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1.
In the present paper we report the first experimental results on ac and dc conductivity and permittivity of adenine hemisulphate hydrate and adenine sulphate measured at atmospheric and high hydrostatic pressures. For both materials ac conductivity is of
s type, where:s 1·1· Room temperature dc conductivity of adenine hemisulphate hydrate equals approximately 5×10–15
–1 cm–1 with an activation energy of 0·86 eV; dc conductivity of adenine sulphate is less than 10–16 cm–1. On the basis of these measurements and those carried out at high pressure, it is concluded that conductivity of adenine hemisulphate hydrate is of electronic type.The authors wish to thank Dr. J. Zachová for the preparation of adenine salts single crystals. 相似文献
2.
J. Krištiak O. Šauša P. Bandžuch J. Bartoš 《Journal of Radioanalytical and Nuclear Chemistry》1996,210(2):563-570
The temperature dependence of positron annihilation characteristics,
3 andI
3, has been studied on sample of poly(butadiene), poly(isobutylene) and poly(chloroprene). The temperature range was between 15 and 470 K. The rate of expansion of holes or free-volume in all samples was deduced belowT
g as well aboveT
g as appr. 3·10–3 K–1 and 2·10–2 K–1, respectively. These values are very close to the rate of the mean squared displacement of scatterer<r
2>observed in neutron scattering experiments. A possibility to use an inverse value of free-volume,V
f
–1
for study of viscoelastic state of polymers is demonstrated. 相似文献
3.
The -decay of83Y isomers (7.06 min and 2.85 min) have been studied by means of Ge (Li) detectors. The proposed level scheme of the83Sr nucleus is based on the coincidence measurement and the analysis of energy sums. The intensity balance requirement leads to
T
(35·5 keV)=3.2 which is consistent with M1 multipolarity of this transition. A probable structure of some of the excited states in the83Sr nucleus is discussed in the framework of Alaga's model and Kuriyama's model. 相似文献
4.
E. Illeková J. Krištiak E. Macová I. Maťko O. Šauša 《Journal of Thermal Analysis and Calorimetry》2013,113(3):1187-1196
The solidification/melting of cetane confined in nine silica glasses with specific controlled pores (CPG) with different pore sizes (r p ranging from 3.7–72 nm) has been studied. Samples with variable coefficient of filling of cetane were prepared and analyzed. Combining the indication of the evolving solidification heats (via differential scanning calorimetry, DSC) with the lifetime spectra of positron annihilation, the mechanism of filling of cetane molecules in the pores of the hosting silica glass matrices has been searched. Three independent solidification effects—three independent DSC peaks—were observed in each measuring cycle, namely one crystallization exotherm Rb of the bulk-cetane (if present) and two crystallization sub-peaks Rc1 and Rc2 of the confined cetane in the case of continuous cooling. The temperatures of both Rc1 and Rc2 effects decrease on decreasing the r p of the CPG matrix. The mutual relation between Rc1 and Rc2 has been analyzed. The kinetics of all three steps of the solidification in the continuous-cooling as well as isothermal regimes have been specified. 相似文献
5.
Esen S Schwartz AJ Adachi I Aihara H Arinstein K Aulchenko V Aushev T Aziz T Bakich AM Balagura V Barberio E Bay A Bischofberger M Bondar A Bozek A Bračko M Browder TE Chang MC Chang P Chen A Chen P Cheon BG Chiang CC Choi Y Dalseno J Dash M Doležal Z Drásal Z Drutskoy A Eidelman S Goldenzweig P Golob B Ha H Haba J Hara T Hayasaka K Higuchi T Hoshi Y Hou WS Hsiung YB Hyun HJ Iijima T Inami K Itoh R Iwabuchi M Joshi NJ Julius T Kang JH Kawasaki T Kichimi H Kim HJ Kim HO Kim JH Kim YJ Kinoshita K 《Physical review letters》2010,105(20):201802
We have made the first observation of B(s)(0)→D(s)(*)+ D(s)(*)- decays using 23.6 fb(-1) of data recorded by the Belle experiment running on the Υ(5S) resonance. The branching fractions are measured to be B(B(s)(0)→D(s)+ D(s)-)=(1.03(-0.32-0.25)(+0.39+0.26))%, B(B(s)(0)→D(s)(*±) D(s)(?))=(2.75(-0.71)(+0.83)±0.69)%, and B(B(s)(0)→D(s)*+ D(s)*-)=(3.08(-1.04-0.86)(+1.22+0.85))%; the sum is B[B(s)(0)→D(s)(*)+ D(s)(*)-]=(6.85(-1.30-1.80)(+1.53+1.79))%. Assuming B(s)(0)→D(s)(*)+ D(s)(*)- saturates decays to CP-even final states, the branching fraction determines the ratio ΔΓ(s)/cosφ, where ΔΓ(s) is the difference in widths between the two B(s)-B(s) mass eigenstates, and φ is a CP-violating weak phase. Taking CP violation to be negligibly small, we obtain ΔΓ(s)/Γ(s)=0.147(-0.030)(+0.036)(stat)(-0.041)(+0.042)(syst), where Γ(s) is the mean decay width. 相似文献
6.
