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排序方式: 共有713条查询结果,搜索用时 32 毫秒
191.
Keisuke Matsuoka Aki Yonekawa Mariko Ishii Chikako Honda Kazutoyo Endo Yoshikiyo Moroi Yutaka Abe Takamitsu Tamura 《Colloid and polymer science》2006,285(3):323-330
Under the limiting conditions, light-scattering method was applied to determine the size and shape of fluorinated micellar structure in aqueous solution. The hydrodynamic radii (r
h) of molecular aggregates were investigated for four amphiphiles with different alkyl chain length: N-(1,1-dihydroperfluorooctyl)-, N-(1,1-dihydroperfluorodecyl)-, N-(1,1-dihydroperfluorododecyl)-, and N-(1,1-dihydroperfluorotetradecyl)-N,N,N-trimethylammonium chloride by dynamic light scattering. Size of these molecular aggregates drastically increased with increasing carbon number of alkyl chain and the concentration. For example, the r
h values were 35, 63, 95, and 136 nm for C8, C10, C12, and C14 of the alkyl chain, respectively, at the concentration of 15× critical micelle concentration (cmc) and at 298.2 K. On the other hand, the mean radius of gyration (r
g) and the apparent molecular weight of these aggregates were measured using static light scattering. The r
g value was found to be 34, 73, and 125 nm for C8, C10, and C12 of the alkyl chain, respectively, at the same condition above. The shape of aggregate was analyzed by comparing the dependence of r
g/r
h with theoretical values. The plots of r
g against r
h almost corresponded with the theoretical line of oblate ellipsoid (disk-like), and which was also expected from calculation of packing parameter value. The measurement for chloride ion activity was made by a chloride ion selective electrode to know the degree of counterion binding to the aggregates, whose values increased with increasing total concentration and with the carbon number of alkyl chain. The chloride ion binding to aggregates neutralized cationic head groups under their electrostatic repulsion and partly promoted the growth of aggregates. 相似文献
192.
Junpei Kuwabara 《Journal of organometallic chemistry》2005,690(2):269-275
[(η5-C5H5)ZrCl2(η5-C5H4)CMe2(C5H5)] reacted with Co2(CO)8 to produce a heterodinuclear Zr(IV)-Co(I) complex [(η5-C5H5)ZrCl2(η5-C5H4)CMe2(η5-C5H4)Co(CO)2] (3). Complex 3 underwent oxidative addition of I2 to give [(η5-C5H5)ZrCl2(η5-C5H4)CMe2(η5-C5H4)CoI2(CO)] (4) having Zr(IV) and Co(III) centers. The carbonyl ligand of 4 was easily replaced with P(OMe)3 and PPh3 to afford [(η5-C5H5)ZrCl2(η5-C5H4)CMe2(η5-C5H4)CoI2(L)] (5: L = P(OMe)3, 6: L = PPh3). Structures of 5 and 6 were determined by X-ray crystallography. These Zr-Co heterodinuclear complexes catalyzed polymerization of ethylene and propylene. 相似文献
193.
Four enantiomerically pure new alpha-tetralones, (4S)- and (4R)-5-hydroxy-4-methoxy-alpha-tetralones and (4S)- and (4R)-5,8-dihydroxy-4-methoxy-alpha-tetralones were isolated, together with five known ones, (4S)- and (4R)-4,8-dihydroxy-alpha-tetralones, (4S)-4,8-dihydroxy-5-methoxy-alpha-tetralone and (4S)- and (4R)-4-hydroxy-alpha-tetralones, from the fruit of Juglans mandshurica MAXIM. var. sieboldiana MAKINO. Their structures were established on the basis of spectral analysis. To the best of our knowledge, this is the first isolation of the (4R)-4-hydroxy-alpha-tetralone derivative from Juglans species. 相似文献
194.
H. Kawamura H. Tagomori N. Matsuoka Y. Takashima S. Tawaki N. Momoshima 《Journal of Radioanalytical and Nuclear Chemistry》1999,242(3):717-720
Microwave digestion was applied as pretreatment of environmental samples for the determination of lead isotope ratios by ICP-MS.
Microwave digestion decomposed the samples easily and rapidly without lead contamination. The lead isotope ratios could be
measured directly by ICP-MS without tedious lead purification, because the influence of the matrix elements on measurements
of lead isotope ratios is small enough to be ignored. 相似文献
195.
196.
K. Schwarz C. Samanta M. Fujiwara H. Rebel R. De Leo N. Matsuoka H. Utsunomiya H. Akimune I. Daito H. Fujimura F. Ihara K. Ishibashi Y. Maeda T. Yamanaka H. Yoshida A. Okihana T. Yoshimura P.K.J. van Aarle W.A.T. Uijen M. Ito Y. Sakuragi 《The European Physical Journal A - Hadrons and Nuclei》2000,7(3):367-375
Elastic scattering and inclusive breakup of 6Li particles on 12C, 58Ni, 90Zr, and 208Pb targets are measured at 100A MeV. The elastic scattering data are compared with single channel and Coupled Discretized
Continuum Channels calculations. The coupling-effect between the elastic and the breakup channels is important even at an
incident energy of 100A MeV and cannot be neglected. The inclusive breakup data are investigated for orbital dispersion effects
which are found to be less significant at 100A MeV. The longitudinal momentum distributions are broader than predicted by
theoretical expectations.
Received: 17 December 1999 / Revised version: 9 February 2000 相似文献
197.
