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221.
Molecular etiology of thyroid cancers has been widely studied, and several molecular alterations have been identified mainly associated with follicular and papillary histotypes. However, the molecular bases of the complex pathogenesis of thyroid carcinomas remain poorly understood. HOX genes regulate normal embryonic development, cell differentiation and other critical processes in eukaryotic cell life. Several studies have shown that HOX genes play a role in neoplastic transformation of several human tissues. In particular, the genes belonging to HOX paralogous group 13 seem to hold a relevant role in both tumor development and progression. We have identified a significant prognostic role of HOX D13 in pancreatic cancer and we have recently showed the strong and progressive over-expression of HOX C13 in melanoma metastases and deregulation of HOX B13 expression in bladder cancers. In this study we have investigated, by immunohistochemisty and quantitative Real Time PCR, the HOX paralogous group 13 genes/proteins expression in thyroid cancer evolution and progression, also evaluating its ability to discriminate between main histotypes. Our results showed an aberrant expression, both at gene and protein level, of all members belonging to paralogous group 13 (HOX A13, HOX B13, HOX C13 and HOX D13) in adenoma, papillary and follicular thyroid cancers samples. The data suggest a potential role of HOX paralogous group 13 genes in pathogenesis and differential diagnosis of thyroid cancers.  相似文献   
222.
Oxidative stress (OS) contributes to the cascade leading to the dysfunction or death of dopaminergic neurons during Parkinson’s disease (PD). A strategy to prevent the OS of dopaminergic neurons may be the use of phytochemicals as inducers of endogenous antioxidants and phase 2 enzymes. In this study, we demonstrated that treatment of the dopaminergic-like neuroblastoma SH-SY5Y cell line with isothiocyanate erucin (ER), a compound of cruciferous vegetables, resulted in significant increases of both total glutathione (GSH) levels and total antioxidant capacity at the cytosolic level. The increase of GSH levels was associated with an increase in the resistance of SH-SY5Y cells to neuronal death, in terms of apoptosis, induced by 6-hydroxydopamine (6-OHDA). The pretreatment of SH-SY5Y cells with ER was also shown to prevent the redox status impairment, in terms of intracellular ROS and O2•− formation, and loss of mitochondrial membrane potential, early events that are initiators of the apoptotic process, induced by 6-OHDA. Last, the antiapoptotic and antioxidant effects of ER were abolished by buthionine sulfoximine, supporting the main role of GSH in the neuroprotective effects recorded by ER. These results suggest that ER may prevent the oxidative damage induced by 6-OHDA.  相似文献   
223.
We describe the role of formamide, a product of the hydrolysis of hydrogen cyanide, as precursor of several components of nucleic acids under prebiotic conditions. When formamide is heated in the presence of montmorillonites, the efficient one-pot synthesis of purine, adenine, cytosine, and uracil is obtained. Along with these nucleobases, several components of the inosine pathway are obtained: 5-aminoimidazole-4-carboxamide, 5-formamidoimidazole-4-carboxamide and hypoxanthine. This almost complete catalogue of nucleic acid precursors is accompanied by N(9)-formylpurine, which, containing a masked glycosidic bond in its formyl moiety, is a plausible precursor of purine acyclonucleosides. In addition, montmorillonites differentially affect the rate of degradation of nucleobases when embedded in 2'-deoxyoligonucleotides; namely, montmorillonites protect adenine and guanine from the degradative action of formamide, while thymine degradation is enhanced. The oligonucleotide backbone reactivity to formamide is also affected; this shows that the interaction with montmorillonites modifies the rate of abstraction of the Halpha and Hbeta protons on the sugar moieties.  相似文献   
224.
The isothermal crystallization kinetics of biodegradable blends made of poly(lactic acid) (PLA) and poly(ε‐caprolactone) (PCL) compatibilized with two different low molecular weight block copolymers, that is, ε‐caprolactone/tetramethylene ether glycol and ε‐caprolactone/aliphatic polycarbonate (CB), was done. Blends were prepared by melt mixing in an extruder, while isothermal crystallization kinetics and morphologies were investigated by thermal (differential scanning calorimetry) and thermo‐optical (quantitative polarized light optical microscopy [qPLOM]) quantitative methods. Data were analyzed using the Avrami equation, revealing 2D and 3D growth and simultaneous heterogeneous nucleation. The presence of low molecular weight compatibilizers, that is, 2,000 g mol?1, accelerated the PLA crystallization rate by two to threefold when compared with neat PLA, with high degrees of crystallinity (40–43%) as confirmed by PLOM images. The activation energy (Ea) showed that PCL inhibits PLA crystallization; however, the addition of block copolymers used as compatibilizers of the blends reduced Ea values, increasing the chain mobility of PLA and thus increasing the crystallization rate. POLYM. ENG. SCI., 59:E161–E169, 2019. © 2018 Society of Plastics Engineers  相似文献   
225.
