检索结果-南通市图书馆

Flight Characteristics Analysis Based on QAR Data of a Jet Transport During Landing at a High-altitude Airport

Chinese Journal of Aeronautics 2012年第1期25卷 13-24页

作者： C.edward Lan WU Kaiyuan YU Jiang Department of Aerospace Engineering The University of KansasKansas 66045USA China Aerodynamics Research and Development Center Mianyang 622661China Scientific Research Base Civil Aviation Flight University of ChinaGuanghan 618307China

Flight data of a twin-jet transport aircraft in revenue flight are analyzed for potential safety problems. Data from the quick access recorder （QAR） are first filtered through the kinematic compatibility analysis. The filtered data are then organized into longitudinal- and lateral-directional aerodynamic model data with dynamic ground effect. The dynamic ground effect requires the radio height and sink rate in the models. The model data are then refined into numerical models through a fuzzy logic algorithm without data smoothing in advance. These numerical models describe nonlinear and unsteady aerodynamics and are used in nonlinear flight dynamics simulation. For the jet transport under study, it is found that the effect of crosswind is significant enough to excite the Dutch roll motion. Through a linearized analysis in flight dynamics at every instant of time, the Dutch roll motion is found to be in nonlinear oscillation without clear damping of the amplitude. In the analysis, all stability derivatives vary with time and hence are nonlinear functions of state variables. Since the Dutch roll motion is not damped despite the fact that a full-time yaw damper is engaged, it is concluded that the design data for the yaw damper is not sufficiently realistic and the contribution of time derivative of sideslip angle to damping should be considered. As a result of nonlinear flight simulation, the vertical wind acting on the aircraft is estimated to be mostly updraft which varies along the flight path before touchdown. Varying updraft appears to make the descent rate more difficult to control to result in a higher g-load at touchdown.

关键词： jet transport unsteady aerodynamics nonlinear aerodynamics flight dynamics flight safety quick access recorder data

来源：

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

Extraction of 17β-estradiol in water using non-imprinted polymer submicron particles in membrane filters

引用

Journal of Environmental Sciences 2010年第11期22卷 1820-1825页

作者： Yiyan Li edward P. C. Lai Institute of Environmental Science Carleton University 1125 Colonel By Drive Ottawa Ontario K1S 5B6 Canada. Department of Chemistry Carleton University 1125 Colonel By Drive Ottawa Ontario K1S 5B6 Canada

17β-Estradiol （E2） is an endocrine disrupting chemical of harm to both animals and human beings at a low concentration level （ng/L）. It cannot be completely removed by wastewater treatments, and is often detected in both environment and drinking waters. The purpose of this feasibility study, towards environmental engineering in the field of water analysis and treatment, was to remove E2 by extraction using non-imprinted polymer （NIP） submicron particles. Experimental results showed that 0.5 mg/L of E2 could be completely extracted by adding 10 mg of NIP particles directly into 10 mL of water. However, the extraction efficiency decreased to 64% for 100 mL of water. prefilling the NIP particles inside a membrane filter showed a potential for water treatment of a large volume, requiring no effort to distribute the particles uniformly in the water. High extraction efficiency （80 ± 10）% for E2 was achieved for 100 mL of water. A total mass of 0.29 mg E2 was extracted from 1000 mL of water containing 0.8 mg/L E2 （by using only 10 mg of NIP particles）. Both efficiency and mass capacity can be increased, by scaling up the amount of NIP particles, towards environmental engineering applications.

