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61.
Lucy Bullivant looks at the shape of the new office to come. With the onset of increasingly sophisticated communications devices, how is the organisation of space in our immediate working environments going to change? Will the lines between furniture and dynamic electronic devices simply blur? Will the structure of commercial office buildings themselves be required to become increasingly reflexive to meet environmental demands in the face of dwindling energy reserves? Or is the mobile nature of electronic communications actually in danger of rendering the permanent office as we know it extinct? Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   
62.
境外建筑师事务所如何适应当前国内的建筑潮流并在其中有所作为?除了在方案竞赛中能展现具有“视觉震撼性”的透视效果图外,还要具备一套行之有效的设计管理系统。主要包括三方面内容:1.团队精神,2.各专业之间的协调,3.阶段性设计质量的保证。文章将就这三个内容展开讨论。  相似文献   
63.
Tropomyosin (Tpm) has been regarded as the master regulator of actin dynamics. Tpms regulate the binding of the various proteins involved in restructuring actin. The actin cytoskeleton is the predominant cytoskeletal structure in dendritic spines. Its regulation is critical for spine formation and long-term activity-dependent changes in synaptic strength. The Tpm isoform Tpm3.1 is enriched in dendritic spines, but its role in regulating the synapse structure and function is not known. To determine the role of Tpm3.1, we studied the synapse structure and function of cultured hippocampal neurons from transgenic mice overexpressing Tpm3.1. We recorded hippocampal field excitatory postsynaptic potentials (fEPSPs) from brain slices to examine if Tpm3.1 overexpression alters long-term synaptic plasticity. Tpm3.1-overexpressing cultured neurons did not show a significantly altered dendritic spine morphology or synaptic activity. Similarly, we did not observe altered synaptic transmission or plasticity in brain slices. Furthermore, expression of Tpm3.1 at the postsynaptic compartment does not increase the local F-actin levels. The results suggest that although Tpm3.1 localises to dendritic spines in cultured hippocampal neurons, it does not have any apparent impact on dendritic spine morphology or function. This is contrary to the functional role of Tpm3.1 previously observed at the tip of growing neurites, where it increases the F-actin levels and impacts growth cone dynamics.  相似文献   
64.
The LH surge initiates the luteinization of preovulatory follicles and causes hormonal and structural changes that ultimately lead to ovulation and the formation of corpora lutea. The objective of the study was to examine gene expression in ovarian follicles (n = 11) collected from pigs (Sus scrofa domestica) approaching estrus (estrogenic preovulatory follicle; n = 6 follicles from two sows) and in ovarian follicles collected from pigs on the second day of estrus (preovulatory follicles that were luteinized but had not ovulated; n = 5 follicles from two sows). The follicular status within each follicle was confirmed by follicular fluid analyses of estradiol and progesterone ratios. Microarrays were made from expressed sequence tags that were isolated from cDNA libraries of porcine ovary. Gene expression was measured by hybridization of fluorescently labeled cDNA (preovulatory estrogenic or -luteinized) to the microarray. Microarray analyses detected 107 and 43 genes whose expression was decreased or increased (respectively) during the transition from preovulatory estrogenic to -luteinized (P<0.01). Cells within preovulatory estrogenic follicles had a gene-expression profile of proliferative and metabolically active cells that were responding to oxidative stress. Cells within preovulatory luteinized follicles had a gene-expression profile of nonproliferative and migratory cells with angiogenic properties. Approximately, 40% of the discovered genes had unknown function.  相似文献   
65.
