检索结果-南通市图书馆

Review on Liquefaction Potential of Silts from CPT Data

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

j.urnal of Geological Resource and Engineering 2014年第2期2卷 131-138页

作者： M. Farooq Ahmed j. David Rogers j.seph Cravens Department of Geological Sciences and Engineering Missouri University of Science and Technology Rolla 65401 MO USA (Onleave from University of Engineering and Technology Lahore Pakistan) Department of Geological Sciences and Engineering Missouri University of Science and Technology Rolla 65401 MO USA Department of Civil Architectural and Environmental Engineering Missouri University of Science and Technology Rolla 65401MO USA

Soil liquefaction occurs when pore water pressure of low cohesion materials equals or exceeds the effective confining pressure. Sudden increases in pore water pressure may occur in response to dynamic loads, such as earthquake shaking, or shear strain engendered by sudden movement （static liquefaction）. This study focused on the evaluation of the liquefaction potential of silty soils using CPT （cone penetration test） data. There is much less CPT data on the behavior of silts under dynamic loading, as compared to sandy soil mixtures. Robertson and Wride proposed a method of evaluating liquefaction evaluation for silt-sand mixtures using CPT data, when the soils contain less than 35% fines. Until more research is conducted, soils comprised of more than 35% fines cannot be reliably evaluated using CPT data alone. This is true for isolated silts or silt mixtures, which require laboratory testing to evaluate their liquefaction potential. Experience has shown that soils with 〉 35% silt can liquefy if drainage is retarded or severely restricted by bounding low permeability horizons, such as silty clays or clayey silts, which prevent dissipation of dynamically induced pore water pressures.

关键词： Liquefaction pore pressure dynamic loading CPT permeability.

Spions Increase Biofilm Formation by <i>Pseudomonas aeruginosa</i>

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

j.urnal of Biomaterials and Nanobiotechnology 2012年第4期3卷 508-518页

作者： Carl Haney j.hn j. Rowe j.yne B. Robinson Department of Biology University of Dayton Dayton USA

Limited research has suggested iron oxide nanoparticles (FeNP) have an inhibitory effect against several different genera of bacteria: Staphylococcus, Bacillus and Pseudomonas spp. In this study we looked at the effect of three different sets of Fe3O4 nanoparticles (FeNPs) on the development of Pseudomonas aeruginosa PAO1 biofilms. Two of the tested NPs were SPIONs (Superparamagnetic Iron Oxide Nanoparticles). Exposure of cells to the SPIONs at concentrations up to 200 μg/ml resulted in an increase in biofilm biomass by 16 h under static conditions and a corresponding increase in cell density in the bulk liquid. In contrast, these biofilms had decreased levels of extracellular DNA (eDNA). Fe(II) levels in the supernatants of biofilms formed in the presence of FeNPs exceeded 100 μM compared with 20 μM in control media without cells. Spent cell supernatants had little effect on Fe(II) levels. Cells also had an effect on the aggregation behavior of these nanoparticles. SPIONs incubated with cells exhibited a decrease in the number and size of FeNP aggregates visible using light microscopy. SPIONs resuspended in fresh media or spent culture supernatants formed large aggregates visible in the light microscope upon exposure to a supermagnet;and could be pelleted magnetically in microtitre plate wells. In contrast, SPION FeNPs incubated with cells were unaffected by exposure to the supermagnet and could not be pelleted. The results of this study indicate a need to reconsider the effects of FeNPs on bacterial growth and biofilm formation and the effect the bacterial cells may have on the use and recovery of SPIONs.

关键词： Spion Iron Oxide Nanoparticles Biofilms Pseudomonas Aeruginosa Magnetism Nanotechnology

Evaluation of phytophthora root rot-resistant <i>Capsicum annuum</i>accessions for resistance to phytophthora foliar blight and phytophthora stem blight

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Agricultural Sciences 2012年第5期3卷 732-737页

作者： Byron L. Candole Patrick j. Conner Pingsheng j. Horticulture Department University of Georgia-Tifton Campus Tifton USA Plant Pathology Department University of Georgia Athens USA

A mixture of six Georgia isolates of Phytophthora capsici (Leon.), the causal agent of phytophthora blight, were used for greenhouse mass screening of over 700 accessions of Capsicum annuum for both stem blight and foliar blight. From this screening, it was determined that resistance to both forms of the disease were relatively common in the germplasm, but resistance to one form of the disease was not strongly correlated to resistance to the other form. Ten accessions previously shown to possess root rot resistance were tested for resistance to stem rot and leaf blight, and were found to also be highly resistant to these forms of the disease. It appears that single accessions have resistance to foliar, stem and root rot caused by P. capsici, which may simplify breeding for resistance to all three forms of the disease.

