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81.
S2-gated (the second heart sound) method was designed by authors. In 6 normal subjects and 16 patients (old myocardial infarction 12 cases, hypertension 2 cases and aortic regurgitation 2 cases), radioisotope (RI) angiography using S2-gated equilibrium method was performed. In RI angiography, 99mTc-human serum albumin (HSA) 555MBq (15 mCi) as tracer, PDP11/34 as minicomputer and PCG/ECG synchronizer (Metro Inst.) were used. Then left ventricular (LV) volume curve by S2-gated and electrocardiogram (ECG) R wave-gated method were obtained. Using LV volume curve, left ventricular ejection fraction (EF), mean ejection rate (mER, s-1), mean filling rate (mFR, s-1) and rapid filling fraction (RFF) were calculated. mFR indicated mean filling rate during rapid filling phase. RFF was defined as the filling fraction during rapid filling phase among stroke volume. S2-gated method was reliable in evaluation of early diastolic phase, compared with ECG-gated method. There was the difference between RFF in normal group and myocardial infarction (MI) group (p less than 0.005). RFF in 2 groups were correlated with EF (r = 0.82, p less than 0.01). RFF was useful in evaluating MI cases who had normal EF values. The comparison with mER by ECG-gated and mFR by S2-gated was useful in evaluating MI cases who had normal mER values. mFR was remarkably lower than mER in MI group, but was equal to mER in normal group approximately. In conclusion, the evaluation using RFF and mFR by S2-gated method was useful in MI cases who had normal systolic phase indices. 相似文献
82.
Sun XM Manabe K Lam WW Shiraishi N Kobayashi J Shiro M Utsumi H Kobayashi S 《Chemistry (Weinheim an der Bergstrasse, Germany)》2004,11(1):361-368
A synthetic route to enantiomerically pure (1R,2S)-1-phenylphospholane-2-carboxylic acid (1), which is a phosphorus analogue of proline, has been established. A key step is the deprotonation-carboxylation of the 1-phenylphospholane borane complex 3 by using sBuLi/1,2-dipiperidinoethane (DPE). Configurational stability of the key intermediate, the amine-coordinated alpha-phosphinoalkyllithium borane complex 4, was investigated by employing lithiodestannylation-carboxylation of both diastereomers of the 1-phenyl-2-trimethylstannylphospholane borane complex 7 in the presence of several kinds of amines, and as a result, 4 was found to be configurationally labile even at -100 degrees C. The key intermediate, the DPE-coordinated trans-1-phenyl-2-phospholanyllithium borane complex 9, was isolated, and the structure was identified by X-ray crystal structure analysis. This is the first X-ray crystal structure determined for an alpha-monophosphinoalkyllithium borane complex. Remarkably, the alkyllithium complex is monomeric and tricoordinate at the lithium center with a slightly pyramidalized environment, and the existence of a Li--C bond (2.170 A) has been confirmed. Moreover, (1)H-(7)Li HOESY and (6)Li NMR analyses suggested the structure of 9 in solution as well as the existence of an equilibrium between 9, its cis isomer, and the ion pair 8 at room temperature, which was extremely biased towards 9 at -100 degrees C. Finally, 1 was used as a chiral ligand in a palladium-catalyzed allylic substitution, and the desired product was obtained in high yield with good enantioselectivity. 相似文献
83.
Hidefumi Hirai Yukihide Shiraishi Hiroaki Shirai 《Macromolecular rapid communications》1995,16(9):697-701
The one-step synthesis of 2,6-naphthalenedicarboxylic acid from naphthalene with carbon tetrachloride, copper powder and aqueous alkali has been achieved under mild conditions by the use of β-cyclodextrin as catalyst, producing 2,6-naphthalenedicarboxylic acid in 65 mol-% yield with 79% selectivity. 相似文献
84.
85.
Y. Kawabata V. Aparin M. Nagai M. Yamamoto K. Shiraishi Y. Katayama 《Journal of Radioanalytical and Nuclear Chemistry》2008,278(2):459-462
Uranium and thorium concentrations in water and in soil from Kazakhstan have been investigated. In some sampling points the
uranium concentrations of drinking water, exceeded the WHO guideline level for drinking water. Thus, the human effect of uranium
exposure from drinking water in these areas is significant. However, soil samples were the same as in the Nature. Irrigation
systems in these areas would be easy for water carried in the drains mix with groundwater. The results here suggest that the
uranium passes into the groundwater through the agriculture land by the above mechanism. 相似文献
86.
