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81.
Shobhana Sharma Asha Jain Sanjiv Saxena 《Phosphorus, sulfur, and silicon and the related elements》2013,188(7):1676-1688
Titanium(IV) complexes of the general formula TiL(OPr i )2 [where LH2 = R CH3 where R = ─C6H5, ─C6H4Cl(p)] were prepared by the interaction of titanium isopropoxide with sterically hindered Schiff bases derived from heterocyclic β -diketones in 1:1 molar ratio in dry benzene. The complexes TiL(OPr i )2 were used as versatile precursors for the synthesis of other titanium(IV) complexes. Titanium(IV) complexes of the type TiLL'(OPr i ) (where L'H═R1R2C═NOH, R1 = R2 = ─CH3; R1 = ─CH3,R2 = ─C6H5; R1 = ─COC6H5, R2 = ─C6H5) were synthesized by the reaction of TiL(OPr i )2 with ketooximes (L'H) in equimolar ratio in dry benzene. Another type of titanium(IV) complexes having the general formula TiLGH(OPr i ) (where GH2═HO─G─OH, G = ─CH2─CH2─) have been prepared by the reaction of TiL(OPr i )2 with glycol in 1:1 molar ratio in dry benzene. Plausible structures of these new titanium(IV) complexes have been proposed on the basis of analytical data, molecular weight measurements, and spectral studies. 相似文献
82.
Shobhana Sharma Asha Jain Sanjiv Saxena 《Phosphorus, sulfur, and silicon and the related elements》2013,188(7):1689-1701
Zirconium(IV) Schiff base chelates having the general formula ZrL(OPr i )2 [where LH 2 = R CH 3 , R = –C 6 H 5 , –C 6 H 4 Cl(p)] were synthesized by the reaction of Zr(OPr i )4.Pr i OH with sterically constrained sulfur-containing Schiff bases of heterocyclic β -diketones in a 1:1 molar ratio in dry refluxing benzene. The complexes ZrL(OPr i ) 2 were used as important precursors for the synthesis of the complexes of the type Zr(L) 2 . The complexes, Zr(L) 2 , were prepared by the interaction of precursor ZrL(OPr i ) 2 with sterically constrained sulfur-containing Schiff bases of heterocyclic β -diketones in a 1:1 molar ratio in dry benzene. The structures of these zirconium(IV) chelates have been discerned with the help of elemental analyses, physicochemical studies, and spectral [IR and NMR ( 1 H and 13 C)] data. A distorted trigonal bipyramidal and a distorted octahedral geometry may be assigned to zirconium(IV) chelates of the types ZrL(OPr i ) 2 and Zr(L) 2 , respectively. 相似文献
83.
Asha Chilwal Priti Malhotra A. K. Narula 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3):410-421
Abstract Six organotin(IV) complexes of type Me2SnL2, Bu2SnL2, and Ph3SnL [where L = indole-3-butyric acid (1, 2 and 3) or indole-3-propionic acid (4, 5 and 6)] have been synthesized by the reactions of the corresponding diorganotin(IV) oxide and triphenyltin(IV) hydroxide with respective indole-3-butyric acid (IBH) or indole-3-propionic acid (IPH) in the desired molar ratios of 1:2/1:1. All of the compounds have been characterized by elemental analysis, IR, 1H NMR, 13C NMR, and 119Sn NMR spectroscopy. Thermal studies of all synthesized complexes have been carried out using thermogravimetry (TG) technique under a nitrogen atmosphere. The thermal decompositions for compounds Me2SnL2 and Bu2SnL2 occurred in two steps, whereas in compounds Ph3SnL, it exhibited as three steps decomposition and resulted into the formation of pure SnO2. The complexes were also screened against three gram-positive (Staphylococcus aureus, Staphylococcus epidermidis, and Micrococcus luteus) and three gram-negative (Escherichia coli, Pseudomonas aeruginosa, and Enterobacter aerogenes) bacteria using minimum inhibition concentration (MIC) method, and all of these complexes showed significant antibacterial activity. [Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental files: Additional text, tables, and figures.] 相似文献
84.
Asha Chilwal Preeti Malhotra A. K. Narula 《Journal of Thermal Analysis and Calorimetry》2013,112(1):345-351
Six diorganotin(IV) compounds with amino acids of general formula [(CH3)2SnAACl]2 and [(CH3CH2CH2CH2)2SnAACl]2 (where AA = l-methioninate, l-cysteinate, and l-tryptophanate) were synthesized by reacting dimethyltin(IV) dichloride (M) and dibutyltin(IV) dichloride (B) with l-methionine (M1) or l-cysteine (C) or l-tryptophan (T) using acetonitrile as solvent and designated as MM1, MC, MT, BM1, BC, and BT. The structural characterization of dimethyltin(IV) and dibutyltin(IV) compounds were done using elemental analysis, FT-IR, 1H-NMR, 13C-NMR, and 119Sn-NMR spectroscopy. The thermal properties of the synthesized compounds were studied by thermogravimetric analysis and differential scanning calorimetry techniques in a dynamic atmosphere of nitrogen. The thermal decomposition mechanisms were similar for compounds MM1, BM1, MC, BC, and occurred in one step, while in compounds MT and BT it occurred in two consecutive steps. The TG curves of the MT and BT compounds suggest the loss of the ligand (AA) in the first step, with probable formation of a tin oxide R2SnO intermediate. At the end of the second step free tin is obtained similar to the MM1, BM1, MC, BC in accordance with the stoichiometry of the related compounds. 相似文献
85.
