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101.
Hojo H Matsumoto Y Nakahara Y Ito E Suzuki Y Suzuki M Suzuki A Nakahara Y 《Journal of the American Chemical Society》2005,127(39):13720-13725
Peptide thioester corresponding to a MUC2 tandem repeat unit, which retains seven GalNAc moieties, was prepared by the Fmoc method followed by the low TfOH treatment to remove benzyl groups at the carbohydrate portions. The glycosylated peptide thioester was then consecutively joined by the activation of a thioester group by silver ions to obtain a MUC2 tandem repeat model composed of 141 amino acids with 42 GalNAc moieties. 相似文献
102.
Toru Nakahara 《Monatshefte für Mathematik》1982,94(2):125-132
In this note we shall prove that there exist infinitely many cyclic biquadratic fieldsK whose integral bases are neither {1, , 2, } nor {1, , , 3) for any numbers , inK. Next, we shall construct infinitely many cyclic biquadratic fieldsK which have the index 1, but still have not the integral basis {1, , 2, 3) for every inK. Finally we shall give a class of biquadratic fields for a problem of Hasse concerning an integral basis. 相似文献
103.
104.
105.
Yutaka Kawahara Wataru Takarada Masaki Yamamoto Yasuhito Kondo Kohji Tashiro Takeshi Kikutani 《Journal of Macromolecular Science: Physics》2020,59(7):440-456
AbstractVarious types of bicomponent fibers composed of polylactide (PLA) and poly(butylene terephthalate) (PBT) with different molecular weights, arranging the polymers separately in the skin or core, were produced by high-speed melt-spinning. The bicomponent spinning, arranging the PLA with high molecular weight (melt flow rate =1.9?g/10?min, L-lactide content = 98.7%) in the skin and the PBT with low molecular weight (IV = 0.835–0.865 dL/g) in the core, resulted in orientation-induced crystallization in the PLA component at the spinning speed of 2?km/min. This crystallization effect was ascribed to a chain-extending treatment applied to the original PLA (MFR = 4.0?g/10?min) to increase its molecular weight. By the treatment the PLA could crystallize when spun even at 1?km/min in its single-component spinning. On the other hand, the bicomponent spinning system interfered with the orientation-induced crystallization of PBT in the core. As a result, the critical spinning speed needed to generate the orientation-induced crystallization in the core PBT was elevated to 4?km/min. The inferior tensile behavior of the bicomponent fibers, as compared to the single-component PLA or PBT fibers, suggested poor compatibility between PLA and PBT. Transesterification reactions rarely occurred at the interface of the two polymers. The bicomponent fibers prepared from high molecular weight PLA and low molecular weight PBT, however, showed sufficient antibacterial activity and physical properties to be suitable for designing medical clothing materials. 相似文献
106.
W. Sato K. Sueki K. Kikuchi K. Kobayashi S. Suzuki Y. Achiba H. Nakahara Y. Ohkubo F. Ambe K. Asai 《Journal of Radioanalytical and Nuclear Chemistry》1999,241(1):187-190
Time-differential perturbed angular correlation method was applied to Ce@C82 in order to investigate the electronic properties of the encaged Ce atom. The nuclear quadrupole frequency of the nuclear
spin of the Ce was successfully determined as ωQ = 6.5(3)·107 rad/s, which is much greater than what has already been estimated for Ce4+ and La3+ in other compounds. By comparing the present value with the values for the Ce4+ and La3+, it was inferred that the valence state of the encaged Ce atom is trivalent. 相似文献
107.
108.
Yasuhito Yokoi Yugo Kawabuchi Abdullah Adham Zulmajdi Reiji Tanaka Toshiyuki Shibata Takahiro Muraoka Tetsushi Mori 《Molecules (Basel, Switzerland)》2022,27(24)
Approximately 30% or more of the total proteins annotated from sequenced bacteria genomes are annotated as hypothetical or uncharacterized proteins. However, elucidation on the function of these proteins is hindered by the lack of simple and rapid screening methods, particularly with novel or hard-to-transform bacteria. In this report, we employed cell-penetrating peptide (CPP) –peptide nucleotide acid (PNA) conjugates to elucidate the function of such uncharacterized proteins in vivo within the native bacterium. Paenibacillus, a hard-to-transform bacterial genus, was used as a model. Two hypothetical genes showing amino acid sequence similarity to ι-carrageenases, termed cgiA and cgiB, were identified from the draft genome of Paenibacillus sp. strain YYML68, and CPP–PNA probes targeting the mRNA of the acyl carrier protein gene, acpP, and the two ι-carrageenase candidate genes were synthesized. Upon direct incubation of CPP–PNA targeting the mRNA of the acpP gene, we successfully observed growth inhibition of strain YYML68 in a concentration-dependent manner. Similarly, both the function of the candidate ι-carrageenases were also inhibited using our CPP–PNA probes allowing for the confirmation and characterization of these hypothetical proteins. In summary, we believe that CPP–PNA conjugates can serve as a simple and efficient alternative approach to characterize proteins in the native bacterium. 相似文献
109.
