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141.
Hiroki Hirai Kiichi Nakajima Soichiro Nakatsuka Kazushi Shiren Jingping Ni Shintaro Nomura Toshiaki Ikuta Takuji Hatakeyama 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(46):13785-13789
The development of a one‐step borylation of 1,3‐diaryloxybenzenes, yielding novel boron‐containing polycyclic aromatic compounds, is reported. The resulting boron‐containing compounds possess high singlet‐triplet excitation energies as a result of localized frontier molecular orbitals induced by boron and oxygen. Using these compounds as a host material, we successfully prepared phosphorescent organic light‐emitting diodes exhibiting high efficiency and adequate lifetimes. Moreover, using the present one‐step borylation, we succeeded in the synthesis of an efficient, thermally activated delayed fluorescence emitter and boron‐fused benzo[6]helicene. 相似文献
142.
One‐Pot Synthesis of 3‐Acetyl‐2‐aryl‐3,4‐dihydroquinazolines from N‐[2‐(Azidomethyl)phenyl]benzamides Utilizing Intramolecular Aza‐Wittig Reaction 下载免费PDF全文
Kazuhiro Kobayashi Naoki Matsumoto Mika Nagashima Hiroki Inouchi 《Helvetica chimica acta》2015,98(2):184-189
A new and convenient method for the preparation of 3,4‐dihydroquinazolines 5 with aryl and Ac groups at C(2) and N(3), respectively, has been developed. The key sequence is the formation of aza‐phosphorane intermediates by the reaction of N‐[2‐(azidomethyl)phenyl]benzamides 1 with Ph3P, followed by intramolecular aza‐Wittig reaction and 3‐acetylation, which can be conducted in one‐pot. 相似文献
143.
High‐performance liquid chromatography separation of unsaturated organic compounds by a monolithic silica column embedded with silver nanoparticles 下载免费PDF全文
Yang Zhu Kei Morisato George Hasegawa Nirmalya Moitra Tsutomu Kiyomura Hiroki Kurata Kazuyoshi Kanamori Kazuki Nakanishi 《Journal of separation science》2015,38(16):2841-2847
The optimization of a porous structure to ensure good separation performances is always a significant issue in high‐performance liquid chromatography column design. Recently we reported the homogeneous embedment of Ag nanoparticles in periodic mesoporous silica monolith and the application of such Ag nanoparticles embedded silica monolith for the high‐performance liquid chromatography separation of polyaromatic hydrocarbons. However, the separation performance remains to be improved and the retention mechanism as compared with the Ag ion high‐performance liquid chromatography technique still needs to be clarified. In this research, Ag nanoparticles were introduced into a macro/mesoporous silica monolith with optimized pore parameters for high‐performance liquid chromatography separations. Baseline separation of benzene, naphthalene, anthracene, and pyrene was achieved with the theoretical plate number for analyte naphthalene as 36 000 m?1. Its separation function was further extended to cis/trans isomers of aromatic compounds where cis/trans stilbenes were chosen as a benchmark. Good separation of cis/trans‐stilbene with separation factor as 7 and theoretical plate number as 76 000 m?1 for cis‐stilbene was obtained. The trans isomer, however, is retained more strongly, which contradicts the long‐ established retention rule of Ag ion chromatography. Such behavior of Ag nanoparticles embedded in a silica column can be attributed to the differences in the molecular geometric configuration of cis/trans stilbenes. 相似文献
144.
Aya Yoshimura Akihiro Nomoto Mari Uchida Hiroki Kusano Tomokazu Saeki Akiya Ogawa 《Research on Chemical Intermediates》2017,43(6):3433-3443
The functionalization of polysilanes is an important subject in materials science because functionalized polysilanes are expected to exhibit potentially innovative properties. This research aims at the addition of a water-shedding property to polysilanes by introducing perfluoroalkyl groups into their skeleton. The photoinduced iodoperfluoroalkylation of various vinylsilanes takes place successfully upon irradiation with a xenon lamp: vinylmonosilanes undergo iodoperfluoroalkylation with perfluoroalkyl iodides (RfI) regioselectively, and the corresponding perfluoroalkylated silanes are obtained in moderate to high yields. Detailed optimization of the photoinduced iodoperfluoroalkylation has been investigated to apply this method to the functionalization of polysilanes. Polysilanes having vinyl groups can be synthesized by the reductive coupling of dichlorovinylsilanes with samarium diiodide (SmI2) and samarium metal (Sm) upon irradiation with visible light. The synthesized vinylpolysilanes and RfI (about 1.0 mM CHCl3 solution) are coated on a glass plate sequentially, and then the following photoirradiation with light of a wavelength over 300 nm successfully adds an excellent water-shedding property to the glass plate. 相似文献
145.
