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71.
A novel one-dimensional chain-like coordination polymer constructed from 3-nitrobenzene-1,2-dicarboxylic acid, [Cd2(C8H3NO6)2(H2O)4]n·2nH2O, has been synthesized and its structure was determined by X-ray crystallography method. The crystal belongs to monoclinic, space group P21/c with a = 6.1252(8), b = 20.706(3), c = 8.8067(11) (A), β = 95.608(2)°, V= 1111.6(2)(A)3, Mr =751.12, Dc = 2.244 g/cm3, F(000) = 736, μ = 2.011 mm-1, Z = 2, the final R = 0.0262 and wR = 0.0692for 2338 observed reflections with I > 2σ(I). The structure of the title compound presents a 1-D chain-like structure constructed by dimer units, [Cd2(CsH3NO6)2(H2O)4]n, through two carboxylate oxygen atoms. The fluorescence of the tifle compound has been also discussed in this paper.  相似文献   
72.
Self-assembly of Ag(Ⅰ) nitrate, 1,3-bis(4-pyridyl)propane (bpp) and phthalic acid monopotassium salt (KHphth) in CH3OH-H2O solution produced the title complex,{[Ag(bpp)]2(Hphth)(NO3)·(H2O)2}n, which was characterized by single-crystal X-ray diffraction,elemental analysis, IR spectrum, and photoluminescent spectrum. Single-crystal X-ray analysis revealed that the complex crystallizes in a monoclinic system, space group P21/c, with α =15.4174(5), b = 8.6398(2), c = 25.2466(8) (A), β = 91.072(1)°, V = 3362.34(17) (A)3, Z = 4,C34H37N5O9Ag2, Mr = 875.43, Dc = 1.729 g/cm3, μ = 1.228 mm-1, F(000) = 1768, the final R =0.0749 and wR = 0.1580 for 5754 reflections with I > 2σ(I). The Ag atom is coordinated by two N atoms from two bpp molecules in an approximately linear geometry. The Ag(Ⅰ) ions are linked by the bpp molecules to form one-dimensional zigzag chains propagating along the c axis. The Hphth-and nitrate counter-ions are bridged by solvent water molecules through hydrogen bonds to generate a one-dimensional chain extending along the b axis. Electrostatic interactions between cations and anions, extensive hydrogen bonds and π-π interactions are responsible for the three-dimensional supramolecular structure. In the solid state, the compound exhibits blue photoluminescence with the maximum at 436 nm upon excitation at 344 nm.  相似文献   
73.
A new approach to the synthesis and 1,3-dipolar cycloadditions of nitrones has been described from 2,3-dihydro-4H-pyran and various hydroxylamines, with electron-deficient alkynes for the synthesis of isoxazoline derivatives. Significant rate acceleration and improved yields of exclusively exo isoxazolines in 1-butyl-3-methylimidazolium based ionic liquids have been observed. Novel isoxazolines may be used as a precursor for the synthesis of variety of peptides.  相似文献   
74.
胶体与界面化学的研究进展   总被引:1,自引:0,他引:1  
郭荣  黄建滨  陈晓 《化学通报》2014,77(7):677-691
胶体与界面化学是研究胶体分散体系和界面现象的一门科学,在能源、材料、生物、化学制造和环境科学等领域具有广泛的应用。近年来,由于先进功能材料、仿生学和生物医药等学科的迅速发展,在纳米尺寸(胶体)的范围内进行分子组装和材料的制备已经引起了人们的高度关注。过去两年里,中国胶体与界面化学领域的科学家的创新性研究工作层出不穷,国际影响力日益提升,所获得的研究成果越来越受到国际同行的关注。这些成果可概括为:(1)系列新型有序分子组合体的构建及其在生物医药领域的应用,尤其是超分子组装、表面图案化有序组装材料的设计和应用;(2)胶体与界面化学方法在微纳米功能材料合成中的应用,包括形貌可控的无机材料、有机-无机复合功能材料、贵金属纳米材料以及小分子凝胶的合成及其应用;(3)胶体与界面化学在生物传感领域的新应用;(4)胶体与界面化学研究新方法。作为一门与实际应用密切结合的学科,现代经济社会为胶体与界面化学的发展提供了广阔的空间。可以预期,未来胶体与界面化学将更注重其基本的物理化学问题,如:新颖有序分子组合体的构建和理论认识;功能性微纳米材料界面结构与性能调控的理论指导。此外,新的手段和方法在胶体与界面体系的不断渗透,将不断产生新的学科交叉点,从而有力地促进胶体与界面化学的学科发展。共引用参考文献96篇。  相似文献   
75.
Infrared images always suffer from blurring edges, fewer details and low signal-to-noise ratio. So, sharpening edges and suppressing noise become the urgent techniques in infrared image technology field. However, they are contradictories in most cases. Hence, to depict correctly infrared image features under low signal-to-noise ratio circumstance, a novel prior, which is immune to noise, is presented in this paper. The proposed method scopes noise suppression and details enhancement. In noise suppression, the prior is introduced into Bayesian model to obtain optimal estimation through iteration. In details enhancement, based on the proposed prior, the final image is obtained by the improved unsharp mask algorithm which enhances adaptively details and edges of optimal estimation. The effectiveness and robustness of the proposed method is analyzed by testing the infrared images obtained from different signal-to-noise ratio conditions. Compared with other well-established methods, the proposed method shows a significant performance in terms of noise suppression, actual scene reappearance, enhancing the details and sharpening edges.  相似文献   
76.