Yasuhiro Shiraishi Ryo Miyamoto Takayuki Hirai 《Journal of photochemistry and photobiology. A, Chemistry》2008,200(2-3):432-437
A simple copolymer, poly(NIPAM-co-RD), consisting of N-isopropylacrylamide (NIPAM) and rhodamine (RD) units, behaves as a fluorescent temperature sensor exhibiting selective fluorescence enhancement at a specific temperature range (25–40 °C) in water. This is driven by a heat-induced phase transition of the polymer from coil to globule. At low temperature, the polymer exists as a polar coil state and shows very weak fluorescence. At >25 °C, the polymer weakly aggregates and forms a less polar domain within the polymer, leading to fluorescence enhancement. However, at >33 °C, strong polymer aggregation leads to a formation of huge polymer particles, which suppresses the incident light absorption by the RD units and shows very weak fluorescence. In the present work, effects of polymer concentration and type of acrylamide unit in the polymer have been investigated. The increase in the polymer concentration in water leads to a formation of less polar domain even at low temperature and, hence, widens the detectable temperature range to lower temperature. Addition of N-n-propylacrylamide (NNPAM) or N-isopropylmethacrylamide (NIPMAM) component to the polymer, which has lower or higher phase transition temperature than that of NIPAM, enables the aggregation temperature of the polymer to shift. This then shifts the detectable temperature region to lower or higher temperature. 相似文献
87.
S. Shiraishi M. Kibe T. Yokoyama H. Kurihara N. Patel A. Oya Y. Kaburagi Y. Hishiyama 《Applied Physics A: Materials Science & Processing》2006,82(4):585-591
The double layer capacitance properties of multi-walled carbon nanotubes (MWCNTs) prepared by CVD were investigated using
propylene carbonate electrolytes. The original MWCNTsare typically entangled tubes with 10∼20 nm outer diameter, around 5 nm
inner diameter, and around 220 m2 g-1 of BET specific surface area. The galvanostatic measurement (40 mA g-1, 2∼4 V vs. Li/Li+) in a three-electrode system showed 15 F g-1 of gravimetric capacitance and a good rate of this property. Due to the tips opening by thermal oxidation, the specific surface
area and the capacitance increased. In contrast, heat-treatment at 3000 °C decreased the surface area and the capacitance
of the MWCNT due to defect recovery. A small amount (<1 at. %) of boron was doped to the MWCNT by heat-treatment at 2200 °C
or 2300 °C with a B-contained graphite crucible. The B-doping can improve the specific capacitance per surface area for the
MWCNTswhile maintaining the tube morphology. This effect of B-doping on the capacitance can be explained by modification of
the space charge layer in carbon.
PACS 81.07.De; 81.65.Mq; 82.47.Uv; 61.72.Vv 相似文献
88.
Masafumi?IdeEmail author Akira?Suguro Yasushi?Hosaka Atsushi?Katsunuma Kouzou?Takahashi Atsushi?Shiraishi 《Optical Review》2004,11(2):132-139
We apply liquid crystal on silicon (LCOS) in 0.8-$mUm standard complementary metal-oxide semiconductor (CMOS) technology to demonstrate a low-cost, high-performance pixelized liquid crystal variable optical attenuator (VOA) with pulse width modulation. We then build a prototype tunable filter by using this VOA along with a grating in the Littrow configuration. With the application of 5-V pulse width modulation, the proposed VOA achieves a 5.6-dB insertion loss, a dynamic range of more than 20 dB, a 50-GHz channel spacing capability, and a polarization-dependent loss (PDL) of less than 0.6 dB at 15-dB attenuation. Our VOA is suitable for applications such as dynamic channel gain equalizers, channel-blocking filters, sub-components of re-configurable add-drop modules, and wavelength selectors. 相似文献
89.
A new configuration is proposed for continuously transforming aspect ratios of field-intensity distributions in optical fibers. The field aspect ratio varies in proportion to the angle between the principal axes of two cascaded graded-index oval-core fibers. The highest aspect-ratio conversion is obtained at an angle of 90 degrees. The conversion effect is numerically and experimentally confirmed, showing that a circular field is successfully transformed into an elliptical one with an aspect ratio as high as 9 at a wavelength of 0.98 microm. 相似文献
90.
Dimerization of planarized diamine 2 using benzoyl peroxide gave dihydrazine 1 in about 70% yield; that is, three dehydrogenations (one CC- and two NN-homocouplings) and two ring closures were attained in one synthetic step. Dihydrazine 1 may be viewed as a chiral pi-conjugated conjoined double helicene, with two homochiral [5]helicene-like fragments, annelated in their mid-sections. A relatively high barrier of approximately 35 kcal mol-1 for inversion of configuration for one of the [5]helicene-like helices in 1 was found. 相似文献