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151.
Tomonori Mori Dr. Shuhei Higashibayashi Dr. Taiji Goto Mitsunori Kohno Yukiko Satouchi Kazuyuki Shinko Kengo Suzuki Shunya Suzuki Hiraku Tohmiya Kimiko Hashimoto Prof. Dr. Masaya Nakata Prof. Dr. 《化学:亚洲杂志》2008,3(6):984-1012
The five practical segments for the total synthesis of siomycin A, that is, the dehydropiperidine segment A ( 5 ), the pentapeptide segment B ( 3 ), the dihydroquinoline segment C ( 6 ), and the β‐phenylselenoalanine dipeptide segments D ( 7 ) and E ( 4 ), were synthesized. Segment A ( 5 ) was constructed by the coupling of the azomethine ylide and the chiral sulfinimine, followed by the stereoselective reduction of the six‐membered imine function. Segment B ( 3 ) was synthesized by the phenylselenylation of the β‐lactone, stereoselective vinylzinc addition to the chiral sulfinimine, and oxazoline–thioamide conversion. Segment C ( 6 ) was prepared by the one‐pot olefination of the tetrahydroquinoline N‐oxide using triflic anhydride and triethylamine, stereoselective reduction of the methyl ketone function, and regioselective Yb(OTf)3‐catalyzed epoxide opening by the amino group. Segments D ( 7 ) and E ( 4 ) were synthesized by coupling of the properly protected β‐phenylselenoalanines. 相似文献
152.
Tomonori Mori Dr. Shuhei Higashibayashi Dr. Taiji Goto Mitsunori Kohno Yukiko Satouchi Kazuyuki Shinko Kengo Suzuki Shunya Suzuki Hiraku Tohmiya Kimiko Hashimoto Prof. Dr. Masaya Nakata Prof. Dr. 《化学:亚洲杂志》2008,3(6):1013-1025
The total synthesis of siomycin A ( 1 ), a representative compound of the thiostrepton family of peptide antibiotics, was achieved by incorporating the five synthetic segments A ( 2 ), B ( 3 ), C ( 4 ), D ( 5 ), and E ( 6 ). The dehydropiperidine segment A ( 2 ) was esterified with the dihydroquinoline segment C ( 4 ), and the subsequent coupling with the β‐phenylselenoalanine dipeptide segment D ( 5 ) at the segment C portion followed by lactamization between the segments A and D gave segment A‐C‐D ( 27 ). This was amidated with the pentapeptide segment B ( 3 ) at the segment A portion followed by one‐pot cyclization (between segments A and B) and elongation (with the β‐phenylselenoalanine dipeptide segment E ( 6 ) at the segment A portion), thus furnishing siomycin A ( 1 ). 相似文献
153.
A cationic gold(I) complex with a semihollow-shaped trialkynylphosphine catalyzed 5-exo-dig and 6-endo-dig cyclizations of various internal alkynic beta-keto esters, showing a marked advantage over a gold(I)-PPh3 complex with respect to the rates of the reactions and the product yields. It is proposed that the gold-bound alkynic substrate in a catalytic pocket must be somewhat folded and that such a steric effect makes the carbon-carbon bond formation entropically more favorable. 相似文献
154.
Takashi Toyao Masakazu Saito Satoru Dohshi Katsunori Mochizuki Masatoshi Iwata Hideyuki Higashimura Yu Horiuchi Masaya Matsuoka 《Research on Chemical Intermediates》2016,42(11):7679-7688
The present article deals with Pt complex construction within Zr-based MOF having bipyridine units in the framework (Zr-MOF-bpy-PtCl2) and its photocatalytic activity for hydrogen production under visible-light irradiation (λ > 420 nm). Zr-MOF-bpy-PtCl2 is prepared by the construction of a Zr-based MOF using 2,2′-bipyridine-5,5′-dicarboxylic acid (Zr-MOF-bpy), and subsequent complexation reaction with K2PtCl4. XRD and N2 adsorption–desorption measurements have revealed that both Zr-MOF-bpy and Zr-MOF-bpy-PtCl2 have a UiO-type structure. From the results of UV–Vis and XAFS measurements, the incorporated Pt species has been proven to be in square planar geometry involving two N atoms and two Cl atoms as a result of the Pt coordination with bipyridine units in the framework. Zr-MOF-bpy-PtCl2 has been employed for a hydrogen production reaction from water containing a sacrificial electron donor under visible-light irradiation (λ > 420 nm). Zr-MOF-bpy-PtCl2 realizes steady hydrogen production, and the amount of evolved hydrogen reaches 8.3 μmol after the 9 h reaction period, while Zr-MOF-bpy exhibits no photocatalytic activity under the same conditions. It has also been found that the activity of Zr-MOF-bpy-PtCl2 is superior to that of the corresponding homogeneous complex analogue (bpy)PtCl2. 相似文献
155.
