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131.
[structure: see text] An O-glycosylated peptide carrying two core 2 sialopentasaccharides of different glycoform was synthesized as a model of the heterogeneous surface of mucin glycoprotein. Solid-phase synthesis and the subsequent enzymatic sialylation gave two segments, which were coupled by selective thioester activation to produce the title compound. 相似文献
132.
Pentacoordinated Carboxylate π‐Allyl Nickel Complexes as Key Intermediates for the Ni‐Catalyzed Direct Amination of Allylic Alcohols
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Dr. Yusuke Kita Hironobu Sakaguchi Dr. Yoichi Hoshimoto Daisuke Nakauchi Dr. Yasuhito Nakahara Prof. Dr. Jean‐François Carpentier Prof. Dr. Sensuke Ogoshi Prof. Dr. Kazushi Mashima 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(41):14571-14578
Direct amination of allylic alcohols with primary and secondary amines catalyzed by a system made of [Ni(1,5‐cyclooctadiene)2] and 1,1′‐bis(diphenylphosphino)ferrocene was effectively enhanced by adding nBu4NOAc and molecular sieves, affording the corresponding allyl amines in high yield with high monoallylation selectivity for primary amines and high regioselectivity for monosubstituted allylic alcohols. Such remarkable additive effects of nBu4NOAc were elucidated by isolating and characterizing some nickel complexes, manifesting the key role of a charge neutral pentacoordinated η3‐allyl acetate complex in the present system, in contrast to usual cationic tetracoordinated complexes earlier reported in allylic substitution reactions. 相似文献
133.
In Vivo Spectrum of UVC‐induced Mutation in Mouse Skin Epidermis May Reflect the Cytosine Deamination Propensity of Cyclobutane Pyrimidine Dimers
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Hironobu Ikehata Toshio Mori Masayuki Yamamoto 《Photochemistry and photobiology》2015,91(6):1488-1496
Although ultraviolet radiation (UVR) has a genotoxicity for inducing skin cancers, the skin may tolerate UVC component because the epidermal layer prevents this short wavelength range from passing through. Here, UVC genotoxicity for mouse skin was evaluated in terms of DNA damage formation and mutagenicity. UVC induced UVR photolesions and mutations remarkably in the epidermis but poorly in the dermis, confirming the barrier ability of the epidermis against shorter UVR wavelengths. Moreover, the epidermis itself responded to UVC mutagenicity with mutation induction suppression, which suppressed the mutant frequencies to a remarkably low, constant level regardless of UVC dose. The mutation spectrum observed in UVC‐exposed epidermis showed a predominance of UV‐signature mutation, which occurred frequently in 5′‐TCG‐3′, 5′‐TCA‐3′ and 5′‐CCA‐3′ contexts. Especially, for the former two contexts, the mutations recurred at several sites with more remarkable recurrences at the 5′‐TCG‐3′ sites. Comparison of the UVC mutation spectrum with those observed in longer UVR wavelength ranges led us to a mechanism that explains why the sequence context preference of UV‐signature mutation changes according to the wavelength, which is based on the difference in the mCpG preference of cyclobutane pyrimidine dimer (CPD) formation among UVR ranges and the sequence context‐dependent cytosine deamination propensity of CPD. 相似文献
134.
Back Cover: Indolizino[5,6‐b]quinoxaline Derivatives: Intramolecular Charge Transfer Characters and NIR Fluorescence (Chem. Asian J. 11/2015)
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135.
Indolizino[5,6‐b]quinoxaline Derivatives: Intramolecular Charge Transfer Characters and NIR Fluorescence
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Mitsuru Kojima Dr. Hironobu Hayashi Dr. Tatsuya Aotake Dr. Shinya Ikeda Dr. Mitsuharu Suzuki Prof. Dr. Naoki Aratani Dr. Daiki Kuzuhara Prof. Dr. Hiroko Yamada 《化学:亚洲杂志》2015,10(11):2337-2341
Indolizino[5,6‐b]quinoxaline derivatives ( 1 a and 1 b ) with a push–pull structure were prepared to show intramolecular charge‐transfer properties. Compounds 1 a and 1 b are strongly fluorescent in aprotic solvents while symmetrical derivatives ( 2 a and 2 b ) were non‐fluorescent. The π‐expanded α–α linked dimer ( 10 ) of indolizino[5,6‐b]quinoxaline 1 b was serendipitously obtained to show NIR absorption over 800 nm and the fluorescence edge reached to 1400 nm. 相似文献
136.
Umemoto H 《The Journal of chemical physics》2007,127(1):014304
The production yields of H(D) atoms in the reactions of N(2)(A (3)Sigma(u) (+)) with C(2)H(2), C(2)H(4), and their deuterated variants were determined. N(2)(A (3)Sigma(u) (+)) was produced by excitation transfer between Xe(6s[32](1)) and ground-state N(2) followed by collisional relaxation. Xe(6s[32](1)) was produced by two-photon laser excitation of Xe(6p[12](0)) followed by concomitant amplified spontaneous emission. H(D) atoms were detected by using vacuum-ultraviolet laser-induced fluorescence (LIF). The H(D)-atom yields were evaluated from the LIF intensities and the overall rate constants for the quenching, which were determined from the temporal profiles of the NO tracer emission. The absolute yields were evaluated by assuming that the yield for NH(3)(ND(3)) is 0.9. Although no HD isotope effects were observed in the overall rate constants, there were isotope effects in the H(D)-atom yields. The H-atom yields for C(2)H(2) and C(2)H(4) were 0.52 and 0.30, respectively, while the D-atom yields for C(2)D(2) and C(2)D(4) were 0.33 and 0.13, respectively. The presence of isotope effects in yields suggests that H(2)(D(2)) molecular elimination processes are competing and that molecular elimination is more dominant in deuterated species than in hydrides. 相似文献
137.
