检索结果-南通市图书馆

美元与美元替代:从顺差和逆差、储蓄和投资的角度分析

在线全文

学校读者我要写书评

暂无评论

金融发展研究 2022年第7期 32-35页

作者：迈克尔·佩蒂斯王宇(译) 不详中国人民银行研究局

世界性储蓄与投资失衡是美国贸易逆差的主要原因,而贸易逆差支撑了美元的世界货币地位。从实质上看,贸易顺差国将美国市场作为储蓄与投资的平衡器,通过将其过剩生产转化为储备资产来弥补国内需求不足。因此,美元作为世界货币,在赋予华... 详细信息

世界性储蓄与投资失衡是美国贸易逆差的主要原因,而贸易逆差支撑了美元的世界货币地位。从实质上看,贸易顺差国将美国市场作为储蓄与投资的平衡器,通过将其过剩生产转化为储备资产来弥补国内需求不足。因此,美元作为世界货币,在赋予华盛顿和华尔街较大的地缘政治权力的同时,给美国工人、农民和小企业带来了巨大的成本。随着这一成本的不断上升,在全球范围内限制美元的使用符合美国的长期利益。但是,就目前情况看,其他货币或国际大宗商品储备难以代替美元储备,美国还无法放弃美元的世界货币地位。

关键词：美元世界货币贸易顺差贸易逆差储蓄投资失衡

维普期刊数据库博看期刊

CAN TRICHLOROMETHANE SULFONYL BROMIDE BE USED AS AN ADDENDUM AS WELL AS A TELOGEN IN ITS ADDITION REACTION T0 VINYLIDENE FLUORIDE?

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1993年第7期4卷 583-586页

作者： michael yu ZHU Susan Si Xun SUN yu Buang ZHANG Xi Kui JIANG Shanghai Institute of Organic Chemistry, 345 Ling-Ling Lu, Shanghai 200032

CCl_3SO_2Br used as a 'telogen' reacts with CH_2=CF_2 to give mainly the 'mono- adduct' CCl_3CH_2CF_2Br, together with very small amouats of CCl_3CF_2CH_2Br, CCl_2BrCH_2CF_2Br and the 'di-adduct' CCl_3(CH_2CF_2)_2Br. The result indicates that CCl_3SO_2Br can be used as an addendum in trichloromethyl-bromo-addition reactions to olefins.

关键词： CF Br CCI CAN TRICHLOROMETHANE SULFONYL BROMIDE BE USED AS AN ADDENDUM AS WELL AS A TELOGEN IN ITS ADDITION REACTION T0 VINYLIDENE FLUORIDE CII AS BE ITS

Organocatalytically Enantioselective Approach to Polysubsti- tuted Tetrahydropyridines and Piperidines

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2011年第9期29卷 1873-1879页

作者： yu, Fang Zhang, Xiaojing Jiang, Yongwen Shenyang Pharmaceutical University 103 Wenhua Lu Shenyang Liaoning 110016 China State Key Laboratory of Bioorganic and Natural Products Chemistry Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200032 China

A convenient and highly enanfioselecfive method for assembly of functionalized 1,2,3,4,5-pentasubstituted tetrahydropyridines and piperidines was developed. This method relies on preparing the required enantiopure cyclic semi-acetals via an organocatalyzed michael addition/cyclization cascade reaction of aldehydes and a-keto-α,β- unsaturated esters, and subsequent reductive amination/condensation with primary amines.

