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901.
902.
Photoswitchable organic materials have shown significant advancement for photonic applications,however,the polynuclear metal clusters conjugated with photoswitching properties are still formidable.Herein,a novel octanuclear Zn(Ⅱ) nanocage{[Zn8-(Me4Si4O8)2(azopz)8]·4CH2Cl2·MeOH·MeCN}(SD/Zn8)(Hazopz=3,5-dimethyl-4-(phenyldiazenyl)-1H-pyrazole),based on multidentate silsesquioxane and pyrazole modified by photoisomerizable azo group has been designed and synthesized to realize the reversible photoswitching behavior.X-ray crystallographic study reveals that the unique metal core consists of two annular Me4Si4O84-sandwiching a ring of eight Zn atoms where the pyrazole end of azopz-bridges them together.The azopz-ligands diverge above and below the plane defined by eight Zn atoms.Importantly,SD/Zn8 shows quick trans-to-cis transformation upon 365 nm light irradiation,which can be easily changed back by 450 nm light,but slow cis-to-trans reversibility at room temperature as confirmed by UV-V is and 1H NMR spectroscopies.This process,which presumably regulates the spaces,acts like a pump and is completely repetitive.As such,it can be considered as a molecular pump energized by light.Importantly,the molecule is an energy reservoir where it absorbs the light energy and releases it slowly with time. 相似文献
903.
Ioana Alexandra Cardos Dana Carmen Zaha Rakesh K. Sindhu Simona Cavalu 《Molecules (Basel, Switzerland)》2021,26(19)
The prevalence of Helicobacter pylori infection remains significant worldwide and it depends on many factors: gender, age, socio-economic status, geographic area, diet, and lifestyle. All successful infectious diseases treatments use antibiotic-susceptibility testing, but this strategy is not currently practical for H. pylori and the usual cure rates of H. pylori are lower than other bacterial infections. Actually, there is no treatment that ensures complete eradication of this pathogen. In the context of an alarming increase in resistance to antibiotics (especially to clarithromycin and metronidazole), alternative and complementary options and strategies are taken into consideration. As the success of antibacterial therapy depends not only on the susceptibility to given drugs, but also on the specific doses, formulations, use of adjuvants, treatment duration, and reinfection rates, this review discusses the current therapies for H. pylori treatment along with their advantages and limitations. As an alternative option, this work offers an extensively referenced approach on natural medicines against H. pylori, including the significance of nanotechnology in developing new strategies for treatment of H. pylori infection. 相似文献
904.
Sanjay Kumar Sherif A. El-Kafrawy Shiv Bharadwaj S. S. Maitra Thamir A. Alandijany Arwa A. Faizo Aiah M. Khateb Vivek Dhar Dwivedi Esam I. Azhar 《Molecules (Basel, Switzerland)》2022,27(8)
Zika virus (ZIKV) has been characterized as one of many potential pathogens and placed under future epidemic outbreaks by the WHO. However, a lack of potential therapeutics can result in an uncontrolled pandemic as with other human pandemic viruses. Therefore, prioritized effective therapeutics development has been recommended against ZIKV. In this context, the present study adopted a strategy to explore the lead compounds from Azadirachta indica against ZIKV via concurrent inhibition of the NS2B-NS3 protease (ZIKVpro) and NS5 RNA dependent RNA polymerase (ZIKVRdRp) proteins using molecular simulations. Initially, structure-based virtual screening of 44 bioflavonoids reported in Azadirachta indica against the crystal structures of targeted ZIKV proteins resulted in the identification of the top four common bioflavonoids, viz. Rutin, Nicotiflorin, Isoquercitrin, and Hyperoside. These compounds showed substantial docking energy (−7.9 to −11.01 kcal/mol) and intermolecular interactions with essential residues of ZIKVpro (B:His51, B:Asp75, and B:Ser135) and ZIKVRdRp (Asp540, Ile799, and Asp665) by comparison to the reference compounds, O7N inhibitor (ZIKVpro) and Sofosbuvir inhibitor (ZIKVRdRp). Besides, long interval molecular dynamics simulation (500 ns) on the selected docked poses reveals stability of the respective docked poses contributed by intermolecular hydrogen bonds and hydrophobic interactions. The predicted complex stability was further supported by calculated end-point binding free energy using molecular mechanics generalized born surface area (MM/GBSA) method. Consequently, the identified common bioflavonoids are recommended as promising therapeutic inhibitors of ZIKVpro and ZIKVRdRp against ZIKV for further experimental assessment. 相似文献
905.
