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排序方式: 共有319条查询结果,搜索用时 187 毫秒
31.
Hu HJ Jin EH Yim SH Yang SY Jung SH Shin SH Kim WU Shim SC Kim TG Chung YJ 《Experimental & molecular medicine》2011,43(11):613-621
Although the genetic component in the etiology of rheumatoid arthritis (RA) has been consistently suggested, many novel genetic loci remain to uncover. To identify RA risk loci, we performed a genome-wide association study (GWAS) with 100 RA cases and 600 controls using Affymetrix SNP array 5.0. The candidate risk locus (APOM gene) was re-sequenced to discover novel promoter and coding variants in a group of the subjects. Replication was performed with the independent case-control set comprising of 578 RAs and 711 controls. Through GWAS, we identified a novel SNP associated with RA at the APOM gene in the MHC class III region on 6p21.33 (rs805297, odds ratio (OR) = 2.28, P = 5.20 × 10-7). Three more polymorphisms were identified at the promoter region of the APOM by the re-sequencing. For the replication, we genotyped the four SNP loci in the independent case-control set. The association of rs805297 identified by GWAS was successfully replicated (OR = 1.40, P = 6.65 × 10-5). The association became more significant in the combined analysis of discovery and replication sets (OR = 1.56, P = 2.73 × 10-10). The individuals with the rs805297 risk allele (A) at the promoter region showed a significantly lower level of APOM expression compared with those with the protective allele (C) homozygote. In the logistic regressions by the phenotype status, the homozygote risk genotype (A/A) consistently showed higher ORs than the heterozygote one (A/C) for the phenotype-positive RAs. These results indicate that APOM promoter polymorphisms are significantly associated with the susceptibility to RA. 相似文献
32.
We consider the topology of the BS causal completion, and show that it is not distorted in the causal direction. Using this
result, we show that the causal completion with spacelike causal boundary in the sense of the BS construction satisfies the
formal definition of the global hyperbolicity. We also show that any two causally related points in the causal completion
can be connected by a causal geodesic. 相似文献
33.
Young Boo Kim Soon Seok Lee Chang Hwan Oh Young Sun Kim Chimoon Han Chu Hwan Yim 《ETRI Journal》1996,18(3):107-125
In this paper, we define the general requirements of ATM switching systems such as scalability, distributed fashion, and modularity. Also we propose a practical implementation of a scalable ATM switching system whose capacity can be easily expanded. Firstly, the architecture of the system is discussed with an emphasis on system scalability, modularity of subsystems and the simple control network of the design requirements. Secondly, we suggest the three types of distributed call/connection control schemes that are suitable for our switching system. We also estimate their call processing capacity on the average and make a comparison of them under the various system architectures. Since our scalable switching system can be constructed to perform the call processing functions on the various levels of the system capacity, it has much adaptability at the various evolution phases or regions of the network environment. 相似文献
34.
A new pteridine compound was isolated from green sulfur photosynthetic bacteria, Chlorobium limicola f. thiosulfatophilum NCIB 8327. The structure of this pterin derivative was established to be 1-O-(L -erythro-5,6,7,8- tetrahydropterin-2′-yl)-β-N-acetylglucosamine ( 1 ) from 1H-NMR and CD spectra as well as from various mass spectrometric techniques and chemical-cleavage techniques. Upon acid hydrolysis of 1 , equimolar amounts of biopterin ( 2 ) and N-acetylglucosamine were produced. The structure of the hydrolysis product 2 was confirmed by comparing its NMR, UV, CD, and MS and its chromatographical behavior with those of an authentic specimen. N-Acetylglucosamine was identified by an enzymatic hydrolysis experiment as well as by NMR and thin layer chromatography. Electrospray (ES), fast-atom-bombardment (FAB), and thermospray (TS) mass spectrometry of 1 yielded an MH+ at m/z 441. Periodate-oxidation experiments of the intact molecule 1 and of its hydrolysis product 2 are consistent with the proposed structure. Differential I2 oxidation experiments with the native compound showed that the in vivo oxidation state of this pterin is its tetrahydro form. We propose the trivial name ‘limipterin’ for this new compound. 相似文献
35.
