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61.
Intercalation and Electrochemical Studies of Nitroprusside Anion into Zn-Al Layered Double Hydroxide
Luiz Fernando Da Silva Jairo Tronto Herenilton Paulino Oliveira João Barros Valim 《Journal of inclusion phenomena and macrocyclic chemistry》2003,46(3-4):187-193
The aim of the present work was to investigate the synthesis,characterization and electrochemical properties of the nitroprusside anions (NP)into zinc and aluminium layered double hydroxides (LDHs). The materials were prepared by thecoprecipitation method under constant pH, followed by a hydrothermal treatment. Theprepared materials were characterised by a set of analysis methods, such as powderX-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetry(TG), scanning electron microscopy (SEM) and cyclic voltammetry (CV). The resultsshowed that the electrochemical response of NP ions into LDH structure is similar to thatfound for complex ions free in solution. In addition, our results reveal the dependence ofthe electrochemical response on the nature of the supporting electrolyte, for either cationic oranionic species. 相似文献
62.
Voltammetric response of diclofenac-molecularly imprinted film modified carbon electrodes 总被引:1,自引:0,他引:1
Blanco-López MC Lobo-Castañón MJ Miranda-Ordieres AJ Tuñón-Blanco P 《Analytical and bioanalytical chemistry》2003,377(2):257-261
A voltammetric sensor for the determination of diclofenac was developed, based on the molecular recognition of the analyte by molecularly imprinted methacrylate-ethyleneglycol dimethacrylate co-polymers. Pre-polymerisation solutions were deposited onto the surface of a glassy carbon electrode and a polymer film was obtained after spin coating control of thickness and in situ thermal polymerisation. After the template extraction from the resultant film, re-binding of diclofenac is performed from acetonitrile solutions containing the analyte. The amount of bonded diclofenac was then evaluated by differential pulse voltammetry in different electrolytes. The best results were obtained in 0.025 M citrate solution pH 6 containing 10% of acetonitrile. This medium favours the release of diclofenac from the polymer binding sites. In this way, the voltammetric transduction of the molecular recognition event is achieved. Voltammetric selectivity measurements revealed negligible interferences from diclofenac family of anti-inflammatory drugs, such as niflumic or meclofenamic acids. 相似文献
63.
The Mechanism of Contact Elimination,A Contribution to Understanding the Function of Polar Catalysts
Heinrich Noller Paulino Andru Manfred Hunger 《Angewandte Chemie (International ed. in English)》1971,10(3):172-181
The current ideas of organic chemists based on the work of Ingold and his school are applied to heterogeneous catalytic eliminations (mostly from haloalkanes and aliphatic alcohols). It is deduced from the activity of the catalysts, the reactivity of the substrates (reactants), and the primary product distribution that these eliminations proceed by a heterolytic mechanism similar to that involved in the liquid phase. The activity of the catalysts (salts and oxides) increases with increasing charge and decreasing radius of the cations and with increasing basicity of the anions. The reactivity of the substrates behaves in much the same manner as in the liquid phase. In contrast with the liquid-phase reaction, the cis-olefins are frequently favored as primary products. The stereospecificity of the reaction is determined from the relative strengths of the interactions between the catalyst cation and the leaving group X?, and between the catalyst anion and the leaving proton. Only trans elimination has so far been found in the concerted mechanism. 相似文献
64.
Juan José del Coz Díaz Paulino José García Nieto Felipe Pedro Álvarez Rabanal José Luis Suárez Sierra 《Meccanica》2010,45(5):705-722
The aim of this work is to determine the optimal design of two acoustic test chambers using systems of optimization by means
of finite elements. In this way, we have modelled a set of tests composed of a source chamber and a receiving chamber according
to the basic requirements of the standard rule. The constructive element whose acoustical behaviour is being evaluated is
placed between both chambers. Applying the finite element method (FEM), a two-dimensional coupled finite element model with
fluid-structure interaction has been made, using finite elements of the fluid-type both for the air and fluid-structure interface,
and finite elements of solid-type with its elastic properties for a multilayered wall. The geometry of the chambers has been
parameterized as design variables (DVs) and an objective function has been defined from the absolute value of the difference
between the transmission loss (TL) values of the laboratory test and the TL of the numerical simulation in order to minimize
it. To find an optimal design of the geometry of the acoustic chamber, a new cascade optimization procedure has been successfully
developed. Finally, the numerical simulation results are compared with the acoustic laboratory results, and conclusions are
exposed. 相似文献
65.
