全文获取类型
收费全文 | 133篇 |
免费 | 1篇 |
专业分类
化学 | 117篇 |
物理学 | 17篇 |
出版年
2023年 | 2篇 |
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2017年 | 1篇 |
2015年 | 3篇 |
2014年 | 5篇 |
2013年 | 5篇 |
2012年 | 9篇 |
2011年 | 9篇 |
2010年 | 8篇 |
2009年 | 2篇 |
2008年 | 10篇 |
2007年 | 7篇 |
2006年 | 10篇 |
2005年 | 10篇 |
2004年 | 14篇 |
2003年 | 3篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1997年 | 1篇 |
1994年 | 1篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1977年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有134条查询结果,搜索用时 15 毫秒
81.
82.
Yusuke Kuramochi Dr. Atula S. D. Sandanayaka Dr. Akiharu Satake Prof. Yasuyuki Araki Prof. Kazuya Ogawa Prof. Osamu Ito Prof. Yoshiaki Kobuke Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(10):2317-2327
A mimic for nature's solar cells : Simple mixing of nonaporphyrin macrocycle N‐( 1 –Zn)3 and acceptor ligand C60–ZnP–Tripod affords a supramolecular architecture (see scheme), in which the excitation energy collected by the macrocycle is transferred efficiently to the central ZnP acceptor, inducing charge separation between the ZnP and C60 sites.
83.
Amidosulfuric acid and sodium carbonate as standards for acid–base titrimetry were assayed by coulometric titration and gravimetric
titration. Amidosulfuric acid was directly assayed by coulometric titration with electrogenerated hydroxide ions, and sodium
carbonate was assayed by gravimetric back-titration. For sodium carbonate, excess amount of sulfuric acid, whose concentration
was determined by coulometric titration, was added to sodium carbonate, and then gravimetrically back-titrated using a sodium
hydroxide solution whose concentration was determined by gravimetric titration using the sulfuric acid. The accuracy of the
coulometric titration for amidosulfuric acid and sulfuric acid was evaluated by examining the current efficiency of pulse
electrolysis, the amount of the electrolysis current used, and the time spent for a titration. In addition, the drying conditions
for high purity primary standards have a significant effect on the titration results due to changes in the acid–base assay.
The suitable drying conditions for amidosulfuric acid and sodium carbonate were evaluated by mass-change measurements, coulometric
titration and gravimetric titration. The measurement uncertainties were estimated from the uncertainties on the titration
processes. Finally, the assays of amidosulfuric acid and sodium carbonate were 99.986% ± 0.010% (k = 2) after drying at 50 °C for 2 h, and 99.970% ± 0.016% (k = 2) after drying at 280 °C for 4 h, respectively. In addition, the international consistency was confirmed by measuring
certified reference materials (CRMs) available from different National Metrology Institutes, and the compatibility of values
among CRMs was experimentally ascertained. 相似文献
84.
85.
Role of heavy fermions and heavy Higgs scalars in the electroweak correction to the MW − MZ relation
Zenrō Hioki 《Nuclear Physics B》1983,229(2):284-300
The role of heavy fermions and heavy Higgs-scalars in the MW ? MZ relation resulting from the one-loop-corrected μ decay width Γ(1) and its experimental data Γexp is studied in the framework of the standard electroweak theory. Exact and approximate formulae are both given for these heavy particle effects. The quadratic dependence of Γ(1) on large fermion mass mheavy gives a positive contribution to the calculation of MW from Γ(1) = Γexp for a given MZ, and cancels the light fermion contributions of the form ~ αln(mlight/MW) at the value of mheavy ~ 200 GeV. On the other hand, the Higgs mass dependence of the calculation is, at best, logarithmic, and does not produce visible effects. Applications for deriving constraints for the top-quark mass (or heavier fermion mass) are discussed, and a concrete example is given of the relation between experimental uncertainties in measurements of MW,Z and the corresponding allowed region for mt. 相似文献
86.
Ochiai H Ishida A Ohtani T Kusumi K Kishikawa K Yamamoto S Takeda H Obata T Nakai H Toda M 《Chemical & pharmaceutical bulletin》2004,52(9):1098-1104
A series of 4-anilinopyrazolopyridine derivatives were synthesized and biologically evaluated as inhibitors of phosphodiesterase (PDE4). Chemical modification of 3, a structurally new chemical lead that was found in our in-house library, was focused on 1- and 3-substituents. Full details of the discovery of a new orally active chemical lead 5 are presented. Structure-activity relationship data, pharmacological evaluation, and the subtype selectivity study are also presented. 相似文献
87.
88.
Coulometric titrations with three electrochemical end-point detection methods were performed to assay potassium dichromate
as a standard for oxidation–reduction titration. The assay as an oxidizing agent was carried out with ferrous ions produced
by electrolytically reducing ferric ions. Three end-point detection methods were employed and compared with each other: constant
potential amperometry, potentiometry, and constant voltage biamperometry (a dead-stop method). The last one was found to provide
high accuracy in the coulometric titration of potassium dichromate. Solution form samples were also measured to confirm the
possible existence of chromium(III) in potassium dichromate by both coulometric titration and ion-exchange chromatography
with inductively coupled plasma time-of-flight mass spectrometry. 相似文献
89.
Hideaki Hioki Kimihito MatsushitaTakeshi Noda Kota YamaguchiMiwa Kubo Kenichi HaradaYoshiyasu Fukuyama 《Tetrahedron letters》2012,53(33):4337-4342
An alkoxyamine linker was applied for the solid-phase synthesis of benzothiazoles. The substrate was anchored by aldoxime linkage and products were cleaved from the solid-support by aldoxime-imine exchange coupled with air-oxidation under the weakly acidic conditions. The tether is highly robust under Mitsunobu reaction, nucleophilic substitution reaction, and Pd-catalyzed reaction conditions. 相似文献