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101.
3-[(E)-Arylmethylidene]-3,9-dihydropyrrolo[2,1-b]quinazolin-1(2H)-ones were prepared by reaction of quinazolyl-2-propionic acid
hydrochloride with aromatic aldehydes in acetic anhydride in the presence of Et3N. 3-[(E)-Arylmethylidene]-1,2,3,9-tetrahydropyrrolo[2,1-b]quinazolin-1-ols were formed by reduction of the 3-arylidene derivatives
with sodium borohydride in methanol, readily lost water when heated with acids, and were converted into 3-[(E)-arylmethylidene]-3,9-dihydropyrrolo[2,1-b]quinazolines.
__________
Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 463–467, September–October, 2006. 相似文献
102.
The solid-liquid equilibria of the quasi-quaternary system H2O-Zn(NO3)2·6H2O-Cu(NO3)2·3H2O-NH4NO3 were studied at 25°C by using a synthetic method based on conductivity measurements. Three isoplethic sections has been established at 25°C and the stable solid phases which appear are: NH4NO3(IV), Zn(NO3)2·6H2O, anhydrous Cu(NO3)2, Cu(NO3)2·3H2O and metastable Cu(NO3)·2.5H2O. Neither double salts, nor mixed crystals are observed at these temperatures and composition range. 相似文献
103.
104.
The cerium‐containing MCM‐41 (Ce‐MCM‐41) has been synthesized by direct hydrothermal method. The low‐angle XRD patterns revealed the typical five major peaks of MCM‐41 type hexagonal structures. The interplanar spacing d100 = 38.4 Å was obtained that can be indexed on a hexagonal unit cell parameter with ao = 44.3 Å which was larger than that of pure siliceous MCM‐41 (Si‐MCM‐41). Transmission electron micrograph shows the regular hexagonal array of uniform channel characteristics of MCM‐41. The BET surface area of Ce‐MCM‐41 was 840 m2/g, which is much reduced as compared to that of Si‐MCM‐41, with the pore size of 26.9 Å and mesopore volume of 0.78 cm3/g were measured by nitrogen adsorption‐desorption isotherm at 77 K. Along with the results, the synthesized Ce‐MCM‐41 exhibited a well‐ordered MCM‐41‐type mesoporous structure with the incorporation of cerium. Using Ce‐MCM‐41 as a support, the Rh (0.5 wt%) catalyst exhibited very high activity for the NO/CO reactions. 相似文献
105.
V. V. Kuznetsov Z. V. Bondarenko T. V. Pshenichkina N. V. Morozova V. N. Kudryavtsev 《Russian Journal of Electrochemistry》2007,43(3):349-354
Kinetics of processes of electrochemical production of a cobalt-molybdenum alloy out of an ammonia-citrate electrolyte is studied. The electrolyte’s composition is similar to that used for depositing a nickel-molybdenum alloy. It is established that the cobalt-molybdenum alloy undergoes deposition at smaller values of pH (5.0–6.0) than the nickel-molybdenum alloy (7.0–9.0). The current efficiency for the cobalt-molybdenum alloy is substantially dependent on the electrolyte pH, whereas the chemical composition of the obtained deposits is practically independent of the electrolyte pH in the pH interval 5.0–8.0 at current densities of 0.025 to 0.100 A cm?2. On the other hand, a change in the electrolyte pH produces a considerable effect on the morphology of the obtained deposits. At large values of pH (pH 8.0), one can obtain a powder-like deposit of the cobalt-molybdenum alloy with a small value of the current efficiency. The deposits that are obtained in the pH region 5.0–6.0 have some cracks, with the number of cracks increasing with the electrolyte pH. 相似文献
106.
The nitrosyl-hemoglobin (HbNO) is the carrier of nitric oxide (NO) which is the important messenger molecule displaying multiple physiologic and pathophysiologic roles. However it is still not clear for the fate of HbNO molecules during the venous-arterial transit. In this letter, the HbNO transition in vitro was studied by using the electron paramagnetic resonance (EPR) spectra. It was found that HbNO molecules were stable when oxygen did not exist in the system but not stable in aerobic conditions. The absorption spectra further revealed that the methemoglobin (metHb) was the product of HbNO in aerobic environment, showing that the HbNO changed to metHb when there were enough oxygen molecules in the system. 相似文献
107.
固体氧化物电解池是一种高效、环境友好型的能量转换器件,可以直接将电能转化为化学能. 本文介绍了近年来作者课题组在固体氧化物电解池直接用于CO2还原的研究进展,并以阴极材料为主着重讨论了金属陶瓷电极和混合导电型钙钛矿氧化物电极的研究工作,最后展望了未来固体氧化物电解池直接电解CO2的研究思路和方向. 相似文献
108.
Studies on photo-catalytic reduction of CO2 using TiO2 photo-catalyst (0.1%, w/v) as a suspension in water was carried out at 350 nm light. CO2 from both commercially available source, as well as generated in situ through 2-propanol oxidation, was used for this study. The photolytic products such as hydrogen (H2), carbon monoxide (CO) andmethane (CH4) generated were monitored in TiO2 suspended aqueous solution with and without a hole scavenger, viz., 2-propanol. Similar photolytic experiments were also carried out with varying ambient such as air, O2, N2 and N2O. The yields of CO and CH4 in all these systems under the present experimental conditions were found to be increasing with light exposure time. H2 yield in N2-purged systems containing 2-propanol was found to be more as compared to the without 2-propanol system. The rate of H2 production in N2-purged aqueous solutions containing 0.1% TiO2 suspension were evaluated to be 0.226 and 5.8 μl/h, without and with 0.5 M 2-propanol, respectively. This confirmed that
2-propanol was an efficient hole scavenger and it scavenged photo-generated holes (h+), allowing its counter ion, viz., e−, to react with water molecule/H+ to yield more H2. The formation of both CO and CH4 in the photolysis of CO2-purged aqueous solutions containing suspended TiO2 in absence of 2-propanol reveal that the generation of CH4 is taking place mainly through CO intermediate. In presence of air/O2, the yield of H2 in the system without 2-propanol was observed to be negligible as compared to the system containing 2-propanol in which low
yield of H2 was obtained with a formation rate of approx. 0.5 μl/h. 相似文献
109.
Yi‐Zhen Tang Hao Sun Ya‐Ru Pan Xiu‐Mei Pan Rong‐Shun Wang 《International journal of quantum chemistry》2007,107(6):1495-1501
The mechanisms for the reaction of CH3S with NO2 are investigated at the QCISD(T)/6‐311++G(d,p)//B3LYP/6‐311++G(d,p) on both single and triple potential energy surfaces (PESs). The geometries, vibrational frequencies, and zero‐point energy (ZPE) correction of all stationary points involved in the title reaction are calculated at the B3LYP/6‐311++G(d,p) level. More accurate energies are obtained at the QCISD(T)/6‐311++G(d,p). The results show that 5 intermediates and 14 transition states are found. The reaction is more predominant on the single PES, while it is negligible on the triple PES. Without any barrier height for the whole process, the main channel of the reaction is to form CH3SONO and then dissociate to CH3SO+NO. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007 相似文献
110.
The cathodic electrolysis of esters of 1,1,2,2-ethane- or ethylenetetracarboxylic acids in the presence of dihaloalkanes leads to esters of 1,1,2,2-cycloalkanetetracarboxylic acids.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 217–220, January, 1992. 相似文献