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251.
The 5- and/or 6-alkyl substituted derivatives of 2-aminopyridine-3-carbonitrile were synthesized via dienamine intermediates (3) produced by the addition-elimination reaction of various enamines to methoxymethylene malondinitrile. The reaction can be carried out without the isolation of the dienamine intermediates. 相似文献
252.
Thallada Bhaskar William J. Hall Akinori Muto Yusaku Sakata 《Polymer Degradation and Stability》2007,92(2):211-221
The pyrolysis of polyethylene(PE)/polypropylene(PP)/polystyrene(PS) mixed with high impact polystyrene (HIPS-Br) containing decabromo diphenylethane (DDE) as a brominated flame retardant with antimony trioxide as a synergist was performed under controlled temperature programmed pyrolysis (two steps) conditions to understand the decomposition behaviour and evolution of brominated hydrocarbons from flame-retardant additives. The liquid products were extensively analyzed by gas chromatographs equipped with FID, ECD, MSD, TCD, AED and FT-IR. The solid residue samples were analyzed by powder X-ray diffraction and combustion followed by ion-chromatography. The controlled pyrolysis of PE/PP/PS/HIPS-Br significantly affected the decomposition behaviour of HIPS-Br and subsequently the formation of decomposition products. GC/ECD analysis confirmed that the brominated hydrocarbons were concentrated in step 1 liquid products leaving less brominated hydrocarbons in the step 2 liquid products, similar to the decabromo diphenyl ether flame retardant containing mixed plastics. The yield of liquid products in step 1 from 3P/DDE-Sb(5) was 5 wt% and from 3P/DDE-Sb(0) was 2.4 wt%. The presence of antimony in the DDE containing plastics affected the yield of liquid, gas and residue products. ECD analysis showed that the presence of antimony increased the Br containing hydrocarbons and step 1 has 3-4 times higher brominated compounds than step 2 hydrocarbons in both the samples. 相似文献
253.
The shape of the continuous X-ray spectrum is approximated by the Planck’s distribution law for black-body radiation. The energy distribution of continuum X-rays produced by a bombardment of 30 kV electron beam onto a gold target is reproduced by the black-body radiation at a temperature of 107 K. The continuous spectrum measured when the incident electron energy varies in the range 30, 20, 10, and 5 kV, and for different target elements such as gold, iron, and carbon, are again reproduced in their absolute intensity scale. Consequently, it is speculated that the Stefan–Boltzmann's law as well as the Wien's displacement law also hold for the continuum X-ray radiation. 相似文献
254.
Evaluation of additional absorbed radiation dose from radioactive impurities in radiopharmaceuticals
T Muto 《Radioisotopes》1986,35(6):321-324
The additional absorbed radiation doses to total body from radioactive impurities in radiopharmaceuticals were estimated for a total of 10 samples (i.e., 99mTc generator eluates, 99mTc solutions, 67Ga, 81mKr generator eluates, 111In, 123I, 201Tl, 75Se, 197Hg, 198Au) selected from commonly used radiopharmaceuticals. The radioactive impurities in radiopharmaceuticals used in this estimation were previously identified. The radiation doses were calculated according to the MIRD procedures, assuming each radionuclide to be uniformly distributed throughout the body. In the case of the cyclotron-produced radioisotopes and 198Au, the additional total body absorbed doses from impurities were found to be rather high: 280% for 123I, 55% for 81mKr, 5% for 198Au, 4% for 111In and 2% for 201Tl. The absorbed doses due to impurities in the other radioisotopes were less than 1%. 相似文献
255.
256.
M. Hirsch K. Muto T. Oda H. V. Klapdor-Kleingrothaus 《Zeitschrift für Physik A Hadrons and Nuclei》1994,347(3):151-160
Nuclear matrix elements for double positron emisson (
+
+), positron emission/electron capture (
+/ EC) and double electron capture (EC/EC) in the 2 decay mode and for
+
+ and
+/EC decay in the 0 mode are calculated for the experimentally most promising isotopes58Ni,78Kr,96Ru,106Cd,124Xe,130Ba and136Ce within pn-QRPA. We point out that the matrix element for the 2
+/EC decay differs from the 2
+
+ matrix element, an effect not considered previously. For the neutrino accompanied decays our calculation predicts for the
+/EC and the EC/EC mode half lives which are shorter typically by 4–7 orders of magnitude than those for the double positron emission. However, even for the best candidates typical values for 2
+/EC (2 EC/EC) are still in the range of 1022 ((some) 1021) years. For 0 decay we have calculated all matrix elements relevant for both, the mass mechanism and the right-handed currents for the first time complete. A detailed discussion of the differences between the 0
++, the 0
+/EC and 0
–
– decay is given.This work is supported in part by a Grant-in-Aid for Scientific Research (05243204) from the Ministry of Education, Science and Culture. One of us (M.H.) would like to thank the Japanese Ministry of Education, Science and Culture (Monbusho) for financial support. He also acknowledges valuable discussions with S.S. 相似文献
257.
