检索结果-南通市图书馆

Development and Test of an Experimental Apparatus to Study Thermal-Choking in Ideal Gases and Self-decomposition in Superheated N2O

在线全文

学校读者我要写书评

暂无评论

Journal of Energy and Power Engineering 2015年第1期9卷 25-39页

作者： Patrick Lemieux Alberto Fara Pablo Sanchez william murray California Polytechnic State University San Luis Obispo CA 93407 USA Politecnico di Torino Turin 10129 Italy

N2O represents a popular oxidizer for hybrid rocket motors for a variety of reasons, including safety, ease of access and self-pressurization. It is often used as a saturated two-phase fluid in these applications to take advantage of self-pressurization. Recent interest in using this oxidizer in regeneratively cooled engines requires a detailed heat transfer process analysis to the coolant, in order to quantify performance. Since the injection of N2O typically takes place in the two-phase region, our study focuses on heat transfer rates in this region, and extends the region to include superheated vapor. This analysis is critical for these cooling applications, because the exothermic decomposition nature of N2O also means that unchecked heating in the superheated region may result in a runaway reaction in the cooling passages. Furthermore, provided that sufficient heat transfer rates are available, N2O is expected to accelerate in the cooling passages due to Rayleigh flow effects much like those of a calorically perfect gas. The proximity of superheated N2O to its saturated vapor curve, at the conditions studied here, makes the suitability of a perfect gas model questionable, but that benchmarks is still useful. This paper presents the development of an experimental apparatus （a ＂Rayleigh tube＂）, specifically designed to study this problem, and test the analytical methods developed to model it. Since we focus on the development of the apparatus, the data presented were uses primarily calorically perfect gas surrogates, but the goal is to apply the apparatus and method to N2O. The design and construction of the Rayleigh tube is presented, along with preliminary results with perfect gases. Finally, we present preliminary results on heated N2O flow. Using a simple model for predicted dry-out point, we investigate where superheating may be expected to occur. We present estimates of critical heating and compare them to the heat required to achieve self-decomposition.

关键词： Self-decomposition N2O Rayleigh apparatus

鹿特丹公约:为什么在这里和它试图达到什么目的?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

产业与环境 2005年第2期27卷 9-11页

作者： william murray Sheila Logan 刘志强（译） Programme Officer Rotterdam Convention Secretariat Plant Protection Service Plant Production and Protection Division FAO Viale delle Terme di Caracalla 00100 Rome Italy Scientific Affairs Officer Rotterdam Convention Secritariat UNEP Chemicals 11-13 Chemin des Anemones CH-1219 Chatelaine Geneva Switzerland 不详

在二十世纪,各种合成化学品的使用有着令人注目的增长,特别是在制造产业和农业中.这些化学品中有许多后来显示出大量的不合乎需要的特性,包括在环境中的持久性,在食物链中生物放大的趋势,对于环境的负面影响.某些化学品也显示导致癌症... 详细信息

在二十世纪,各种合成化学品的使用有着令人注目的增长,特别是在制造产业和农业中.这些化学品中有许多后来显示出大量的不合乎需要的特性,包括在环境中的持久性,在食物链中生物放大的趋势,对于环境的负面影响.某些化学品也显示导致癌症或出生率下降.有些是非常危险的,即使在非常有限的暴露之后.

关键词：合成化学品持久性环境管理鹿特丹公约安全管理

Management of monogenic diabetes in pregnancy:A narrative review

在线全文

学校读者我要写书评

暂无评论

World Journal of Diabetes 2024年第1期15卷 15-23页

作者： Mohammad Sadiq Jeeyavudeen Sarah R murray Mark W J Strachan Metabolic Unit Western General HospitalEdinburgh EH42XUUnited Kingdom MRC Centre for Reproductive Health University of Edinburgh Queen’s Medical Research InstituteEdinburgh EH164TJUnited Kingdom

Pregnancy in women with monogenic diabetes is potentially complex,with significant implications for both maternal and fetal *** these,maturity-onset diabetes of the young(MODY)stands out as a prevalent monogenic diabetes subtype frequently encountered in clinical *** subtype of MODY requires a distinct approach tailored to the pregnancy,diverging from management strategies in non-pregnant *** MODY(GCK-MODY)typically does not require treatment outside of pregnancy,but special considerations arise when a woman with GCK-MODY becomes *** glycemic targets in GCK-MODY pregnancies are not exclusively dictated by the maternal/paternal MODY genotype but are also influenced by the genotype of the developing *** pregnancy,the choice between sulfonylurea or insulin for treating hepatocyte nuclear factor 1-alpha(HNF1A)-MODY and HNF4A-MODY depends on the mother’s specific circumstances and the available *** of other rarer MODY subtypes is individu-alized,with decisions made on a case-by-case ***,a collaborative approach involving expert diabetes and obstetric teams is crucial for the compre-hensive management of MODY pregnancies.

