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排序方式: 共有85条查询结果,搜索用时 31 毫秒
1.
Reconstitution of Biosynthetic Machinery for the Synthesis of the Highly Elaborated Indole Diterpene Penitrem 下载免费PDF全文
Dr. Chengwei Liu Koichi Tagami Dr. Atsushi Minami Tomoyuki Matsumoto Jens Christian Frisvad Hideyuki Suzuki Jun Ishikawa Katsuya Gomi Prof. Dr. Hideaki Oikawa 《Angewandte Chemie (International ed. in English)》2015,54(19):5748-5752
Penitrem A is one of the most elaborated members of the fungal indole diterpenes. Two separate penitrem gene clusters were identified using genomic and RNA sequencing data, and 13 out of 17 transformations in the penitrem biosynthesis were elucidated by heterologous reconstitution of the relevant genes. These reactions involve 1) a prenylation‐initiated cationic cyclization to install the bicyclo[3.2.0]heptane skeleton (PtmE), 2) a two‐step P450‐catalyzed oxidative processes forming the unique tricyclic penitrem skeleton (PtmK and PtmU), and 3) five sequential oxidative transformations (PtmKULNJ). Importantly, without conventional gene disruption, reconstitution of the biosynthetic machinery provided sufficient data to determine the pathway. It was thus demonstrated that the Aspergillus oryzae reconstitution system is a powerful method for studying the biosynthesis of complex natural products. 相似文献
2.
Cover Picture: Reconstitution of Biosynthetic Machinery for the Synthesis of the Highly Elaborated Indole Diterpene Penitrem (Angew. Chem. Int. Ed. 19/2015) 下载免费PDF全文
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Miyazaki H. Kato J. Kawai S. Hatayama H. Uchida K. Otsuki M. Tagami J. Yokoo S. 《Laser Physics》2011,21(12):2128-2131
This study evaluated the surgical performance of a 405-nm diode laser in vivo, using living rat liver tissue. Tissue was incised
by irradiation with the laser at low output power ranging from 1 W (722 W/cm2) to 3 W (2165 W/cm2) on a manual control at a rate of 1 mm/s. As a control, incisions using a stainless scalpel were compared. Immediately after
operation, the surface of the incisions was macroscopically observed and histopathologically evaluated by microscopy. Laser-ablated
liver tissue was smooth with observable signs of remnant carbonization and easily acquired hemostasis. The thickness of the
denatured layer increased in proportion to the output power; the coagulation layer did not thicken accordingly. Bleeding could
not be stopped for tissues incised with the stainless scalpel. The 405-nm diode laser thus proved to be effective for ablating
soft tissue with high hemostatic ability at low power. 相似文献
5.
The degradation of SNR caused by the higher uniaxial crystalline anisotropy field (Hk) of medium and small write fields of narrower write width is one of the problems for achieving higher areal density. The SNR dependence on Hk of a medium with different write fields of head using the discrete track medium (DTM) is investigated by using micromagnetics simulation. As a result, the curves of SNR as a function of Hk have peak values. In DTM, the peak values of SNR are almost constant at any Hk of the medium and different write fields. Higher SNR is realized even at low Hk and small write field in DTM. 相似文献
6.
An two-electrode molecular bridge model that consists of two benzene rings was presented. The characteristics of electronic transport through the nano-molecular bridge was investigated theoretically by using the tight binding approach based on the Green’s function with only one π orbital per carbon atom at the site. Electronic transport probabilities through the molecular bridge from the input to the output terminal were obtained. The electronic current distributions inside the molecular bridge were calculated and shown in graphical analogy by the current density method based on Fisher-Lee formula at the energy points E=±0.68 and E=±1.38 where the peaks of transport probabilities appeared, and the maximum bond electronic current was also presented. The reason why the loop current in the benzene ring is induced by the phase difference within the molecular orbits is explained. 相似文献
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K. Tagami S. Uchida M. García-León 《Journal of Radioanalytical and Nuclear Chemistry》1998,234(1-2):147-151
Results of99Tc measurements between radiation and non-radiation counting methods were compared using four radiation sources for which99Tc has been previously determined with a gas-flow proportional counter or a GM counter. Each99Tc source consisted of a stainless steel planchet bound by mylar films. Seaweeds collected from the Irish Sea were analyzed
and99Tc was electroplated on the planchet. The99Tc in each sample was separated and measured again by inductively coupled plasma mass spectrometry (ICP-MS). Tc was continuously
removed from each sample with 2M HNO3 and 2M NaOH. After the solution containing Tc was adjusted to 0.1M HNO3, Tc was extracted on a novel extraction chromatographic resin to separate it from Ru. The total recoveries for Tc on the
planchet samples were almost the same with an average of 91%. The results of99Tc measurements by both radiation and non-radiation counting methods agreed well with each other. 相似文献
10.
Y. Muramatsu K. Tagami S. Uchida 《Journal of Radioanalytical and Nuclear Chemistry》1994,188(4):305-311
Measurements of some selected radionuclides were carried out in rain waters collected from Ibaraki Prefecture, Japan, following the nuclear accident at Tomsk-7, Russian Federation, in April 1993. The concentrations obtained for artificial radionuclides were90Sr1.8 mBq l–1,137Cs0.1 Bq l–1,131I0.1 Bq l–1 and129I4 Bq l–1. Uranium (238U) concentrations in rainfalls in April 1993 were 6.3–39 ng l–1. These data were compared to control values obtained previously and there was no appreciable influence on the radioactivity levels in Japan after the Tomsk-7 accident. Since only limited data on the concentrations of129I and uranium in rain water are available, these new analytical results contribute to understanding the background levels for these nuclides. 相似文献