力。为了研究PBX炸药的动态力学特性,采用分离式霍普金森压杆(Split Hopkinson Pressure Bar,SHPB)作为加载手段,结合半导体应变片测试技术和压电晶体监测技术,保证了实验数据的有效性。利用SHPB加载波整形技术,实现了材料两端应力平衡和常应变率加载,得到了不同应变率(90~410 s-1)下材料的应力-应变曲线。根据材料的模量、破坏强度和破坏应变随应变率的变化规律,采用粘性修正的Sargin模型,得到了该PBX炸药在单轴压缩下的唯象本构模型,模拟结果与实验曲线符合较好。 相似文献
978.
A sensitive and reproducible stir bar sorptive extraction and HPLC-UV detection method was used for the therapeutic drug monitoring of chlorpromazine and trifluoperazine in human serum. The separation was achieved using a C(18) column. The mobile phase consisted of methanol/sodium acetate buffer (pH 4.1; 0.1 M) (95:5, v/v) including 0.5% triethylamine. This miniaturized method can result in faster analysis, lower solvent consumption and less workload per sample while maintaining or even improving sensitivity. In the second part, stir bar sorptive extraction/HPLC-UV method was optimized by a chemometrics approach. An experimental design was therefore used to evaluate the statistically influential and/or interacting factors, among those described in the literature, and to find the best extraction and desorption conditions. Optimal sample volume of 1 mL, extraction time of 24 min at 31°C with pH 8.1 were obtained in a screening 2(5) half fractional factorial design followed by a Box-Behnken design. For the desorption conditions, a Box-Behnken design showed that the best conditions were 150 μL mobile phase for 20 min at 50°C. The optimized method was repeatable (CV<10%, linear (LOQ-500 ng/mL)), with the LOQs equal to 0.7 and 1.5 ng/mL for chlorpromazine and trifluoperazine, respectively. 相似文献
979.
Mohamed Gabr Kassem 《Arabian Journal of Chemistry》2011,4(1):25-35
A review with 75 references is presented that deals with the reported methods for analysis of some important central nervous system (CNS) drugs in biological fluids utilizing stir bar sorptive extraction (SBSE) technique covering the years from 2000 to 2008. The theoretical aspects of SBSE, as well as an significant number of applications have been published, showing the advantages of this technique over the classical extraction techniques (liquid–liquid extraction (LLE) and solid-phase extraction (SFE). In this review, recent SBSE developments and a focus on the development of new instrumental approaches and sorbent phases are presented. 相似文献
980.
利用加长型分离式霍普金森压杆(入射杆长6000mm、子弹长800mm)研究聚氨脂泡沫材料在较
低应变率大应变条件一维应力状态下的动态力学性能,获得了约550s的长加载脉冲,得到了该材料在应变
率520s-1、应变0.15条件下的应力应变曲线,对较低应变率条件下,应变率与动态应力平衡之间的关联进行
了讨论。 相似文献