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71.
Takashi Hayashita Norio Teramae Toshiharu Kuboyama Shigeo Nakamura Hiromasa Yamamoto Hiroshi Nakamura 《Journal of inclusion phenomena and macrocyclic chemistry》1998,32(2-3):251-265
Recent progress in chromoionophores based on (1) spherand and hemispherand, (2) cryptand, and (3) dibenzo-16-crown-5 and calix[4]crown which selectively respond to alkali metal ions in aqueous media is reviewed in relation to their molecular structure and photometric function. The design concept of the chromoionophores for colorimetry in aqueous media is discussed in the light of their acid dissociation and metal complex formation equilibria. 相似文献
72.
Kawamura K Horikiri H Hayakawa J Seki C Yoshizawa K Umeuchi H Nagase H 《Chemical & pharmaceutical bulletin》2004,52(6):670-674
Chemical syntheses of three kinds of potential metabolites of TRK-820, a potent kappa-opioid receptor agonist, were described. One of the potential metabolites 2, 17-N-dealkylated TRK-820, was synthesized starting from noroxycodone through 8 steps in 21% total yield. Glucuronidation of intermediate 10 and compound 1, the free base of TRK-820, was carried out stereoselectively to give 3-O-beta-D-glucuronides 15 and 16 in good yields, respectively. Syntheses of potential conjugated metabolites 3 and 4 were accomplished through 10 steps and 2 steps in 11% and 43% total yields, respectively. Among the potential metabolites of TRK-820, compounds 2 and 4 were identified as metabolites in human hepatocytes. The results of pharmacological studies of compounds 2, 3, and 4 are described. 相似文献
73.
Hiromasa Goto 《Journal of polymer science. Part A, Polymer chemistry》2007,45(11):2085-2090
The electrochemically driven control of the natural optical activity of polyanilines bearing chiral camphorsulfonic acid is reported. Aniline was polymerized in the presence of camphorsulfonic acid by oxidative electrochemical polymerization in water to afford polyanilines containing (+)- or (−)-camphorsulfonic acid. This research elucidated that the polymerization, with cyclic voltammetry scanning up to 1.1 V, produced consistent optically active polyanilines. The polyaniline films thus prepared showed intense and tunable optical activity based on electrochemical reduction/oxidation in a 0.1 M sulfuric acid aqueous solution. The circular dichroism and optical rotation angle of the polymer were tunable by the appropriate adjustment of an externally applied potential as a form of optical modulation. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2085–2090, 2007 相似文献
74.
Dr. Yuya Ashida Akihito Egi Dr. Kazuya Arashiba Prof. Dr. Hiromasa Tanaka Taichi Mitsumoto Dr. Shogo Kuriyama Prof. Dr. Kazunari Yoshizawa Prof. Dr. Yoshiaki Nishibayashi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(25):e202200557
A series of chromium-halide, -nitride, and -dinitrogen complexes bearing carbene- and phosphine-based PCP-type pincer ligands has been newly prepared, and some of them are found to work as effective catalysts to reduce dinitrogen under atmospheric pressure, whereby up to 11.60 equiv. of ammonia and 2.52 equiv. of hydrazine (16.6 equiv. of fixed N atom) are produced based on the chromium atom. To the best of our knowledge, this is the first successful example of chromium-catalyzed conversion of dinitrogen to ammonia and hydrazine under mild reaction conditions. 相似文献
75.
Hiromasa Nishikiori Makoto Tagahara Leo Mukoyama Tsuneo Fujii 《Research on Chemical Intermediates》2010,36(8):947-957
Dichloroacetyl chloride (DCAC) attracted our attention as an intermediate product of the photocatalytic degradation of trichloroethylene
(TCE). The adsorption and photocatalytic reaction of DCAC on TiO2 have been investigated by FTIR spectroscopy. The influence of the surface structure of several TiO2s on the reaction mechanism was discussed in order to understand the complete degradation mechanism of TCE as well as DCAC.
DCAC was transformed into dichloroacetic acid (DCAA) on the relatively hydrophobic TiO2 surface by the small amount of the water molecules weakly adsorbed on the surface. This DCAA was degraded to phosgene, CO2, and CO during UV irradiation. For the hydrophilic TiO2, DCAC was mainly transformed into the dichloroacetate anion. UV irradiation allowed this species to produce chloroform in
addition to phosgene, CO2, and CO. It is suggested that DCAC easily reacts with the Ti–OH group on the hydrophilic TiO2 and forms the bidentate titanium chelate of dichloroacetate, which efficiently degrades into chloroform. 相似文献
76.
Tadatake Sato Ryozo Kurosaki Aiko Narazaki Yoshizo Kawaguchi Hiroyuki Niino 《Applied Physics A: Materials Science & Processing》2010,101(2):319-323
The well-controlled fabrication of microtrenches including inclined features using normal incidence with gradual shifting
of the irradiated area was demonstrated. Based on the variation of trench width depending on the laser fluence, the existence
of gaps between the edge of the irradiated area and sidewall of the trench was shown. Because of these gaps, the shifted laser
pulse can stay at the bottom of the trenches in the fabrication of the inclined features. In laser-induced backside wet etching
(LIBWE), the photo-activated region generated within organic solution would act on the glass surface and results in etching.
It was indicated that the photo-activated region generated at the bottom of the trenches acted not only on the bottom of the
trench but also on the sidewalls. Based on such etching of the sidewall, fabrication of inclined features becomes possible.
In this method, the tilting angle can be changed within one deep trench. Flexible structure formation deep inside the silica
glass can be achieved. 相似文献
77.
