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91.
Tomoya Saito Masakazu Nishida Haruhiko Fukaya Hiroshi Kakehi Yoshihiro Kato Masashi Miura Norifumi Isu Hideo Sawada 《Colloid and polymer science》2013,291(4):945-953
Calcium chloride reacted with potassium fluoride in the presence of low molecular weight aromatic compounds (ArH) such as bisphenol AF, bisphenol A, bisphenol F, biphenyl, and 1-(2-naphthyl)ethanol under alkaline conditions to afford new calcium fluoride/ArH composites. Dynamic light scattering and field emission scanning electron micrographs measurements show that these calcium fluoride/ArH composites are nanometer size-controlled fine particles and have a good dispersibility and stability in water, tetrahydrofuran, 1,2-dichloroethane, methanol, dimethyl sulfoxide, N,N-dimethylformamide, and 2-propanol. Interestingly, aromatic compounds possessing acidic hydroxyl groups in the calcium fluoride nanocomposites were found to exhibit a nonflammable characteristic even after calcination at 800 °C, although the corresponding aromatic compounds possessing neither acidic hydroxyl groups nor hydroxyl groups in the nanocomposites exhibited a usual flammable characteristic under similar conditions. In contrast, calcium fluoride/ArH nanocomposites, which were prepared under no catalytic conditions, afforded a clear weight loss corresponding to the contents of ArH in the composites to exhibit a usual flammable characteristic. Figure
Ar-OH can exhibit a nonflammable characteristic in calcium fluoride nanocomposite matrices even after calcination at 800°C 相似文献
92.
Prof. Dr. Haruhiko Fuwa Masato Kawakami Kenkichi Noto Takashi Muto Yuto Suga Prof. Dr. Keiichi Konoki Prof. Dr. Mari Yotsu‐Yamashita Prof. Dr. Makoto Sasaki 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(25):8100-8110
We describe herein a concise synthesis of (+)‐neopeltolide, a marine macrolide natural product that elicits a highly potent antiproliferative activity against several human cancer cell lines. Our synthesis exploited the powerful bond‐forming ability and high functional group compatibility of olefin metathesis and esterification reactions to minimize manipulations of oxygen functionalities and to maximize synthetic convergency. Our findings include a chemoselective olefin cross‐metathesis reaction directed by H‐bonding, and a ring‐closing metathesis conducted under non‐high dilution conditions. Moreover, we developed a 16‐member stereoisomer library of 8,9‐dehydroneopeltolide to systematically explore the stereostructure–activity relationships. Assessment of the antiproliferative activity of the stereoisomers against A549 human lung adenocarcinoma, MCF‐7 human breast adenocarcinoma, HT‐1080 human fibrosarcoma, and P388 murine leukemia cell lines has revealed marked differences in potency between the stereoisomers. This study provides comprehensive insights into the structure–activity relationship of this important antiproliferative agent, leading to the identification of the pharmacophoric structural elements and the development of truncated analogues with nanomolar potency. 相似文献
93.
Vinyl Polymerization. CLXVII. Vinyl Polymerization Initiated with p-Methoxy p′-nitrobenzoyl Peroxide
It was described in the literature that p-methoxy-p′-nitrobenzoyl peroxide decomposed homolytically in benzene, but heterolytically in acetone. However, in the present study the polymerizations of styrene and acrylonitrile were found to proceed always through radical mechanism in benzene, dimethylformamide, or acetone. And in the above various solvents, the rate of polymerization was found to be almost equal. 相似文献
94.
95.
Shuji Kondo Yasuhito Inagaki Haruhiko Yasui Masaki Iwasaki Kazuichi Tsuda 《Journal of polymer science. Part A, Polymer chemistry》1991,29(2):243-249
Insoluble polystrenes containing formamide and acetamide moieties were prepared by free radical terpolymerization of the corresponding vinyl monomers, styrene, and divinylbenzene. These polymers served as phase transfer catalysts for the reaction of n-octyl bromide with potassium thiocyanate in toluene–water system. The activity of these catalysts was affected by some factors such as stirring speed particle size, and degree of crosslinking. The activity also depended strongly on the structure of active site, copolymer composition, and spacer length which cause the difference in the adsorption of potassium ion and in the microenvironment around the active site. Furthermore, nylon-66 was found to display the activity for phase transfer reactions, and the activity was remarkably increased by replacing the amide hydrogen with an alkyl group. 相似文献
96.