Solid phase absorptiometry was applied to the simultaneous flow analysis of trace metals in combination with a micro black flow-through cell packed with ion exchanger beads and a multi-channel photodetector connected with optical fibers. A 4.0 cm3 sample solution containing five rare earth metal ions (Dy, Ho, Tm, Er and Nd) was introduced into a flow system and these metal ions were concentrated on a cation exchanger (Muromac 50W-X4) in a flow-through cell. The absorbance increases originating from the f-f or d-f transition bands of these metal ions were directly and continuously measured at 910 nm for Dy, at 530 nm for Ho, at 683 nm for Tm, 522 nm for Er and at 790 nm for Nd, respectively. A multi-variable analysis method was combined with the flow analysis because the absorption spectra of the five rare earth metal ions partly overlapped one another. Although no coloring reagents were used, the proposed method was about ¶200 times more sensitive than the corresponding solution method. The reproducibility of this method was less than ± 5%. The detection limits were 0.03, 0.40, 0.30, 0.35 and 0.23 mg dm–3 for Dy, Ho, Tm, Er and Nd, respectively. Five rare earth metal ions could be precisely determined in practical samples such as yttrium concentrate. 相似文献
198.
Atsushi Okamoto Hisashi Matsuoka Motoki Saito Yoshihisa Takayama Mototsugu Takamura 《Optical Review》1999,6(3):189-195
We propose a new optical network device photorefractive connection module (PRCM) which operates as optical switch, amplifier and signal distributor controlled by parallel optical signals. Simple optical control bus systems can be realized by cascade connection of PRCMs. PRCM branches off a desired channel from the spatial multiplexed optical bus line by appropriate setting of the control beam pattern. PRCM uses cross polarized four wave mixing (CPFWM) with extraordinary polarized writing beams and an ordinary polarized reading beam to achieve a high connection gain to the next PRCM stage. We analyze the phase matching angle of CPFWM in which the optical paths of two pump beams are slightly different. The phase conjugate reflectivity indicating a branching ratio of optical signal is derived and calculated in consideration of the phase mismatching Δk. The optimum pump ratio and the grating vector orientation for the largest phase conjugate reflectivity and signal amplification factor are discussed for optical design of PRCM. Since the measured signal beam power after passing through the BaTiO3 crystal is three or four times higher than its incident power, PRCM has a sufficient connection gain for optical bus and interconnection systems. 相似文献
199.
Shota INOUE Hideki MORIYAMA Yoshio WAKIMOTO Changxin LI Junpei HATAKEYAMA Taisei WAKIGAWA Yoshitada SAKAI Toshihiro AKISUE 《Physical Therapy Research》2020,23(2):113
Objective: Joint contractures are a major complication following joint immobilization. However, no fully effective treatment has yet been found. Recently, carbon dioxide (CO2) therapy was developed and verified this therapeutic application in various disorders. We aimed to verify the efficacy of transcutaneous CO2 therapy for immobilization-induced joint contracture. Method: Twenty-two Wistar rats were randomly assigned to three groups: caged control, those untreated after joint immobilization, and those treated after joint immobilization. The rats were treated with CO2 for 20 min once a daily either during immobilization, (prevention) or during remobilization after immobilization (treatment). Knee extension motion was measured with a goniometer, and the muscular and articular factors responsible for contractures were calculated. We evaluated muscle fibrosis, fibrosis-related genes (collagen Type 1α1 and TGF-β1) in muscles, synovial intima''s length, and fibrosis-related proteins (Type I collagen and TGF-β1) in the joint capsules. Results: CO2 therapy for prevention and treatment improved the knee extension motion. Muscular and articular factors decreased in rats of the treatment group. The muscular fibrosis of treated rats decreased in the treatment group. Although CO2 therapy did not repress the increased expression of collagen Type 1α1, the therapy decreased the expression of TGF-β1 in the treatment group. CO2 therapy for treatment improved the shortening of the synovial membrane after immobilization and decreased the immunolabeling of TGF-β1 in the joint capsules. Conclusions: CO2 therapy may prevent and treat contractures after joint immobilization, and appears to be more effective as a treatment strategy for the deterioration of contractures during remobilization. 相似文献
200.
Validation of real-time PCR analyses for line-specific quantitation of genetically modified maize and soybean using new reference molecules 总被引:12,自引:0,他引:12
Shindo Y Kuribara H Matsuoka T Futo S Sawada C Shono J Akiyama H Goda Y Toyoda M Hino A 《Journal of AOAC International》2002,85(5):1119-1126
Novel analytical methods based on real-time quantitative polymerase chain reactions by use of new reference molecules were validated in interlaboratory studies for the quantitation of genetically modified (GM) maize and soy. More than 13 laboratories from Japan, Korea, and the United States participated in the studies. The interlaboratory studies included 2 separate stages: (1) measurement tests of coefficient values, the ratio of recombinant DNA (r-DNA) sequence, and endogenous DNA sequence in the seeds of GM maize and GM soy; and (2) blind tests with 6 pairs of maize and soy samples, including different levels of GM maize or GM soy. Test results showed that the methods are applicable to the specific quantitation of the 5 lines of GM maize and one line of GM soy. After statistical treatment to remove outliers, the repeatability and reproducibility of these methods at a level of 5.0% were <13.7 and 15.9%, respectively. The quantitation limits of the methods were 0.50% for Bt11, T25, and MON810, and 0.10% for GA21, Event176, and Roundup Ready soy. The results of blind tests showed that the numerical information obtained from these methods will contribute to practical analyses for labeling systems of GM crops. 相似文献