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71.
Rudolf F. Stark 《Computer-Aided Civil and Infrastructure Engineering》1992,7(2):161-175
Abstract: A local database manager (LDBM) is presented. It is a software development tool consisting of a set of easy-to-use in-core data management subroutines written in FORTRAN 77. One of the main motivations for the development of this LDBM was to enhance the eflcient use of core memory which seems to be obvious with respect to a PC programming environment. However, even on virtual machines, high performance achieved by minimizing page faults is strongly based on a sophisticated database management system (DBMS). In order to accomplish this objective, the LDBM allows the use of different data types according to the requirements of the actual situation and to the existing programming environment. Integer, short integer, real, double precision, complex, double complex and character data can be handled. Moreover, a two-level hierarchical data structure is used which groups related data in a different and more economic way rather than by means of increasing the number of levels in the DIMENSION statement. Of course, old, no longer used data may be deleted, leaving room for the allocation of new data. Using a technique of 'flexible garbage collection', i.e. the ensuing gap after the deletion of a data block is not automatically closed, the time consumed by the LDBM during a deletion operation is actually not affected by the length of data blocks. 相似文献
72.
T Jiang G Sweeney MT Rudolf A Klip A Traynor-Kaplan RY Tsien 《Canadian Metallurgical Quarterly》1998,273(18):11017-11024
Phosphoinositide 3-OH kinases and their products, D-3 phosphorylated phosphoinositides, are increasingly recognized as crucial elements in many signaling cascades. A reliable means to introduce these lipids into intact cells would be of great value for showing the physiological roles of this pathway and for testing the specificity of pharmacological inhibitors of the kinases. We have stereospecifically synthesized di-C8-PIP3/AM and di-C12-PIP3/AM, the heptakis(acetoxymethyl) esters of dioctanoyl- and dilauroylphosphatidylinositol 3,4,5-trisphosphate, in 14 steps from myo-inositol. The ability of these uncharged lipophilic derivatives to deliver phosphatidylinositol 3,4,5-trisphosphate across cell membranes was demonstrated on 3T3-L1 adipocytes and T84 colon carcinoma monolayers. Insulin stimulation of hexose uptake into adipocytes was inhibited by the kinase inhibitor wortmannin and was largely restored by di-C8-PIP3/AM, which had no effect in the absence of insulin. Thus phosphatidylinositol 3,4,5-trisphosphate or a metabolite was necessary but not sufficient for stimulation of hexose transport. In T84 epithelial monolayers, di-C12-PIP3/AM mimicked epidermal growth factor in inhibiting chloride secretion and potassium efflux, suggesting that phosphatidylinositol 3,4, 5-trisphosphate was sufficient to modulate these fluxes and mediate epidermal growth factor's action. 相似文献
73.
74.
Dipl.-Ing.Dr. techn. Franz G. Rammerstorfer Dipl.-Ing. Dr. techn. Rudolf Beer 《Forschung im Ingenieurwesen》1976,42(5):168-172
Zusammenfassung Eine M?glichkeit, ohne Mehraufwand an Material oder Verwendung teurerer Werkstoffe das dynamische Verhalten oder die Tragf?higkeit
von Bauteilen zu verbessern, wird am Beispiel der Grundfrequenz- und Beullaststeigerung von Kreisplatten durch das Einpr?gen
von geeigneten Eigenspannungszust?nden dargelegt. Die Ergebnisse einer Optimierung solcher Eigenspannungsfelder werden dargestellt,
und die M?glichkeit der Erzeugung geeigneter Eigenspannungszust?nde wird an Hand eines Experiments nachgewiesen. 相似文献
75.
The chlorine and oxygen overpotential in dependence on the current density i (A cm?2) and on the temperature in the range of 15–75°C was measured at γ-MnO2 and β-PbO2 electrodes in concentrated water solutions of sodium chloride and perchlorate. From the measured values the experimental activation energy in dependence on overpotential was calculated and, for the temperature of 25°C, the constants of Tafel's equation (a,b) (α, io respectively) were evaluated. 相似文献
76.
Numbers of Lucilia cuprina (Australian sheep blowfly), Chrysomya spp., and Calliphora spp. blowflies caught on sticky traps baited with various synthetic attractants or a standard liver/sodium sulfide attractant in western Queensland were recorded. Numbers of each genus collected were influenced by the composition of the chemical attractants. Attractant mixtures based on 2-mercaptoethanol, indole, butanoic/pentanoic acid, and a sodium sulfide solution gave 5- to 20-fold higher L. cuprina catches than the liver standard. These blends attracted similar numbers of Chrysomya spp. (0.85-2.7x) and fewer Calliphora spp. (0.02-0.2x) compared to the liver standard. These synthetic attractants were more effective and selective for L. cuprina than the standard liver/sodium sulfide attractant, and they can be packaged in controlled-release dispensers to generate constant, prolonged release of the attractant. 相似文献
77.
Hypoxia occurs over large areas in aquatic systems worldwide, and there is growing concern that hypoxia may affect aquatic animals, leading to population decline and changes in community by elimination of sensitive species. For the first time, we report that sublethal levels of hypoxia can significantly increase (+77.4%) malformation in fish embryonic development. Disruption of apoptotic pattern was clearly evident at 24 h post-fertilization, which may be a major cause of malformation. Furthermore, embryonic development was delayed, and balance of sex hormones (testosterone and estradiol) was disturbed during embryonic stages, implicating that subsequent sexual development may also be affected. Overall, our results imply that hypoxia may have a teratogenic effect on fish and delay fish embryonic development, which may subsequently impair species fitness leading to natural population decline. 相似文献
78.
79.
R. Popper 《Holz als Roh- und Werkstoff》1979,37(3):77-82
A special apparatus which permits continuous, three-dimensional measurements was constructed for the measurement of the kinetic swelling and shrinkage of chemically modified wood. The construction, function and use of this apparatus is the subject of the first report. The apparatus is designed for test pieces with side lengths from 2 mm to 60 mm. The climatic conditions under which the experiments are conducted can be regulated and controlled very accurately. The testing facilities were designed in a way permitting continuous measurements along the complete sorption isotherm from drying to storage in water. Inductive displacement transducers were installed for displacement measurements. The maximum sensitivity for the swelling and shrinkage measurements is 2·10?4 cm/mV. The range of linearity is guaranteed within ±0.8 cm. The average accuracy of measurement is ±2.3%. The measurement technique is considered and discussed. 相似文献
80.
3 ward climate scales were derived from 2 independent studies linking treatment environments as perceived by patients and staff to treatment outcome as assessed by ward dropout, release, and community tenure rates. Patients and staff from 7 large and 8 small Veterans Administration hospital wards completed the Ward Atmosphere Scales. Patients and staff agreed in perceiving wards with high dropout rates as low in involvement, support, order and organization, and program clarity, whereas wards with high release rates were perceived as strongly emphasizing practical orientation, but as relatively "unexpressive." Wards that kept patients out of the hospital longest were seen as emphasizing autonomy and independence, practical orientation, order and organization, and the open expression of feelings, particularly angry feelings. It is concluded that some relatively consistent findings are emerging from studies in this area. (19 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献