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191.
Rahul Bhowmick Abu Saleh Musha Islam Mihir Sasmal Atul Katarkar 《Journal of Coordination Chemistry》2018,71(11-13):2065-2081
A new, highly sensitive probe L2 for the selective detection of Hg2+ in organo-aqueous (H2O:CH3CN, 1:1, v/v, HEPES buffer, pH 7.2) medium has been synthesized from rhodamine 6G-hydrazide and 4-nitroindole-3-carboxaldehyde. It was thoroughly characterized by physicochemical techniques including single crystal X-ray diffraction studies. The reaction of L2 with Hg2+ gives a 1:1 stoichiometry resulting in a 146 fold fluorescence enhancement and a binding constant (Kf) of 3?×?104 M?1. The spirolactam form of the probe is non-fluorescent; however, it shows dual channel (absorbance and fluorescence) recognition of Hg2+ via CHEF effect through the opening of the spirolactam ring. The quantum yields of L2 (0.00045) and L2-Hg2+ (0.29) show the higher stability of complex in the excited state over the free ligand. The 44.5?nM LOD value demonstrates the detection of Hg2+ at a very low concentration range. Cell imaging studies show the cytoplasmic recognition of Hg2+ by L2. Experimental results are comparable with theoretical values obtained by DFT studies. The fluorescence emission of the complex was completely quenched by I- and from the reversibility studies an advance level INHIBIT logic gate and memory device can be framed. 相似文献
192.
通过化学沉淀法制备了CMS@La_2O_3磁性磷吸附剂。结构及磁性表征显示,氧化镧较均匀的包覆在粉煤灰磁珠表面;样品的比磁化强度达20.35 emu·g~(-1),可实现高效磁分离。利用钼酸铵分光光度法对所得磁性吸附剂的磷吸附性能进行了试验研究。研究表明,其最高磷比饱和吸附量可达19.50 mg·g~(-1),吸附时间、pH值、共存阴离子等因素对磷吸附效果均具有显著影响。吸附动力学拟合表明,CMS@La_2O_3对含磷离子的吸附符合准二级动力学方程,以化学吸附为主,磁性吸附剂对含磷离子的吸附反应过程可由La_2O_3表面羟基化-离子交换模型解释。吸附磷后的CMS@La_2O_3吸附剂经处理后可多次循环使用。 相似文献
193.
Nahid Nishat Shahnawaz Ahmad Bhat Abdul Kareem Swati Dhyani Abdulrahman Mohammad Azar Ullah Mirza 《Journal of inclusion phenomena and macrocyclic chemistry》2018,92(3-4):395-409
Macro-cyclic ligands from adipic acid, ethylenediamine with diethyloxalate and diethylmalonate and their respective metal complexes of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) with macro cyclic ligands (LO) and (LM) L [N,N′-bis(2-aminoethyl)hexanediamide] were synthesized successfully. These metal complexes were characterized by Fourier transform infrared, ultraviolet visible spectrometry, proton nuclear magnetic resonance spectroscopy, and mass Spectrometry, CHNS and thermogravimetric analysis. The elemental analysis confirms the structures for Mn(II), Co(II) and Ni(II) complexes similar to octahedral geometry, Cu(II) complexes as a square planar geometry and Zn(II) complexes in the tetrahedral geometry. The molar conductivities of all the metal complexes were taken in 10?3 M DMSO, and values of all the metal complexes showed their electrolytic nature which indicates the presence of chloride ions. Thermal analysis supports as the metal complexes are thermally stable. The result of antimicrobial activity against various microorganisms confirms that the metal complexes are potent bactericides and fungicides than the ligand. Metal complexes of LO with Cu(II) and Zn(II) were found to be highly active against S. typhimurium than the complexes of LM. 相似文献
Graphical abstract
194.
Ashok Kumar Chakraborty Md. Rashidul Islam Md. Helal Uddin Md. Masudur Rhaman 《Journal of Cluster Science》2018,29(1):67-74
A highly efficient and visible light (λ ≥ 420 nm) responsive composite photocatalyst, Co3O4/FeWO4 was prepared by simple impregnation method. The heterojunction semiconductors Co3O4/FeWO4 demonstrated notably high photocatalytic activity over a wide range of composition than the individual component Co3O4 or FeWO4 for the complete degradation of 1,4-dichlorobenzene (DCB) in aqueous phase under visible light irradiation. The photocatalytic activity of composite was optimized at 1/99 Co3O4/FeWO4 composition. After 2 h of visible light irradiation 51% decomposition of 1,4-dichlorobenzene (DCB) was observed utilizing 1/99 Co3O4/FeWO4 photocatalyst while the end members demonstrated a negligible degradation under the same experimental condition. The valence band (VB) and conduction band (CB) of Co3O4 is located above the VB and CB of FeWO4, respectively. Both the semiconductors Co3O4 and FeWO4 exhibit strong absorption over the wide range of visible light. The obviously enhanced photocatalytic performance of Co3O4/FeWO4 composite has been discussed on the hole (h+) as well as electron (e?) transfer mechanism between the VB and CB of individual semiconductors. 相似文献
195.