关键词： Diabetes Pregnancy Maturity-onset diabetes of the young Insulin Sulphonylurea Glucokinase Hepatocyte nuclear factor 1-alpha,hepatocyte nuclear factor 1-beta,and hepatocyte nuclear factor 4-alpha

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

早期膏体胶结充填料的液化分析

矿业研究与开发 2004年第Z1期24卷 174-181页

作者： Kim le Roux william Bawden murray Grabinsky 王维德 University of Toronto University of Toronto University of Toronto 　

评估膏体胶结充填料受动载荷而发生液化的可能性是至关重要的,因为液化的膏体胶结充填料可能会破坏隔墙和流入相邻的巷道而造成生产损失,并耗费许多资金进行清理,甚至有可能造成工伤事故.探讨现场膏体胶结充填料在各种条件下发生液化的... 详细信息

评估膏体胶结充填料受动载荷而发生液化的可能性是至关重要的,因为液化的膏体胶结充填料可能会破坏隔墙和流入相邻的巷道而造成生产损失,并耗费许多资金进行清理,甚至有可能造成工伤事故.探讨现场膏体胶结充填料在各种条件下发生液化的可能性的研究方法是:利用在现场测定的特性,准备有代表性的试样进行试验室试验,然后利用静态的三轴循环试验评估充填料的反应.试验结果表明,对于受试材料而言,早期膏体胶结充填料能抵抗静态液化,但是,当施加的应力比大于0.16时,受循环负荷的材料易被破坏.然而,重要的是不能夸大液化的危险,因为抗液化阻力随着养护期的延长和膏体胶结充填料强度的增长而加大.

关键词：膏体充填充填隔墙

Interactions between maternal parity and feed additives drive the composition of pig gut microbiomes in the post‑weaning period

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Animal Science and Biotechnology 2024年第3期15卷 1241-1257页

作者： Kayla Law Eduardo Rosa Medina Garcia Chad Hastad Deborah murray Pedro E.Urriola Andres Gomez Department of Animal Science University of Minnesota1364 Eckles AvenueSaint PaulMN 55108USA New Fashion Pork 164 Industrial ParkwayJacksonMN 56143USA

Background Nursery pigs undergo stressors in the post-weaning period that result in production and welfare *** challenges disproportionately impact the offspring of primiparous sows compared to those of mul-tiparous *** is known regarding potential interactions between parity and feed additives in the post-weaning period and their effects on nursery pig ***,the objective of this study was to investigate the effects of maternal parity on sow and offspring microbiomes and the influence of sow parity on pig fecal microbi-ome and performance in response to a prebiotic *** weaning,piglets were allotted into three treat-ment groups:a standard nursery diet including pharmacological doses of Zn and Cu(Con),a group fed a commercial prebiotic only(Preb)based on an Aspergillus oryzae fermentation extract,and a group fed the same prebiotic plus Zn and Cu(Preb+ZnCu).Results Although there were no differences in vaginal microbiome composition between primiparous and mul-tiparous sows,fecal microbiome composition was different(R^(2)=0.02,P=0.03).The fecal microbiomes of primiparous offspring displayed significantly higher bacterial diversity compared to multiparous offspring at d 0 and d 21 post-weaning(P<0.01),with differences in community composition observed at d 21(R^(2)=0.03,P=0.04).When analyzing the effects of maternal parity within each treatment,only the Preb diet triggered significant microbiome distinc-tions between primiparous and multiparous offspring(d 21:R^(2)=0.13,P=0.01;d 42:R^(2)=0.19,P=0.001).Composi-tional differences in pig fecal microbiomes between treatments were observed only at d 21(R^(2)=0.12,P=0.001).Pigs in the Con group gained significantly more weight throughout the nursery period when compared to those in the Preb+ZnCu *** Nursery pig gut microbiome composition was influenced by supplementation with an Aspergillus oryzae fermentation extract,with varying effects on performance

关键词： Aspergillus prebiotic Copper Feed additives Maternal Nursery pig microbiome Parity Swine microbiome Trace minerals Zinc

在线全文

学校读者我要写书评

暂无评论

加拿大央行打响了背离美联储的第一枪

商业周刊（中文版） 2024年第9期 20-22页

作者： Erik Hertzberg Randy Thanthong-Knight Jay Zhao-murray 杨(译) 不详

加拿大央行行长蒂夫·麦克勒姆明确表示,尽管加元可能面临下行压力,但加拿大的利率政策不需要与美国亦步亦趋。加拿大央行行长蒂夫·麦克勒姆(Tiff Macklem)率先在七国集团(G-7)中降息,他对这一举措的信心,或有助于让其他央行放下心来,... 详细信息

加拿大央行行长蒂夫·麦克勒姆明确表示,尽管加元可能面临下行压力,但加拿大的利率政策不需要与美国亦步亦趋。加拿大央行行长蒂夫·麦克勒姆(Tiff Macklem)率先在七国集团(G-7)中降息,他对这一举措的信心,或有助于让其他央行放下心来,他们也可以在美联储之前降息。

