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941.
942.
The improved agar diffusion method for determination of residual antimicrobial agents was investigated, and the sensitivities of various combinations of test organisms and assay media were determined using 7 organisms, 5 media, and 31 antimicrobial agents. Bacillus stearothermophilus and synthetic assay medium (SAM) showed the greatest sensitivity for screening penicillins (penicillin G and ampicillin). The combination of Bacillus subtilis and minimum medium (MM) was the most sensitive for tetracyclines (oxytetracycline and chlortetracycline), B. stearothermophilus and SAM or Micrococcus luteus and Mueller-Hinton agar (MHA) for detecting tylosin and erythromycin, B. subtilis and MHA for aminoglycosides (streptomycin, kanamycin, gentamicin, and dihydrostreptomycin), B. stearothermophilus and SAM for polyethers (salinomycin and lasalocid), and B. subtilis and MM or Clostridium perfringens and GAM for polypeptides (thiopeptin, enramycin, virginiamycin, and bacitracin). However, gram-negative bacterium Escherichia coli ATCC 27166 and MM were better for screening for colistin and polymixin-B. For detecting the synthetic drugs tested, the best combination was B. subtilis and MM for sulfonamides, E. coli 27166 and MM for quinolones (oxolinic acid and nalidixic acid), B. subtilis and MM for furans (furazolidone), and the bioluminescent bacterium Photobacterium phosphoreum and luminescence assay medium for chloramphenicol and oxolinic acid. The results showed that the use of four assay plates, B. stearothermophilus and SAM, B. subtilis and MM, M. luteus and MHA, and E. coli 27166 and MM, was superior to the currently available techniques for screening for residual antimicrobial agents in edible animal tissues. 相似文献
943.
Tzong-Yuan?JuangEmail author Jene-Ku?Liu Chia-Cheng?Chang Shi-Min?Shau Mei-Hui?Tsai Shenghong?A.?Dai Wen-Chiung?Su Ching-Hsuan?Lin Ru-Jong?Jeng 《Journal of Polymer Research》2011,18(5):1169-1176
In this study, we synthesized a reactive modifier [DOPO-tris(azetidine-2,4-dione)], terminated with three azetidine-2,4-dione
functional groups, from [(9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-yl)tris(4-aminophenyl)methane; DOPO-triamine] and [4-isocyanato-4′-(3,3-dimethyl-2,4-dioxo-acetidino)diphenylmethane;
IDD]. We embedded this reactive modifier, which contains multiple hydrogen bond donor and acceptor units, into epoxy resins
to promote intermolecular interactions and to tailor its flexibility through the formation of unique pseudo-crosslinked polymer
networks. The resulted epoxy resins were found to exhibit glass transition temperature as high as 187 °C and excellent flame
retardancy with limited oxygen index (LOI) values around 38. Meanwhile, the dynamic mechanical analysis (DMA) of epoxy systems
increases from 0.67 to 2.13 GPa for storage modulus and 0.73–1.67 GPa for loss modulus at 100 °C. Incorporation of reactive
modifier into epoxy networks with noncovalent interactions via thermosetting blend was demonstrated to be an effective way
to enhance the thermal and physical properties simultaneously. 相似文献
944.
Wei Wei Liang Qiu Xin-Ling Wang Hong-Ping Chen Yu-Ching Lai Fang-Chang Tsai Ping Zhu Jen-Taut Yeh 《Journal of Polymer Research》2011,18(6):1841-1850
The influence of calcium chloride (CaCl2) contents on the drawing and tensile properties of polyamide 6 (PA6)/CaCl2 composite fibers prepared at varying drawing temperatures were investigated. At any fixed drawing temperature, the achievable
draw ratio (Dra) values of PA6x(CaCl2)y as-spun fiber specimens approach a maximum value, as their CaCl2 contents are close to the 3 wt% optimum value. The maximum Dra values obtained for PA6x(CaCl2)y as-spun fiber specimens prepared at the optimum CaCl2 content reach another maximum as their drawing temperatures approach the optimum drawing temperature at 120 °C. The initial
modulus, tensile strength and birefringence values of the PA6 and PA6x(CaCl2)y fiber specimens were found to improve consistently with Dra or with drawing temperatures when they were stretched to a fixed Dra. Similar to those found for their achievable drawing properties, the ultimate initial modulus, tensile strength and birefringence
values of PA6x(CaCl2)y fiber specimens approach a maximum value, as their CaCl2 contents and drawing temperatures approach the 3 wt% and 120 °C optimum values, respectively. Experiments including thermal,
FTIR, melt shear viscosity and wide angle X-ray diffraction experiments were performed on the PA6x(CaCl2)y resin and/or fiber specimens to clarify the possible reasons accounting for the interesting drawing, tensile and birefringence
properties found for the PA6x(CaCl2)y fiber specimens. 相似文献
945.