关键词： organocatalysis michael addition reductive amination substituted piperidine tetrahydropyridine

Allergen micro-array detection of specific IgE-reactivity in Chinese allergy patients

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Medical Journal 2011年第24期124卷 4350-4354页

作者： ZHENG Yi-wu LI Jing LAI Xu-xin ZHAO De-yu LIU Xiao-fan LIN Xiao-ping Birgitte Gjesing Paola Palazzo Adriano Mari ZHONG Nan-shan michael D Spangfort Research Asia Pacific ALK A/S Guangzhou Guangdong 510230China State Key Laboratory of Respiratory Disease the First Affiliated Hospital Guangzhou Medical College Guangzhou Guangdong 510230 China Department of Respiratory the Affiliated Children＇s Hospital of Nanjing Medical University Nanjing Jiangsu 210008 China Department of Pediatrics the Affiliated Hospital of Chengdu University of Traditional Chinese Medicine Chengdu Sichuan 610072 China Department of Allergy the General Hospital of Shenyang MilitaryCommand Shenyang Liaoning 110017 China Center for Clinical and Experimental Allergology IDI-IRCCSRome Italy

Background Allergen micro-arrays are powerful tools for screening of serum IgE-reactivity. In this study allergen micro-arrays were used to identify dominating IgE-binding allergens and cross-reactivity patterns among selected Chinese allergy patients. Methods The study was conducted using patient sera from the cities of Guangzhou, Nanjing, Chengdu and Shenyang. In total 100 sera with Dermatophagoides pteronyssinus （Der p） specific IgE-levels higher than 50 kU/L were selected for testing against 103 individual allergens. Results Among 100 selected patients, 95% showed IgE-reactivity towards house-dust mite allergens Dermatophagoides farinae （Der f） 1, Der f 2 and Der p 2 and 94% were IgE positive against Der p 1, and 60% of sera contained IgE reacting against allergen Euroglyphus maynei （Eur m） 2. IgE against cat allergen, Felisdomesticus （Fel d） 1, was seen in 20%. Only 2% showed specific IgE-reactivity to Der p 10, a panallergen belonging to the tropomyosin family. Serum IgE-reactivity towards other allergens was in general low. IgE-reactivity against pollen allergens showed geographic differences. Conclusions This study clearly confirms that group 1 and group 2 are major allergens of house dust mites. These selected house-dust mite allergy patients are close to being mono-sensitized. Der p 10 is not an important allergen for cross-reactivity. Specific IgE-sensitization towards pollen allergens is low in southern China compared to other regions. The prevalence of food and stinging insect allergens known to give rise to IgE-mediated cross-reactivity is 2% or less.

关键词： specific immunoglobulin E micro-array Dermatophagoides pteronyssinus Dermatophagoides farinae cross-reactivity

Novel radioligands for imaging sigma-1 receptor in brain using positron emission tomography(PET)

在线全文

学校读者我要写书评

暂无评论

Acta Pharmaceutica Sinica B 2019年第6期9卷 1204-1215页

作者： yu Lan Ping Bai Zude Chen Ramesh Neelamegam michael SPlaczek Hao Wang Stephanie AFiedler Jing Yang Gengyang yuan Xiying Qu Hayden RSchmidt Jinchun Song Marc DNormandin Chongzhao Ran Changning Wang Athinoula A.Martinos Center for Biomedical Imaging Department of RadiologyMassachusetts General HospitalHarvard Medical SchoolCharlestownMA 02129USA Gordon Center for Medical Imaging Department of RadiologyMassachusetts General HospitalHarvard Medical SchoolCharlestownMA 02129USA Department of Biological Chemistry and Molecular Pharmacology Harvard Medical SchoolBostonMA 02129USA Department of Pharmacy Renmin Hospital of Wuhan UniversityWuhan 430060China

