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61.
We conceptualized security-related stress (SRS) and proposed a theoretical model linking SRS, discrete emotions, coping response, and information security policy (ISP) compliance. We used an experience sampling design, wherein 138 professionals completed surveys. We observed that SRS had a positive association with frustration and fatigue, and these negative emotions were associated with neutralization of ISP violations. Additionally, frustration and fatigue make employees more likely to follow through on their rationalizations of ISP violations by decreased ISP compliance. Our findings provide evidence that neutralization is not a completely stable phenomenon but can vary within individuals from one time point to another.  相似文献   
62.
Near-infrared (NIR) activatable upconversion nanoparticles (UCNPs) enable wireless-based phototherapies by converting deep-tissue-penetrating NIR to visible light. UCNPs are therefore ideal as wireless transducers for photodynamic therapy (PDT) of deep-sited tumors. However, the retention of unsequestered UCNPs in tissue with minimal options for removal limits their clinical translation. To address this shortcoming, biocompatible UCNPs implants are developed to deliver upconversion photonic properties in a flexible, optical guide design. To enhance its translatability, the UCNPs implant is constructed with an FDA-approved poly(ethylene glycol) diacrylate (PEGDA) core clad with fluorinated ethylene propylene (FEP). The emission spectrum of the UCNPs implant can be tuned to overlap with the absorption spectra of the clinically relevant photosensitizer, 5-aminolevulinic acid (5-ALA). The UCNPs implant can wirelessly transmit upconverted visible light till 8 cm in length and in a bendable manner even when implanted underneath the skin or scalp. With this system, it is demonstrated that NIR-based chronic PDT is achievable in an untethered and noninvasive manner in a mouse xenograft glioblastoma multiforme (GBM) model. It is postulated that such encapsulated UCNPs implants represent a translational shift for wireless deep-tissue phototherapy by enabling sequestration of UCNPs without compromising wireless deep-tissue light delivery.  相似文献   
63.
The incorporation of microwave and pulsed electric field (PEF) technologies in optimising the extraction of polyphenols from defatted canola seed cake was determined by Box‐Behnken response surface methodology, using three parameters of microwave treatment (power, time and liquid: solid (L:S) ratio) and four parameters of PEF (ethanol concentration, time, frequency and voltage). After microwave and PEF pretreatments, the polyphenols of defatted canola seed cake were extracted by ultrasound treatment under fixed variables (200 W of ultrasonic power, 70 °C of water bath and 20 min of extraction time). The measured responses were total phenolics, total flavonoids, the DPPH˙ scavenging activity and ferric reducing antioxidant power (FRAP). The maximum yields of all responses were achieved under optimum conditions of microwave processing (5 min, L:S ratio of 6.0 and 633.3 W) and PEF‐assisted extraction (30 V, 30 Hz, 10% ethanol concentration and 10 s).  相似文献   
64.
Cancer prognosis will benefit from a scoring system that could grade malignant traits of patient‐derived cells by assessing their growth and metastasis in a living system. Specific tracking of patient‐derived cells requires labeling by contrast agents with good signal‐to‐noise ratio and no specific stain of host tissues. Towards this aim, aggregation‐induced emission (AIE) dots are developed for in vivo cancer tracking with emphasis on reproducible optimized formulation and specific fluorescent labeling of cells that enable enhanced spatial temporal resolution in vivo. The importance of energy‐dependent AIE dots uptake for patient‐derived cell labeling is emphasized to reveal their specific uptake by viable cancer cells. Using optically transparent zebrafish embryo, the ability is demonstrated to follow the engraftment of transplanted AIE dot labeled cells in zebrafish brains over one week. Cells detected outside the brain after 7 d are quantified as metastatic cells. Results from seven clinical samples demonstrate the utility of this methodology to differentiate low engraftment level of benign neoplasms from higher engraftment level and metastasis detected in malignant ovarian cancer specimens. Achieving clinically validated results supports the use of AIE dot labeled patient derived cells in zebrafish xenografts for future cancer prognosis.  相似文献   
65.
The complex tumor microenvironment (TME) and nonspecific drug targeting limit the clinical efficacy of photodynamic therapy in combination with chemotherapy. Herein, a metal–organic framework (MOF) assisted strategy is reported that modulates TME by reducing tumor hypoxia and intracellular glutathione (GSH) and offers targeted delivery and controlled release of the trapped chemodrug. Platinum(IV)‐diazido complex (Pt(IV)) is loaded inside a Cu(II) carboxylate‐based MOF, MOF‐199, and an aggregation‐induced‐emission photosensitizer, TBD, is conjugated to polyethylene glycol for encapsulating Pt(IV)‐loaded MOF‐199. Once the fabricated TBD‐Pt(IV)@MOF‐199 nanoparticles are internalized by cancer cells, MOF‐199 consumes intracellular GSH and decomposes to fragments to release Pt(IV). Upon light irradiation, the released Pt(IV) generates O2 that relieves hypoxia and produces Pt(II)‐based chemodrug inside cancer cells. Concomitantly, efficient reactive oxygen species generation and bright emission are afforded by TBD, resulting in synergistic image‐guided photo‐chemo therapy with enhanced efficacies and mitigated side effects.  相似文献   
66.