Jolanta Rousseau Vilija Kriščiūnienė Ilona Rimkevičiūtė Cyril Rousseau Virginė Amankavičienė Algirdas Šačkus Arnaud Tatibouët Patrick Rollin 《Monatshefte für Chemie / Chemical Monthly》2009,140(3):339-348
Abstract Modular conditions for the formation of thioureas or pyrimidine-4-one-2-thiones connected to the benzo[b]thiophene, benzene and indole structures were performed. A benzo[b]thiophene isothiocyanate derivative was used as a model to study the condensation with simple aromatic amines and amino-l-sorbose derivative. The construction of pyrimidine-4-one-2-thiones using basic conditions afforded efficiently new heterocyclic
aromatics, which were further transformed using the alkylated sulfur as a leaving group in palladium-catalyzed cross-coupling
reactions.
Graphical abstract
相似文献
7.
The copolyamides consisting of ε-caprolactam and 6.1–24.5 wt.% of nylon salt prepared from adipic acid and 1-(2-aminoethyl)
piperazine were synthesized. Physical and thermal characteristics of polyamide 6 and the copolyamides were compared. Nylon
salt does not influence the polyreaction equilibrium so it is possible to prepare the copolyamides with high molecular weight
and with the content of low-molecular compounds comparable with that of pure PA 6. Melting temperatures of the copolyamides
are lower in comparison with PA 6 and decrease proportionally to the amount of the nylon salt. The thermal stability of the
copolyamides is good and equal to that of PA 6. The melting enthalpies indicate that the process of crystallization of the
copolyamides is influenced by the time of crystallization and the amount of comonomer present. Longer time of the crystallization
assures higher degree of crystallization. The kinetics and the level of crystallization are positively influenced by the mobility
of copolyamide segments mainly up to 10 wt.% of comonomer. 相似文献
8.
9.
Romana Krištof Suzana Košenina Benjamin Zorko Jasmina Kožar Logar 《Journal of Radioanalytical and Nuclear Chemistry》2017,314(2):675-679
The aim of the research was to obtain first results of tritium in the organic matter of environmental samples in the vicinity of Kr?ko NPP. The emphasis was on the layout of suitable sampling network of crops and fruits in nearby agricultural area. Method for determination of tritium in organic matter in the form of Tissue Free Water Tritium (TFWT) and Organically Bound Tritium (OBT) has been implemented. Capabilities of the methods were tested on real environmental samples and its findings were compared to modeled activities of tritium from atmospheric releases and literature based results of TFWT and OBT. 相似文献
10.
K. Kriŝtiaková O. Ŝauŝa J. Kriŝtiak Ŝ. Jánoŝ 《Zeitschrift für Physik B Condensed Matter》1989,75(2):197-199
We have measured the ac susceptibility of a wire with a Nb core (1.27 mm diam.) and a Cu cladding (0.37 mm thickness) atT50 K andB0.1 mG. Due to its proximity to Nb, the Cu becomes fully superconducting. From the data we find a breakdown fieldH
b
=1.2 (mG) and a coherence length =2.2T
–1/2 (m) for the Cu, as well as a field penetration depth -34T
1/2 (m) at the Cu/Nb interface. 相似文献