Y. Fukao M. Togawa A. Bazilevsky L.C. Bland A. Bogdanov G. Bunce A. Deshpande H. En'yo B.D. Fox Y. Goto J.S. Haggerty K. Imai W. Lenz D. von Lintig M.X. Liu Y.I. Makdisi R. Muto S.B. Nurushev E. Pascuzzi M.L. Purschke N. Saito F. Sakuma S.P. Stoll K. Tanida J. Tojo Y. Watanabe C.L. Woody 《Physics letters. [Part B]》2007,650(5-6):325-330
In the 2001–2002 running period of the Relativistic Heavy Ion Collider (RHIC), transversely polarized protons were accelerated to 100 GeV for the first time, with collisions at . We present results from this run for single transverse-spin asymmetries for inclusive production of neutral pions, photons and neutrons of the energy region 20–100 GeV for forward and backward production for angles between 0.3 mrad and 2.2 mrad with respect to the polarized proton direction. An asymmetry of was observed for forward neutron production, where the errors are statistical and systematic, and the scale error is from the beam polarization uncertainty. The forward photon and π0, and backward neutron, photon, and π0 asymmetries were consistent with zero. The large neutron asymmetry indicates a strong interference between a spin–flip amplitude, such as one pion exchange which dominates lower energy neutron production, and remaining spin–non-flip amplitudes such as reggeon exchange. 相似文献
258.
Seki T Shinohara K Kato N Uchida M Natsume H Morimoto K Juni K 《Chemical & pharmaceutical bulletin》2007,55(3):403-406
Polypropyleneglycol (PPG) was used as a dispersion medium for the preparation of microspheres (MS) consisting of starch, gelatin, whey protein or dextran. Aqueous solutions of the polymers were dispersed in PPG at various initial temperatures and then the systems were cooled to 0.5 degrees C to allow water in the dispersed phase to dissolve in PPG. The particle size of the starch-MS was dependent on the initial temperature of PPG in the preparation process. There were two different processes for particle generation in the procedure. One of them was via the formation of a temporary emulsion during the early phase of dispersion of the aqueous polymer solution into PPG. The other was via the stable emulsion in which the aqueous polymer solution was dispersed in water-saturated PPG. The particle size generated in the former process was dependent on the initial temperature: a high temperature gave large particles but a low temperature gave small particles, while that in the latter process was temperature-independent. This preparation method for MS will be useful for the formulation of heat-sensitive material, such as protein-containing drugs. 相似文献
259.
Sakuma F Chiba J En'yo H Fukao Y Funahashi H Hamagaki H Ieiri M Ishino M Kanda H Kitaguchi M Mihara S Miwa K Miyashita T Murakami T Muto R Nakura T Naruki M Ozawa K Sasaki O Sekimoto M Tabaru T Tanaka KH Togawa M Yamada S Yokkaichi S Yoshimura Y;KEK-PS E Collaboration 《Physical review letters》2007,98(15):152302
The invariant mass spectra of phi-->K+K- are measured in 12 GeV p+A reactions in order to search for the in-medium modification of phi mesons. The observed K+K- spectra are well reproduced by the relativistic Breit-Wigner function with a combinatorial background shape in three betagamma regions between 1.0 and 3.5. The nuclear mass number dependence of the yields of the K+K- decay channel is compared to the simultaneously measured e+e- decay channel for carbon and copper targets. We parameterize the production yields as sigma(A)=sigma0Aalpha and obtain alphaphi-->K+K- -alphaphi-->e+e- to be 0.14+/-0.12. Limits are obtained for the partial decay widths of the phi mesons in nuclear matter. 相似文献
260.
CH Activation Generates Period‐Shortening Molecules That Target Cryptochrome in the Mammalian Circadian Clock 下载免费PDF全文
Tsuyoshi Oshima Dr. Iori Yamanaka Dr. Anupriya Kumar Dr. Junichiro Yamaguchi Dr. Taeko Nishiwaki‐Ohkawa Kei Muto Rika Kawamura Dr. Tsuyoshi Hirota Prof. Dr. Kazuhiro Yagita Prof. Dr. Stephan Irle Prof. Dr. Steve A. Kay Prof. Dr. Takashi Yoshimura Prof. Dr. Kenichiro Itami 《Angewandte Chemie (International ed. in English)》2015,54(24):7193-7197
The synthesis and functional analysis of KL001 derivatives, which are modulators of the mammalian circadian clock, are described. By using cutting‐edge C? H activation chemistry, a focused library of KL001 derivatives was rapidly constructed, which enabled the identification of the critical sites on KL001 derivatives that induce a rhythm‐changing activity along with the components that trigger opposite modes of action. The first period‐shortening molecules that target the cryptochrome (CRY) were thus discovered. Detailed studies on the effects of these compounds on CRY stability implicate the existence of an as yet undiscovered regulatory mechanism. 相似文献