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61.
非织造布在世界范围内广泛生产.全球标准是非织造布生产的一个竞争因素.目前,非织造布在市场中的优势不仅是价格便宜,而且质量优良.因此,为了保持非织造布的市场,有必要提高非织造布质量.在线检测系统可检测破洞、薄区、厚区等疵点,但影响非织造布质量的不仅仅是疵点,还取决于其光学均匀性.尤其对于面密度较小(如15 g/m2)的非织造布,明显的不规则纤维分布会影响顾客的主观评价.阐述了一种代表主观评价的客观图像分析方法.  相似文献   
62.
63.
A modelocked integrated external-cavity surface emitting laser (MIXSEL) is a novel type of ultrafast semiconductor laser that integrates a saturable absorber directly into a vertical external cavity surfaceemitting laser. The saturable absorber requirements and integration challenges to obtain self-starting and stable pulse formation are discussed. One single quantum dot absorber layer was optimised for this application. Since the first feasibility demonstration of an optically pumped MIXSEL, the authors have further improved the average output power to 185 mW with 32 ps pulses at around 3 GHz pulse repetition rate at a centre wavelength of ∼957 nm. The authors analyse and discuss the challenges for further power scaling and pulse shortening. The MIXSEL concept appears suitable for cost-efficient wafer-scale mass production when the external cavity is defined by a transparent wafer into which the curved output coupler can be etched. The semiconductor MIXSEL structure would then be glued to such a transparent wafer. The potential for electrically pumped MIXSELs will make this laser technology even more attractive.  相似文献   
64.
The biodegradable strong transition metal chelant [S,S] stereoisomer of ethylenediamine disuccinate was investigated for its applicability for the washing extraction of heavy metals from soil, sewage sludge, and harbor sediment. Heavy metals Pb, Zn, Cu, and Cd were extracted from authentically polluted samples by means of an ex situ washing procedure at the laboratory scale. The exposure time necessary to achieve maximum metal extraction from the authentically polluted solids used in this study was longer than that reported elsewhere with solids polluted artificially in the laboratory. Required exposure time was 1 day for the extraction of Pb, 3 days for Zn, and 6 days for Cu, irrespective of solid type. Speed and extent of metal extraction were increased by facilitating mass transfer from the solids to the liquid (e.g., by lowering calcium concentration, increasing temperature, adding fatty acid soap, and most of all, by using intermittent but intense agitation). Slightly alkaline pH was necessary to eliminate the interference by iron. This pH effect as well as observed metal selectivity was explained with a speciation model. It was feasible to achieve 70–90% extraction of Zn, Pb, and Cu from all three solids tested. These extraction efficiencies were equal or superior to those obtained with the benchmark chelants, ethylenediamine tetraacetic acid and nitrilotriacetate, provided extraction time was sufficient.  相似文献   
65.
Chen YC  Higgins MJ  Maas NA  Murthy SN 《Water research》2006,40(16):3037-3044
Accurate enumeration of indicator organisms such as Escherichia coli is important for assessing the safety of water and wastewater samples. Recent research has shown that E. coli can enter a viable but non-culturable state; therefore, traditional cultivation methods could potentially underestimate the quantities of the organisms. The goals of the research were to develop and verify a DNA extraction protocol and a quantitative polymerase chained reaction (PCR) method for E. coli enumeration in digested biosolids. A solvent-based DNA extraction protocol with extensive cell lysis recovered approximately 78-84% of spiked DNA. In comparison, a commercial kit only recovered 28-42% of DNA, likely from inefficient cell lysis. The developed competitive touchdown PCR (cPCR) method for E. coli enumeration was comparable to both real-time PCR (rt-PCR) and cultivation methods with sensitivity of approximately 50,000-500,000 E. coli per gram dry solids (DS), which is suitable for Class B biosolids monitoring in the US and "conventional" biosolids in the European Union. The cPCR protocol provides a less expensive alternative than the rt-PCR as a culturing independent method for enumerating E. coli.  相似文献   
66.
MATISSE is a design environment intended for developing systems characterized by a tight interaction between control and data-flow behavior, intensive data storage and transfer, and stringent real-time requirements. Matisse bridges the gap from a system specification, using a concurrent object-oriented language, to an optimized embedded single-chip hardware/software implementation. Matisse supports stepwise exploration and refinement of dynamic memory management, memory architecture exploration, and gradual incorporation of timing constraints before going to traditional tools for hardware synthesis, software compilation, and inter-processor communication synthesis. With this approach, specifications of embedded systems can be written in a high-level programming language using data abstraction. Application of MATISSE on telecom protocol processing systems in the ATM area shows significant improvements in area usage and power consumption.  相似文献   
67.
Supporting Information for this article is available on the WWW under http://www.wiley‐vch.de/home/asc Cyclopropanation of trisubstituted alkenes with diazoacetates can be achieved with remarkabe syn‐selectivity when the polymeric ruthenium(I) complex [Ru2(CO)4(μ‐OAc)2]n is used as catalyst.  相似文献   
68.
A rapid procedure for the determination of sulfamethazine in swine muscle and kidney is described. The method comprises sonication-aided extraction with dichloromethane, cleaning-up of the extract on a combination of silica and reversed-phase C18 Sep-Pak cartridges and analysis by high-performance liquid chromatography on a Hypersil ODS column using acetonitrile/ammonium acetate solution (10 mmol X 1(-1), pH 6.8) 1 + 3 v/v as the mobile phase. Detection was performed at 254 nm. Mean recoveries of added sulfamethazine from swine muscle and kidney, at levels of 0.05 to 0.5 micrograms X g-1, were 89.5 and 80.5%, respectively. After intramuscular injection of sulfamethazine into swine, residues in tissues were also determined. The application of ultrasonic energy for the extraction of sulfamethazine residues from animal tissues is also discussed.  相似文献   
69.
It is noted that electrical contacts have not been experimentally investigated at velocities above a few hundred meters per second. The authors describe a ballistic technique which can be used to measure friction coefficient and contact resistance at velocities up to several kilometers per second (i.e. at railgun armature operating conditions). The theoretical basis of the technique is described, and the experimental hardware is presented  相似文献   
70.
A mathematical model is used to describe uptake by a countertransport system and subsequent flow of three amino acids (AA), Phe, Val, and Met, from arterial blood to milk protein in the mammary gland of a lactating cow. The model suggests that total uptake of all AA is higher than net uptake and that a large proportion of the incoming AA is released from the cell directly back to blood. The model is used to predict which of the three AA is limiting the rate of milk protein synthesis and the response to increased arterial concentration of the first-limiting AA. Simulations are performed to predict possible outcomes of several experimental protocols to AA infusion, which might be used to test in vivo the responsiveness of the bovine mammary gland to an altered arterial concentration of AA. Of the three AA considered, arterial Met concentration appears to be first-limiting. The infusion profile that gives the greatest response in milk protein synthesis rate alters the arterial profile of AA such that it is identical to that of proteins originating in the mammary gland. Model construction can be simplified by acknowledging normal biological constraints.  相似文献   
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