The electrochemical entrapment of polyaniline (PANI) onto sol-gel derived tetraethylorthosilicate (TEOS) films deposited onto indium-tin-oxide (ITO) coated glass has been utilized for immobilization of lactate dehydrogenase (LDH). The performance of these sol-gel/PANI/LDH electrodes has been investigated as a function of the lactate concentration, applied potential, pH of the medium and interferents. The amperometric response of the electrodes under optimum conditions exhibited a linear relationship from 1 mM to 4 mM. An attempt has been made to extend the linearity up to 10 mM for lactate by coating an external layer of polyvinyl chloride (PVC) over the sol-gel/PANI/LDH electrodes with a correlation coefficient of 0.89. These sol-gel/PANI/LDH electrodes have a response time of about 60 s, a shelf life of about 8 weeks at 0-4 degrees C and have implications in a lactate biosensor. 相似文献
86.
Some Classes of Multivariate Life Distributions in Discrete Time 总被引:1,自引:0,他引:1
New classes of multivariate survival distribution functions based on monotonic behaviour of a multivariate failure rate are developed in the discrete set up. Relationship among the classes along with multivariate geometric distributions that act as boundaries of the various classes are identified. 相似文献
87.
Asha V. Chate Ankita S. Kulkarni Chetan K. Jadhav Amol S. Nipte Girabala M. Bondle 《Journal of heterocyclic chemistry》2020,57(5):2184-2193
In this article, we have developed a straightforward, easy and exceedingly competent approach for the synthesis of 5-phenyl-5,6-dihydropyrido[2,3-d]pyrimidine-2,4,7(1H,3H,8H)-triones obtain in superior yields in a sole reaction pace with an air and humidity steady catalyst in water as a green solvent at 100°C. The present procedure paves the approach for the synthesis of biologically fascinating molecular frameworks and has reward in conditions of little catalyst loading with palpable ambiguous and straightforward-to-do reaction circumstances with easy purification process. The used β-cyclodextrin catalyst was recuperated and repeated several times devoid of noteworthy loss of catalytic activity, which is a crucial parameter of green synthesis. 相似文献
88.
Acid phosphatase is ubiquitous in distribution in various organisms. Although it catalyzes simple hydrolytic reactions, it is considered as an interesting enzyme in biological systems due to its involvement in different physiological activities. However, earlier reviews on acid phosphatase reveal some fragmentary information and do not give a holistic view on this enzyme. So, the present review summarizes studies on biochemical properties, structure, catalytic mechanism, and applications of acid phosphatase. Recent advancement of acid phosphatase in agricultural and clinical fields is emphasized where it is presented as potent agent for sustainable agricultural practices and diagnostic marker in bone metabolic disorders. Also, its significance in prostate cancer therapies as a therapeutic target has been discussed. At the end, current studies and prospects of immobilized acid phosphatase are included. 相似文献
89.
Structural Chemistry - The current study primarily involves the investigation of reducing properties of dithia-substituted bicyclic hydrocarbons. Adiabatic electron affinities (AEA) of the selected... 相似文献
90.
Liquid crystalline supramolecular crosslinked polymer complexes of ditopic rylenebisimides and P4VP 下载免费PDF全文
Perylenebisimide and naphthalenebisimide (PBI‐PDP and NBI‐PDP) end functionalized with pentadecyl phenol is designed as ditopic hydrogen bonding acceptors to form supramolecular crosslinked network with poly(4‐vinyl pyridine) (P4VP). The pristine PBI‐PDP has been grown as single crystals from DCM‐MeOH (dichloromethane‐methanol) mixture at room temperature, which revealed a P21 space group. Noticeably, the pentadecyl alkyl chain shields the aromatic perylene core on both sides resulting in the absence of π–π interaction in single‐crystal assembly. The naphthalenebisimide derivative exhibits thermotropic liquid crystalline behavior, while both the molecules exhibits lyotropic liquid crystalline phases in tetrahydrofuran (THF), which were characterized using a combination of differential scanning calorimeter, X‐ray diffraction, and polarized light microscopy. The hydrogen‐bonded complex of both the rylenebisimides with P4VP preserves the mesomorphic properties in THF. The electron transport mobility measured by space charge limited current measurements reveals a two orders of magnitude increase in the charge transport in the P4VP complex compared to that of the pristine molecule. The average electron mobility obtained is μ e,avg: 10?3 cm2/Vs for P4VP‐PBI compared to μ e,avg: 10?5 cm2/Vs for pristine PBI derivative. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55 , 951–959 相似文献