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111.
K. Ravikumar K. Chandra Mohan M. Bidyasagar G. Y. S. K. Swamy 《Journal of chemical crystallography》1995,25(6):325-329
Delocalization of the imidazole electron density is observed in both structures. In the dichlorocobalt complex structure, the two crystallographically independent mercaptobenzimidazole molecules are attached together through the direct bonding of the Co(II) ion with two S atoms. The cohesion of the molecules in the crystals is due to intermolecular N–H...S, and; intra and intermolecular N–H...Cl hydrogen bonds, respectively. 相似文献
112.
Bhargav Shreevatsa Chandan Dharmashekara Vikas Halasumane Swamy Meghana V. Gowda Raghu Ram Achar Vivek Hamse Kameshwar Rajesh Kumar Thimmulappa Asad Syed Abdallah M. Elgorban Salim S. Al-Rejaie Joaquín Ortega-Castro Juan Frau Norma Flores-Holguín Chandan Shivamallu Shiva Prasad Kollur Daniel Glossman-Mitnik 《Molecules (Basel, Switzerland)》2021,26(22)
NAD(P)H:quinone acceptor oxidoreductase-1 (NQO1) is a ubiquitous flavin adenine dinucleotide-dependent flavoprotein that promotes obligatory two-electron reductions of quinones, quinonimines, nitroaromatics, and azo dyes. NQO1 is a multifunctional antioxidant enzyme whose expression and deletion are linked to reduced and increased oxidative stress susceptibilities. NQO1 acts as both a tumor suppressor and tumor promoter; thus, the inhibition of NQO1 results in less tumor burden. In addition, the high expression of NQO1 is associated with a shorter survival time of cancer patients. Inhibiting NQO1 also enables certain anticancer agents to evade the detoxification process. In this study, a series of phytobioactives were screened based on their chemical classes such as coumarins, flavonoids, and triterpenoids for their action on NQO1. The in silico evaluations were conducted using PyRx virtual screening tools, where the flavone compound, Orientin showed a better binding affinity score of −8.18 when compared with standard inhibitor Dicumarol with favorable ADME properties. An MD simulation study found that the Orientin binding to NQO1 away from the substrate-binding site induces a potential conformational change in the substrate-binding site, thereby inhibiting substrate accessibility towards the FAD-binding domain. Furthermore, with this computational approach we are offering a scope for validation of the new therapeutic components for their in vitro and in vivo efficacy against NQO1. 相似文献
113.
In this paper, we report the molecular mechanics and molecular dynamics studies of the hydration of papain using the AMBER and CHARMm programs. We studied papain in an environment with minimal hydration involving only the X-ray waters and also in the hydrated environment by adding an extra 9 Å layer of water around the residues. The effect of nonbond cutoff was studied by performing minimizations with 8 Å and 15 Å nonbond cutoffs using the program AMBER. Two different solvent models—a constant dielectric and a distance-dependent dielectric—were considered. The AMBER-minimized structure and the average structure obtained from the CHARMm simulations for papain solvated with X-ray waters are presented and compared with the X-ray crystal structure results. Results of a similar comparison of the hydrated structures were also presented. The calculated root mean square deviation between the minimized structure and the X-ray structure is smaller for the hydrated system than for the system hydrated with only the X-ray waters. Results of the molecular mechanics and molecular dynamics simulations were presented for the various regions of papain. The hydration of the active site of papain and the effect of hydration on the torsional motion of the active site residues are presented. © 1996 by John Wiley & Sons, Inc. 相似文献
114.
B. S. Sherigara B. E. Kumara Swamy E. V. S. Subrahmanyam K. Ishwar Bhat 《国际化学动力学杂志》2001,33(8):449-457
Manganese(III) (Mn(III)) has been stabilized in weakly acidic solution by means of pyrophosphate and the nature of the complex was elucidated spectrophotometrically. Stoichiometry of Mn(III)‐oxidation of levodopa and methyl dopa in pyrophosphate medium was established in the pH range 2.5–4.0 by iodometric and spectrophotometric methods. The reaction shows a distinct variation in kinetic order with respect to [Mn(III)], a first‐order dependence in the pH range 1.9–2.6, decreasing to fractional order above pH 3. Other common features include first‐order dependence on [dopa], positive fractional order dependence on [H+], and inverse first‐order dependence on [Mn(III)] in the pH range studied. The effects of varying ionic strength and solvent composition were studied. Added ions such as SO42? and ClO4? alter the reaction rate, probably due to the change in the formal redox potential of Mn(III)–Mn(II) couple because of the changes in coordination environment of the oxidizing species. Evidence for the transient existence of the free radical intermediate is given. Cyclic voltametric sensing of levodopa and methyl dopa has ruled out the formation of dopaquinones as oxidation products in the pH range studied. Activation parameters have been evaluated using the Arrhenius and Erying plots. Mechanisms consistent with the kinetic data have been proposed and discussed. These studies are expected to throw some light on dopa metabolism. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 449–457, 2001 相似文献
115.
Bioleaching with ultrasound 总被引:5,自引:0,他引:5
Application of bioleaching of metals in a large-scale operation is reviewed briefly. Continued technical innovation is vital for the wider utilisation of this extraction process within the mineral industries. Therefore, the use of power ultrasound in combination with bioleaching (referred to as sonobioleaching) has been studied and is shown to be beneficial in the recovery of nickel from lean grade ores. The role of ultrasound in improving the benefits and lowering the drawbacks of bioleaching to an acceptable level are described. A possible mechanism for improving and intensifying this process is hypothesised. 相似文献
116.
The concept of a pseudo-complementation * on an almost distributive lattice (ADL) with 0 is introduced and it is proved that it is equationally definable. A one-to-one correspondence between the pseudo-complementations on an ADL L with 0 and maximal elements of L is obtained. It is also proved that L* = {a*|a L} is a Boolean algebra which is independent (upto isomorphism) of the pseudo-complementation * on L.AMS Subject Classification (1991): 06D99 06D15 相似文献
117.
J. Burmester L. Criegee H.C. Dehne K. Derikum R. Devenish J.D. Fox G. Franke G. Flügge Ch. Gerke G. Horlitz Th. Kahl G. Knies M. Rössler S. Wolff R. Schmitz T.N. Ranga Swamy U. Timm K. Wacker 《Physics letters. [Part B]》1976,64(3):369-372
We have observed Kos production in e+e? annihilation between 3.6 and 4.4 GeV CMS energy. In the 4.0–4.1 GeV range Kos mesons occur correlated with prompt electrons, indicating the formation and weak decay of charmed particle. Within the sensitivity of the experiment, no Kos-electron correlation is seen at 3.6 and around 4.4 GeV. 相似文献
118.
119.
120.
Self-assembled growth of an ordered layer of Pt-Br-Pt chains on a Pt(110) surface is demonstrated. Upon slight doping with excess bromine, charge-density wave (CDW) domains separated by well-localized solutions are observed in the Br/Pt layer by scanning tunneling microscopy. Depending on annealing and adatom concentration, a global, long-range-ordered CDW ground state can be established. Angle-resolved UV photoemission data reveal the corresponding Fermi surface and its removal upon the Peierls transition. The CDW phase is stable to well above room temperature. 相似文献