The objective of this study was to examine the effect of intravenous infusion of glucose on early embryonic development in lactating dairy cows. Nonpregnant, lactating dairy cows (n = 12) were enrolled in the study (276 ± 17 d in milk). On d 7 after a synchronized estrus, cows were randomly assigned to receive an intravenous infusion of either 750 g/d of exogenous glucose (GLUC; 78 mL/h of 40% glucose wt/vol) or saline (CTRL; 78 mL/h of 0.9% saline solution). The infusion period lasted 7 d and cows were confined to metabolism stalls for the duration of the study. Coincident with the commencement of the infusion on d 7 after estrus, 15 in vitro-produced grade 1 blastocysts were transferred into the uterine horn ipsilateral to the corpus luteum. All animals were slaughtered on d 14 to recover conceptuses, uterine fluid, and endometrial tissue. Glucose infusion increased circulating glucose concentrations (4.70 ± 0.12 vs. 4.15 ± 0.12 mmol/L) but did not affect milk production or dry matter intake. Circulating β-hydroxybutyrate concentrations were decreased (0.51 ± 0.01 vs. 0.70 ± 0.01 mmol/L for GLUC vs. CTRL, respectively) but plasma fatty acids, progesterone, and insulin concentrations were unaffected by treatment. Treatment did not affect either uterine lumen fluid glucose concentration or the mRNA abundance of specific glucose transporters in the endometrium. Mean conceptus length, width, and area on d 14 were reduced in the GLUC treatment compared with the CTRL treatment. A greater proportion of embryos in the CTRL group had elongated to all length cut-off measurements between 11 and 20 mm (measured in 1-mm increments) compared with the GLUC treatment. In conclusion, infusion of glucose into lactating dairy cows from d 7 to d 14 post-estrus during the critical period of conceptus elongation had an adverse impact on early embryonic development.  相似文献   
66.
Abstract:

This article presents a Commercial-Off-The-Shelf (COTS) evaluation and selection process that utilizes a weighted scoring model to facilitate the comparison of COTS components relative to a number of pre-established evaluation criteria. The application of a COTS evaluation methodology will enable project teams responsible for designing complex systems to take advantage of potential economic leverage and performance advantages COTS technology presents. More importantly, this approach provides a mechanism for careful evaluation of the candidate COTS components to ensure engineers developing COTS-intensive systems give appropriate consideration to critical COTS attributes such as operational requirements, risk, cost, technology maturity, and supplier viability.  相似文献   
67.
Cold-pressed seed flours from pumpkin, parsley, mullein, cardamom, and milk thistle were examined for total oil, fatty acid profile of the oil, total phenolic content (TPC), scavenging activities against peroxyl (ORAC), hydroxyl (HOSC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) (RDSC) radicals, and antiproliferative capacity against HT-29 human colon cancer cells. The cold-pressed parsley seed flour contained a very high concentration of total oil—17.6 g/100 g flour—with primarily C18:1 fatty acid at 86.2 g/100 g fatty acids. All other flour oils had relatively high levels of saturated fats, ranging from 39.0 to 62.9 g/100 g fatty acids. The tested seed flours demonstrated significant TPC and free radical scavenging activities. Milk thistle seed flour had the highest TPC value of 25.2 mg gallic acid equivalent per g flour (GAE mg/g) followed by that of parsley seed flour at 8.1 GAE mg/g. Milk thistle seed-flour extract also had significantly higher antioxidant activities than all other extracts against all tested radicals. The milk thistle seed-flour extract had an ORAC value of 1131 μmol trolox equivalents (TE) per g flour (TE μmol/g), a HOSC value of 893 TE μmol/g, and an RDSC value of 61 TE μmol/g. Also, ORAC, HOSC, and TPC values were significantly correlated (P < 0.01) under the experimental conditions. The cold-pressed milk thistle seed flour inhibited the proliferation of HT-29 cancer cells in a dose-dependent manner. Results from this study suggest that these cold-pressed seed flours may serve as natural sources of antioxidants and may be used to improve human health.  相似文献   
68.
