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61.
Cell Penetrating Synthetic Antimicrobial Peptides (SAMPs) Exhibiting Potent and Selective Killing of Mycobacterium by Targeting Its DNA
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Aashish Sharma Amol Arunrao Pohane Dr. Sandhya Bansal Dr. Avinash Bajaj Dr. Vikas Jain Dr. Aasheesh Srivastava 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(9):3540-3545
Naturally occurring antimicrobial peptides (AMPs) are powerful defence tools to tackle pathogenic microbes. However, limited natural production and high synthetic costs in addition to poor selectivity limit large‐scale use of AMPs in clinical settings. Here, we present a series of synthetic AMPs (SAMPs) that exhibit highly selective and potent killing of Mycobacterium (minimum inhibitory concentration <20 μg mL?1) over E. coli or mammalian cells. These SAMPs are active against rapidly multiplying as well as growth saturated Mycobacterium cultures. These SAMPs are not membrane‐lytic in nature, and are readily internalized by Mycobacterium and mammalian cells; whereas in E. coli, the lipopolysaccharide layer inhibits their cellular uptake, and hence, their antibacterial action. Upon internalization, these SAMPs interact with the unprotected genomic DNA of mycobacteria, and impede DNA‐dependent processes, leading to bacterial cell death. 相似文献
62.
Lead borate glasses containing 30 to 60?mol% PbO were prepared by melt quenching technique and devitrified by long duration heat treament in the supercooled region. Glasses crystallized on heating above their glass transition temperature, and the crystalline phases produced on devitrification were characterized by XRD and DSC analyses. Glass with 30?mol% PbO slowly formed a solid solution of Pb6B10O21 and Pb5B8O17 crystalline phases, while glasses with 40 and 50?mol% PbO formed a mixture of Pb6B10O21, Pb5B8O17 and the remanent glassy phase. Glasses with higher PbO concentration of 56 to 60?mol% devitrified completely and produced only Pb5B8O17 crystalline phase. Lead borate glasses with PbO concentration of 40 to 50?mol% showed maximum thermal stability against devitrification, the ease of crystallization of glasses was correlated with the fraction of tetrahedral borons in them. 相似文献
63.
64.
In this paper,we present a stable,reliable and robust method for reconstructing a three dimensional density function from a set of two dimensional electric tomo... 相似文献
65.
66.
S. H. R. Abdi R. I. Kureshy N. H. Khan V. J. Mayani H. C. Bajaj 《Catalysis Surveys from Asia》2009,13(2):104-131
This review is based on dimeric and polymeric chiral Schiff base metal complexes and chiral BINOL supported metal complexes
as potential recyclable catalysts for kinetic resolution of racemic and meso epoxide and asymmetric C–C bond formation reactions e.g., asymmetric addition of diethylzinc to aldehydes, enantioselective
addition of phenylacetylene to aldehydes, asymmetric nitro-Aldol reactions and asymmetric cyanation reaction. 相似文献
67.
Tetrahydropyran (THP) undergoes photodissociation on excitation with ArF laser at 193 nm, generating OH radical as one of the transient photoproducts. Laser-induced fluorescence technique is used to detect the nascent OH radical and measure its energy state distribution. The OH radical is formed mostly in the ground vibrational level (v"=0), with low rotational excitation. The rotational distribution of OH (v"=0,J) is characterized by a temperature of 433+/-31 K, corresponding to a rotational energy of 0.86+/-0.06 kcalmol. Two Lambda-doublet levels, 2Pi+(A') and 2Pi-(A"), and the two spin-orbit states, the 2Pi(3/2) and 2Pi(1/2), of OH are populated statistically for all rotational levels. The relative translational energy associated with the photoproducts in the OH channel is calculated to be 21.9+/-3.2 kcal mol(-1), from the Doppler-broadened linewidth, giving an ft value of approximately 43%, and most of the remaining 57% of the available energy is distributed in the internal modes of the other photofragment, C5H9. The observed distribution of the available energy is explained well, using a hybrid model of energy partitioning, with an exit barrier of 40 kcal mol(-1). The potential-energy surface of the reaction channel was mapped by ab initio molecular-orbital calculations. Based on experimental and theoretical results, a mechanism for OH formation is proposed. Electronically excited THP relaxes to the ground electronic state, and from there, a sequence of reactions takes place, generating OH. The proposed mechanism first involves C-O bond scission, followed by a 1,3 H atom migration to O atom, and finally, the C-OH bond cleavage giving OH. 相似文献
68.
Noor-ul H. Khan S. Saravanan Rukhsana I. Kureshy Sayed H.R. Abdi Arghya Sadhukhan Hari C. Bajaj 《Journal of organometallic chemistry》2010,695(8):1133-6983
Chiral dimeric vanadium (V) salen complex (10 mol%) derived from 5,5-Methylene di-[(S,S)-{N-(3-tert-butyl salicylidine)-N′-(3′,5′-di-tert-butyl salicylidene)]-1,2-cyclohexanediamine] with vanadyl suphate followed by auto oxidation was used as efficient catalyst for enantioselective Strecker reaction of N-benzylimines with TMSCN at −30 °C. Excellent yield (92%) of α-aminonitrile and high chiral induction was achieved (ee up to 94%) in case of 2-methoxy substituted N-benzylimines in 10 h. The catalytic system worked well up to four cycles with retention of enantioselectivity. 相似文献
69.
Relationship between topochemical indices and inhibition of CDK2/cyclin A by 3-aminopyrazoles was investigated using a data set comprising of 42 3-aminopyrazoles. Three topochemical indices--the Wiener's topochemical index--a distance based topochemical index, atomic molecular connectivity index--an adjacency based topochemical index and superadjacency topochemical index--an adjacency-cum-distance based topochemical index were used for the present investigations. The values of Wiener's topochemical index, atomic molecular connectivity index and superadjacency topochemical index for each of the 42 compounds comprising the data set were computed using an in-house computer program. Resultant data was subsequently analyzed and suitable models were developed after identification of the active ranges. Subsequently, a biological activity was assigned to each of the compounds using these models, which was then compared with the reported CDK2/cyclin A inhibitory activity. High accuracy of prediction ranging from 86 to 89% was observed using these models. 相似文献
70.
Ramachandran R Ladizhansky V Bajaj VS Griffin RG 《Journal of the American Chemical Society》2003,125(50):15623-15629
The rotational resonance width (R2W) experiment is a constant-time version of the rotational resonance (R2) experiment, in which the magnetization exchange is measured as a function of sample spinning frequency rather than the mixing time. The significant advantage of this experiment over conventional R2 is that both the dipolar coupling and the relaxation parameters can be independently and unambiguously extracted from the magnetization exchange profile. In this paper, we combine R2W with two-dimensional 13C-13C chemical shift correlation spectroscopy and demonstrate the utility of this technique for the site-specific measurement of multiple 13C-13C distances in uniformly labeled solids. The dipolar truncation effects, usually associated with distance measurements in uniformly labeled solids, are considerably attenuated in R2W experiments. Thus, R2W experiments are applicable to uniformly labeled biological systems. To validate this statement, multiple 13C-13C distances (in the range of 3-6 A) were determined in N-acetyl-[U-13C,15N]l-Val-l-Leu with an average precision of +/-0.5 A. Furthermore, the distance constraints extracted using a two-spin model agree well with the X-ray crystallographic data. 相似文献