Hirata Y Nakamura S Watanabe N Kataoka O Kurosaki T Anada M Kitagaki S Shiro M Hashimoto S 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(35):8898-8925
A carbonyl ylide cycloaddition approach to the squalene synthase inhibitors zaragozic acids A and C is described. The carbonyl ylide precursor 8 was synthesized starting from di-tert-butyl D-tartrate (47) via an eleven-step sequence involving the regioselective reduction of the mono-MPM (MPM=4-methoxybenzyl) ether 48 with LiBH4 and the diastereoselective addition of sodium tert-butyl diazoacetate to alpha-keto ester 10. The reaction of alpha-diazo ester 8 with 3-butyn-2-one (40) in the presence of a catalytic amount of [Rh2(OAc)4] gave the desired cycloadduct 59 as a single diastereomer. The dihydroxylation of enone 59 followed by sequential transformations permitted the construction of the fully functionalized 2,8-dioxabicyclo[3.2.1]octane core 5. Alkene 79 derived from 5 serves as a common precursor to zaragozic acids A (1) and C (2), since the elongation of the C1 alkyl side chain can be attained by olefin cross-metathesis, especially under the influence of Blechert's catalyst (85). 相似文献
78.
Kurosaki Y Abe H Morioka H Hirayama J Ikebuchi K Kamo N Nikaido O Azuma H Ikeda H 《Photochemistry and photobiology》2003,78(4):349-354
The mechanism by which UV-C irradiation inactivates M13 bacteriophage was studied by analyzing the M13 genome using agarose gel electrophoresis and South-Western blotting for pyrimidine dimers. The involvement of singlet oxygen (1O2) was also investigated using azide and deuterium oxide and under deoxygenated conditions. With a decrease in M13 infectivity on irradiation, single-stranded circular genomic DNA (sc-DNA) was converted to Form I and Form II, which had an electrophoretic mobility between that of sc-DNA and linear-form DNA. However, the amount of sc-DNA remaining was not correlated with the survival of M13. The formation of cyclobutane pyrimidine dimers (CPD) and pyrimidine (6-4) pyrimidone photoproducts ((6-4)PP) increased as a function of irradiation dose. The decrease in M13 infectivity was highly correlated with the increase in CPD and (6-4)PP, whereas no change was seen in M13 coat protein on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. 8-Oxo-7,8-dihydro-2'-deoxyguanosine did not form in the M13 genome after UV-C irradiation. Inactivation of M13 was neither enhanced by deuterium oxide nor inhibited by azide. Deoxygenation of the M13 suspension did not affect the inactivation, indicating that 1O2 did not participate in the inactivation of M13 by UV-C irradiation under these conditions. These results indicated that UV-C irradiation induced not only CPD and (6-4)PP formation but also additional tertiary structural change in DNA inside the M13 virions, resulting in primary damage and a loss of infectivity. The indirect effect of UV-C irradiation such as 1O2 production followed by oxidative damage to nucleic acids and proteins might have contributed less, if at all, to the inactivation of M13 than the direct effect of UV-C. 相似文献
79.
Kurosaki H Ishikawa Y Ishihara T Yamamoto T Yamaguchi Y Goto M 《Dalton transactions (Cambridge, England : 2003)》2005,(6):1086-1092
The order of relative reactivity of nitriles for the formation of Fe(II) complexes (2s) with 3-(1-alkyl(or aryl)methyl)-1-imino-2,4-bis(2-pyridylmethylimine)(L(2)s) from that with 2,4-bis(2-pyridylmethylimono)pentane (L1), trans-[FeL(1)(MeCN)(2)][ClO(4)](2).MeCN (1), and various nitriles has been determined based on the following order: C(6)F(5)CN > 3,4-difluorobenzonitrile > 4-fluorobenzonitrile > C(6)H(5)CN > C(6)H(5)CH(2)CN > C(2)H(5)CN > MeCN > Me(2)CHCN >Me(3)CN. An iron(II) complex with L1 in a cis-configuration was prepared as the ternary complex [FeL(1)(bpy)][ClO(4)](2).1.5MeNO(2).0.5H(2)O, 3a (bpy = bipyridine). Compounds 2s and 3a undergo enantiomeric interconversion with an activation energy of ca. 60 kJ mol(-1). 相似文献
80.
Shunsaku Shiotani Masahide Kurosaki Katsunori Taniguchi Miwa Moriyama 《Journal of heterocyclic chemistry》1997,34(3):941-952
Nitration of 2,3-dihydrofuro[3,2-b]- N-oxide 3b and -[2,3-c]pyridine N-oxide 3c afforded the nitropyridine compounds 4b, 5b and 6 from 3b and 4c, 5c, 5′c and 7 from 3c , while -[2,3-b]- N-oxide 3a and -[3,2-c]pyridine N-oxide 3d did not give the nitro compound. Chlorination of 3b and 3c with phosphorus oxychloride yielded mainly the chloropyridine derivatives 15b, 15′b from 3b and 15c and 15′c from 3c , whereas 3a and 3d gave pyridine derivatives formed through fission of the 1–2 ether bond of the furo-pyridines 13a , 14 and 13d . Acetoxylation of 3b and 3c gave 3-acetoxy derivatives 18b and 18c and the parent compound 1b and 1c . Acetoxylation of 3a yielded compounds formed through fission of the 1–2 bond 16 and 17 and 3d gave furopyridones 19 and 19 ′. Cyanation of 3b and 3c yielded mainly the cyanopyridine compounds 20b, 20c and 20′c . Cyanation of 3a and 3d gave the cyanopyridine compounds 20a , 20d and 20′d accompanying formation of the pyridine derivatives 21a, 21d and 21′d . 相似文献