全文获取类型
收费全文 | 114篇 |
免费 | 9篇 |
国内免费 | 3篇 |
专业分类
化学 | 104篇 |
晶体学 | 2篇 |
力学 | 5篇 |
物理学 | 15篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 6篇 |
2020年 | 16篇 |
2019年 | 8篇 |
2018年 | 10篇 |
2017年 | 5篇 |
2016年 | 3篇 |
2015年 | 9篇 |
2014年 | 7篇 |
2013年 | 7篇 |
2012年 | 8篇 |
2011年 | 2篇 |
2010年 | 5篇 |
2009年 | 4篇 |
2007年 | 7篇 |
2006年 | 7篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2003年 | 4篇 |
2002年 | 1篇 |
2001年 | 2篇 |
1997年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1988年 | 2篇 |
排序方式: 共有126条查询结果,搜索用时 468 毫秒
31.
Nagaraju Kerru Sandeep V.H.S. Bhaskaruni Lalitha Gummidi Surya Narayana Maddila Surjyakanta Rana Parvesh Singh Sreekantha B. Jonnalagadda 《应用有机金属化学》2019,33(5)
An efficient approach for the synthesis of 10 novel pyrazole‐based 1,2,4‐triazolidin‐3‐one derivatives catalyzed by ZnO‐loaded ZrO2 as heterogeneous catalyst with ethanol as solvent is described. The structure of the mixed metal oxide catalyst was characterized by various instrumental techniques (scanning electron microscopy, transmission electron microscopy, X‐ray diffraction and Brunauer–Emmett–Teller). In smooth reactions, products were accomplished in excellent yields (90–94%) with short reaction times (≈ 45 min). ZnO/ZrO2 catalyst exhibited good recyclability. The catalyst is reused six times without any noticeable loss of activity. The major advantages of this method are operational simplicity, mild conditions, simple work‐up procedure and broad functional group tolerance. 相似文献
32.
Dr. Nagaraju Mupparapu Lauren Brewster Katrina F. Ostrom Prof. Sherif I. Elshahawi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(20):e202104614
The late-stage functionalization of indole- and tryptophan-containing compounds with reactive moieties facilitates downstream diversification and leads to changes in their biological properties. Here, the synthesis of two hydroxy-bearing allyl pyrophosphates is described. A chemoenzymatic method is demonstrated which uses a promiscuous indole prenyltransferase enzyme to install a dual reactive hydroxy-bearing allyl moiety directly on the indole ring of tryptophan-containing peptides. This is the first report of late-stage indole modifications with this reactive group. 相似文献
33.
Amorphous aluminophosphate (AlP) and metal‐aluminophosphates (MAlPs, where M=2.5 mol%Cu, Zn, Cr, Fe, Ce, or Zr) were prepared by coprecipitation method. Their surface properties and catalytic activity ... 相似文献
34.
A. S. Pradeep G. J. Nagaraju P. Sarita A. Durga Prasada Rao B. Seetharami Reddy G. Bhagya Rao S. Bhuloka Reddy 《Journal of Radioanalytical and Nuclear Chemistry》2012,294(2):271-276
A number of essential trace elements play a major role in various metabolic pathways and in many diseases like autoimmune, neurological and psychiatric. This study is undertaken with an aim to evaluate the levels of different trace elements in the scalp hair samples of patients suffering from alcohol induced psychosis by particle induced X-ray emission technique (PIXE). It is observed that Fe (p?<?0.0005), Cu (p?<?0.001) are significantly higher in the hair samples of alcohol induced psychosis patients compared to those in normals while concentrations of Mn (p?<?0.005) and Zn (p?<?0.0001) are lower. The concentrations of Co and Ni in the hair samples are found to be in consonance with the concentrations in the normals. 相似文献
35.
Sakkani Nagaraju Kota Sathish Dhurke Kashinath 《Journal of heterocyclic chemistry》2021,58(6):1252-1258
A green, efficient, and one-pot method synthesis of functionalized 4H-chromene-isoxazole hybrids is reported via o-hydroxy group directing cyclization of isoxazole-styrenes and Michael addition of 3,5-dimethyl-4-nitroisoxazole on 2-imino-2H-chromene-3-carbonitrile (independent methods). The developed methodology was further extended for nitromethane, malononitrile, and alkylcyanoacetates as Michael donors. 相似文献
36.
