改善梳理的新技术

梳棉机性能改进为纺纱厂提供了更大的生产潜力。对梳理过程的分析促使了针布和盖板的改进并由此改善了生条质量以及落棉的数量和种类。借助特殊的软件优化梳理针布和运转条件,可生产和提供理想的针布。     

43—THE INFLUENCE OF COTTON-SPINNING MACHINERY ON THE RANDOM IRREGULARITY OF SLIVERS AND YARNS PART I: THEORETICAL CONSIDERATIONS

The regularity of slivers and yarns is analysed by the mathematical and experimental method of system analysis. After the mathematical background has been sketched, appropriate parameters are defined, and a mathematical model—in the statistical sense—is developed. Special considerations concerning the effect of ‘doubling’ conclude the paper.     

Number of operations for updating the elimination form of the basis-inverse of the revised simplex-algorithm

Some results on the number of operations, that are needed to update the elimination form of the basis inverse of a linear program and to perform the revised simplex-algorithm, are given for different updating methods.     

Energy scaling and beam quality studies of a zigzag solid-stateplastic dye laser

Studies of the energy scaling and beam quality improvement of a long-pulse laser pumped solid-state dye laser using a unique new zigzag optical configuration are presented. A beam quality of 1.7 XDL was measured using an unstable optical cavity at a laser output of 200 mJ. Single pulse energies as high as 1 J have been achieved. The laser has been operated at 5 Hz with an average output of about 250 mJ for runs up to 200 pulses     

Time Resolution Measurements with Fast Photomultipliers

A comparision of experimental data and theoretical predictions on time resolution limits of fast photomultipliers has been performed. XP 1020 photomultipliers have been used and measurements were done with a fast electronic system built in our laboratory. This system was tested with a Co60 source, the best time resolutions achieved over a period of two hours being 164 psec at f.w.h.m. A hydrogen discharge lamp has been built which produced short light pulses whose shape is determinated by a sampling method. Several light intensities were used to simulate different energy losses in plastic scintillators and time resolution measurements were performed for different threshold settings of the discriminator. The results of these measurements were compared to theoretical data calculated by means of a statistical model of the photomultiplier. Good agreement was found assuming a photoelectronic yield of one photoelectron per 2.5 KeV in Naton 136 plastic scintillator and a single electron response (SER) variance of 500 psec. The necessity of having more accurate data on photomultiplier parameters, mainly concerning the transit time jitter, was pointed out in order to have a better understanding of the photomultiplier's behaviour.     

更新的梳棉机可获得新梳棉机的加工质量

在二手梳棉机装上一些新型装置后，可获得像新梳棉机那样的加工质量。旧梳棉机经过翻新和改进之后，其运转性能可以达到新型机的水平，产量大约可比原来增加一倍，而不需对建筑物及其基本结构进行匹配。这种改进或翻新的梳棉机成本低，对纺纱厂来说，无疑是一种经济的明智选择。     

Lernen mit neuen Medien — eine Chance für neue Konzepte und innovative Ideen

The potentials of the new information and communication technologies are being described: for the realisation of the basic idea of selfguided learning, for the furtherance of problem-oriented learning, for the incitation and guidance of cooperative learning and for the warranty of instructional guidance and support. Moreover it is being discussed in how far the new information and communication technologies are fit to cause a changed understanding of the role of lecturers and trainers in training and further education and how far the new information and communication technologies contribute to a structural change in the system of education.     

Numerical differentiation and parameter estimation in higher-orderlinear stochastic systems

For a linear time-invariant system of order d⩾2 with a white noise disturbance, the input and the output are assumed to be sampled at regular time intervals. Using only these observations, some approximate values of the first d-1 derivatives are obtained by a numerical differentiation scheme, and the unknown system parameters are estimated by a discretization of the continuous-time least-squares formulas. These parameter estimates have an error which does not approach zero as the sampling interval approaches zero. This asymptotic error is shown to be associated with the inconsistency of the quadratic variation estimate of the white noise local variance based on the sampled observations. The use of an explicit correction term in the least-squares estimates or the use of some special numerical differentiation formulas eliminates the error in the estimates     

Expression of DSD-1-PG in primary neural and glial-derived cell line cultures, upregulation by TGF-beta, and implications for cell-substrate interactions of the glial cell line Oli-neu

DSD-1-PG is a chondroitin sulfate proteoglycan with neurite-outgrowth promoting properties expressed during development and upon lesion of neural tissues which has been defined with the specific monoclonal antibody 473HD. Double immunofluorescence studies performed on primary cerebellar cultures document that the proteoglycan is expressed on the surface of immature glial cells and the neural cell line Oli-neu, a model of mouse oligodendrocyte progenitors. Biochemical and immunoprecipitation studies performed with biosynthetically labelled Oli-neu and primary neural cells demonstrated that DSD-1-PG is expressed in vitro as a proteoglycan of 1000 kD apparent Mr with two core glycoproteins of 250 kD and 400 kD. In order to study the regulation of DSD-1-PG expression, an in vitro enzyme-linked immunosorbent assay based on Oli-neu and mAb 473HD was established. TGF-beta1-3 induced up-regulation of the proteoglycan, while various growth factors and cytokines did not significantly affect DSD-1-PG expression in both the supernatant and the extract of the culture monolayer. FACSCAN analysis suggested that the proteoglycan is upregulated on the surface of Oli-neu. Cell substrate adhesion assays revealed that this enhanced expression correlates with a selective reduction of adhesion to laminin, but not fibronectin or merosin, which could specifically be neutralized by antibodies to DSD-1-PG. We conclude that the proteoglycan contributes to the regulation of glial precursor interactions with the extracellular matrix.     

Ligand-Directed Chemistry on Glycoside Hydrolases – A Proof of Concept Study

Selective covalent labelling of enzymes using small molecule probes has advanced the scopes of protein profiling. The covalent bond formation to a specific target is the key step of activity-based protein profiling (ABPP), a method which has become an indispensable tool for measuring enzyme activity in complex matrices. With respect to carbohydrate processing enzymes, strategies for ABPP so far involve labelling the active site of the enzyme, which results in permanent loss of activity. Here, we report in a proof of concept study the use of ligand-directed chemistry (LDC) for labelling glycoside hydrolases near – but not in – the active site. During the labelling process, the competitive inhibitor is cleaved from the probe, departs the active site and the enzyme maintains its catalytic activity. To this end, we designed a building block synthetic concept for small molecule probes containing iminosugar-based reversible inhibitors for labelling of two model β-glucosidases. The results indicate that the LDC approach can be adaptable for covalent proximity labelling of glycoside hydrolases.