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61.
Joo Yang Mang 《Journal of fluorine chemistry》2009,130(2):259-1161
The catalytic enantioselective electrophilic α-hydrazination promoted by chiral nickel complexes is described. Treatment of α-fluoro-β-ketoesters with azodicarboxylates as electrophilic amination reagents under mild reaction conditions afforded the corresponding α-amino α-fluoro-β-ketoesters with high yields (80-96%) and enantioselectivities (up to 78% ee). 相似文献
62.
Synthesis of MCM-22 zeolite using rice husk as a silica source under varying-temperature conditions 总被引:1,自引:0,他引:1
Cheng Y Lu M Li J Su X Pan S Jiao C Feng M 《Journal of colloid and interface science》2012,369(1):388-394
In this study, rice husk, an abundant agricultural byproduct, was utilized as an alternative silica source for the synthesis of MCM-22. The zeolite with high crystalline was synthesized using a three-stage varying-temperature hydrothermal method. The prepared silica and MCM-22 were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The results showed that the duration required for zeolite crystallization was significantly decreased under varying-temperature conditions. The MCM-22 was in the form of thin platelet-like crystals, and no amorphous material existed in the framework of the MCM-22 after calcination and ammonium exchange. Cationic brilliant red 5GN, a basic dye used in the wool and blanket factories for fiber dyeing, was selected as the adsorptive to study the adsorption performance of the MCM-22. Adsorption experiments indicated that the maximum extent of adsorption was obtained at pH of 10, contact time of 60 min, and MCM-22 dose of 1.0 g/L. The adsorption kinetic has been described by first-order and pseudo-second-order models. It was observed that the rate of dye adsorption followed pseudo-second-order model. 相似文献
63.
A small shielding effect on the hydrogen atoms of chiral carbons of β-cyclodextrin (β-CD) was detected by 1H nuclear magnetic resonance, but a large environmental change of the chiral carbon atoms at high concentration ratios of lithium carbonate (Li2CO3) to β-CD was observed by polarimetry in aqueous solution. These findings urged us to investigate whether different formation conditions of the molecule-ion system between Li2CO3 and β-CD in solid state were involved in different spectral performances. To answer the question, we prepared three adducts of Li2CO3 to β-CD, i.e., samples 1, 2, and 3, by magnetic stirring, solvothermal and grinding conditions, respectively. Powder X-ray diffraction and Fourier transformation infrared spectroscopy provided the information of formation of the three molecule-ion adducts. Besides, scanning electron microscope images provided different surface information of the three adducts. Further, significant spectral differences in thermal behavior of these adducts were found by thermogravimetry and derivative thermogravimetry. 相似文献
64.
65.
C. Müntz P. Baltes H. Oeschler C. Sartorius C. Sturm A. Wagner C. Bormann D. Brill Y. Shin J. Stein H. Ströbele W. Ahner R. Barth M. Cieślak M. Deȩbowski E. Grosse W. Henning P. Koczoń M. Mang D. Miśkowiec R. Schicker P. Senger B. Kohlmeyer H. Pöppl F. Pühlhofer J. Speer K. Völkel W. Waluś 《Zeitschrift für Physik A Hadrons and Nuclei》1997,357(4):399-409
Double differential cross sections of positively charged pions and protons have been measured in nuclear collisions of mass-symmetric systems (Ne+NaF, Ni+Ni, Au+Au, Bi+Pb) at incident energies between 0.8 and 1.8 AGeV as a function of the centrality of the reaction. Using a magnetic spectrometer pions and protons were detected with laboratory angles between 40 and 48 degrees, and with momenta up to about 1400 MeV/c. This setting allows for the study of pions and protons emitted close to midrapidity. The center-of-mass pion spectra deviate from a Boltzmann distribution. The inverse slope parameters of the high-energetic pions are smaller than those of the proton spectra and they exhibit a weaker centrality dependence. A scenario is presented where the shape of the pion spectra reflects the decay kinematics of nucleonic resonances embedded in the thermal and the collective motion of the nucleons in the reaction zone. The number of emitted pions per participating nucleon is higher for light than for heavy mass systems. For a given mass system, the total pion multiplicity increases linearly with the number of participating nucleons, whereas the multiplicity of high-energy pions increases more than linearly. This result is consistent with a scenario where the high-energy pions are produced in multiple energetic baryon-baryon collisions occurring in the high-density phase of the collision. 相似文献
66.
