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排序方式: 共有521条查询结果,搜索用时 31 毫秒
81.
Sonomi Arata Dr. Yuna Kim Prof. Norihisa Hoshino Dr. Keishiro Tahara Dr. Kiyonori Takahashi Dr. Tomofumi Kadoya Tomonori Inoue Prof. Takayoshi Nakamura Prof. Tomoyuki Akutagawa Prof. Jun-ichi Yamada Prof. Kazuya Kubo 《欧洲无机化学杂志》2023,26(12):e202300017
Unsymmetrical gold(III)-dithiolene complexes are potential candidates for molecular materials that exhibit thermal structural phase transitions. In this study, unsymmetrical ppy-gold(III) (ppy−=C-deprotonated-2-phenylpyridine(−)) complexes [AuC5] and [AuC6] coordinated by dithiolene ligands containing tetrathiafulvalene (TTF) skeletons with pentylthio (2-{bis(pentylthio)-1,3-dithiol-2-ylidene}-1,3-dithiol-4,5-dithiolate(2−)) and hexylthio groups (2-{bis(hexylthio)-1,3-dithiol-2-ylidene}-1,3-dithiol-4,5-dithiolate(2−)) were synthesized. Both complexes exhibited a large absorption band at approximately 508 nm, owing to intramolecular ligand-to-ligand charge transfer. One-dimensional columnar structures with head-to-tail molecular arrangements around the metal ions were constructed in the crystals. The flexible alkylthio groups were intercalated into crystalline spaces between dithiolene ligands in the columns. [AuC5] exhibits a simple phase transition at 198 °C between crystalline and isotropic phases irreversibly. The crystalline phase of [AuC6] observed at 25 °C melted at 148 °C. Another crystalline phase grew above 148 °C with a very slow crystallization rate from the liquid phase and was completely transformed into an isotropic phase at 200 °C. 相似文献
82.
We study the global Cauchy problem for the mass critical nonlinear Schrödinger equations. We prove the global existence of analytic solutions in both space and time variables for sufficiently small and exponentially decaying Cauchy data. The method of proof depends on the Leibniz rule for the generator of pseudo-conformal transforms at the L 2 critical level. 相似文献
83.
Yuki H Tanaka Y Hata M Ishikawa H Neya S Hoshino T 《Journal of computational chemistry》2007,28(6):1091-1099
No explicit pi-pi interaction term has been incorporated in the conventional molecular dynamics (MD) simulation programs in spite of its significant role in the folding of biomolecules and the clustering of organic chemicals. In this article, we propose a technique to emphasize the effect of pi-pi interactions using a function of energy and implement it into an MD simulation program. Several trial calculations show that the pi-pi incorporated program gives improved results consistent with experimental data on atom geometry and has no unfavorable interference with the conventional computational framework. This indicates an importance of the explicit consideration of pi-pi interactions in MD simulation. 相似文献
84.
Shinoda K Hasegawa T Sato H Shinozaki M Kuramoto H Takamiya Y Sato T Nikaidou N Watanabe T Hoshino T 《Chemical communications (Cambridge, England)》2007,(40):4140-4142
A biosynthetic intermediate of violacein produced by the mixed enzymes of VioABDE was elucidated to be 5-(5-hydroxy-1H-indol-3-yl)-3-(1H-indol-3-yl)-1H-pyrrole-2-carboxylic acid, named protoviolaceinic acid, indicating that VioC, responsible for the final biosynthetic step, works to oxygenate at the 2-position of the right side indole ring, and that the oxygenation reaction to form the central pyrrolidone core proceeds in a non-enzymatic fashion. 相似文献
85.
Thomas TD Püttner R Fukuzawa H Prümper G Ueda K Kukk E Sankari R Harries J Tamenori Y Tanaka T Hoshino M Tanaka H 《The Journal of chemical physics》2007,127(24):244309
The boron 1s photoelectron spectrum of (11)BF(3) has been measured at a photon energy of 400 eV and a resolution of about 55 meV. The pronounced vibrational structure seen in the spectrum has been analyzed to give the harmonic and anharmonic vibrational frequencies of the symmetric stretching mode, 128.1 and 0.15 meV, as well as the change in equilibrium BF bond length upon ionization, -5.83 pm. A similar change in bond length has been observed for PF(3) and SiF(4), but a much smaller change for CF(4). Theoretical calculations for BF(3) that include the effects of electron correlation give results that are in reasonable accord with the experimental values. The Lorentzian (lifetime) width of the boron 1s core hole in BF(3) is found to be 72 meV, comparable to the value of 77 meV that has been reported for CF(4). 相似文献
86.
