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1.
Nonionic microemulsions containing triglycerides and fatty acid esters as lipophilic components have been studied. The phase inversion temperature (PIT) of the systems was determined by a conductometric method. Partial phase diagrams were constructed in the phase inversion temperature range. Water solubilization capacity of the nonionic surfactant systems studied was dependent on surfactant and oil types in analogy to ordinary hydrocarbon systems. The PIT:s increased with increased molecular weight for both esters and triglycerides.  相似文献   
2.
Inclusion distribution was studied in commercial aluminum DC-cast billets and slabs using a newly developed deep-etching method. Analyses revealed a nonuniform distribution of nonmetallic inclusions across billet diameters and lengths, and also across slab thicknesses and widths. In as-cast billets, more inclusions were found at the beginning and end of the billet length; more were present near the cross-section center than near the surface. In slabs, inclusions were located mostly within 13 mm of the surface and in a band between the centerline and the surface. Few inclusions were found 60 to 100 mm from the slab surface or at the centerline. In addition, comparing slab quality after casting using three types of ceramic foam filters (CFFs; i.e., 30 ppi, 50 ppi, and 50 ppi + HF) revealed significant differences in inclusion size, number, and distribution. Casting slabs using a finer pore-size filter (50 ppi) reduced the number of non-metallic inclusions greatly. The inclusion distribution patterns observed in the solidified slabs are discussed in terms of melt flow during casting.  相似文献   
3.
The main aim of the present study was to compare risk perception among Norwegians (n = 512) living in the region of Oslo. This study was part of an ERANET 13 project entitled PETRIS, Perception of transport risk in France and Norway. The data collection was carried out in January 2011. The response rate was 51 percent. The results showed that respondents, divided in two groups according to their transport mode preferences, assessed differently risk perception in public and private transportation. Respondents who preferred collective transportation assessed the probability of experiencing criminality in collective transport modes as higher than those who preferred private modes. They were also more worried of experiencing accidents, criminality, and terror attacks in collective transportation. The relationship between transport mode preferences and use, risk perception and worry are discussed.  相似文献   
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5.
There is currently scant research on the role of transport priorities, risk perception and worry for travel mode use and preferences. The present study aims to examine these factors in relation to mode use and preferences among Norwegian commuters. A web-based survey was conducted in a randomly obtained representative sample of daily commuters in the extended greater Oslo area (n = 690). The results showed that those who prioritized efficiency and flexibility tended to commute by car, while those who prioritized safety and comfort used public (e.g. metro, tram, and train) or active (e.g. walking and cycling) transport. In a free choice scenario, the respondents who prioritized flexibility reported a preference for using a car, whereas those who prioritized safety and comfort preferred public and active transport for their commuter travels. Risk perception of high impact events, such as terrorism and major accidents, as well as risk perception related to personal impact risks (theft, violence etc.) were related to car use on commuter travels. Transport-related worry exerted weak influences on mode use and preferences. Increased speed on rail transport and more frequent departures may be effective in reducing car use on commuter travels. Risk communication should focus on highlighting the low risk of experiencing security and safety issues in the public transport sector, and this message should be complemented by efforts to reduce the probability of negative events affecting public transport.  相似文献   
6.
We have created protein domains with extreme surface charge.These mutated domains allow for ion-exchange chromatographyunder conditions favourable for selective and efficient capture,using Escherichia coli as a host organism. The staphylococcalprotein A-derived domain Z (Zwt) was used as a scaffold whenconstructing two mutants, Zbasic1 and Zbasic2, with high positivesurface charge. Far-ultraviolet circular dichroism measurementsshowed that they have a secondary structure content comparableto the parental molecule Zwt. Although melting temperatures(Tm) of the engineered domains were lower than that of the wild-typeZ domain, both mutants could be produced successfully as intracellularfull-length products in E.coli and purified to homogeneity byion-exchange chromatography. Further studies performed on Zbasic1and Zbasic2 showed that they were able to bind to a cation exchangereven at pH values in the 9 to 11 range. A gene fusion betweenZbasic2 and the acidic human serum albumin binding domain (ABD),derived from streptococcal protein G, was also constructed.The gene product Zbasic2–ABD could be purified using cation-exchangechromatography from a whole cell lysate to more than 90% purity.  相似文献   
7.
