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31.
A high voltage electric pulse can be applied to induce the uptake of DNA into cells and the release of protein from cells.
In transformation procedures, electroporation is widely used since the technique is simple, rapid, reproducible, and highly
efficient. In extraction of protein, on the other hand, electroextraction has many advantages over other conventional extractions.
We have developed a highly efficient method for the electroporation of fission yeast. In particular, application of a high
voltage electric pulse to fission yeast improves the cellular uptake and release of macromolecules controlled by both osmotic
conditions and electric field strength.
相似文献
Minoru SugaEmail: |
32.
Hand's method is typically used to empirically calculate the equilibrium compositions for ternary systems between two liquid phases. Oil field application of Hand's method is generally limited to surfactant phase behavior with oil and brine, primarily because the excess oil and brine phases are nearly immiscible. Hand's method is not accurate to represent liquid–vapor equilibrium, especially as oil and gas become miscible. It also requires iterations, which means there is no guarantee of convergence. 相似文献
33.
Yutaka Aoyagi Kei Ozawa Tatsuya Kobayashi Tomoyo Hasuda Ming-Yu Gui Yong-Ri Jin Xu-Wen Li Haruhiko Fukaya Reiko Yano Yukio Hitotsuyanagi Koichi Takeya 《Tetrahedron》2014
Transformation of plant-origin 7,14-dihydroxy-ent-kaurenes to ent-abietanes having a cis-fused α-methylene γ-lactones was accomplished efficiently under the Mitsunobu reaction conditions. The yields of the desired products were apparently influenced by the steric hindrance at C-1. The cytotoxic activity on P388 murine leukemia cells of the ent-abietanes having cis-fused α-methylene γ-lactones produced were assayed. 相似文献
34.
The Lanthanumiodideethanide o‐La5I9(C2) – The Orthorhombic High Temperature Modification o‐La5I9(C2) is synthesized by reaction of LaI3, La metal and graphite powder in sealed Ta containers at 850 °C < T < 900 °C. It crystallizes in the orthorhombic space group Pbca with a = 8.0247(16) Å, b = 16.887(3) Å, c = 35.886(7) Å. o‐Ce5I9(C2) is isotypic with the lattice parameters a = 7.9284(4) Å, b = 16.714(1) Å, c = 35.530(3) Å. o‐La5I9(C2) transforms at 800 °C to the triclinic low temperature modification t‐La5I9(C2). The transformation is reversible. The La atoms form trigonal bipyramids centered by C2 groups. These units are connected by iodine atoms above the faces (f), edges (e) and corners according to La5(C2)I(f)iI(e)i?i2/2I(e)i?a7/2I(e)a?i7/2. The C‐C distance in the C2 unit is 1.45(2) Å. The crystals with greenish luster are moisture sensitive. 相似文献
35.
抗坏血酸是许多生化过程所必需的一种生物小分子。借助于羟基氧化钴纳米片的氧化性和钴离子与硫氰酸根离子之间强的螯合作用,本文报道了一种基于钴离子介导信号转换的新方法用于抗坏血酸的比色分析。在抗坏血酸存在时,羟基氧化钴纳米片被还原降解产生二价钴离子,钴离子与硫氰酸根离子之间通过螯合作用生成蓝色的阴离子络合物[Co(NCS)4]2-,在625nm处产生可见吸收信号。在优化条件下,体系625nm处的吸收值与抗坏血酸浓度在0.03~0.45 mmol/L范围内呈良好的线性关系,线性方程为A625=0.638c(mmol/L)+0.042,相关系数R=0.993,检测限(3S/N)为1.5μmol/L。 相似文献
36.