This paper uses the recently developed novel robust terminal sliding mode control (NRTSMC) and under-actuated system sliding mode control (USSMC) approaches to solve the strong coupling and under-actuated problems of a small quad-rotor unmanned helicopter (QRUH). The two controllers have been widely adopted to act as a single control algorithm in many fields, respectively. However, this paper just displays the useful composite application of the two controllers. The QRUH model can be divided into two subsystems, including a fully actuated subsystem (FAS) and an under-actuated subsystem (UAS). For the FAS, the NRTSMC is used to solve the strong coupling problem, it can guarantee the FAS states converge to the desired equilibrium in a very short time, then the states are treated as time invariants and the UAS gets simplified. For the UAS, the USSMC is utilized to solve the under-actuated problem. The obtained simulation results show the applicability of the composite control when faced with external disturbances.  相似文献   
77.
The present work gives an in depth discussion related to the development of a hybrid advanced oxidation reactor, which can be effectively used for the treatment of various types of water. The reactor is based on the principle of intensifying degradation/disinfection using a combination of hydrodynamic cavitation, acoustic cavitation, ozone injection and electrochemical oxidation/precipitation. Theoretical studies have been presented to highlight the uniform distribution of the cavitational activity and enhanced generation of hydroxyl radicals in the cavitation zone, as well as higher turbulence in the main reactor zone. The combination of these different oxidation technologies have been shown to result in enhanced water treatment ability, which can be attributed to the enhanced generation of hydroxyl radicals, enhanced contact of ozone and contaminants, and the elimination of mass transfer resistances during electrochemical oxidation/precipitation. Compared to the use of individual approaches, the hybrid reactor is expected to intensify the treatment process by 5–20 times, depending on the application in question, which can be confirmed based on the literature illustrations. Also, the use of Ozonix® has been successfully proven while processing recycled fluids at commercial sites on over 750 oil and natural gas wells during hydraulic operations around the United States. The superiority of the hybrid process over conventional chemical treatments in terms of bacteria and scale reduction as well as increased water flowability and better chemical compatibility, which is a key requirement for oil and gas applications, has been established.  相似文献   
78.
Eight novel ethoxylated nonionic surfactants were prepared based on oil soluble α-amino acids. The L-phenylalanine and L-leucine were esterified and amidated with cetyl alcohol and palamitic acid, respectively; two amides and two esters of α-amino acids were obtained. The ethylene oxide was condensed with the prepared amides and esters to get three different polyethylene oxide units (40, 60, and 100) as phenylalanine derivatives. The amide and ester of α-L-leucine were ethoxylated at (60 ethylene oxides units). The analytical micro analysise, FTIR, 1H NMR, 13C NMR, mass spectra were carried out to confirm the chemical structures. The surface tension of the water soluble prepared compounds was measured at 25°C, further the surface active properties were determined and calculated. Such that critical micelle concentration (CMC), surface excess (Γmax); area per molecule (Amin), effectiveness (γCMC) free energy of micellization and adsorption (ΔGmic, ΔGad). From the data obtained it was found that the CMC of phenylalanine esters is greater than that obtained for the amide derivatives. The Γmax decreased as the ethylene oxide units (EO) increased. It was found also that the ΔGad was greater than the ΔGmic. The obtained data and discrepancy were discussed on the light of surfactant chemical structure.  相似文献   
79.
A novel, simple and sensitive method for the determination of Lusutrombopag in rat plasma using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was developed and validated. The determination was performed on an API4000 triple quadrupole mass spectrometry in the multiple reaction monitoring mode using the respective [M+H]+ ions m/z 593.1 → 272.3 for Lusutrombopag. The limit of detection was 0.5 ng/mL, and the lower limit of quantification was 2.0 ng/mL in rat plasma. Good linearity was obtained over the range of 2.0–150.0 ng/mL and the correlation coefficient was found to be 0.9998. The intra and inter-day precisions were found to be 3.8–6.9% and 6.8–10.5%, respectively. The intra and inter-day accuracy derived from QC samples was found to be 2.5–4.9% and 5.5–7.2%, respectively. The analyte was stable under various conditions (at room temperature, during freeze-thaw, in the autosampler and under deep-freeze conditions). The F-test and t-test at 95% confidence level were subjected on data for statistical analysis. The developed method was successfully applied to the pharmacokinetic study in rats.  相似文献   
80.
A multi-class, multi-residue method for the analysis of 13 novel flame retardants, 18 representative pesticides, 14 polychlorinated biphenyl (PCB) congeners, 16 polycyclic aromatic hydrocarbons (PAHs), and 7 polybrominated diphenyl ether (PBDE) congeners in catfish muscle was developed and evaluated using fast low pressure gas chromatography triple quadrupole tandem mass spectrometry (LP-GC/MS–MS). The method was based on a QuEChERS (quick, easy, cheap, effective, rugged, safe) extraction with acetonitrile and dispersive solid-phase extraction (d-SPE) clean-up with zirconium-based sorbent prior to LP-GC/MS–MS analysis. The developed method was evaluated at 4 spiking levels and further validated by analysis of NIST Standard Reference Materials (SRMs) 1974B and 1947. Sample preparation for a batch of 10 homogenized samples took about 1 h/analyst, and LP-GC/MS–MS analysis provided fast separation of multiple analytes within 9 min achieving high throughput. With the use of isotopically labeled internal standards, recoveries of all but one analyte were between 70 and 120% with relative standard deviations less than 20% (n = 5). The measured values for both SRMs agreed with certified/reference values (72–119% accuracy) for the majority of analytes. The detection limits were 0.1–0.5 ng g−1 for PCBs, 0.5–10 ng g−1 for PBDEs, 0.5–5 ng g−1 for select pesticides and PAHs and 1–10 ng g−1 for flame retardants. The developed method was successfully applied for analysis of catfish samples from the market.  相似文献   
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