ZhengLongYANG HongZhengCHEN LeiCAO HartYinLI MangWANG 《中国化学快报》2004,15(6):717-720
The multiwall carbon nanotube (MWCNT) bonded to 2, 9, 16, 23-tetraamino manganese phthalocyanine (TAMnPc) was obtained by covalent functionalization, and its chemical structure was characterized by TEM. The photoconductivity of single-layered photoreceptors, where MWCNT bonded by TAMnPc (MWCNT-b-TAMnPc) served as the charge generation material(CGM), was also studied. 相似文献
67.
Kunde GJ Hsi WC Kunze WD Schüttauf A Wörner A Begemann-Blaich M Blaich T Bowman DR Charity RJ Cosmo A Ferrero A Gelbke CK Hubele J Immé G Iori I Kreutz P Lindenstruth V Lisa MA Lynch WG Lynen U Mang M Möhlenkamp T Moroni A Müller WF Neumann M Ocker B Ogilvie CA Peaslee GF Pochodzalla J Raciti G Rubehn T Sann H Seidel W Serfling V Sobotka LG Stroth J Stuttge L Tomasevic S Trautmann W Tsang MB Tucholski A Verde G Williams CW Zude E Zwieglinski B 《Physical review letters》1995,74(1):38-41
68.
Abstract— Experimental mouse mammary tumor cells (EMT-6) were subjected to PDT (30 u-g/mt DHE,620–640 nm at 3.94 mW/cnr) and hyperthermia (45.2°C, Haake FK2 waterbath) for varying lengths of time and sequences. The results show that the two modalities interact in a manner which is more cytotoxic than the sum of the individual treatments, and the sequence of administration is a determining factor in the degree of interaction. The greatest potentiation of PDT is seen when hyperthermia is administered immediately after PDT. Introducing a time interval at 37°C, between treatments, leads to a rapid loss of interaction. Analysis of dose-response curves reveals a return of the shoulder and an increase in the D., after various incubation periods at 37°C. These data suggest that the cells accumulate and demonstrate recovery from sub-lethal damage and also develop a tolerance to a second challenge. The appearance of stress proteins was also detected after PDT treatments, which may account for some of the phenomena observed. 相似文献
69.
A Simple Synthetic Method of a 1,3,5‐Triazine UV Absorbent CGL‐479 and Its Characterization 下载免费PDF全文
As a novel ultraviolet (UV) absorbent with excellent performance in UVA section (320 ~ 400 nm), 2‐{2‐hydroxy‐4‐[(octyloxycarbonyl)ethylideneoxy]phenyl}‐4,6‐Bis(4‐biphenylyl)‐1,3,5‐triazine (CGL‐479) was synthesized in a simple method with a total yield of 45.3% in four steps. Its outstanding UV absorption capability (λmax = 326 nm, εmax = 4.15 × 104 L?mol?1?cm?1), high thermostability [T5 (the temperature of losing 5% in weight) = 385 °C], and compatibility with polymer materials make it a potential substitute of the traditional UV absorbents. 相似文献
70.
合成了萘酞菁锌, 利用傅立叶红外光谱、元素分析和MALDI-TOF质谱等手段表征了分子结构; 循环伏安测试和吸收光谱确认了共轭体系的扩大使分子带隙下降. 根据材料加工性能的不同, 分别采用溶液法、层-层蒸镀(Layer-by-layer evaporation)法和单层分散旋涂法, 将给体分子萘酞菁锌与三种受体分子1-(3-甲氧基羧基)丙基-1-苯 基-[6,6]C61, C60和N,N’-二嘧啶基苝四羧基二酰亚胺进行了复合, 通过研究复合前后荧光变化, 确认了给体-受体两相界面处发生了由分子能级差引发的光致电荷转移, 为制备更宽光伏响应范围的太阳能电池器件提供了潜在的新途径. 相似文献