Janine S. Cardoso‐Rurr Juliana Patro de Paiva Ivan G. Paulino‐Lima Tatiana A.M. de Alencar Claudia A.S. Lage Alvaro C. Leito 《Photochemistry and photobiology》2019,95(2):618-626
Rational use of water is a major challenge for governments and global organizations, with easy and inexpensive interventions being sought by communities that are not supplied with drinking water. In this context, solar disinfection (SODIS) has shown great efficiency for water disinfection. To speed up the process and improve inactivation, we studied the effects of methylene blue (MB) as a photodynamic agent because of its ability to absorb visible light (red wavelength) and generate singlet oxygen as a reactive species, thereby inactivating bacteria and viruses present in water. In this study, samples of clean mineral water were artificially contaminated with Gram‐positive (Staphylococcus epidermidis or Deinococcus radiodurans) or with Gram‐negative strains (Escherichia coli or Salmonella typhimurium) and exposed to traditional SODIS or to MB‐SODIS. A lethal synergistic effect was observed when cultures were illuminated in the presence of MB. The obtained results indicate that bacterial inactivation can be achieved in a much shorter time when using MB associated with SODIS treatment. Therefore, this technique was able to provide safe water for consumption through the inactivation of microorganisms in general, including pathogens and some strains resistant to the traditional SODIS procedure, thus allowing its use in areas usually less exposed to sunlight. 相似文献
66.
de-los-Santos-Alvarez P Lobo-Castañón MJ Miranda-Ordieres AJ Tuñón-Blanco P 《Analytical and bioanalytical chemistry》2004,378(1):104-118
A review of current strategies aimed at detecting nucleic acids (NA) using NA-modified solid electrodes reveals the versatility and potential of electrochemical detection in this field. What emerged at the beginning of 90s as a very promising detection system in DNA technology is now resulting in the first commercial devices. Many aspects of the experimental design, for example surface immobilisation and detection schemes, are outlined and evaluated. Although most approaches use hybridisation as the recognition reaction, those not based on hybridisation are also included. As is finally shown, great advances have been achieved, although further developments are required if electrochemical devices are to be suitable for routine measurement.Abbreviations A
Adenine
- a.c.V
Alternating current voltammetry
- Amp.
Amperometry
- Apo E
Apolipoprotein E
- BCB
Brilliant cresyl blue
- BLM
Bilayer lipid membrane
- bp
Base pairs
- BPPG
Basal planar pyrolytic graphite
- bpy
2,2-Bipyridine
- C
Cytosine
- CMV
Citomegalovirus
- CPE
Carbon paste electrode
- CPSA
Constant-current chronopotentiometric stripping analysis
- Cronoamp.
Chronoamperometry
- CSPE
Carbon screen-printed electrode
- CV
Cyclic voltammetry
- dmb
4,4-Dimethyl-2,2-bipyridine
- dmphen
Dimethylphenanthroline
- DPPZ
Dipyrido[3,2-a.2,3-c]phenazine
- DPV
Differential pulse voltammetry
- dsDNA
Double-stranded DNA
- EtBr
Ethidium bromide
- Fc
Ferrocene
- Fc-CA
Ferrocenecarboxaldehyde
- Fc-CTPPZ
Di[1-ferrocenecarbamoylpropyl)tetrahydropyrazine-4-(propylcarbamoylpyridine)]phenazine
- Fc-NH2
Aminoferrocene
- FET
Field-effect transistor
- G
Guanine
- GCE
Glassy carbon electrode
- HBV
Hepatitis B virus
- HGH1
Human growth hormone 1
- HIV
Human immunodeficiency virus
- HRP
Horseradish peroxidase
- HOPGE
Highly oriented pyrolytic graphite electrode
- IPA
Intermittent pulse amperometry
- ISFET
Ion-selective field-effect transistor
- ITO
Tin-doped indium oxide electrode
- LSV
Linear sweep voltammetry
- Nano-Au
Au nanoparticles
- NMP
Nucleotide monophosphate
- ODN
Oligodeoxynucleotide
- ox.