Richard B Kreider Mike Iosia Matt Cooke Geoffrey Hudson Chris Rasmussen Helen Chen Olof Mollstedt Men-Hwei Tsai 《Nutrition journal》2011,10(1):1-8
Background
Inadequate eating behavior and physical inactivity contribute to the current epidemic of childhood obesity. The aim of this study was to assess the association between eating behavior scores and childhood obesity in Chilean children.Design and methods
We recruited 126 obese, 44 overweight and 124 normal-weight Chilean children (6-12 years-old; both genders) according to the International Obesity Task Force (IOTF) criteria. Eating behavior scores were calculated using the Child Eating Behavior Questionnaire (CEBQ). Factorial analysis in the culturally-adapted questionnaire for Chilean population was used to confirm the original eight-factor structure of CEBQ. The Cronbach's alpha statistic (>0.7 in most subscales) was used to assess internal consistency. Non-parametric methods were used to assess case-control associations.Results
Eating behavior scores were strongly associated with childhood obesity in Chilean children. Childhood obesity was directly associated with high scores in the subscales "enjoyment of food" (P < 0.0001), "emotional overeating" (P < 0.001) and "food responsiveness" (P < 0.0001). Food-avoidant subscales "satiety responsiveness" and "slowness in eating" were inversely associated with childhood obesity (P < 0.001). There was a graded relation between the magnitude of these eating behavior scores across groups of normal-weight, overweight and obesity groups.Conclusion
Our study shows a strong and graded association between specific eating behavior scores and childhood obesity in Chile. 相似文献946.
Ching-Chang Cho Chieh-Li Chen Rei-Tang Tsai Cha'o-Kuang Chen 《Chemical engineering science》2011,(23):6159
A novel technique is proposed for enhancing the mixing performance of a ‘crisscross’ microfluidic mixer by means of aperiodically-varying perturbation flows. The effects of the perturbation and geometry parameters on the fluid flow characteristics and mixing performance are analyzed numerically. In performing the simulations, the flow field and species concentration field are obtained by solving the two-dimensional time-dependent Navier–Stokes equations and the convection–diffusion equation, respectively. In addition, the oscillating source used to modulate the perturbation flows is modeled using the Sprott system. The results show that the irregularly-alternating flow perturbations cause a repeated stretching and folding of the species streams and enhance the mixing performance as a result. It is shown that an effective improvement in the mixing performance can be obtained through a suitable choice of the Sprott system scaling factor. Moreover, it is shown that having assigned an appropriate scaling factor, the mixing performance can be further improved by specifying suitable values of the geometry and perturbation parameters. 相似文献
947.
Mu-Yi Hua Yu-Chen Lin Rung-Ywan Tsai Hsiao-Chien Chen Yin-Chih Liu 《Electrochimica acta》2011,(25):49
We have developed a polyaniline/carboxy-functionalized multiwalled carbon nanotube (PAn/MWCNTCOOH) nanocomposite by blending the emeraldine base form of polyaniline (PAn) and carboxy-functionalized multiwalled carbon nanotubes (MWCNT) in dried dimethyl sulfoxide (DMSO) at room temperature. The conductivity of the resulting PAn/MWCNTCOOH was 3.6 × 10−3 S cm−1, mainly as a result of the protonation of the PAn with the carboxyl group and the radical cations of the MWCNT fragments. Horseradish peroxidase (HRP) was immobilized within the PAn/MWCNTCOOH nanocomposite modified Au (PAn/MWCNTCOOH/Au) electrode to form HRP/PAn/MWCNTCOOH/Au for use as a hydrogen peroxide (H2O2) sensor. The adsorption between the negatively charged PAn/MWCNTCOOH nanocomposite and the positively charged HRP resulted in a very good sensitivity to H2O2 and an increased electrochemically catalytical current during cyclic voltammetry. The HRP/PAn/MWCNTCOOH/Au electrode exhibited a broad linear response range for H2O2 concentrations (86 μM–10 mM). This sensor exhibited good sensitivity (194.9 μA mM−1 cm−2), a fast response time (2.9 s), and good reproducibility and stability at an applied potential of −0.35 V. The construction of the enzymatic sensor demonstrated the potential application of PAn/MWCNTCOOH nanocomposites for the detection of H2O2 with high performance and excellent stability. 相似文献
948.