Protic NNN and NCN Pincer‐Type Ruthenium Complexes Featuring (Trifluoromethyl)pyrazole Arms: Synthesis and Application to Catalytic Hydrogen Evolution from Formic Acid 下载免费PDF全文
Yoshiko Nakahara Tatsuro Toda Prof. Dr. Asuka Matsunami Prof. Dr. Yoshihito Kayaki Prof. Dr. Shigeki Kuwata 《化学:亚洲杂志》2018,13(1):73-80
NNN and NCN pincer‐type ruthenium(II) complexes featuring two protic pyrazol‐3‐yl arms with a trifluoromethyl (CF3) group at the 5‐position were synthesized and structurally characterized to evaluate the impact of the substitution on the properties and catalysis. The increased Brønsted acidity by the highly electron‐withdrawing CF3 pendants was demonstrated by protonation–deprotonation experiments. By contrast, the IR spectra of the carbonyl derivatives as well as the cyclic voltammogram indicated that the electron density of the ruthenium atom is negligibly influenced by the CF3 group. Catalysis of these complexes in the decomposition of formic acid to dihydrogen and carbon dioxide was also examined. The NNN pincer‐type complex 1 a with the CF3 group exhibited a higher catalytic activity than the tBu‐substituted analogue 1 b . In addition, the bis(CF3‐pyrazolato) ammine derivative 4 catalyzed the reaction even in the absence of base additives. 相似文献
110.
Hiroshi Watanabe Tomohiro Sato Kunihiro Osaki Mutsuo Matsumoto Dobrin P. Bossev Cathy E. McNamee Masaru Nakahara 《Rheologica Acta》2000,39(2):110-121
Linear viscoelastic behavior was investigated for aqueous solutions of perfluorooctyl sulfonate (C8F17SO−
3; abbreviated as FOS) micelles having a mixture of tetraethylammonium (N+(C2H5)4; TEA) and lithium (Li+) ions as the counter-ions. The solutions had the same FOS concentration (0.1 mol l−1) and various Li+ fractions in the counter-ions, φLi = 0−0.6, and the FOS micelles in these solutions formed threads which further organized into dendritic networks. At T ≤ 15 °C,
the terminal relaxation time τ and the viscosity η, governed by thermal scission of the networks, increased with increasing
φLi up to 0.55. A further increase of φLi resulted in decreases of τ and η and in broadening of the relaxation mode distribution. These rheological changes are discussed
in relation to the role of TEA ions in thermal scission: Previous NMR studies revealed that only a fraction of TEA ions were
tightly bound to the FOS micellar surfaces and these bound ions stabilized the thread/network structures. The concentration
of non-bound TEA ions, CTEA
*, decreased and finally vanished on increasing φLi up to φLi
* ≅ 0.6, and the concentration of the bound TEA ions significantly decreased on a further increase of φLi. The non-bound TEA ions appeared to catalyze the thermal scission of the FOS threads, and the observed increases of τ and
η for φLi < 0.55 were attributed to the decrease of CTEA
*. On the other hand, the decreases of τ and η as well as the broadening of the mode distribution, found for φLi > 0.55 (where CTEA
* ≅ 0), were related to destabilization of the FOS threads/networks due to a shortage of the bound TEA ions and to the existence
of concentrated Li+ ions. Viscoelastic data of pure FOSTEA and FOSTEA/FOSLi/TEACl solutions lent support to these arguments for the role of TEA
ions in the relaxation of FOSTEA/FOSLi solutions.
Received: 12 October 1999/Accepted: 1 November 1999 相似文献