Generation of Aryl(2‐lithiophenyl)methanone O‐Methyl Oximes and Their Use for the Synthesis of N‐(3‐Alkyl‐1‐aryl‐ or 1,3‐diaryl‐1H‐isoindol‐1‐yl)‐O‐methylhydroxylamines via the Reaction with Nitriles 下载免费PDF全文
Kazuhiro Kobayashi Kota Matsumoto Yuu Shirai Hiroaki Ishikawa Hiroki Inouchi Miyuki Tanmatsu 《Helvetica chimica acta》2014,97(7):915-922
An efficient two‐step procedure for the preparation of a new type of 1H‐isoindoles, i.e., N‐(3‐alkyl‐1‐aryl‐ or 1,3‐diaryl‐1H‐isoindol‐1‐yl)‐O‐methylhydroxylamines 5 , from readily available aryl(2‐bromophenyl)methanones 1 has been developed. Aryl(2‐bromophenyl)methanone O‐methyloximes 2 , derived from the corresponding ketones, were treated with BuLi in Et2O at 0° to generate novel lithium compounds, aryl(2‐lithiophenyl)methanone O‐methyloximes 3 , which were allowed to react with nitriles to give the desired products 5 in moderate‐to‐fair yields. 相似文献
146.
Kenji ArimitsuSayo Nomura Hiroki IwasakiMinoru Ozeki Masayuki Yamashita 《Tetrahedron letters》2011,52(52):7046-7048
The first total synthesis of (±)-adunctin B (1), a natural product isolated from Piper aduncum (Piperaceae) and having antibacterial activity, was achieved in 1.26% overall yield in 15 steps from 5,7-dimethoxycoumarin-3-carboxylate (8). 相似文献
147.
Matsukuma D Watanabe H Yamaguchi H Takahara A 《Langmuir : the ACS journal of surfaces and colloids》2011,27(4):1269-1274
We demonstrate the successful preparation of stable liquid marbles from various liquids. This is accomplished by using low-surface-energy poly[2-(perfluorooctyl)ethyl acrylate] (PFA-C(8)) as microparticles. The PFA-C(8) microparticles were prepared by the spontaneous self-organized microparticulation of PFA-C(8). The physical properties remained intact in the polymer morphology as confirmed by wide-angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC) measurements. The extremely low surface energy of PFA-C(8) provides a high solid-liquid spreading coefficient (S(S/L)) value for various combinations of liquids. As a result, liquid marbles were obtained from various liquids, unlike the case with other fluorine polymer particles such as poly(tetrafluoroethylene) (PTFE) and poly(vinilydene fluoride) (PVDF). These results suggest that the technique is widely applicable for preparing novel functional materials. 相似文献
148.
Determination methods of halide ions (X(-) = F(-), Cl(-), Br(-) and I(-)) by electrospray ionization mass spectrometry (ESIMS) were developed, where negative ions of the ternary complexes of group-13 elements, nitrilotriacetic acid (NTA), and halides were measured. In particular, these halides were simultaneously determined by measuring [InX(nta)](-), and the limits of detection (LODs) were 1.1 μmol dm(-3) for F(-), 0.32 μmol dm(-3) for Cl(-), 3.8 nmol dm(-3) for Br(-), and 1.6 nmol dm(-3) for I(-), respectively. This approach was extended to the determination of CN(-), where the ternary complex of Cu(II), CN(-) and 4-(2-pyridylazo)resorcinol (PAR), i.e., [(63)Cu(II)(CN)(par)](-) (m/z 302) was measured. The LOD for CN(-) was 20 nmol dm(-3). 相似文献
149.
New structurally constrained BODIPY dyes having electron-donating substituents were synthesized. As the key compounds for the construction of the BODIPY dyes, 1′H-spiro-[fluorene-9,4′-indeno[1,2-b]pyrrole] (sp-FIP) derivatives with electron-donating groups, such as OMe and NMe2 at its 6′-position, were prepared using palladium-catalyzed intramolecular direct C-H arylation of a pyrrole moiety. The resulting BODIPY dyes showed bathochromic shift in absorption and fluorescence spectra in comparison to the unsubstituted analogs. Furthermore, pH-dependent reversible spectrum changes of the BODIPY dye were observed with the addition of trifluoroacetic acid (TFA) and subsequent addition of i-Pr2NEt. 相似文献
150.
Mitsumoto K Oshiro E Nishikawa H Shiga T Yamamura Y Saito K Oshio H 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(35):9612-9618
Cyanide‐bridged metal complexes of [Fe8M6(μ‐CN)14(CN)10 (tp)8(HL)10(CH3CN)2][PF6]4?n CH3CN?m H2O (HL=3‐(2‐pyridyl)‐5‐[4‐(diphenylamino)phenyl]‐1H‐pyrazole), tp?=hydrotris(pyrazolylborate), 1 : M=Ni with n=11 and m=7, and 2 : M=Co with n=14 and m=5) were prepared. Complexes 1 and 2 are isomorphous, and crystallized in the monoclinic space group P21/n. They have tetradecanuclear cores composed of eight low‐spin (LS) FeIII and six high‐spin (HS) MII ions (M=Ni and Co), all of which are bridged by cyanide ions, to form a crown‐like core structure. Magnetic susceptibility measurements revealed that intramolecular ferro‐ and antiferromagnetic interactions are operative in 1 and in a fresh sample of 2 , respectively. Ac magnetic susceptibility measurements of 1 showed frequency‐dependent in‐ and out‐of‐phase signals, characteristic of single‐molecule magnetism (SMM), while desolvated samples of 2 showed thermal‐ and photoinduced intramolecular electron‐transfer‐coupled spin transition (ETCST) between the [(LS‐FeII)3(LS‐FeIII)5(HS‐CoII)3(LS‐CoIII)3] and the [(LS‐FeIII)8(HS‐CoII)6] states. 相似文献