The sigma-1 receptor(σ1R)is a unique intracellular protein.σ1R plays a major role in various pathological conditions in the central nervous system(CNS),implicated in several neuropsychiatric *** ofσ1R in the brain using positron emission tomography(PET)could serve as a noninvasively tool for enhancing the understanding of the disease’s ***,σ1R PET tracers can be used for target validation and quantification in ***,we describe the radiosynthesis,in vivo PET/CT imaging of novelσ1R11C-labeled radioligands based on 6-hydroxypyridazinone,[11C]HCC0923 and[11C]*** radioligands have high affinities toσ1R,with good *** mice PET/CT imaging,both radioligands showed appropriate kinetics and ***,the specific interactions of two radioligands were reduced by compounds 13 and 15(self-blocking).Ofthe two,[11C]HCC0929 was further investigated in positive ligands blocking studies,using classicσ1R agonist SA 4503 andσ1R antagonist PD ***σ1R ligands could extensively decreased the uptake of[11C]HCC0929 in mice ***,the biodistribution of major brain regions and organs of mice were determined in *** studies demonstrated that two radioligands,especially[11C]HCC0929,possessed ideal imaging properties and might be valuable tools for non-invasive quantification ofσ1R in brain.

关键词： σ1R PET Brain imaging 6-Hydroxypyridazinone 11C-labeled radioligand

Microbial responses to combined oxidation and catalysis treatment of 1,4-dioxane and co-contaminants in groundwater and soil

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2018年第5期12卷 168-180页

作者： yu Miao Nicholas W.Johnson Kimberly Heck Sujin Guo Camilah D.Powell Thien Phan Phillip B.Gedalanga David T.Adamson Charles J.Newell michael S.Wong Shaily Mahendra Department of Civil and Environmental Engineering University of CaliforniaLos AngelesCA 90095USA Department of Chemical and Biomolecular Engineering Rice UniversityHoustonTX 77005USA Department of Health Science California State UniversityFullertonCA 92834USA GSI Environmental Inc. HoustonTX 77098USA

Post-treatment impacts of a novel combined hydrogen peroxide(H2O_(2))oxidation and WOx/ZrO_(2) catalysis used for the removal of 1,4-dioxane and chlorinated volatile organic compound(CVOC)contaminants were investigated in soil and groundwater microbial *** treatment train removed~90%1,4-dioxane regardless of initial concentrations of 1,4-dioxane and *** Illumina Miseq platform and bioinformatics were used to study the changes to microbial community *** approach determined that dynamic shifts of microbiomes were associated with conditions specific to treatments as well as 1,4-dioxane and CVOCs *** biodiversity was observed to decrease only after oxidation under conditions that included high levels of 1,4-dioxane and CVOCs,but increased when 1,4-dioxane was present without ***_(x)/ZrO_(2) catalysis reduced biodiversity across all *** classification demonstrated oxidative tolerance for members of the genera Massilia and Rhodococcus,while catalyst tolerance was observed for members of the genera Sphingomonas and *** discriminant analysis effect size was a useful statistical tool to highlight representative microbes,while the multidimensional analysis elucidated the separation of microbiomes under the low 1,4-dioxane-only condition from all other conditions containing CVOCs,as well as the differences of microbial population among original,post-oxidation,and post-catalysis *** results of this study enhance our understanding of microbial community responses to a promising chemical treatment train,and the metagenomic analysis will help practitioners predict the microbial community status during the post-treatment period,which may have consequences for long-term management strategies that include additional biodegradation treatment or natural attenuation.

关键词： Coupled treatments Chlorinated solvents Diethylene ether Biological diversity Microbial populations Biomarkers

核-壳结构CdSe/ZnS量子点的制备、硫醇修饰及其光学性能

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中国科学：化学 2010年第10期40卷 1496-1502页

作者：朱华平廖世军 HU michael 邵磊 yu Kui 华南理工大学化学化工学院广州510641 Oak Ridge National Laboratory Oak Ridge Tennessee 37831-6181 USA 纳米材料先进制备技术与应用科学教育部重点实验室北京化工大学北京100029 Steacie Institute for Molecular Sciences National Research Council of Canada Ottawa Ontario KIA 0R6 Canada

采用高温有机相包覆技术制备了CdSe/ZnS核壳结构量子点材料,考察了包覆量对量子点材料的光学性能的影响,研究了含脂肪链和芳香基的双硫醇分子1,4-苯二甲硫醇和1,8-辛二硫醇对于具有核-壳结构的CdSe/ZnS量子点材料的修饰作用,考察了修饰... 详细信息