Rong‐Jer Lee Wei‐Cheng Tsai Wen‐Tung Cheng Bin‐Chen Shiue Jiang‐Jen Lin 《应用聚合物科学杂志》2011,119(6):3437-3445
Self‐assembled and crystallized composites made from montmorillonite (MMT) by intercalation with poly(ether amine) salts and copper(II) [Cu(II)] ions simultaneously were studied. The manipulation of the silicate unit structure of the secondary (001) lattice by physically imposed osmotic pressure on the platelet interlayer was used. Divalent copper salt assisted a strong depletion effect with balancing the counterions in the clay interlayer and resulted in the extension of the dimensions of the (001) plane by increasing the spacing expansion by more than two orders of magnitude. The simultaneous adsorption of Cu(II) and intercalation of poly(oxypropylene)amine (POP) salts onto the MMT units ultimately minimized their amorphous aggregation through electrostatic attraction between the negative surface and positive edge among the silicate units. Alternatively, the attraction force through face‐to‐face stacking on the silicate surface is proposed, and the conformation of the POP/Cu(II) complex aligned with the approaching platelets to form orderly structures. X‐ray diffraction of the MMT units exhibited a high order of reflection (i.e., (006)) in Bragg's pattern; this implied a repetitive regularity between the plate–plate distances. The high regularity disappeared when the Cu(II) adsorption exceeded the critical clay cation‐exchange capacity of 1.4. The conformation of the flexible polyether backbone was altered and could no longer sustain the plate distance and the symmetric packing was destroyed when the basal spacing was decreased from 82.6 to 18.0 Å. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
949.
Chiou‐Juy Chen Hsu‐Tung Lu Wen‐Yen Tseng I‐Hsiang Tseng Shih‐Liang Huang Mei‐Hui Tsai 《应用聚合物科学杂志》2011,122(1):648-656
Polyimide (PI)/silica hybrid membranes with high contact angles were prepared through the in situ sol–gel process. The precursor, poly(amic acid) with controlled block chain length, was synthesized using 4,4′‐diaminodiphenyl ether (ODA), 3,3′,4,4′‐benzophenone‐tetracarboxylic dianhydride (BTDA) and 3‐aminopropyl‐trimethoxysilane (APrTMOS) or 3‐aminopropyldimethylethoxysilane (APDiMOS). And then, phenyltrimethoxysilane (PTS) or tetramethoxysilane (TMOS) or methyltrimethoxysilane (MTrMOS) was respectively, added to the above polyamic acid and mixed thoroughly. Following curing reaction, the PI/silica hybrid membranes with different cross‐linkages, silica content, and hydrophobic properties were prepared. The effect on the formation of PI imide ring during imidization reaction is increased as the increase of silanes content and characterized by frequency shiftment and absorbance ratio of Fourier transform infrared (FTIR) measurements. All the hybrid membranes show high transparency though with high silica contents. The storage modulus, tan δ, and damping intensity by DMA measurements are all correlated with silane content or block chain length. And all these membranes with silane content possess high contact angle as compared to pure PI without any silanes added and the contact angles increase with increasing the silane content. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
950.
Ying‐Gev Hsu Xing‐Wei Su Kuan‐Hung Lin Yen‐Shen Wan Jhih‐Cheng Chen Jan‐An Guu Pi‐Chen Tsai 《应用聚合物科学杂志》2011,119(2):693-701
The surface‐modified diamond and PET film underwent photopolymerization rapidly with a binder agent to afford coating films of interpenetrating network (IPN) structure. The coating films thus formed exhibit higher tensile strength, thermal stability, and adhesion strength to the PET film. The inert surfaces of pristine diamond (PD) and PET film were modified by different chemicals and procedures to introduce epoxide and methacryloyl groups, respectively, on their surfaces. A coating agent consisting of an epoxide group containing modified diamond (called ED), a binder agent, and photoinitiators was prepared. After applying the coating agent to the substrate (a glass plate or a methacryloyl group containing PET film, MMA‐PET) and degassing under reduced pressure, the thin film of the coating agent was exposed to UV light (λmax; 365 nm) at room temperature to yield a coating film of IPN‐structure. The tensile strength and thermal properties of the ED‐containing free coating film (called free film) increased with the amount of ED embedded, whereas the strength of the PD‐containing free film decreased with the amount of PD embedded. The adhesion strength of the coating film on the MMA‐PET improved significantly by the free radical polymerization of the methacryloyl groups on the MMA‐PET and the acrylate resin in the binder agent. The surface photoreactions of ED and MMA‐PET with the binder agent were confirmed by modeling. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献