全文获取类型
收费全文 | 171篇 |
免费 | 4篇 |
国内免费 | 3篇 |
专业分类
化学 | 133篇 |
力学 | 3篇 |
数学 | 1篇 |
物理学 | 41篇 |
出版年
2023年 | 1篇 |
2022年 | 5篇 |
2021年 | 8篇 |
2020年 | 10篇 |
2019年 | 7篇 |
2018年 | 13篇 |
2017年 | 5篇 |
2016年 | 12篇 |
2015年 | 5篇 |
2014年 | 9篇 |
2013年 | 15篇 |
2012年 | 13篇 |
2011年 | 12篇 |
2010年 | 13篇 |
2009年 | 8篇 |
2008年 | 8篇 |
2007年 | 3篇 |
2006年 | 9篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2002年 | 5篇 |
2001年 | 1篇 |
1998年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1981年 | 2篇 |
排序方式: 共有178条查询结果,搜索用时 62 毫秒
61.
Nitin D. Gaikwad Sachin V. Patil Vivek D. Bobade 《Journal of heterocyclic chemistry》2013,50(3):519-527
A series of new 1‐[4‐(2,3,4‐substituted‐phenyl) thiazol‐2‐yl]‐3‐(2,3,4‐substituted‐phenyl)‐1H‐pyrazole‐4‐carbaldehyde ( 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i , 4j , 4k , 4l , 4m ), 4‐[4‐(4‐substituted‐phenyl) thiazol‐2‐yl]‐3‐(4‐substituted‐phenyl)‐1‐phenyl‐1H‐pyrazole ( 7a , 7b , 7c , 7d , 7e , 7f , 7g , 7h , 7i ), 4‐[4‐(4‐substituted phenyl)thiazol‐2‐yl]‐1‐phenyl‐1H‐pyrazol‐3‐amine ( 10a , 10b , 10c , 10d , 10e , 10f , 10g ) have been synthesized by using Vilsmeier Haack formylation and Hantzsch reaction in high yield. All the synthesized compounds were tested qualitative (Zone of inhibition) and quantitative antimicrobial activities (MIC). Most of the synthesized compounds showed potent antimicrobial activity against gram positive and gram negative bacteria as well as fungi species. 相似文献
62.
Dipake Sudarshan S. Lande Machhindra K. Rajbhoj Anjali S. Gaikwad Suresh T. 《Research on Chemical Intermediates》2021,47(6):2245-2261
Research on Chemical Intermediates - Zeolite ZSM-11 catalyst was prepared by hydrothermal method and characterized by FTIR, XRD, SEM, HRTEM, EDS, and BET analysis techniques. The catalyst shows... 相似文献
63.
Holothuria scabra produces a monomeric lectin (HSL) of 182 kDa. HSL showed strong antibacterial activity and induced bacterial agglutination under in vitro conditions, indicating its role in animals’ innate immune responses. Very few lectins have been reported from echinoderms and none of these lectins have been explored in detail for their sugar-binding kinetics. Affinity, kinetics and thermodynamic analysis of glycans and glycoproteins binding to HSL were studied by fluorescence and surface plasmon resonance spectroscopy. Lectin binds with higher affinity to O-linked than N-linked asialo glycans, and the affinities were relatively higher than that for sialated glycans and glycoproteins. T-antigen α-methyl glycoside was the most potent ligand having the highest affinity (Ka 8.32 ×107 M?1). Thermodynamic and kinetic analysis indicated that the binding of galactosyl Tn-antigen and asialo glycans is accompanied by an enthalpic contribution in addition to higher association rate coupled by low activation energy for the association process. Presence of sialic acid or protein matrix inhibits binding. Higher affinity of HSL for O-glycans than N-glycans had biological implications; since HSL specifically recognizes bacteria, which have mucin or O-glycan cognate on their cell surfaces and play a major role in animal innate immunity. Since, HSL had higher affinity to T-antigen, makes it a useful tool for cancer diagnostic purpose. 相似文献
64.
(2-Amino-3-cyano-4H-chromen-4-yl) phosphonic acid diethyl esters are prepared via a single-step multi-component reaction of structurally diverse salicylaldehydes with malononitrile and triethyl phosphite using a catalytic amount of potassium phosphate in ethanol at ambient temperature. Use of potassium phosphate as an inexpensive catalyst makes the protocol more economical. Mild reaction conditions, simple work-up procedure are the added advantages of the present method. 相似文献
65.
