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排序方式: 共有557条查询结果,搜索用时 15 毫秒
91.
MICHAEL C. WEINBERG PAULETTE I. K. ONORATO DONALD R. UHLMANN 《Journal of the American Ceramic Society》1980,63(3-4):175-180
The quasi-stationary approximation was used to calculate the rates of dissolution of O2 and CO2 gas bubbles from a soda-lime glassmelt. An analytic expression for the bubble radius as a function of time, R(t) , was obtained when surface tension was neglected and numerical results for R(t) were found when surface-tension effects were included. These results were compared with those found by previous investigators. Also, an asymptotic expression for R (t) was derived and used to calculate bubble dissolution times. 相似文献
92.
93.
TUCKER MICHAEL F.; CLINE VICTOR B.; SCHMITT JAMES R. 《Canadian Metallurgical Quarterly》1967,51(2):131
A 160-ITEM BIOGRAPHICAL INVENTORY WAS ADMINISTERED TO 157 PHARMACEUTICAL SCIENTISTS WHO WERE RANDOMLY ASSIGNED TO 2 GROUPS OF 79 AND 78 SS. EACH ALTERNATIVE FROM EACH ITEM IN THE INVENTORY WAS CORRELATED WITH 19 CRITERION MEASURES OBTAINED ON EACH OF THE SCIENTISTS. THESE PRIMARILY INVOLVED RATINGS OF CREATIVITY, QUANTITY OF WORK PRODUCED, SKILL WITH PEOPLE, ETC., OBTAINED FROM SUPERVISORS, PEERS, AND SUBORDINATES. REMARKABLY LITTLE RELATIONSHIP EXISTED BETWEEN SUPERVISORY AND PEER RATINGS OF THE SCIENTISTS ON MOST VARIABLES. USING A DOUBLE CROSS-VALIDATION DESIGN, INVENTORY PREDICTOR KEYS WERE DEVELOPED FOR EACH OF THE CRITERION RATINGS AND APPLIED ACROSS TO THE NEW INDEPENDENT SAMPLE. SIGNIFICANT CROSS VALIDITIES WERE OBTAINED, NOTABLY IN THE PREDICTION OF THE CREATIVITY CRITERION, WHERE CORRELATIONS OF .36 AND .42 RESULTED ACROSS THE 2 SUBSAMPLES. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
94.
Both boron and silicon were detected on the surface of porous glass. Infrared and adsorption data show five or six times more boron in the surface than can be expected from chemical analysis of the porous glass. It is suggested that the excess of boron in the surface occurs during the leaching of the base glass. 相似文献
95.
MARK S. ROSENTRAUB DAVID SWINDELL MICHAEL PRZYBYLSKI DANIEL R. MULLINS 《Journal of Urban Affairs》1994,16(3):221-239
ABSTRACT: Many policy analysts have cautioned against public spending for professional and amateur sports. Within the last year, numerous cities have received demands from major and minor league teams for investments. These investments by the public sector can involve hundreds of millions of dollars and are usually defended by the economic impact of the facilities or teams and the economic development and revitalization which will follow. Indianapolis formulated an economic development strategy which relied substantially on sports. In addition, its development policies did not involve one team or facility, but a series of investments. As a result, the policies followed in Indianapolis afford an opportunity to measure the ability of sport facilities to encourage other investments and enhance economic development. The results reported here indicate that a sports strategy, even one as pronounced and as articulated as that of Indianapolis, is likely to have an inconsequential impact on development and economic growth. 相似文献
96.
Assay Systems and Characterization of Pacific Whiting (Merluccius productus) Protease 总被引:2,自引:0,他引:2
HAEJUNG AN THOMAS A. SEYMOUR JUWEN WU MICHAEL T. MORRISSEY 《Journal of food science》1994,59(2):277-281
Commonly used protease assays and substrates were compared for sensitivity and simplicity in analyzing proteolytic activity in Pacific whiting causing gel weakening of surimi during heat-setting. Assay based on detection of trichloroacetic acid (TCA)-soluble products, using azocasein as substrate, showed highest sensitivity. By that assay, optimal pH of the protease was 5.5, and optimal temperature, 55°. The validity of the assay for measuring activity was confirmed by pH profiles of residual proteolytic and autolytic activities of uncooked surimi. These analyses showed pH profiles similar to those of fish juice with a pH optimum of 5.5. 相似文献
97.
Microbiological medium was used to study the effect of caffeine on sterigmatocystin, citrinin, and patulin production by Aspergillus versicolor, Penicillium citrinum, and Penicillium urticae, respectively. Caffeine inhibited the growth of the three fungal species and decreased sterigmatocystin and patulin production. The effect on citrinin production appeared to be limited to a delay in toxin synthesis. A preliminary examination of P. urticae suggested that caffeine's anti-mycotoxigenic activity does not involve a generalized inhibition of lipid synthesis. 相似文献
98.
Mast cells (MCs), hematopoietic cells of the myeloid lineage, are well-known for their pro-inflammatory nature contributing to the development of various allergic and autoimmune diseases. One of the characteristic receptors on MCs, the high-affinity receptor for IgE (FcεRI), is activated in its IgE-bound state via binding and crosslinking by polyvalent antigen. This results in its phosphorylation by the SRC family kinase LYN, initiating differential signaling pathways, eventually triggering immunological effector functions, such as degranulation and cytokine production. Few publications have reported on FcεRI-dependent but antigen-independent MC activation by antibody-mediated crosslinking of membrane molecules (e.g., transmembrane proteins and glycosphingolipids) that are both localized in membrane rafts and in close vicinity to the FcεRI. In this Viewpoint we will briefly introduce FcεRI-mediated MC stimulation, cite examples of FcεRI-proximal molecules, the crosslinking of which can cause FcεRI-dependent MC activation, and discuss the potential of certain viruses as well as auto-antibodies to act as indirect FcεRI-crosslinking agents. In latter cases, antigen-independent FcεRI-mediated pro-inflammatory MC activation could contribute to the development of detrimental cytokine storms. 相似文献
99.
100.
The well-known "quenching technique" has been used to determine liquidus and solidus phase relations in the system MgO-NiO-SiO2 . Oxide mixtures were heated at selected temperatures for sufficient lengths of time for attainment of equilibrium, followed by quenching to room temperature, and phase identification by optical microscopy (transmitted-and reflected-light examination) and X-ray diffraction. Two ternary liquidus invariant points are present in the system. One is characterized by the coexistence of pyroxene (Mg-SiO3 -NiSiO3 solid solution), olivine (Mg2 SiO4 -Ni2 SiO4 solid solution), silica (cristobalite), and liquid at 1547°C. The other eutectic is at 1633°C and is characterized by the coexistence of olivine, oxide (MgO-NiO solid solution), silica, and liquid. There is a temperature maximum on the olivine-silica liquidus boundary curve at 1639°C. Reversals in the distribution ratios of magnesium and nickel between solid and liquid phases coexisting in equilibrium during crystallization of melts in this system may occur, depending on the compositions of the mixtures. 相似文献