关键词： 17β-estradiol non-imprinted polymer submicron particles membrane filter pollution abatement technology

来源：

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

Purification of total DNA extracted from activated sludge

引用

Journal of Environmental Sciences 2008年第1期20卷 80-87页

作者： SHAN Guobin JIN Wenbiao edward KHLAM XING Xinhui Baolimei Chemical Engineering Co. Ltd. Dongguan 523581 China. Institute of Biochemical Engineering Department of Chemical Engineering Tsinghua University Beijing 100084 China Department of Urban and Civil Engineering Harbin Institute of Technology Shenzhen Graduate School Shenzhen 518055 China

Purification of the total DNA extracted from activated sludge samples was studied. The effects of extraction buffers and lysis treatments （lysozyme, sodium dodecyl sulfate （SDS）, sonication, mechanical mill and thermal shock） on yield and purity of the total DNA extracted from activated sludge were investigated. It was found that SDS and mechanical mill were the most effective ways for cell lysis, and both gave the highest DNA yields, while by SDS and thermal shock, the purest DNA extract could be obtained. The combination of SDS with other lysis treatment, such as sonication and thermal shock, could apparently increase the DNA yields but also result in severe shearing. For the purification of the crude DNA extract, polyvinyl polypyrrolidone was used for the removal of humic contaminants. Cetyltrimethyl ammonium bromide, potassium acetate and phenol/chloroform were used to remove proteins and polysaccharides from crude DNA. Crude DNA was further purified by isopropanol precipitation. Thus, a suitable protocol was proposed for DNA extraction, yielding about 49.9 mg （total DNA）/g volatile suspended solids, and the DNA extracts were successfully used in PCR amplifications for 16S rDNA and 16S rDNA V3 region. The PCR products of 16S rDNA V3 region allowed the DGGE analysis （denatured gradient gel electrophoresis） to be possible.

关键词： 16S rDNA activated sludge PCR lysis treatment DNA purification wasterwater biotreatment

来源：

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

Multi-length scale modeling of carburization,martensitic microstructure evolution and fatigue properties of steel gears

引用

Journal of Materials Science & Technology 2020年第14期47卷 157-165页

作者： edward Charles Henry Crawford O’Brien Hemantha Kumar Yeddu School of Engineering Newcastle UniversityNewcastle upon TyneNE17RUUnited Kingdom

Multi-length scale modeling is performed to(i)predict the carburized case depth of SAE8620 steel gears by solving the Fick’s second law of diffusion,(ii)model the martensitic microstructure evolution in a grain inside the carburized case as well as to study the effect of stress cycling on retained austenite(RA)and martensite using a 3D phase-field model,(iii)simulate the effect of carburization and different RA contents on macroscale fatigue behavior of SAE8620 steel spur gear using the finite element *** diffusion model predicts that the case depth increases with increasing heat treatment time and *** phase-field simulations show that RA can transform to martensite during fatigue loading,where the extent of the transformation will depend on the type of stresses applied,*** in a high stress regime or low stress regime of fatigue *** transformation of martensite to austenite is also observed in low RA sample under high stress *** macroscale simulations show that the carburized case with high RA gives rise to better fatigue life compared to that with low RA.

关键词： Phase-field model Martensitic transformation Microstructure Gear steel Carburization

来源：

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

Rapid destruction of sarin surrogates by gas phase reactions with focus on diisopropyl methylphosphonate(DIMP)

引用

Defence Technology（防务技术） 2021年第3期17卷 703-714页

作者： Elif Irem Senyurt Mirko Schoenitz edward L.Dreizin New Jersey Institute of Technology NewarkNJ07102USA Tomsk State University TomskRussia

Rapid destruction of stockpiles of sarin and other chemical weapon agents(CWA)requires understanding and quantitative description of the relevant chemical *** reactions at elevated temperatures are of particular interest for prompt agent defeat *** methylphosphonate(DIMP)is a sarin surrogate particularly well suited to model sarin thermal decomposition and is often used in *** article is a review of different experimental methods addressing decomposition of gasified DIMP,respective results and their *** early decomposition products are propene,methylphosphonic acid,methyl(oxo)phosphoniumolate,and *** computational work using available kinetic data for fluorine and the phosphorus-fluorine bond predicted the decomposition under incineration *** using an isothermal flow reactor operated at 700-800 K were used to model DIMP decomposition as unimolecular reaction with results that were consistent with the earlier theoretical *** in dynamic environments was studied using DIMP supported on rapidly heated *** results showed different decomposition products and product sequences forming at different heating rates,suggesting the need for revised reaction ***,species quantification in such experiments is difficult because of inherent large temperature *** produced in a corona discharge was also reported to lead to rapid DIMP decomposition at low *** products were distinct from those observed at high *** tube experiments may be well suited to study decomposition of organophosphorus compounds like DIMP following their rapid heating in diverse ***,presently,only sarin surrogates other than DIMP have been investigated,and no intermediate reaction products,important for developing a validated mechanism,could be detected.

