全文获取类型
收费全文 | 249篇 |
免费 | 10篇 |
国内免费 | 2篇 |
专业分类
化学 | 217篇 |
力学 | 5篇 |
数学 | 8篇 |
物理学 | 31篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 9篇 |
2021年 | 8篇 |
2020年 | 12篇 |
2019年 | 11篇 |
2018年 | 9篇 |
2017年 | 12篇 |
2016年 | 15篇 |
2015年 | 10篇 |
2014年 | 14篇 |
2013年 | 27篇 |
2012年 | 16篇 |
2011年 | 20篇 |
2010年 | 14篇 |
2009年 | 3篇 |
2008年 | 10篇 |
2007年 | 8篇 |
2006年 | 9篇 |
2005年 | 4篇 |
2004年 | 1篇 |
2003年 | 5篇 |
2002年 | 8篇 |
2001年 | 5篇 |
2000年 | 2篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1972年 | 1篇 |
1918年 | 1篇 |
排序方式: 共有261条查询结果,搜索用时 31 毫秒
11.
Total synthesis of (Z) pulchellalactam, a CD protein tyrosine phosphatase inhibitor, from commercially available methallyl chloride employing ring‐closure metathesis (RCM) as a key step is described. 相似文献
12.
Cyriac Vipin Ismayil Noor I. M. Mishra Kuldeep Chavan Chetan Bhajantri Rajashekhar F. Masti Saraswati P. 《Cellulose (London, England)》2022,29(6):3271-3291
Cellulose - In this paper, we report the effect of doping sodium iodide (NaI) salt into a polymer blend matrix of sodium carboxymethyl cellulose (NaCMC) and poly(vinyl alcohol) (PVA). Solution... 相似文献
13.
Lutfun Nahar Shaymaa Al-Majmaie Afaf Al-Groshi Azhar Rasul Satyajit D. Sarker 《Molecules (Basel, Switzerland)》2021,26(6)
Dihydrofuranocoumarin, chalepin (1) and furanocoumarin, chalepensin (2) are 3-prenylated bioactive coumarins, first isolated from the well-known medicinal plant Ruta chalepensis L. (Fam: Rutaceae) but also distributed in various species of the genera Boenminghausenia, Clausena and Ruta. The distribution of these compounds appears to be restricted to the plants of the family Rutaceae. To date, there have been a considerable number of bioactivity studies performed on coumarins 1 and 2, which include their anticancer, antidiabetic, antifertility, antimicrobial, antiplatelet aggregation, antiprotozoal, antiviral and calcium antagonistic properties. This review article presents a critical appraisal of publications on bioactivity of these 3-prenylated coumarins in the light of their feasibility as novel therapeutic agents and investigate their natural distribution in the plant kingdom, as well as a plausible biosynthetic route. 相似文献
14.
Prashant Thakare Abhijit Shinde Sagar Dakhane Abhijit Chavan Vivek D. Bobade Pravin C. Mhaske 《Journal of heterocyclic chemistry》2021,58(9):1867-1877
Cyclocondensation reaction of 4-(2-bromoacetyl)quinolin-1-ium bromide ( 4a–d ) with substituted arylthiourea, ( 5a–g ) afforded 4-(6-substituted quinolin-4-yl)-N-aryl/pyridyl thiazol-2-amine ( 6a-ab ). These newly synthesized derivatives were evaluated for in vitro antibacterial activity against Escherichia coli (NCIM 2574), Proteus mirabilis (NCIM 2388) (Gram-negative strains), Bacillus subtilis (NCIM 2063), Staphylococcus albus (NCIM 2178) (Gram-positive strains) and in vitro antifungal activity against Aspergillus niger (ATCC 504) and Candida albicans (NCIM 3100). Compounds 6a , 6b , 6d , 6f , 6k , and 6l showed moderate to good antibacterial activity against S. albus. Ten derivatives 6c , 6q , 6r , 6s , 6t , 6v , 6w , 6x , 6y , and 6aa , showed moderate to good activity against A. niger. N-[4-(Quinolin-4-yl)-1,3-thiazol-2-yl]pyridin-2-amine presented comparable activity against A. niger with respect to standard drug Rouconazole. 相似文献
15.
Effect of Controlled Deposition of ZnS Shell on the Photostability of CdTe Quantum Dots as Studied by Conventional Fluorescence and FCS Techniques
下载免费PDF全文
![点击此处可从《Chemphyschem》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The effect of one and two monolayers of ZnS shells on the photostability of CdTe quantum dots (QDs) in aqueous and nonaqueous media has been studied by monitoring the fluorescence behavior of the QDs under ensemble and single‐molecule conditions. ZnS capping of the CdTe QDs leads to significant enhancement of the fluorescence brightness of these QDs. Considerable enhancement of the photostability of the shell‐protected QDs, including the suppression of photoactivation, is also observed. Fluorescence correlation spectroscopy measurements reveal an increase in the number of particles undergoing reversible fluorescent on–off transitions in the volume under observation with increasing excitation power; this effect is found to be more pronounced in the case of core‐only QDs than for core–shell QDs. 相似文献
16.
Bhaskar Das Amit Kar Rudranil Bhowmik Sanmoy Karmakar Satyajit Tripathy Motlalepula G. Matsabisa Pulok Kumar Mukherjee 《Molecules (Basel, Switzerland)》2022,27(4)
A South African traditional formulation, PHELA®, is consumed by the traditional people for severe chest problems with coughing, diarrhea, oral ulcers etc. The present study focused on establishing the anti-infective properties of a safe and standardized poly-herbal formulation through a series of criteria and specifications. 相似文献
17.
18.
Chavan SP Sharma P Sivappa R Bhadbhade MM Gonnade RG Kalkote UR 《The Journal of organic chemistry》2003,68(17):6817-6819
Introduction of natural menthol as the chiral auxiliary in a gamma-Br-alpha,beta-unsaturated ester leads to enantioselective generation of three chiral centers in a single step on reaction with a glycine anion equivalent to provide L-CCG-I in 94% ee. 相似文献
19.
Sudrik SG Maddanimath T Chaki NK Chavan SP Chavan SP Sonawane HR Vijayamohanan K 《Organic letters》2003,5(13):2355-2358
In situ-generated silver nanoclusters(Ag(n)) during the reduction of either silver(I) oxide or other salts presumably catalyze the Wolff rearrangement of alpha-diazoketones. Their optical, physical, and catalytic properties depend on the starting silver(I) compound and the reaction conditions. [reaction: see text] 相似文献
20.
Sangmeshwer P. SawargaveAnanada S. Kudale Jaydeep V. DeoreDattatry S. Bhosale Jaisingh M. DivseSubhash P. Chavan Hanumant B. Borate 《Tetrahedron letters》2011,52(42):5491-5493
A three-component, one-step method for the synthesis of 4-alkyl-3-aryl-2,6-dicyanoanilines involving reaction of alkyl aldehyde, malononitrile and aryl aldehyde in presence of morpholine is reported. Highly functionalized 2,3,5,6,7- and 2,3,4,5,7-substituted indoles were prepared from these dicyanoanilines by reaction with ethyl bromoacetate. These substituted dicyanoanilines and indoles have a potential to be converted into various other compounds taking advantage of various functional groups present in these molecules. 相似文献