Hideho Okamoto Haruhiko Nakajima Yasaku Wada 《Journal of Polymer Science.Polymer Physics》1974,12(6):1035-1052
The dynamic viscosity of aqueous solutions of poly(acrylic acid) at a polymer concentration of ca. 0.15 g/100 ml has been measured at frequencies from 2 to 500 kHz as a function of degree of polymerization P, degree of neutralization α, and salt (NaCl) concentration Cs. Relaxation spectra have been obtained from the dynamic viscosity. The spectra in the short relaxation time region can be approximated by the Zimm theory for the conformational relaxation of nonionic polymers. The maximum relaxation time τ1 of the Zimm spectra is proportional to P2 and depends rather moderately on α and Cs. Increased deviation is found, however, in the long relaxation time region, in particular for high values of P and α and low values of Cs. The major part of the deviation is interpreted in terms of rotational relaxation of a molecule as a whole. The rotational relaxation time τR is proportional to P3 and increases with increasing α and decreasing Cs. The remaining part of the excess spectra located between τ1 and τR is ascribed to the deviation of the conformational relaxation from the Zimm theory arising from ionization of the polymer. 相似文献
97.
An efficient strategy for the synthesis of endocyclic enol ethers based on a Suzuki-Miyaura coupling/ring-closing metathesis sequence has been developed. The strategy has successfully been applied to the synthesis of spiroacetals, including cytotoxic marine metabolites attenols A and B. 相似文献
98.
Makoto ASAHINA Reiko FUJINAWA Haruhiko FUJIHIRA Yuki MASAHARA-NEGISHI Tomohiro ANDOU Ryuichi TOZAWA Tadashi SUZUKI 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2021,97(2):89
N-Glycanase 1 (NGLY1) deficiency is a congenital disorder caused by mutations in the NGLY1 gene. Because systemic Ngly1−/− mice with a C57BL/6 (B6) background are embryonically lethal, studies on the mechanism of NGLY1 deficiency using mice have been problematic. In this study, B6-Ngly1−/+ mice were crossed with Japanese wild mice-originated Japanese fancy mouse 1 (JF1) mice to produce viable F2 Ngly1−/− mice from (JF1×B6)F1 Ngly1−/+ mice. Systemic Ngly1−/− mice with a JF1 mouse background were also embryonically lethal. Hybrid F1 Ngly1−/− (JF1/B6F1) mice, however, showed developmental delay and motor dysfunction, similar to that in human patients. JF1/B6F1 Ngly1−/− mice showed increased levels of plasma and urinary aspartylglycosamine, a potential biomarker for NGLY1 deficiency. JF1/B6F1 Ngly1−/− mice are a useful isogenic animal model for the preclinical testing of therapeutic options and understanding the precise pathogenic mechanisms responsible for NGLY1 deficiency. 相似文献
99.
Tomoaki Seyama Toshifumi Tanimura Keigo Tashiro Suzuko Yamazaki 《Research on Chemical Intermediates》2017,43(9):5025-5039
Porous platinum ion-doped TiO2 (Pt–TiO2) was prepared by a sol–gel method and demonstrated to have superior photocatalytic activity for the photodegradation of gaseous trichloroethylene (TCE) under visible light (VL) irradiation from a xenon lamp equipped with 422-nm cut-off filter. Kinetic studies were performed to clarify the effect of the doping amounts, space times, VL intensity, and mole fractions of TCE, O2, and H2O on the degradation of TCE. Under ultraviolet (UV) irradiation, the photocatalytic activity of Pt–TiO2 was the same as that of TiO2, indicating that the doped Pt ion did not act as a recombination center for the photogenerated holes and electrons. Based on the kinetic data and reaction products, we conclude that the photocatalytic degradation of TCE on Pt–TiO2 under VL irradiation proceeds similarly to TiO2 under UV irradiation. We also performed the photocatalytic degradation of TCE at the space time of 7.5 × 107 g s mol?1 in a tubular reactor packed with the Pt–TiO2 pellets which are more suitable than the Pt–TiO2 powder for the practical remediation of the contaminated gas. TCE was completely degraded, i.e. 100% conversion was achieved under VL irradiation but only a small quantity of CO2 was formed with the stoichiometric ratio of [CO2]formed/[TCE]degraded of ca. 0.33. By switching the gas stream containing TCE to humid air, more CO2 was formed, indicating that the dichloroacetates accumulated on the Pt–TiO2 surface are photodegradable to CO2 under VL irradiation. 相似文献
100.
Synchronization phenomena in coupled circadian oscillators of plant leaves were investigated experimentally using bioluminescence technology for a clock gene. Analyzing the phase of circadian oscillation, the phase-wave propagations and the phase delay caused by the vein network were observed. We describe these phase dynamics using a two-layer model with coupled Stuart-Landau equations. Global synchronization of circadian oscillators in the leaf is also investigated. 相似文献