Sarita Kushwaha Suhas Monika Chaudhary Inderjeet Tyagi Rakesh Bhutiani Joanna Goscianska Jahangeer Ahmed Manila Shubham Chaudhary 《Molecules (Basel, Switzerland)》2022,27(10)
In the present work, an effort has been made to utilize Phyllanthus emblica (PE) fruit stone as a potential biomaterial for the sustainable remediation of noxious heavy metals viz. Pb(II) and Cd(II) from the aqueous solution using adsorption methodology. Further, to elucidate the adsorption potential of Phyllanthus emblica fruit stone (PEFS), effective parameters, such as contact time, initial metal concentration, temperature, etc., were investigated and optimized using a simple batch adsorption method. It was observed that 80% removal for both the heavy metal ions was carried out within 60 min of contact time at an optimized pH 6. Moreover, the thermodynamic parameters results indicated that the adsorption process in the present study was endothermic, spontaneous, and feasible in nature. The positive value of entropy further reflects the high adsorbent–adsorbate interaction. Thus, based on the findings obtained, it can be concluded that the biosorbent may be considered a potential material for the remediation of these noxious impurities and can further be applied or extrapolated to other impurities. 相似文献
906.
Gelation of crosslinking polymers, with ionic groups, is of interest in membrane processing of these materials. The gelation
of polyvinyl alcohol in the presence of an ionic crosslinker, sulfosuccinic acid, was monitored through rheological measurements.
The evolution of rheological material functions during film formation, which involves solvent evaporation and crosslinking,
was observed at different polymer and crosslinker concentrations. Relative effect of water evaporation leading to physical
gelation and the chemical crosslinking was examined. To understand the effect of crosslinker type, the rheology of nonionic
crosslinker, glutaraldehyde was also examined. The gel points as well as network parameters for these covalent networking
systems were different and depended on crosslinker type and polymer/crosslinker concentrations. However, qualitative evolution
of rheological behavior during film formation was largely similar, demonstrating the dominating effect of solvent evaporation.
Crosslinking in the absence of solvent evaporation was examined at different temperatures. It can be concluded that similar
mechanism was involved, independent of temperature, in the temperature range of interest. The effect of crosslinker concentration
on evolution of rheological properties near gelation was insignificant for ionic crosslinker though marginally significant
for nonionic crosslinker. 相似文献
907.
The reaction of chlorosulfonyl isocyanate (CSI) with 1,2,3-triphenylaziridine (1) and some cis- and trans-1-cyclohexyl-2-aroyl-3-phenylaziridines, 4-7 and 19-22 has been described. The cis-isomers of aziridines, 4-7 , undergo a smooth reaction with CSI to give the corresponding cis-isomers of 2-chlorosulfonylimino-1,3-oxazolidines, 8-11 , in good yields (65-67%). While the trans-isomers, 19-22 , gave unusual products 23-26 which have been assigned a bicyclic structure, based on their physical and spectral (ir, pmr, ms) data. Plausible mechanisms have been postulated to explain the transformations. 相似文献
908.
Patel Rohit Prajapati Jignesh Rao Priyashi Rawal Rakesh M. Saraf Meenu Goswami Dweipayan 《Molecular diversity》2022,26(4):2189-2209
Molecular Diversity - Papain-like protease (nsp-3; non-structural protein) of novel corona virus is an ideal target for developing drugs as it plays multiple important functions for viral growth... 相似文献
909.
Rakesh Biswas Sumit Naskar Surya Ghosh Prof. Dr. Mousumi Das Prof. Dr. Supratim Banerjee 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(60):13595-13600
Signal transduction is essential for the survival of living organisms, because it allows them to respond to the changes in external environments. In artificial systems, signal transduction has been exploited for the highly sensitive detection of analytes. Herein, a remarkable signal transduction, upon ATP binding, in the multivalent fibrillar nanoaggregates of anthracene conjugated imidazolium receptors is reported. The aggregates of one particular amphiphilic receptor sensed ATP in high pm concentrations with one ATP molecule essentially quenching the emission of thousands of receptors. A cooperative merging of the multivalent binding and signal transduction led to this superquenching and translated to an outstanding enhancement of more than a millionfold in the sensitivity of ATP detection by the nanoaggregates; in comparison to the “molecular” imidazolium receptors. Furthermore, an exceptional selectivity to ATP over other nucleotides was demonstrated. 相似文献
910.
G. Naaresh Reddy Rakesh Parida Prof. Dr. Puru Jena Prof. Dr. Madhurima Jana Prof. Dr. Santanab Giri 《Chemphyschem》2019,20(12):1607-1612
Lewis acids play an important role in synthetic chemistry. Using first-principle calculations on some newly designed molecules containing boron and organic heterocyclic superhalogen ligands, we show that the acid strength depends on the charge of the central atom as well as on the ligands attached to it. In particular, the strength of the Lewis acid increases with increasing electron withdrawing power of the ligand. With this insight, we highlight the importance of superhalogen-based ligands in the design of strong Lewis acids. Calculated fluoride ion affinity (FIA) values of B[C2BNO(CN)3]3 and B[C2BNS(CN)3]3 show that these are super Lewis acids. 相似文献