The single greatest influence on the mesophase microstructure is the chemical composition of the organic precursor. The effects of oxygen content and structural parameters of precursors from solvent fractions of coal liquefaction products on the microstructure and pyrolysis yields were determined. The fractions were analysed using the Brown-Ladner method to obtain average molecular structural parameters. It was found that pyrolysis yield increases with increased aromaticity and oxygen content and that mesophase microstructure is determined primarily by the oxygen content of the precursors.  相似文献   
67.
The structure and mechanical properties of blends of low-density polyethylene and isotactic polypropylene were studied. The blends behaved like a simple composite obeying the rule of mixture for the modulus dependence on composition. Tensile strength of the LDPE was enhanced with the addition of PP but elongation at break was drastically reduced for all blend compositions. Studies with WAXD, hot-stage microscope, and DSC indicated lack of interaction between the LDPE and the PP. The crystallographic structure of LDPE and PP remained unchanged. However, the spherulite size of the PP was found to be reduced in the presence of LDPE, possibly due to an increase in nucleation density.  相似文献   
68.
A radio frequency (RF) plasma system has been used to decompose 1,2‐dichloroethane (DCE). Final products were identified by a Fourier transform infrared (FTIR) spectrometer. The main products of DCE decomposition in O2/Ar plasma were CO2, CO, and HCl. Other minor chlorinated products were CCl4, C2HCl3, C2H3Cl, C2Cl4, CHCl3, C2HCl5, and COCl2. Nonchlorinated products were C2H2, C2H4, C2H6, and HCOOH. The plasma reactor with a brass electrode had a higher decomposition fraction of DCE [η, (Cin ? Cout)/Cin × 100%] than that obtained with other materials (Au, Ni, and Cr). Different electrode configurations (inner and outer) were also evaluated for the decomposition of DCE. Argon plus oxygen was found to be the most suitable carrier/auxiliary gas for DCE decomposition. In addition, operational parameters for DCE decomposition in RF plasma including concentration, operational pressure, and total gas flow rate were evaluated. Copyright © 2003 Society of Chemical Industry  相似文献   
69.
Bright and red‐emissive organic nanoparticles (NPs) are demonstrated as promising for in vivo fluorescence imaging. However, most red organic dyes show greatly weakened or quenched emission in the aggregated state. In this work, a robust red fluorophore (t‐BPITBT‐TPE) with strong aggregate‐state photoluminescence and good biocompatibility is presented. The NPs comprised of t‐BPITBT‐TPE aggregates encapsulated within 1,2‐distearoyl‐sn‐glycero‐3‐phosphoethanolamine‐N‐[methoxy(polyethylene glycol) (DSPE‐mPEG) micelles exhibit a photoluminescence peak at 660 nm with a high fluorescence quantum yield of 32% in aqueous media. The NPs can be facilely charged by using the same polymeric matrix with different terminal groups, e.g., methoxy (DSPE‐mPEG), amine (DSPE‐PEG‐NH2), or carboxymethyl (DSPE‐PEG‐COOH) groups. The biocompatibility, toxicity, circulation, and biodistribution of the NPs are assessed using the zebrafish model through whole embryo soaking and intravenous delivery. Furthermore, HeLa and MCF‐7 cells tagged with t‐BPITBT‐TPE in DSPE‐PEG‐NH2‐TAT polymer NPs are xenografted into zebrafish larvae to successfully track the cancer cell proliferation and metastasis, demonstrating that these new NPs are efficient cancer cell trackers. In addition, the NPs also show good in vivo imaging ability toward 4T1 tumors in xenografted BALB/c mice.  相似文献   
70.
The effects of methylmercury (MeHg) and selenium (Se) contamination on food webs in the San Francisco Estuary have received considerable attention during the past decade. However, knowledge of their effects on native fishes of California is lacking. This study investigated the interactive effects of dietary MeHg and seleno-methionine (SeMet) on Sacramento splittail (Pogonichthys macrolepidotus) larvae. Twelve diets containing increasing levels of SeMet (0.64, 8.2 and 35.0 microg Se g(-1) diet) and MeHg (0.01, 0.13, 4.7 and 11.7 microg Hg g(-1) diet) were fed to 21-day post-hatch larvae for 4 weeks in 2-L beakers at 25 degrees C. Fish were fed twice a day at a feeding rate of 40, 30, 25 and 20% of body weight during the 1st, 2nd, 3rd and 4th week, respectively. At the end of week 4, no significant difference (P>0.05) was observed among treatments for mortality, body length or weight, and condition factor. Bioaccumulation of Hg and Se responded positively and significantly (P<0.05) to their dietary concentrations. The molar ratio of Se/Hg in diets was linearly correlated to the ratio of Se/Hg in fish. Dietary Se inhibited Hg accumulation, which was negatively correlated to the dietary Se/Hg ratio. Histopathological examination revealed severe gill anomaly and liver glycogen depletion in fish fed the 11.7 microg Hg g(-1) diet. Liver glycogen depletion and kidney tubular dilation were found in larvae fed the 11.7 microg Hg and 11.7 microg Hg+35 microg Se g(-1) diets. In conclusion, dietary Hg enhanced Se accumulation but dietary Se inhibited Hg accumulation in splittail. Dietary Se showed a protective effect in fish fed the high MeHg diet. This protection was related to the dietary Se/Hg ratio, which is a more reliable criterion for evaluating the interactive effect between Se and Hg in splittail.  相似文献   
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