O. V. Krokhin A. V. Adamov H. Hoshino O. A. Shpigun T. Yotsuyanagi 《Journal of chromatography. A》1999,850(1-2):269-276
The complexes of Mn2+, Cd2+, Fe3+, Pb2+, Ni2+, Co2+, Zn2+ and Cu2+ with EDTA and cyclohexane-1,2-diaminetetraacetic acid (CDTA) were separated and detected in column and ion electrokinetic chromatography with suppressed conductivity and direct UV detection, respectively. In column ion chromatography (IC) these complexes were separated on an IonPac AS4A anion-exchange column (Dionex, USA). Parameters of carrier electrolyte, which were examined in the ion electrokinetic chromatography (IEKC) mode, include polymer and sulfate concentrations. In IEKC separation selectivity of complexes with poly(diallyldimethylammonium) cation as modifier is similar as for an IonPac AS4A column both for EDTA and CDTA chelates. It was shown that the ion-exchange capacity of the electrokinetic system is more than 100-times lower than the capacity of the IC column for the same peak resolution. In comparison with column main advantages of electrokinetic version are high separation efficiency (220 000–390 000 theoretical plates) and the absence of the analyte interaction with the sorbent matrix. 相似文献
87.
Guohao Yuan Yuko Kimura Takayuki Kobayashi Takashi Takeda Norihisa Hoshino Tomoyuki Akutagawa 《Chemical science》2021,12(40):13520
An alkylamide-substituted (−NHCOC10H21) hydrogen-bonded dibenzo[18]crown-6 derivative (1) was prepared to stabilise the ionic channel structure in a discotic hexagonal columnar (Colh) liquid crystal. The introduction of simple M+X− salts such as Na+PF6− and K+I− into the ionic channel of 1 enhanced the ionic conductivity of the Colh phase of the M+·(1)·X− salts, with the highest ionic conductivity reaching ∼10−6 S cm−1 for K+·(1)·I− and Na+·(1)·PF6− at 460 K, which was approximately 5 orders of magnitude higher than that of 1. The introduction of non-ferroelectric 1 into the ferroelectric N,N′,N′′-tri(tetradecyl)-1,3,5-benzenetricarboxamide (3BC) elicited a ferroelectric response from the mixed Colh phase of (3BC)x(1)1−x with x = 0.9 and 0.8. The further doping of M+X− into the ferroelectric Colh phase of (3BC)0.9(1)0.1 enhanced the ferroelectric polarisation assisted by ion displacement in the half-filled ionic channel for the vacant dibenzo[18]crown-6 of (3BC)0.9[(M+)0.5·(1)·(X−)0.5]0.1.An alkylamide-substituted (−NHCOC10H21) hydrogen-bonded dibenzo[18]crown-6 derivative (1) was prepared to stabilise the ionic channel structure in a discotic hexagonal columnar (Colh) liquid crystal. 相似文献
88.
We report expanded porphyrins with pyridine rings and two neighboring carbonyl groups, which allow NiII ions to coordinate to the tripyrrinone‐type NNNO coordination structure with Ni?O bonds. The selectivity of tripyrrinone is superior to other pyrrolic or pyridinic cavities of expanded porphyrins. Introduction of α‐carbonyl pyridine next to the tripyrrolic conjugated structure is a powerful strategy for regioselective metalation of flexible expanded porphyrinoids. 相似文献
89.
We introduce a notion of Gorenstein algebras of codimension c and demonstrate that Serre duality theory plays an essential role in the theory of derived equivalences for Gorenstein algebras. 相似文献
90.
Neya S Imai K Hiramatsu Y Kitagawa T Hoshino T Hata M Funasaki N 《Inorganic chemistry》2006,45(10):4238-4242
The iron complex of a new type of corrphycene bearing two ethoxycarbonyl (-CO2C2H5) groups on the bipyrrole moiety was introduced into apomyoglobin. The reconstituted ferric myoglobin has a coordinating water molecule that deprotonates to hydroxide with a pK(a) value of 7.3 and exhibits 3-10-fold higher affinities for anionic ligands when compared with a counterpart myoglobin with the same substituents on the dipyrroethene moiety. In the ferrous state, the oxygen affinity of the new myoglobin was decreased to 1/410 of the native protein. The anomalies in the ligand binding, notably dependent on the side-chain location, were interpreted in terms of a characteristic core shape of corrphycene that produces the longer and shorter Fe-N(pyrrole) bonds. The spin-state equilibrium analysis of the ferric azide myoglobin containing the new iron corrphycene supported the nonequivalence of the Fe-N(pyrrole) bonds. These results demonstrate that the trapezoidal molecular shape of corrphycene exerts functional significance when the iron complex is placed in a protein pocket. 相似文献