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991.
Yuliya V. Markina Tatiana V. Kirichenko Alexander M. Markin Irina Y. Yudina Antonina V. Starodubova Igor A. Sobenin Alexander N. Orekhov 《Molecules (Basel, Switzerland)》2022,27(15)
Cardiovascular diseases associated with atherosclerosis are the major cause of death in developed countries. Early prevention and treatment of atherosclerosis are considered to be an important aspect of the therapy of cardiovascular disease. Preparations based on natural products affect the main pathogenetic steps of atherogenesis, and so represent a perspective for the long-term prevention of atherosclerosis development. Numerous experimental and clinical studies have demonstrated the multiple beneficial effects of licorice and its bioactive compounds—anti-inflammatory, anti-cytokine, antioxidant, anti-atherogenic, and anti-platelet action—which allow us to consider licorice as a promising atheroprotective agent. In this review, we summarized the current knowledge on the licorice anti-atherosclerotic mechanisms of action based on the results of experimental studies, including the results of the in vitro study demonstrating licorice effect on the ability of blood serum to reduce intracellular cholesterol accumulation in cultured macrophages, and presented the results of clinical studies confirming the ameliorating activity of licorice in regard to traditional cardiovascular risk factors as well as the direct anti-atherosclerotic effect of licorice. 相似文献
992.
Summary: Planar polymer brush formed by semirigid chains of freely jointed rigid segments and immersed into a solvent is considered. Brush collapse induced by deterioration of the solvent quality and its deformation by external normal or lateral force is studied. It is demonstrated that these three different situations can be described in the framework of the common approach. It is shown that the collapse is accompanied by liquid‐crystalline (LC) ordering within the brush. The LC transition can be jump‐like (the first order) or continuous, depending on the segment's aspect ratio and grafting density. Transition point is investigated in detail, the corresponding phase diagrams are calculated. It is shown that the phase diagrams of a normally deformed brush have different structures, with a narrow ‘leg’ in the good solvent region for sparsely grafted brush, with two coexistence regions and a triple point, in addition, for shorter segment length or without these features if the chains are densely grafted. For the laterally deformed brush, phase diagrams have similar structures with a critical point in the good solvent regime.
993.
LI Lin CHONG Wesley K.M DUVADIE Rohit K CHU Shao Song YANG Y.Michelle NONOMIYA Jim TUCKER Kadthleen D KNIGHTON Daniel R FERRE RoseAnn LUNDGREN Karen ESCOBAR Jorge MINNICK Sharon price HUBER Andrea KOUDRIAKOVA Tatiana ARRUDA Jeannie SISSON Wes AUST Robert M VERKHIVKER Gennady M SCHAFFER Lana ROSE Peter w LEWIS Cristrina T 《高等学校化学研究》2001,17(3)
Control of the cell cycle could be applicable in new approaches for cancer chemotherapy. The cyclin-dependent kinases (CDK's) and their corresponding complexes with cyclins are regulatory enzymes for which we have discovered a novel small molecule series of inhibitors, with potencies in the nanomolar range and good selectivity for the CDK's versus other kinases. We will discuss structure-based drug design efforts with crystal structures of complexes with certain CDK's. Cellular effects and some preliminary examination of in vivo cancer efficacy by these inhibitors will also be discussed. 相似文献
994.
Tatiana M. Birshtein Ekaterina B. Zhulina Anna A. Mercurieva 《Macromolecular theory and simulations》2000,9(1):47-55
An analogue of the Alexander‐DeGennes box model is used for theoretical investigation of polymer brushes in a mixture of two solvents. The basic solvent A and the admixture B are assumed to be highly incompatible (Flory‐Huggins parameter χAB = 3.5). Thermodynamics of a polymer in the solvents A and B are described by parameters χB < χA ≤ 1/2. The equilibrium behavior of a brush is investigated in dependence on solvent composition, grafting density, polymer‐solvents and solvent‐solvent interactions. The possibility of a phase transition related with a strong preferential solvation of a brush by a minor solvent component with higher affinity to polymer is shown and examined. Microphase segregation inside a brush is also demonstrated despite overestimating of the brush homogeneity given by the box model. A further simplification of the model permits to obtain scaling formulas and to investigate main regularities in the brush behavior. This offers a clear physical picture of the phase segregation inside a brush in correlation with the phase state of a bulk solvent. 相似文献
995.
The theory of lamellar superstructures in ternary mixtures of ab and bc diblock and linear ABC triblock copolymers under the condition of strong segregation between chemically different blocks is developed. This system is considered using Alexander‐de Gennes (box) and self‐consistent field (SCF) models. The theory predicts the possibility of phase segregation in the microphase‐segregated superstructures. It is shown that the ABC triblock copolymer has unlimited capacity with respect to ab and bc diblock copolymers which include cooperatively into mixed lamella. 相似文献
996.