Borhade N Pathan AR Halder S Karwa M Dhiman M Pamidiboina V Gund M Deshattiwar JJ Mali SV Deshmukh NJ Senthilkumar SP Gaikwad P Tipparam SG Mudgal J Dutta MC Burhan AU Thakre G Sharma A Deshpande S Desai DC Dubash NP Jain AK Sharma S Nemmani KV Satyam A 《Chemical & pharmaceutical bulletin》2012,60(4):465-481
In continuation of our efforts to discover novel nitric oxide-releasing non-steroidal anti-inflammatory drugs (NO-NSAIDs) as potentially "Safe NSAIDs," we report herein the design, synthesis and evaluation of 21 new NO-NSAIDs of commonly used NSAIDs such as aspirin, diclofenac, naproxen, flurbiprofen, ketoprofen, sulindac, ibuprofen and indomethacin. These prodrugs have NO-releasing disulfide linker attached to a parent NSAID via linkages such as an ester (compounds 9-16), a double ester (compounds 17-24), an imide (compounds 25-30) or an amide (compounds 31-33). Among these NO-NSAIDs, the ester-containing NO-aspirin (9), NO-diclofenac (10), NO-naproxen (11), and the imide-containing NO-aspirin (25), NO-flurbiprofen (27) and NO-ketoprofen (28) have shown promising oral absorption, anti-inflammatory activity and NO-releasing property, and also protected rats from NSAID-induced gastric damage. NO-aspirin compound 25, on further co-evaluation with aspirin at equimolar doses, exhibited comparable dose-dependent pharmacokinetics, inhibition of gastric mucosal prostaglandin E(2) (PGE(2)) synthesis and analgesic properties to those of aspirin, but retained its gastric-sparing properties even after doubling its oral dose. These promising NO-NSAIDs could therefore represent a new class of potentially "Safe NSAIDs" for the treatment of arthritic pain and inflammation. 相似文献
66.
Sreejith RK Suresh CG Bhosale SH Bhavnani V Kumar A Gaikwad SM Pal JK 《Journal of fluorescence》2012,22(1):431-441
In mammalian cells, the heme-regulated inhibitor (HRI) plays a critical role in the regulation of protein synthesis at the
initiation step through phosphorylation of α-subunit of the eukaryotic initiation factor 2 (eIF2). In this study we have cloned
and performed biophysical characterization of the kinase catalytic domain (KD) of rabbit HRI. The KD described here comprises
kinase 1, the kinase insertion domain (KI) and kinase 2. We report here the existence of an active and stable monomer of HRI
(KD). The HRI (KD) containing three tryptophan residues was examined for its conformational transitions occurring under various
denaturing conditions using steady-state and time-resolved tryptophan fluorescence, circular dichroism (CD) and hydrophobic
dye binding. The parameter A and phase diagram analysis revealed multi-state unfolding and existence of three stable intermediates
during guanidine hydrochloride (Gdn-HCl) induced unfolding of HRI (KD). The protein treated with 6 M Gdn-HCl showed collisional
and static mechanism of acrylamide quenching and the constants (K
sv
= 3.08 M−1and K
s
= 5.62 M−1) were resolved using time resolved fluorescence titration. Based on pH, guanidine hydrochloride and temperature mediated
transitions, HRI (KD) appears to exemplify a rigid molten globule-like intermediate with compact secondary structure, altered
tertiary structure and exposed hydrophobic patches at pH 3.0. The results indicate the inherent structural stability of HRI
(KD), a member of the class of stress response proteins. 相似文献
67.
Netaji K. Desai Prasad G. Mahajan Dhanaji P. Bhopate Dattatray K. Dalavi Avinash A. Kamble Anil H. Gore Tukaram D. Dongale Govind B. Kolekar Shivajirao R. Patil 《Journal of fluorescence》2018,28(1):51-63
A simple solid state reaction technique was employed for the preparation of polycrystalline luminophors of p-terphenyl containing different amounts of perylene followed by spectral characterization techniques viz. XRD, SEM, TGA-DSC, UV–Visible spectroscopy, thermo-electrical conductivity, fluorescence spectroscopy, fluorescence life time spectroscopy and temperature dependent fluorescence. X-ray diffraction profiles of the doped p-terphenyl reveal well-defined and sharp peaks indicate homogeneity and crystallinity. The SEM micrograph of pure p-terphenyl exhibit flakes like grains and then compact and finally gets separately with perylene amounts. The observed results indicate that closed packed crystal structures of doped p-terphenyl during crystal formation. The band gaps estimated from UV–visible spectroscopy decreased from 5.20 to 4.10 eV, while thermo-electrical conductivity increases with perylene content. The fluorescence spectra showed partial quenching of p-terphenyl fluorescence and simultaneously sensitization of perylene fluorescence at the excitation wavelength of p-terphenyl (290 nm) due to excitation energy transfer from p-terphenyl to perylene. The observed sensitization results are in harmony with intense blue color seen in fluorescence microscopy images and has high demand in scintillation process. 相似文献
68.
Ultrasound emulsification: effect of ultrasonic and physicochemical properties on dispersed phase volume and droplet size 总被引:2,自引:1,他引:1
Ultrasonic emulsification of oil and water was carried out and the effect of irradiation time, irradiation power and physicochemical properties of oil on the dispersed phase volume and dispersed phase droplet size has been studied. The increase in the irradiation time increases the dispersed phase volume while decreases the dispersed phase droplets size. With an increase in the ultrasonic irradiation power, there is an increase in the fraction of volume of the dispersed phase while the droplet size of the dispersed phase decreases. The fractional volume of the dispersed phase increases for the case of groundnut oil-water system while it is low for paraffin (heavy) oil-water system. The droplet size of soyabean oil dispersed in water is found to be small while that of paraffin (heavy) oil is found to be large. These variations could be explained on the basis of varying physicochemical properties of the system, i.e., viscosity of oil and the interfacial tension. During the ultrasonic emulsification, coalescence phenomenon which is only marginal, has been observed, which can be attributed to the collision of small droplets when the droplet concentration increases beyond a certain number and the acoustic streaming strength increases. 相似文献
69.
70.