Ki Won Sung Chae Y. Lee Kwang Hyuk Yim Agnes Gravrand 《Wireless Personal Communications》2009,50(4):469-481
Traffic asymmetry between uplink and downlink is expected to be a remarkable 3G characteristic in cellular mobile multimedia
communications. CDMA system with TDD is a good solution to this traffic asymmetry. However, the level of traffic asymmetry
may be significantly different from a cell to another cell. To tackle this problem and to support the traffic hot spot, crossed
slots are examined. The use of crossed slots is restricted within a certain range of a cell by investigating the inter-cell
interference and the maximum planned load factor. We examine the radius of inner zone and discuss the capacity of downlink
crossed slots for various neighbor cell environments. Computational results show that the capacity increase in the target
cell is outstanding by reducing the service range of neighbor cells. When all six neighbors reduce their service range by
20%, the capacity at target cell crossed slot is increased by 35%. Monte Carlo simulation is performed with large scale fading
to verify the numerical analysis.
相似文献
Chae Y. LeeEmail: |
36.
Sonochemical degradation of dilute aqueous solutions of 2-, 3- and 4-chlorophenol and pentachlorophenol has been investigated under air or argon atmosphere. The degradation follows first-order kinetics in the initial state with rates in the range 4.5-6.6 microM min-1 under air and 6.0-7.2 microM min-1 under argon at a concentration of 100 microM of chlorophenols. The rate of OH radical formation from water is 19.8 microM min-1 under argon and 14.7 microM min-1 under air in the same sonolysis conditions. The sonolysis of chlorophenols is effectively inhibited, but not completely, by the addition of t-BuOH, which is known to be an efficient OH radical scavenger in aqueous sonolysis. This suggests that the main degradation of chlorophenols proceeds via reaction with OH radicals; a thermal reaction also occurs, although its contribution is small. The addition of appropriate amounts of Fe(II) ions accelerates the degradation. This is probably due to the regeneration of OH radicals from hydrogen peroxide, which would be formed from recombination of OH radicals and which may contribute a little to the degradation. The ability to inhibit bacterial multiplication of pentachlorophenol decreases with ultrasonic irradiation. 相似文献
37.
C.I. Calle P.J. Mackey M.D. Hogue M.R. Johansen H. Yim P.B. Delaune J.S. Clements 《Journal of Electrostatics》2013,71(3):257-259
Electrodynamic Dust Shields (EDS) have been in development at NASA as a dust mitigation method for lunar and Martian missions. An active dust mitigation strategy, such as that provided by the EDS, that can remove dust from surfaces, is of crucial importance to the planetary exploration program. We report on the development of a flight experiment to fully expose four EDS panels to the space environment. This flight experiment is part of the Materials International Space Station experiment X (MISSE-X), an external platform on the International Space Station that will expose materials to the space environment. 相似文献
38.
39.
AbstractIn the course of our continuing investigation of bioactive secondary metabolites from marine-derived fungal strains, a racemate of a novel diphenolic derivative named (±)-tylopilusin D (1) along with ten previously known secondary metabolites (2–11) were isolated from a marine-derived fungal strain Aspergillus sp. SF-5929. Their structures were elucidated mainly by analysis of NMR and MS data. In addition, the inhibitory effects of the isolated compounds against protein tyrosine phosphatase 1B (PTP1B) activity were evaluated, and compounds 1, 2, and 5–7 inhibited PTP1B activity with IC50 values ranging from 3.3 to 8.1?µM. Kinetics studies suggested that compounds 1, 2, and 5 had noncompetitive inhibitory effects against PTP1B. 相似文献
40.