N. S. Prostakov Islam Nazrul A. V. Varlamov 《Chemistry of Heterocyclic Compounds》1985,21(11):1261-1264
Under conditions of the Mencke reaction, 10,10-dimethyl-9,10-dihydro-10-sila-2-azaanthracene is nitrated on the benzene fragment of the molecule, but the corresponding ketone is nitrated on the pyridine fragment. Dihydrosilaazaanthrone is nitrated by nitrating mixture in positions 5, 7, and 8 of the benzene fragment of the molecule. The nitro-substituted dihydrosilazaanthrones have been reduced to the corresponding amino derivatives.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1528–1531, November, 1985. 相似文献
196.
N. A. Prostakov A. V. Varlamov M. A. Ryashentseva A. A. Fomichev V. A. Rezakov Kossuo Kozm V. M. Polosin Nazrul Islam V. K. Shevtsov 《Chemistry of Heterocyclic Compounds》1990,26(9):1068-1072
The corresponding 1,2,3,4,4a, 9,9a, 10-octahydro derivatives were obtained in the catalytic hydrogenation of 10,10-dimethyl- and 10-methyl-10-phenyl-9,10-dihydro-10-sila-2-azaanthracenes. The hydrogenation of 10,10-dimethyl-10-sila-2-azaanthrone also leads to a substituted octahydrosilaazaanthracene. Isomeric (with respect to the position of the double bond in the nitrogen-containing ring) hexahydrosilaaza-9-anthrols were isolated as a result of the reduction of the methiodide of this silaazaanthrone with sodium borohydride.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1279–1284, September, 1990. 相似文献
197.
E. Hallaba E. Abdel-Wahab A. Islam M. Hamza 《Fresenius' Journal of Analytical Chemistry》1969,247(5-6):283-287
Summary The falling drop method for the isotopic analysis of water sample is fully described. The optimum parameters of the ultra thermostat, the micropipet, the drop size, and the dropping medium for maximum accuracy are discussed. The o-fluorotoluene used should be of the highest purity elsewhere non-reproducible results are obtained. The accuracy obtained is 0.001% up to 0.096 mole% D2O and 0.01% up to 0.994 mole% D2O, although the relative accuracy is the same ±1.4% through the whole calibration curve and is comparable with that of mass spectrometry.
Bestimmung von Deuterium in Wasser mit Hilfe der Methode des fallenden Tropfens
Zusammenfassung Das Verfahren wird beschrieben und die optimalen Arbeitsbedingungen diskutiert. Das als Medium verwendete o-Fluortoluol muß von höchster Reinheit sein, da sonst keine reproduzierbaren Ergebnisse erhalten werden. Die Genauigkeit beträgt 0,001%–0,096 Mol-% D2O und 0,01%–0,994 Mol-% D2O. Die relative Genauigkeit, die im gesamten Bereich ±1,4% beträgt, ist mit der von massenspektrometrischen Bestimmungen vergleichbar.相似文献
198.
Pierce ME Harris GD Islam Q Radesca LA Storace L Waltermire RE Wat E Jadhav PK Emmett GC 《The Journal of organic chemistry》1996,61(2):444-450
DMP 323, a potent HIV-1 protease inhibitor, has been synthesized by an efficient stereoselective process, amenable to large scale preparations. The core C(2) symmetric diol was synthesized by a stereoselective pinacol coupling of CBZ protected D-phenylalanine. Judicious selection of protecting groups allowed cyclic urea formation under mild conditions, enhanced the ease of bis-alkylation, and led to intermediates which were easily purified without chromatography. Additionally, a one-pot, high yield process was developed to prepare the alkylating agent, 4-[(triphenylmethoxy)methyl]benzyl chloride from 1,4-benzenedimethanol. 相似文献
199.
New mono- and bis[4-(3-hydroxy-2-methyl-4-quinolinoyloxy)-2,2,6,6-tetramethylpiperidin-1-oxyl](meso-tetraphenylporphyrinato)yttrium(III) complexes have been synthesized, and the properties of the excited states generated by photoexcitation of porphyrin were studied by time-resolved (TR) and pulsed two-dimensional electron paramagnetic resonance (EPR) spectroscopy. A TR-EPR spectrum was observed in the quartet (S=3/2) or quintet (S=2) states generated from interactions of one or two radicals with the photoexcited triplet state of the porphyrin. The zero-field splitting D values of these states were analyzed in terms of those of the triplet and the radical-triplet pair. The spin states of the excited states were definitely assigned by measuring the mutation frequencies with pulsed EPR. 相似文献
200.
Spectrophotometric Determination of Prochlorperazine Maleate in Pure and Pharmaceutical Preparations
Tehseen Aman Zeeshan Majeed Asrar Ahmad Kazi Islam Ullah Khan 《Mikrochimica acta》2002,138(1-2):13-17
Prochlorperazine maleate reacts with 1-naphthylamine and sodium nitrite, after heating for 110 s at 80 °C to give an orange
red colour having maximum absorbance at 460 nm. The reaction is selective for prochlorperazine maleate with 0.01 mg/mL as
visual limit of quantitation and provides a basis for a new spectrophotometric determination. The colour reaction obeys Beer’s
law from 0.01 mg/10 mL to 0.33 mg/10 mL of prochlorperazine maleate and the relative standard deviation is 0.68%. The quantitative
assessment of tolerable amounts of other drugs is also studied.
Received September 22, 2000. Revision June 19, 2001 相似文献