Oxidation
- PCR
Polymerase chain reaction
- PET
Poly(ethylene terephthalate)
- PGE
Pyrolytic graphite electrode
- phen
1,10-Phenanthroline
- PNA
Peptide nucleic acid
- Ppy
Polypyrrole
- (PQQ)GDH
Pyrroline quinone glucose dehydrogenase
- red.
Reduction
- SAM
Self-assembled monolayer
- SBP
Soybean peroxidase
- SNP
Single nucleotide polymorphism
- ssDNA
Single-stranded DNA
- SWV
Square-wave voltammetry
- T
Thymine
- Th
Thionine
- TTV
TT virus
- Ep
Difference of peak potential 相似文献
67.
Roberto Martínez Paulino Arteaga Claudia Mancera 《Journal of heterocyclic chemistry》1996,33(2):489-491
The preparation of novel azo-dyes from p-aminophenylbenzacridinones is described. The structure of all the products was corroborated by ir, mass spectrometry and 1H-nmr. 相似文献
68.
69.
Summary Quantitative structure-activity relationships were performed on a set of 5-nitrofuran derivatives. The correlation parameters used were hydrophobicity and connectivity. The former was measured by means of the capacity factor (log k
o
) obtained by HPLC and the latter through the molecular valence connectivity index1
v obtained by computational methods. The biological activity data considered were growth inhibition percentages ofT. cruzi (GI % (48 h)) and half-maximal inhibitory concentration of Glutathione Reductase (I0.5 (max)). Good adjustment, r=0.98, was obtained if a logarithmic model is used for I0.5 (max) correlations. When GI% is considered, correlations were poorer and the consideration of both structural parameters was necessary for their improvement, r=0.94. 相似文献
70.
Direct Extraction of Cohesive Fracture Properties from Digital Image Correlation: A Hybrid Inverse Technique 总被引:2,自引:0,他引:2
The accuracy of an adopted cohesive zone model (CZM) can affect the simulated fracture response significantly. The CZM has
been usually obtained using global experimental response, e.g., load versus either crack opening displacement or load-line
displacement. Apparently, deduction of a local material property from a global response does not provide full confidence of
the adopted model. The difficulties are: (1) fundamentally, stress cannot be measured directly and the cohesive stress distribution
is non-uniform; (2) accurate measurement of the full crack profile (crack opening displacement at every point) is experimentally
difficult to obtain. An attractive feature of digital image correlation (DIC) is that it allows relatively accurate measurement
of the whole displacement field on a flat surface. It has been utilized to measure the mode I traction-separation relation.
A hybrid inverse method based on combined use of DIC and finite element method is used in this study to compute the cohesive
properties of a ductile adhesive, Devcon Plastic Welder II, and a quasi-brittle plastic, G-10/FR4 Garolite. Fracture tests
were conducted on single edge-notched beam specimens (SENB) under four-point bending. A full-field DIC algorithm was employed
to compute the smooth and continuous displacement field, which is then used as input to a finite element model for inverse
analysis through an optimization procedure. The unknown CZM is constructed using a flexible B-spline without any “a priori”
assumption on the shape. The inversely computed CZMs for both materials yield consistent results. Finally, the computed CZMs
are verified through fracture simulation, which shows good experimental agreement. 相似文献