关键词： Pepper Phytophthora Blight Root Rot Stem Blight Foliar Blight

PHYSICAL MODELING FOR THE MECHANISMS OF BEAD FORMATION DEFECTS BASED ON THE STABILITY OF LIQUID METAL

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2000年第1期13卷 123-127页

作者： S. Y. Yin L. Feng j. Z. Ding and S. j. Chan( 1) Beij.ng Polytechnic University, Beij.ng 100022, China 2) National Key Laboratory of Advanced Wdlding Production Technology, HIT, Harbin 150001, China)

Based on the theory of stability of the liquid metal under the action of surface tension,a physical mod- el is established for the mechanisms of the bead formation deferct' humping', which is generated during high - speed welding.A boundary function is introduced to correct the model,theoretical results got by the model correspond well with the experimental phenomena. A two - dimensional conducting model is adoopted in the simulation of the temperature field during high - speed ***, the factors acting upon the stability of liquid metal are analyzed.

关键词： high - speed welding bead formation stability

Acquired Immune Deficiency Syndrome in Man and Animals—A Review

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

World j.urnal of AIDS 2015年第1期5卷 50-57页

作者： Maduike C. O. Ezeibe Ij.oma j. Ogbonna Department of Veterinary Medicine Michael Okpara University of Agriculture Umudike Nigeria

The paper defined acquired immune deficiency syndrome (AIDS) as a hematological abnormality rather than a clinical abnormality. Viruses that cause AIDS in man and animals are reviewed. Suggestion that human immune deficiency virus (HIV) which causes HIV/AIDS in man is a mutant of simian immune deficiency virus (SIV) which causes SIV/AIDS in nonhuman primates is also re-viewed. For a simple test to enable researchers in the developing countries which have the highest incidences of HIV/AIDS, j.in the global search for more effective treatment for the pandemic, direct passive hemagglutination test has been developed for in vitro testing of drugs, herbs and minerals that may have antiretroviral effects. Also reviewed are the similarities in pathogenesis of HIV infection in man and pathogenesis of infectious bursa disease virus (IBDV) in chicks to assess possibility of developing vaccine for HIV/AIDS. Finally, antiretroviral effects of medicinal synthetic aluminum-magnesium silicate as cure for HIV/AIDS were reviewed.

关键词： HIV In Vitro Test Prospect of Vaccine A Potential Cure

3D Fluorescence Characterization of Synthetic Organic Dyes—Effect of pH

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

American j.urnal of Analytical Chemistry 2013年第10期4卷 531-576页

作者： Leonard j. Soltzberg Sarah Flynn Vera Kirch Richard Newman Department of Chemistry & Physics Simmons College Boston USA Scientific Research Lab Museum of Fine Arts Boston USA

The fingerprint character and high sensitivity of 3D UV-vis fluorescence spectra offer special advantages for identification of dyes in a museum or forensic setting. However, the extraction process is likely to affect the pH of the medium and, in some cases, may alter the dye itself. We report a study of 65 dyes extracted from wool fibers that are part of the Schweppe Collection of Important Synthetic Dyes. The 3D fluorescence spectra of the dye extracts at pH 1 and pH 14 are compared with the same dyes from the Schweppe solution library, run under the same conditions, as well as with the 3D fluorescence spectra of the dyes taken directly from the solution library without pH control. This analysis leads to guidelines for the use of such spectra in identifying unknown dye samples.

关键词： Fluorescence Spectrophotometry Dye Analysis Textile Analysis

A Decade of j.delle Subdermal Implant Contraception in a Tertiary Health Institution in Port Harcourt, Southern Nigeria

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

j.urnal of Biosciences and Medicines 2018年第3期6卷 123-130页

作者： E. O. Oranu j. D. Oj.le Department of Obstetrics and Gynecology University of Port Harcourt Teaching Hospital Port Harcourt Nigeria

Background: j.delle, a long acting reversible progesterone contraceptive, has been in use in our centre for over 10 years and has not been comprehensively evaluated. Obj.ctives: To determine the acceptance, efficacy, and safety profile associated with the use of j.delle contraceptive implant in the University of Port Harcourt Teaching hospital, Port Harcourt. Methods: This is a 10-year retrospective study of clients who accepted and used j.delle for contraception in the university of Port Harcourt Teaching Hospital (UPTH), Port Harcourt. The case files were retrieved and information on their socio demographic profile, source of information, side effects, failures and reason for removal were extracted using a proforma. Data were filled into a spread sheet, analyzed using SPSS version 21.0 and presented in tables of frequencies and percentages. Results: Within the period under review, March 2007 to February 2017, 569 clients used j.delle out of the 3829 women who accepted and used modern contraceptive in the UPTH. The mean age of users was 33.7 ± 4.2, 536 (94.2%) were multipara with a mean parity of 4.5 ± 3.8 while 541 (95.1%) had secondary education and above. The maj.r side effect was irregular vaginal bleeding 36 (60.9%) while the main reason for removal of the device was expiration of method 272 (53.9%). A pregnancy was recorded during this period giving a pearl index of 0.002. Conclusion: j.delle is a popular and a very effective means of contraception with increasing acceptance among our clients. The safety profile is high.

关键词： j.delle High Efficacy Safe Port Harcourt

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

探索者

作者： (美)丹尼尔·j.布尔斯廷(Daniel j. Boorstin)

来源：南通市图书馆图书评论

学校读者我要写书评

暂无评论

虚数的故事