This paper presents a study of a prospective photoeletrocatalytic oxidation treatment system for disperse dyes obtained from a textile industry. The process utilizes titanium dioxide thin-film electrodes prepared by the sol-gel method as a photo-oxidative anode. Using UV irradiation and an applied potential of + 1.0 V on the nanoporous photoanode of Ti/TiO2 it is possible to reach a reduction of color removal of 90%, 94% and 100% and 63%, 45% and 61% for TOC removal of DOD, DRD and DRR dyes. The method has been successfully applied to treat textile industry effluent collected at different steps in the industrial process namely before and after conventional wastewater treatment. The results were satisfactory for both effluent samples, leading to a reduction from 52.6% to 69.0% of COD, a diminishing of 80-89% of discoloration and a removal of TOC in the range of 47 to 50%.  相似文献   
226.
The trans-[RuCl2(L)4], trans-[Ru(NO)Cl (L)4](PF6)2 (L = isonicotinamide and 4-acetylpyridine) and trans-[Ru(NO)(OH)(py)4]Cl2 (py = pyridine) complexes have been prepared and characterized by elemental analysis, UV–visible, infrared, and 1H NMR spectroscopies, and cyclic voltammetry. The MLCT band energies of trans-[RuCl2(L)4] increase in the order 4-acpy < isn < py. The reduction potentials of trans-[RuCl2(L)4] and trans-[Ru(NO)Cl(L)4]2+ increase in the order py < isn < 4-acpy. The stretching band frequency, νNO, of the nitrosyl complexes ranges from 1913 to 1852 cm?1 indicating a nitrosonium character for the NO ligand. Due to the large π-acceptor ability of the equatorial ligands, the coordinated water is much more acidic in the water soluble trans-[Ru(NO)(H2O)(py)4]3+ than in trans-[Ru(NO)(H2O)(NH3)4]3+.  相似文献   
227.
Several conservation strategies regarding minimally processed vegetables (MPV) are applied keep organoleptic features and quality, in particular the use of active packaging to slow down enzymatic browning reactions and microbial growth. Based on such context, polyvinyl chloride (PVC) films with antimicrobial and antibrowning properties—due to the addition of a mix of additives (MA) that comprise pure (KM) and encapsulated (EKM) potassium metabisulfite—are the core of the current study to find out their influence on the quality parameters applied to minimally processed apples. The sol–gel method was used in the encapsulation process and the PVC films were prepared by applying 0.1 (w/w; F01), 1.0 (w/w; F1), and 2.0 (w/w; F2) of MA (KM and EKM), as well as the use of control film, for industrial extrusion processing. The EKM was chemically and morphologically characterized and the mechanical properties of the films were set. Minimally processed apples were prepared and packed in films for 20 days. The prepared packages were stored at different temperatures and evaluated for color variations as well as for chemical and microbiological quality. The encapsulation process increased the additive's thermal resistance. It also preserved the main characteristics of the additives that were incorporated into the process. It did not interfere in the machinability conditions of the films. The outcomes showed satisfactory effects regarding the maintenance of color and microbiological qualities. The F2 film could show toxicological safety for the minimally processed apples for 10 days at 8 °C. Therefore, duofunctional films are a good alternative for minimally processed apples storage.  相似文献   
228.
Magnesium has been deeply studied as a possible hydrogen storage material for both, mobile and static applications. In this article we continued the work presented in our previous paper by modeling the hydrogen absorption in Ni-catalyzed magnesium in the range of pressures of 500 kPa–5000 kPa and temperatures from 423 K to 468 K. A new model based in the Ginstling–Brounshtein diffusion equation was proposed for the hydrogen absorption kinetics. It adds the contribution of the pressure of the gaseous phase and the enthalpy of reaction to the previously mentioned diffusive model. An activation energy for the process was estimated and the value obtained (112 kJ/mol) was concordant with previous values reported in the literature.  相似文献   
229.
This study evaluated the effect of the supplementation of total dietary fiber from apple, banana or passion fruit processing by-products on the post-acidification, total titratable acidity, bacteria counts and fatty acid profiles in skim milk yoghurts co-fermented by four different probiotics strains: Lactobacillus acidophilus L10 and Bifidobacterium animalis subsp. lactis BL04, HN019 and B94. Apple and banana fibers increased the probiotic viability during shelf-life. All the fibers were able to increase the short chain and polyunsaturated fatty acid contents of yoghurts compared to their respective controls. A synergistic effect between the type of fiber and the probiotic strain on the conjugated linoleic acid content was observed, and the amount of α-linolenic acid was increased by banana fiber. The results of this study demonstrate, for the first time, that fruit fibers can improve the fatty acid profile of probiotic yoghurts and point out the suitability of using fibers from fruit processing the by-products to develop new high value-added fermented dairy products.  相似文献   
230.
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