156.
Suzuki Jun-ichi Takegahara Yutaro Oikawa Yuri Chiba Masaya Yamada Satoshi Sugiya Masashi Sawada Hideo 《Journal of Sol-Gel Science and Technology》2017,81(2):611-622
Journal of Sol-Gel Science and Technology - Fluoroalkyl end-capped vinyltrimethoxysilane oligomer [R F-(CH2CHSi(OMe)3) n -R F; R F?=?CF(CF3)OC3F7, n?=?2, 3: R F-(VM) n -R F... 相似文献
157.
Modulation of a Molecular π‐Electron System in a Purely Organic Conductor that Shows Hydrogen‐Bond‐Dynamics‐Based Switching of Conductivity and Magnetism 下载免费PDF全文
Dr. Akira Ueda Akari Hatakeyama Dr. Masaya Enomoto Prof. Dr. Reiji Kumai Prof. Dr. Youichi Murakami Prof. Dr. Hatsumi Mori 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(42):15020-15028
New important aspects of the hydrogen‐bond (H‐bond)‐dynamics‐based switching of electrical conductivity and magnetism in an H‐bonded, purely organic conductor crystal have been discovered by modulating its tetrathiafulvalene (TTF)‐based molecular π‐electron system by means of partial sulfur/selenium substitution. The prepared selenium analogue also showed a similar type of phase transition, induced by H‐bonded deuterium transfer followed by electron transfer between the H‐bonded TTF skeletons, and the resulting switching of the physical properties; however, subtle but critical differences due to sulfur/selenium substitution were detected in the electronic structure, phase transition nature, and switching function. A molecular‐level discussion based on the crystal structures shows that this chemical modification of the TTF skeleton influences not only its own π‐electronic structure and π–π interactions within the conducting layer, but also the H‐bond dynamics between the TTF π skeletons in the neighboring layers, which enables modulation of the interplay between the H‐bond and π electrons to cause such differences. 相似文献
158.
Synthesis of 1,1‐Diborylalkenes through a Brønsted Base Catalyzed Reaction between Terminal Alkynes and Bis(pinacolato)diboron 下载免费PDF全文
Akira Morinaga Kazunori Nagao Prof. Dr. Hirohisa Ohmiya Prof. Dr. Masaya Sawamura 《Angewandte Chemie (International ed. in English)》2015,54(52):15859-15862
A method for the synthesis of 1,1‐diborylalkenes through a Brønsted base catalyzed reaction between terminal alkynes and bis(pinacolato)diboron has been developed. The procedure allows direct synthesis of functionalized 1,1‐diborylalkenes from various terminal alkynes including propiolates, propiolamides, and 2‐ethynylazoles. 相似文献
159.
Van Do Dang Hosokawa Takuya Horiuchi Yu Matsuoka Masaya 《Research on Chemical Intermediates》2020,46(12):5297-5306
Research on Chemical Intermediates - The present article describes the construction of the organoruthenium complex catalyst within carbon-coated mesoporous silica and its application to a... 相似文献
160.
Lingli Zhu Dr. Jiahui Ji Jun Liu Dr. Shinya Mine Prof. Dr. Masaya Matsuoka Prof. Dr. Jinlong Zhang Prof. Dr. Mingyang Xing 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(33):14072-14080
3D-MoS2 can adsorb organic molecules and provide multidimensional electron transport pathways, implying a potential application for environment remediation. Here, we study the degradation of aromatic organics in advanced oxidation processes (AOPs) by a 3D-MoS2 sponge loaded with MoS2 nanospheres and graphene oxide (GO). Exposed Mo4+ active sites on 3D-MoS2 can significantly improve the concentration and stability of Fe2+ in AOPs and keep the Fe3+/Fe2+ in a stable dynamic cycle, thus effectively promoting the activation of H2O2/peroxymonosulfate (PMS). The degradation rate of organic pollutants in the 3D-MoS2 system is about 50 times higher than without cocatalyst. After a 140 L pilot-scale experiment, it still maintains high efficiency and stable AOPs activity. After 16 days of continuous reaction, the 3D-MoS2 achieves a degradation rate of 120 mg L−1 antibiotic wastewater up to 97.87 %. The operating cost of treating a ton of wastewater is only US$ 0.33, suggesting huge industrial applications. 相似文献