An outbreak of waterborne cryptosporidiosis in a town in northern Sweden during winter 2010 resulted in the potential exposure of cured meat products to Cryptosporidium oocysts during their manufacture. The purpose of this work was to develop a method for analyzing cured meat products for contamination with Cryptosporidium oocysts and use this method to analyze potentially contaminated product samples. A simple method of elution, concentration, separation, and detection was used, based on work with other food matrices but adapted for the relatively high fat content of cured meat surfaces. Using spiking experiments, the recovery efficiency of this method was found to be over 60%. In the analysis of the potentially contaminated products, only one putative Cryptosporidium oocyst was detected, and this was sufficiently deformed so that it could not be confirmed as an oocyst; if it was an oocyst, it was considered to have been probably deformed and inactivated prior to analysis. Based on the results of the analyses, together with data on the probable extent of contamination of the products and on our knowledge of factors, such as water activity, which affect oocyst survival, the products were safely released to the market.  相似文献   
69.
Rutherford LD  Gieseg SP 《Lipids》2012,47(3):239-247
The growth of the necrotic core region within advanced atherosclerotic plaque is thought to be driven by oxidised low density lipoprotein (oxLDL)-induced death of macrophage cells. OxLDL and atherosclerotic plaque are rich in oxysterols, especially 7-ketocholesterol (7KC). As 7KC triggers cell death at physiological concentrations when added directly to the cell culture media, 7KC and other oxysterols have been suggested to be the main cytotoxic agent of oxLDL. We investigated this hypothesis by examining the toxicity of 7KC to monocyte-like U937 cells when incorporated into high-uptake non-toxic acetylated LDL (acLDL). Incorporation of 7KC into acLDL greatly reduced the oxysterol toxicity when compared with an equivalent amount of 7KC added directly to U937 cells. Enrichment of oxLDL with 7KC did not significantly enhance lipoprotein toxicity. OxLDL was highly cytotoxic yet generated only low levels of intracellular 7KC. In comparison, 7KC-acLDL generated high intracellular 7KC concentrations with little loss in cell viability. The data show that when incorporated into lipoprotein, 7KC cytotoxicity is greatly reduced, even though intracellular levels exceed those measured when cells are incubated with oxLDL, which suggests 7KC is not the significant toxic agent within oxLDL.  相似文献   
70.
Ultraviolet-visible absorption spectroscopy and purge-and-trap GC-MS were used to determine the rates and products of the photodissociation of low concentrations of CH2I2, CH2IBr, and CH2ICl in water, saltwater (0.5 M NaCl), and seawater in natural sunlight. Photoproducts of these reactions include iodide (I-) and, in salt- and seawater environments, CH2XCl (where X = Cl, Br, or I). Thus, CH2ICl was produced during CH2I2 photolysis (with a molar yield of 35 +/- 20%), CH2BrCl from CH2IBr photolysis, and CH2Cl2 from CH2ICl photolysis (in lower yields of 6-10%). Formation of these chlorine-atom-substituted products may be via direct reaction of Cl- with either (A) the isopolyhalomethane photoisomer or associated ion pair (e.g., CH2I+-I-) or (B) the initially produced CH2I. photofragment. Estimated quantum yields for photodissociation were 0.62 +/- 0.09, 0.17 +/- 0.03, and 0.26 +/- 0.06 for CH2I2, CH2IBr, and CH2ICl, respectively, in 0.5 M NaCl, with only small differences from these values in water and seawater. The much higher quantum yield of CH2I2 photolysis compared to CH2IBr and CH2ICl photolysis may be explained by the higher yield of the isodiiodomethane photoisomer of CH2I2, resulting in reduced geminate recombination of the initially produced radical photofragments back to the parent molecule. We use a radiative transfer model with measured absorption cross-sections in saltwater to calculate seasonal values of CH2I2, CH2IBr, and CH2ICl photodissociation in surface seawater at midlatitudes (50 degrees N) and show that a significant proportion of CH2ICl in surface seawater may arise from CH2I2 photodecomposition. We also suggest that surface seawater photolysis of CH2I2 over an 8 h period may contribute up to approximately 10% of the surface seawater I- levels, with implications for the increased deposition of O3 to the surface ocean.  相似文献   
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