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51.
Summary The possibility of using the parameters connected to delayed luminescence to detect thermal stress conditions in soya seeds
is discussed here and the results of the measurement of photoinduced emission conducted on soya seeds characterized by a different
vegetative vigour are presented. A phenomenological relationship between the total re-emission and the growth velocity was
found. The distributions of the decay times relative to the different conditions of stress on the seeds have given indications
towards the existence of different dynamics. On the basis of the results it seems that a correlation exists between the functional
state of the seeds and delayed luminescence.
The authors of this paper have agreed to not receive the proofs for correction. 相似文献
52.
Laser-induced photodissociation of NaCs molecule has been observed when a mixture of Na and Cs metal vapour in a glass cell was irradiated by most of the lines of an argon ion laser. The photodissociation results in the 3P state of Na atoms which is correlated with theF 1Σ+ and G1π molecular states of NaCs. Distribution of photofragments over fine structure components 32 P 3/2 and 32 P 1/2 of Na has been studied. The ratio of intensity ofD 2 line (5890 Å) toD 1 line (5896 Å) of Na varies from around 2 at 5145 Å to about 3.5 at 4579 Å. The relative photodissociation cross-section increases monotonically as the wave-length of laser light decreases from 5145 Å to 4579 Å. It is seen that the 4579 Å photon is about 200 times more effective than the 5145 Å photon in causing the photoreaction NaCs + (Ar+ photon) → Na*(3P) + Cs(6S). 相似文献
53.
The photodissociation mechanism of benzyl chloride (BzCl) under 248 nm has been investigated by the complete active space SCF (CASSCF) method by calculating the geometries of the ground (S0) and lower excited states, the vertical (Tv) and adiabatic (T0) excitation energies of the lower states, and the dissociation reaction pathways on the potential energy surfaces (PES) of SI, TI and T2 states. The calculated results clearly elucidated the photodissociation mechanism of BzCl, and indicated that the photodissociation on the PES of T1 state is the most favorable. 相似文献
54.
The dynamic behavior of highly excited molecular states in an external monochromatic field has been investigated in order to establish the general trends in the Rydberg state manifestations in collisional and radiative processes. The effects of interference between direct (background) and resonant interactions and coupling between the continua on the fine structure of collision cross sections and near-threshold photoabsorption spectra are discussed. Analytical expressions for the widths and intensities of the Rydberg lines induced by mixing the field with other quasistationary states are derived and their dependence on the external field strength and frequency are analyzed. It was found that the appreciable stabilization of isolated Rydberg levels observed previously in superstrong fields is also possible in fields much weaker than atomic fields. The possibility of laser control for the energy averaged cross sections and reaction rate constants are considered. All effects are illustrated for thee
– + H2
+ system.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 367–386, March, 1994.This work was supported by the Russian Foundation for Basic ReSearch (Grant No. 93-03-4700). 相似文献
55.
M. F. Budyka N. V. Biktimirova T. N. Gavrishova 《Chemistry of Heterocyclic Compounds》2007,43(4):454-459
Isomeric azidostyrylquinolines with a 4-azidostyryl group in position 2 or 4 of the quinoline ring have been synthesized.
In the neutral form the azidostyrylquinolines absorb in the near UV but the protonated species absorb in the short wavelength
region of the visible spectrum. In both forms the azides are lightsensitive and decompose under the influence of light with
a quantum yield close to 1.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 555–561, April, 2007. 相似文献
56.
57.
The reaction pathways for CH(3)COCH(2)OH (hydroxyacetone) photodissociation on the low-lying electronic states have been studied with use of the CASSCF energy gradient techniques. The S(0)/S(1) and S(1)/T(1) intersection points were determined by the state-average CASSCF method. Two main reaction pathways, which are possible to the photodissociation, have been studied. It has been found that the mechanism is stepwise, and belongs to Norrish type-I reaction. The n --> pi* excitation leads to the first excited singlet state, followed by the intersystem crossing from S(1) to T(1). On the T(1) potential energy surface, the system can dissociate adiabatically to CH(3)(x) +COCH(2)OH( x) and CH(3)CO(x)+CH(2)OH(x). The COCH(2)OH(x) and CH(3)CO(x) radicals can further dissociate into CO, OH, and other fragments. Our calculated results are in good agreement with recent experimental results. 相似文献
58.
Production of CH (A2△) by multi-photon dissociation of (CH3)2CO,CH3NO2, CH2Br2, and CHBr3 at 213 nm 下载免费PDF全文
In order to realize electrostatic Stark deceleration of CH radicals and study cold chemistry, the fifth harmonic of a YAG laser is used to prepare CH(A2△) molecules through using the multi-photon dissociation of(CH3)2CO, CH3NO2, CH2Br2,and CHBr3 at ~ 213 nm. The CH product intensity is measured by using the emission spectrum of CH(A2△→ X2Π). The dependence of fluorescence intensity on laser power is studied, and the probable dissociation channels are analyzed. The relationship between the fluorescence intensity and some parameters, such as the temperature of the beam source, stagnation pressure, and the time delay between the opening of pulse valve and the photolysis laser, are also studied. The influence of three different carrier gases on CH signal intensity is investigated. The vibrational and rotational temperatures of the CH(A2△) product are obtained by comparing experimental data with the simulated ones from the LIFBASE program. 相似文献
59.
通过密度泛函理论计算研究了1, 2-环己二酮(α-CHD)基态光解离反应的势能面. 通过IRC方法确定了5个主要的反应通道, 相应的产物分别为P1(c-C5H8O+CO), P2(2C2H4+2CO), P3(CH2CHCH2CH2CHO+CO), P4(2CH2CO+C2H4)和P5(CH3CHCO+CH2CHCHO). 获得了反应过程中反应物、产物、中间体和过渡态的结构参数. 详细阐述了这些通道的反应过程, 分析了其反应机理, 总结出最优的反应路径为α-CHD→c-C5H8O+CO. 理论分析与实验结果相符. 获得的结果为进一步进行与1, 2-环己二酮相关的研究提供有价值的信息. 相似文献
60.
利用团簇模型研究了二氧化碳对质子化甲醇的溶剂化作用.H+(CH3OH)(CO2)n+(n=1~7)的量子化学计算结果表明,需要3个或4个二氧化碳分子完成甲醇的羟基第一溶剂层.除了氢键,二氧化碳分子间的相互作用对大团簇的稳定性也起到了重要的作用.在这些溶剂化作用的早期阶段,不容易发生质子从甲醇到二氧化碳的转移过程.模拟的红外光谱揭示了自由O-H伸缩振动、氢键作用后的O-H伸缩振动、以及二氧化碳的O-C-O伸缩振动频率是研究质子化甲醇溶剂化过程的灵敏探针. 相似文献