A technique for proton labelling of selected amino acids indeuterated calbindin D9K, heterologously expressed in E.coli,was developed in order to simplify and obtain higher resolutionin 1H-NMR spectra. The spectra from two double-labelling experiments,Val plus Ser and Val plus Leu, when compared to the uniformlyprotonated protein showed a dramatically simpler pattern withlow background signals and gave considerably sharper resonancesdue to reduced relaxation rates in the deuterated proteins.The selective proton labelling technique will enable detailedand rapid analysis of interesting domains of proteins and willalso make the analysis of larger proteins feasible.  相似文献   
8.
A deep-etching method was used to determine inclusions in solidified direct chill cast aluminum ingots. The technique was developed to allow easy quantification of the amount and size distribution of inclusions over billet lengths and cross sections. A pressure filtration (Prefil) test also was used to verify molten alloy cleanliness during casting, and the results of these measurements then were compared. The amount and distribution of nonmetallic inclusions were analyzed, as determined using a NaOH deep-etching method over billet lengths and cross sections. A higher inclusion count was observed at both billet ends, with more inclusions located nearer the billet section centerline. Furthermore, the inclusion density in the radial direction at every distance along the billet length was distributed inhomogeneously. Differences were observed between Prefil samples taken at different casting stages. The Prefil curves and metallographic analysis of Prefil residue obtained from melt samples, at an early casting stage or before degassing, indicate more oxides than in a melt sample taken under steady-state casting conditions. A reasonable correlation was established between the number of inclusions in the molten alloy (measured using Prefil and LiMCA) and the etch pits on deep-etched surfaces of billet cross sections.  相似文献   
9.
Alkaline conditions are generally preferred for sanitizationof chromatography media by cleaning-in-place (CIP) protocolsin industrial biopharmaceutical processes. The use of such rigorousconditions places stringent demands on the stability of ligandsintended for use in affinity chromatography. Here, we describeefforts to meet these requirements for a divalent proteinaceoushuman serum albumin (HSA) binding ligand, denoted ABD*dimer.The ABD*dimer ligand was constructed by genetic head-to-taillinkage of two copies of the ABD* moiety, which is a monovalentand alkali-stabilized variant of one of the serum albumin-bindingmotifs of streptococcal protein G. Dimerization was performedto investigate whether a higher HSA-binding capacity could beobtained by ligand multimerization. We also investigated theinfluence on alkaline stability and HSA-binding capacity ofthree variants (VDANS, VDADS and GGGSG) of the inter-domainlinker. Biosensor binding studies showed that divalent ligandscoupled using non-directed chemistry demonstrate an increasedmolar HSA-binding capacity compared with monovalent ligands.In contrast, equal molar binding capacities were observed forboth types of ligands when using directed ligand coupling chemistryinvolving the introduction and recruitment of a unique C-terminalcysteine residue. Significantly higher molar binding capacitieswere also detected when using the directed coupling chemistry.These results were confirmed in affinity chromatography bindingcapacity experiments, using resins containing thiol-coupledligands. Interestingly, column sanitization studies involvingexposure to 0.1 M NaOH solution (pH 13) showed that of all thetested constructs, including the monovalent ligand, the divalentligand construct containing the VDADS linker sequence was themost stable, retaining 95% of its binding capacity after 7 hof alkaline treatment. Received May 12, 2003; revised October 8, 2003; accepted October 21, 2003  相似文献   
10.
A safety procedure for application in the design of automatic production systems is outlined. It involves the specification on safety requirements for a particular system on the basis of general safety requirements and of the results of a safety analysis. During the safety analysis, work tasks inside the danger zone of the system and potential accident scenarios related to these tasks are identified, and safety measures are evaluated. Various checklists have been developed to support each step in the analysis. The method for safety analysis has been tested in field studies of three automatic production systems in operation: two mechanical systems and one process plant. The aim has been to evaluate the method and to collect operational experience concerning accident risks and preventive measures to be considered in design. The main results of the studies are presented, and considerations for the use of the method during the design phases are discussed. It is concluded that the approach that has been selected satisfies the needs of a safety procedure for use in design.  相似文献   
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