Yoshio Imai Hironobu Ishikawa Ki-Hong Park Masa-Aki Kakimoto 《Journal of polymer science. Part A, Polymer chemistry》1997,35(10):2055-2061
A facile method for the synthesis of high-molecular-weight aromatic polyethers was developed with the use of cesium fluoride as a base. The high-temperature solution polycondensation between bisphenols and activated aromatic dihalides with cesium fluoride in polar aprotic solvents readily afforded a series of aromatic polyethers having inherent viscosities of 0.5–1.0 dL/g under essentially neutral and milder reaction conditions, compared with the conventinal method using alkali hydroxides or alkali carbonates. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 2055–2061, 1997 相似文献
138.
Kozo Matsumoto Hironobu Shimazu Masaki Deguchi Hitoshi Yamaoka 《Journal of polymer science. Part A, Polymer chemistry》1997,35(15):3207-3216
Anionic polymerizations of 1,1-dimethylsilacyclobutane, 1,1-diethylsilacyclobutane and 1-methyl-1-phenylsilacyclobutane were investigated. Addition of 5 mol % of butyllithium to a solution of 1,1-dimethylsilacyclobutane in THF-hexane (1 : 1) at −48°C provided poly(1,1-dimethylsilabutane) in 99% yield. Mn and Mw/Mn of the obtained polymer were 2400 and 1.10. This polymerization proceeded with a living nature. Mn increased in proportion as the yield of polymer increased. Addition of the second fresh feed of the monomer to the reaction mixture restarted polymerization of the second monomer at the same rate as in the initial stage. Addition of styrene to the living poly(1,1-dimethylsilabutane) provided a poly(1,1-dimethylsilabutane-b-styrene) block copolymer. It was also found that a polymerization of 1,1-diethylsilacyclobutane in THF-hexane at −48°C showed a living nature. In contrast, a polymerization of 1-methyl-1-phenylsilacyclobutane in THF at −78°C did not show a living nature. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 3207–3216, 1997 相似文献
139.
Shinya MATSUSHIMA Yusuke KASAHARA Shun AIKAWA Takeru FUZIMURA Hitoshi YOKOYAMA Hironobu KATATA 《Physical Therapy Research》2021,24(3):285
Background: Early mobilization and rehabilitation interventions should be provided to patients who survived severe COVID-19 to improve their physical function and activities of daily living (ADL). However, their physical and mental status at discharge has not been well described in Japan. We report the intervention provided for a survivor of severe COVID-19 and his physical and mental status at discharge from an acute care hospital. Case Report: A 62-year-old man was admitted to our emergency department with a diagnosis of COVID-19 with severe acute respiratory dysfunction. He had complicated intensive care unit-acquired weakness (ICU-AW) and delirium during mechanical ventilation therapy. Rehabilitation intervention was initiated on the seventh day post-admission and was gradually performed according to his respiratory and hemodynamic status. As a result of the rehabilitation intervention, ICU-AW and cognitive function gradually improved. On hospital day 37, he independently performed basic ADL and was discharged. However, he lost approximately 9% of his body weight at discharge. In addition, his hand grip strength and six-minute walking distance were lower and shorter than the reference values, respectively. His mental component summary of the Short Form-8™ was lower than the national standard deviation for the Japanese population. Conclusion: Although survivors of severe COVID-19 who undergo early rehabilitation can be discharged from an acute care hospital, they may have several impairments in their physical and mental status, including muscle function, diffusion capacity, exercise tolerance, and health-related quality of life. 相似文献
140.
Dr. Manabu Ohtomo Dr. Hironobu Hayashi Dr. Kenjiro Hayashi Dr. Hideyuki Jippo Juanjuan Zhu Ryunosuke Hayashi Dr. Junichi Yamaguchi Dr. Mari Ohfuchi Prof. Hiroko Yamada Dr. Shintaro Sato 《Chemphyschem》2019,20(24):3366-3372
We demonstrate the effect of edge functionalization on the on-surface Ullmann coupling of nano-carbon materials. Unlike 10,10′-Dibromo-9,9′-bianthryl (DBBA), which is widely known to form anthracene polymers and armchair-edge graphene nanoribbons on Au(111), newly-developed precursor named 5-bromo-11(10-bromoanthracene-9-yl)anthra[2,3-b : 7,6-b′]dithiophene (BABAT) with isomers, which has similar structure as DBBA with one anthracene substituted with anthradithiophene, was found to make intramolecular C−C bonding instead of long anthracene polymers after annealing at 200 °C on Au(111). The mechanism was investigated using first-principle density functional theory, which revealed that on-surface polymerization is not kinetically preferred in case of BABAT. The reaction rate of intramolecular C−C bonding of BABAT is ∼206 times faster than that of DBBA. The intramolecular C−C bonding in DBBA biradicals, on the other hand, do not take place because of faster reverse reaction. By referring to electron density of BABAT biradicals, it was concluded that thiophene functionalization modifies distribution of electron density in BABAT radicals and facilitates electrophilic addition, leading to intramolecular C−C bonding after 200 °C annealing. These results indicate that the design of radical moiety is particularly important in the on-surface Ullmann-type coupling. 相似文献