Dongamanti Ashok M. Ram Reddy Katta Ramakrishna Nalaparaju Nagaraju Ravinder Dharavath Madderla Sarasija 《Journal of heterocyclic chemistry》2020,57(6):2528-2534
Herein, we reported a series of new 2-(5-methyl-1-aryl-1H-1,2,3-triazol-4-yl)imidazo[1,2-a]pyridines by using iodine and NH4OAc in good yields. The structures of the titled compounds were characterized by the elemental analysis, 1H NMR, 13C NMR, IR, and mass spectral analysis. All the titled compounds were screened for their in vitro antibacterial and antifungal activities by using streptomycin and Nystatin as standard drugs. The compounds 3k , 3l , 3g , and 3c exhibited potent activity against the tested bacterial strains and 3k , 3l , and 3c exhibited potent activity against the tested fungal strains than the reference drugs. 相似文献
37.
Mavallur Varalakshmi Chamarthi Nagaraju Palaa Krishna 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):853-857
AbstractA series of new class of diethyl N-2-hydroxyethyl-N'-substituted phosphoramidimidates 6(a–e) and diethyl P-morpholino-N-substituted phosphonimidates 6(f–j) was synthesized. The precursor intermediates, diethyl substituted phosphoramidites 3(a–b) were prepared initially by a reaction of various amines 1(a–b) and diethyl phosphorochloridite (2) and then they were treated by in situ with aromatic/alkyl azides through Staudinger reaction to accomplish title products. Structures of all the synthesized compounds were characterized by spectroscopic data such as IR, NMR (1H, 13C, 31P), mass, and elemental analyses. The synthesized compounds were screened for their in vitro antimicrobial activity to understand their biological potency. The biological screening results disclosed that compounds 6b, 6c, 6e, 6g, 6h and 6j having potent antimicrobial activity against all the tested pathogens. 相似文献
38.
The structure of the title compound was determined by the Patterson method and refined to anR of 0·10 for 8065 observed reflections. The crystals are triclinicP1,a=12·408(2),b=13·157(2),c=14·479(8)?, α=74·706(8), β=88·728(9), γ=88·660(13)° withZ=4. The intensity data were collected on an Enraf-Nonius CAD-4 single crystal X-ray diffractometer. The benzoxazaphosphorine
ring adopts a conformation intermediate between a half-chair and a sofa with the phosphoryl oxygen O(2) in an axial and the
2-chlorophenyl andt-butyl groups which aretrans to each other in equatorial positions. The cyclohexyl ring adopts a chair conformation with the nitrogen atomN(5) in an equatorial position. In one conformation of the molecule (I) thet-butyl group atoms and one of the carbon atoms, C(24) in the cyclohexyl ring are disordered. In the other conformation (molecule
II) the 2-chlorophenyl ring adopts a conformation midway between a half-chair and a sofa. The molecular packing involves mainly
van der Waals contacts. 相似文献
39.
Velupula Nagaraju Dasari Sreenath Jammula Tirumala Rao Ramisetti Nageswara Rao 《Analytical sciences》2003,19(7):1007-1011
A simple and rapid high-performance liquid chromatographic method for the separation and determination of process-related impurities of sildenafil was developed. The separation was achieved on a reversed-phase C18 column using acetonitrile-0.05 M potassium dihydrogen orthophosphate (70:30 v/v) as a mobile solvent at a flow rate of 1.0 ml/min and UV detection at 230 nm. The method was used not only for quality assurance, but also for monitoring the chemical reactions during the synthesis of sildenafil. It was found to be specific, precise and reliable for the determination of all process-related impurities of sildenafil in bulk drugs and formulations. 相似文献
40.
Chaitanya Ittamalla Saikrishna Chintha Dr. Nagaraju Medishetti Dr. Jagadeesh Babu Nanubolu Dr. Krishnaiah Atmakur 《European journal of organic chemistry》2023,26(22):e202300357
Synthesis of title compounds were accomplished by a reaction of vinyl malononitriles and arylidene pyrazolones catalyzed by base. This protocol proceeds via Michael addition followed by intramolecular cyclization leading to the formation of two new C−C bonds. Further the same reaction was also conducted with α,α-dicyano olefins and vinyl malononitriles to furnish 1,6-dihydro biphenyl compounds. Simple reaction conditions, high yields and compatibility are the advantages of this protocol. 相似文献