Tatiana M. Birshtein Ekaterina B. Zhulina Alexey A. Polotsky Volker Abetz Reimund Stadler 《Macromolecular theory and simulations》1999,8(2):151-160
The theory of lamellar superstructures in binary mixtures of AB diblock and linear ABC triblock copolymers under the condition of strong segregation between chemically different blocks is developed. This system is considered using Alexander‐de Gennes (box‐model) and self‐consistent field (SCF) models. The formation of a mixed lamellar superstructure comprising both mixture components is proved. It is shown that a mixed lamella may be the only type of lamellae in the mixture, or it may coexist with pure diblock lamellae, depending on the mixture composition, local characteristics of blocks (thickness and Kuhn segment length), and surface tension coefficients at the A/B and B/C interfaces. Preliminary experimental results provide support of these theoretical estimations. The formation of mixed lamellae in a mixture of linear ABC and branched (AB)2C block copolymers is also considered. 相似文献
997.
Leonid I. Klushin Tatiana M. Birshtein Anna A. Mercurieva 《Macromolecular theory and simulations》1998,7(5):483-495
A mean-field theory of deformation-induced microphase segregation in bridging polymeric brushes anchored to two parallel surfaces is presented. Models with isotropic and orientation-dependent liquid-crystalline interactions between segments are considered. For the first model, the problem is similar to that of classical liquid-vapor phase separation, and the phase diagram in the P-T plane has a line of first-order transitions terminating at the critical point. We show that the critical pressure is negative implying that a free brush tethered only to one surface always exists at supercritical conditions and hence cannot undergo the collapse phase transition. In the second model, the free energy density depends on two coupled order parameters, one related to segment density and the other to the orientational order, which strongly modifies the phase behavior. Depending on the grafting density the system is described by a phase diagram of a regular or a singular type. In the regular phase diagram the first-order transition line terminates at the critical point. In a singular diagram, the first-order transition line extends to infinity; the critical point corresponds to infinite pressure so that the system undergoes the phase transition at arbitrary external pressures. Regular phase diagrams correspond to dense grafting, and singular ones to sparse grafting. The change from a regular phase behavior to another occurs at a certain marginal value of the grafting density. On approaching this value the critical point on the regular diagram moves to infinity, logarithmically with the deviation from the critical grafting density. We relate the analytical properties of the free energy density as a function of the segment concentration to the type of the phase diagram and the shape of the coexistence curve in the temperature- concentration plane. 相似文献
998.
Alexander E. Baranchikov Mikhail I. Razumov Svetlana V. Kameneva Madina M. Sozarukova Tatiana S. Beshkareva Arina D. Filippova Daniil A. Kozlov Olga S. Ivanova Alexander B. Shcherbakov Vladimir K. Ivanov 《Molecules (Basel, Switzerland)》2022,27(15)
A method is proposed for the preparation of stable sols of nanocrystalline cerium dioxide in nonpolar solvents, based on surface modification of CeO2 nanoparticles obtained by thermal hydrolysis of concentrated aqueous solutions of ammonium cerium(IV) nitrate with residues of 2-ethylhexanoic and octanoic acids. The synthesis was carried out at temperatures below 100 °C and did not require the use of expensive and toxic reagents. An assessment of the radical-scavenging properties of the obtained sols using the superoxide anion-radical neutralization model revealed that they demonstrate notable antioxidant activity. The results obtained indicate the potential of the nanoscale cerium dioxide sols in nonpolar solvents to be used for creating nanobiomaterials possessing antioxidant properties. 相似文献
999.
Jajcay Robert Jajcayová Tatiana Szakács Nóra Szendrei Mária B. 《Journal of Algebraic Combinatorics》2021,53(3):829-849
Journal of Algebraic Combinatorics - A partial automorphism of a finite graph is an isomorphism between its vertex-induced subgraphs. The set of all partial automorphisms of a given finite graph... 相似文献
1000.
Xavier Deraet Tatiana Woller Ruben Van Lommel Prof. Frank De Proft Prof. Guido Verniest Prof. Mercedes Alonso 《ChemistryOpen》2019,8(6):788-806
The performance of density functionals and wavefunction methods for describing the thermodynamics and kinetics of hydride reductions of 2-substituted cyclohexanones has been evaluated for the first time. A variety of exchange correlation functionals ranging from generalized gradient approximations to double hybrids have been tested and their performance to describe the facial selectivity of hydride reductions of cyclohexanones has been carefully assessed relative to the CCSD(T) method. Among the tested methods, an approach in which single-point energy calculations using the double hybrid B2PLYP−D3 functional on ωB97X−D optimized geometries provides the most accurate transition state energies for these kinetically-controlled reactions. Moreover, the role of torsional strain, temperature, solvation, noncovalent interactions on the stereoselectivity of these reductions was elucidated. Our results indicate a prominent role of the substituent on the cis/trans ratios driven by the delicate interplay between torsional strain and dispersion interactions. 相似文献