关键词：七国集团克勒姆降息利率政策央行第一枪美联储加拿大

Comprehensive Transcriptome Analysis of Auxin Responses in Arabidopsis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Molecular Plant 2008年第2期1卷 321-337页

作者： Ivan A. Paponov Martina Paponovt william Teale Margit Menges Sohini Chakrabortee James A.H. murray Klaus Palme Faculty of Biology University of Freiburg Schanzlestrasse 1 79104 Freiburg Germany Institute of Biotechnology University of Cambridge Cambridge CB2 1QT United Kingdom

In plants, the hormone auxin shapes gene expression to regulate growth and development. Despite the detailed characterization of auxin-inducible genes, a comprehensive overview of the temporal and spatial dynamics of auxinregulated gene expression is lacking. Here, we analyze transcriptome data from many publicly available Arabidopsis profiling experiments and assess tissue-specific gene expression both in response to auxin concentration and exposure time and in relation to other plant growth regulators. Our analysis shows that the primary response to auxin over a wide range of auxin application conditions and in specific tissues comprises almost exclusively the up-regulation of genes and iden- tifies the most robust auxin marker genes. Tissue-specific auxin responses correlate with differential expression of Aux/ IAA genes and the subsequent regulation of context- and sequence-specific patterns of gene expression. Changes in transcript levels were consistent with a distinct sequence of conjugation, increased transport capacity and down-regulation of biosynthesis in the temperance of high cellular auxin concentrations. Our data show that auxin regulates genes associated with the biosynthesis, catabolism and signaling pathways of other phytohormones. We present a transcriptional overview of the auxin response. Specific interactions between auxin and other phytohormones are highlighted, particularly the regulation of their metabolism. Our analysis provides a roadmap for auxin-dependent processes that underpins the concept of an ＇auxin code＇-a tissue-specific fingerprint of gene expression that initiates specific developmental processes.

关键词： Alcohol Abstinence Genes transport capacity transcriptomics Tissue-Specific Gene Expression Auxins Arabidopsis Plant Growth Regulators

Competitive effects of humic acid and wastewater on adsorption of Methylene Blue dye by activated carbon and non-imprinted polymers

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2018年第4期30卷 310-317页

作者： Audrey murray Banu Ormeci Department of Civil and Environmental Engineering Carleton UniversityOttawa ON K1S 5B6 Canada

Natural organic matter（NOM）, present in natural waters and wastewater, decreases adsorption of micropollutants, increasing treatment costs. This research investigated mechanisms of competition for non-imprinted polymers（NIPs） and activated carbon with humic acid and wastewater. Three different types of activated carbons（Norit PAC 200,Darco KB-M, and Darco S-51） were used for comparison with the NIP. The lower surface area and micropore to mesopore ratio of the NIP led to decreased adsorption capacity in comparison to the activated carbons. In addition, experiments were conducted for single-solute adsorption of Methylene Blue（MB） dye, simultaneous adsorption with humic acid and wastewater, and pre-loading with humic acid and wastewater followed by adsorption of MB dye using NIP and Norit PAC 200. Both the NIP and PAC 200 showed significant decreases of 27% for NIP（p = 0.087） and 29% for PAC 200（p = 0.096） during simultaneous exposure to humic acid and MB dye. There was no corresponding decrease for NIP or PAC 200 pre-loaded with humic acid and then exposed to MB. In fact, for PAC 200, the adsorption capacity of the activated carbon increased when it was pre-loaded with humic acid by 39%（p = 0.0005）. For wastewater, the NIP showed no significant increase or decrease in adsorption capacity during either simultaneous exposure or pre-loading. The adsorption capacity of PAC 200 increased by 40%（p = 0.001） for simultaneous exposure to wastewater and MB. Pre-loading with wastewater had no effect on MB adsorption by PAC 200.

关键词： Molecularly imprinted polymer Non-imprinted polymer Water treatment Wastewater treatment Activated carbon Micropollutants Pore-blocking Adsorption

Use of polymeric sub-micron ion-exchange resins for removal of lead,copper,zinc,and nickel from natural waters

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2019年第1期31卷 247-254页

作者： Audrey murray Banu ?rmeci Department of Civil and Environmental Engineering Carleton University

This research investigated the removal capacity of polymeric sub-micron ion-exchange resins(SMR) for removal of lead, copper, zinc, and nickel from natural waters in competition with natural organic matter(NOM). Polymeric SMR particles were created and tested to ensure that they were adequately dispersed in the solution. They removed little NOM(10%or less) from river water and wastewater, indicating that competition from NOM was not a major concern. SMR were able to remove 82% ± 0.2% of lead, 46% ± 0.6% of copper, 55% ±20% of zinc, and 17% ± 2% of nickel from river water spiked with 500 μg/L of each. Similarly,in wastewater, they were able to remove 86% ± 0.1% of lead, 38% ± 0.8% of copper, 28% ± 1%of zinc, and 11% ± 1% of nickel.

关键词： Water Wastewater Heavy metals Ion exchange Polymeric submicron resin Natural organic matter (NOM)