采用高温有机相包覆技术制备了CdSe/ZnS核壳结构量子点材料,考察了包覆量对量子点材料的光学性能的影响,研究了含脂肪链和芳香基的双硫醇分子1,4-苯二甲硫醇和1,8-辛二硫醇对于具有核-壳结构的CdSe/ZnS量子点材料的修饰作用,考察了修饰作用对于量子点的量子效率和荧光强度等光学性能的影响.实验结果表明:随着硫化锌包覆量的增加,量子点的量子效率及其荧光发射强度明显提高;硫醇的修饰能显著增强量子点的发光强度,随着硫醇浓度的增加,其发光性能增强,但是达到一定程度后,光学性能基本不随硫醇浓度的变化而变化.根据固体核磁共振等实验结果推测:硫醇分子可能部分替代了量子点体系中的正三辛基氧膦配体,稳定了量子点体系,对量子点起修饰保护作用,从而提高了量子点的光学性能.

关键词：核-壳结构量子点量子效率修饰

Evaluation of a point of care ultrasound curriculum for Indonesian physicians taught by fi rst-year medical students

在线全文

学校读者我要写书评

暂无评论

World Journal of Emergency Medicine 2017年第4期8卷 281-286页

作者： Jonathan B.Lee Christina Tse Thomas Keown michael Louthan Christopher Gabriel Alexander Anshus Bima Hasjim Katrina Lee Esther Kim Luke yu Allen yu Shadi Lahham Steven Bunch Maili Alvarado Abdulatif Gari John C.Fox School of Medicine University of CaliforniaIrvineUSA Department of Emergency Medicine University of CaliforniaIrvineOrangeCalifornia 92868USA

BACKGROUND: The purpose of this study was to assess the short-term efficacy of a 4-week ultrasound curriculum taught by American first-year medical students to general practitioners working in public health care clinics, or puskesmas, in Bandung, ***: We performed a prospective, observational study of Indonesian health care practitioners from public clinics in Bandung, Indonesia. These practitioners were enrolled in a 4-week ultrasound training course taught by first-year American medical students. A total of six sessions were held comprising of 38 ultrasound milestones. A pre-course and post-course written exam and practical exam was taken by each ***: We enrolled 41 clinicians in the course. The average pre-course exam score was 35.2% with a 2.4% pass rate, whereas the average post-course exam score was 82.0% with a 92.7% pass rate. The average practical score at the completion of the course was 83.2%(SD=0.145) with 82.9% of the class passing(score above 75.0%).CONCLUSION: Our data suggests that first-year medical students can effectively teach ultrasound to physicians in Indonesia using a 4-week intensive ultrasound training course. Future studies are needed to determine the amount of training required for proficiency and to evaluate the physicians' perceptions of the student-instructors' depth of knowledge and skill in point of care ultrasound.

关键词： Ultrasound education Ultrasound teaching Indonesia

Simple and Efficient Procedure for Highly Diastereoselective Synthesis of trans- 1,1-Disubstituted-2,6-diarylcyclohexane-4-ones

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2013年第6期29卷 1115-1118页

作者： yu Ya-qin WANG Zhong-liang Tianjin Key Laboratory of Water Resources and Environment Tianjin Normal UniversityTianjin 300387 P.R.China State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of Sciences Guiyang 550002 P.R.China

A simple and efficient method has been developed for highly diastcreoselective synthesis of trans-1,1-disubstituted-2,6-diarylcyclohexane-4-ones from dibenzalacetone and malononitril with trans-1,2-diaminocyclohexane as catalyst. The substrate 1,5-diaryl-1,4-pentadien-3-ones and active methylene compounds proceeded to give the products with good to excellent yield within a short time.

关键词： Substituted cyclohexanone Double michael addition Malononitrile