The first one-dimensional (1-D) indiumphosphate chain, In2(HPO4)2(H2PO4)2F2·C4N2H12 (1), has been hydrothermally prepared using piperazine (PIP) as a template. The structure consists of infinite chains of trans,trans-corners-sharing InO4F2 octahedra with the adjacent octahedra being bridged by tetrahedral PO3(OH) and PO2(OH)2 units, which are H-bonded with amine groups of the organic cations. Interestingly, this macroanionic chain InP2O8H3F− is similar to that found in the mineral tancoite-like chains and has potential to further set up higher-dimensional networks. On heating 1 in the presence of additional phosphoric acid at 180 °C under hydrothermal condition, compound 2, In2(OH)(H2O)(PO4)2·H3O·H2O, possessed a 3-D structure building from the repetition of a secondary building unit is obtained. When 1 is heated with additional PIP, an unknown phase, compound 3 is formed. Finally, on treatment with another amine, such as diethylenetriamine or 1,4-diaminobutane, at 180 °C, 1, as a precursor, can convert into a previously known 3-D framework structure with 16-membered ring compound 4. Compounds 1 and 2 are determined by single-crystal X-ray diffraction. Furthermore, 1 is characterized by X-ray powder diffraction, IR spectroscopy, inductively coupled plasma analysis, thermogravimetric analysis and differential thermal analysis. 相似文献
37.
Determination of halogenated flame retardants by liquid chromatography coupled to mass spectrometry 总被引:1,自引:0,他引:1
We present an overview of current analytical methods for selected halogenated flame retardants (HFRs), focusing on instrumental determination using liquid chromatography coupled to mass spectrometry. We based the strategy for literature search on recent articles published in peer-reviewed scientific journals or conference proceedings. We report on selected HFRs and some metabolites and transformation products, and on the analytical performances of different ionization modes, with emphasis on selectivity and sensitivity. Moreover, we compare these parameters with those obtained by gas chromatography. 相似文献
38.
S. Steffen M. Otto L. Niewoehner M. Barth Z. Bro¿żek-Mucha J. Biegstraaten R. Horváth 《Spectrochimica Acta Part B: Atomic Spectroscopy》2007
A gunshot residue sample that was collected from an object or a suspected person is automatically searched for gunshot residue relevant particles. Particle data (such as size, morphology, position on the sample for manual relocation, etc.) as well as the corresponding X-ray spectra and images are stored. According to these data, particles are classified by the analysis-software into different groups: ‘gunshot residue characteristic’, ‘consistent with gunshot residue’ and environmental particles, respectively. Potential gunshot residue particles are manually checked and – if necessary – confirmed by the operating forensic scientist. 相似文献
39.
Oxidation of N-carbonylhydrazones of 7-hydroxy-8-acetylcoumarin with lead tetraacetate results in the synthesis of 7,8-diacylcoumarins in good yields. The reaction proceeds via the transformation of a hydroxy into an acyl group reported for the first time in heterocyclic chemistry. 相似文献
40.
Until now, time-of-flight (TOF) mass analysers have only been very rarely used in pesticide residue analysis (PRA) of water
samples. However, the inherent characteristics of TOF MS make these analysers well-suited to this field, mainly for qualitative
purposes. Thus, the high sensitivity obtained from full-scan acquisition in comparison to other MS analysers and the high
resolution of TOF MS suggest its suitability for screening purposes; it also increases the multiresidue capabilities of methods
based on it and decreases the chance of recording false positives. Although these characteristics can also be helpful for
quantification, confirmation and elucidation, some limitations on the use of TOF for these purposes have been observed. These
limitations are more noticeable when dealing with samples containing very low analyte concentrations, which is the normal
situation for PRA in water. The use of hybrid quadrupole–time-of-flight instruments (QTOF) minimises the limitations of TOF,
facilitating the simultaneous detection and unequivocal confirmation of pesticides found in the sample. Additionally, the
acquisition of accurate product ion full-scan mass spectra can help to elucidate the structures of unknown compounds. In this
paper, the potential of TOF and QTOF hyphenated to liquid chromatography for PRA in water is explored, emphasizing both the
advantages and limitations of this approach for screening, quantification, confirmation and elucidation purposes. Emphasis
is placed on the determination of polar pesticides and transformation products—the analytes that fit well with LC–API–(Q)TOF
MS technology. 相似文献