关键词： Chemical weapon agent Agent defeat Thermal decomposition Incineration Prompt reactions

来源：

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

Treatment of hydrofluoric acid exposure to the eye

引用

International Journal of Ophthalmology(English edition) 2015年第1期8卷 157-161页

作者： Katherine Atley edward Ridyard Oxford University Hospital NHS Trust

AIM: To review the current evidence of the treatment of hydrofluoric acid(HF) exposure to the human ***: A comprehensive manual search of the literature was conducted through the Ovid interface to assess the mechanism and efficacy of each irrigator through a variety of clinical cases and experimental studies.· RESULTS: Ocular exposure to HF is extremely damaging to the eye and swift recognition and decontamination with an appropriate agent forms the basis of treatment. Although there are various decontamination solutions that have efficacy against the corrosive action of HF, irrigation with Hexafluorine proved to be the most safe and effective treatment for the ***: In conclusion emergency departments could benefit from the availability of Hexafluorine for the treatment of HF ocular burns in patients.

关键词： hydrofluoric acid cornea ocular injury

来源：

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

Design of an Optical Water Pollution Sensor Using a Single-Layer Guided-Mode Resonance Filter

引用

Photonic Sensors 2013年第3期3卷 224-230页

作者： edward SADER Abdallah SAYYED-AHMAD Department of Physics Birzeit University Birzeit Palestine

The optical characteristics of a simple, planar, single layer, dielectric Mg-based guided mode resonance filter (GMRF) were investigated by means of rigorous-coupled wave analysis (RCWA). This filter has great potential for real-life applications, especially as bio- and environmental sensors. The structure of the proposed sensor is compact, and all of its layers can be grown in a single process. In this paper, we present results on the design of a water pollution sensor in the violet region of the visible spectrum. The spectral and angular sensitivities of the sensor for both the transverse electric (TE) and transverse magnetic (TM) polarization modes were estimated and compared for various regions in the violet spectrum. A spectral response characterized with a narrow bandwidth and low reflection side bands was realized by carrying out extensive parameter search and optimization. Optimal spectral and angular sensitivities were found for the sensor with a grating thickness of 100 nm in the TM polarized mode where we found them to be 100 nm and 40 degrees, per index refraction unit, respectively.

关键词：滤波器设计导模共振光学特性传感器水污染单层严格耦合波分析可见光谱

来源：

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

HBV genotype characterization and distribution in patients with HBV-related liver diseases in Zhejiang Province, P. R. China: possible association of co-infection with disease prevalence and severity

引用

Hepatobiliary & Pancreatic Diseases International 2005年第4期4卷 535-543页

作者： edward Zumbika Institute of Infectious Diseases the First Affiliated HospitalZhejiang University School of MedicineHangzhou 310003People's Republic of China

BACKGROUND: There are 8 well-documented genotypes of hepatitis B virus (HBV) at this time point. Genotyping can be accomplished based on a partial sequence of hepatitis B virus (HBV) genome such as the pre-S or S gene. Several methods have been developed and used for HBV genotyping including direct sequencing, restriction fragment length polymorphism, line probe assay and enzyme-linked immunoassay. Recently, a novel, rapid and cost-effective genotyping method based on PCR amplification assay using type-specific primers that can identify all six major genotypes has been developed. This study was undertaken to characterise HBV genotypes and investigate the association between the prevalence of different genotypes and the severity of HBV-induced liver diseases. METHODS: Serum samples from carriers of HBV and patients with HBV-related liver diseases from Zhejiang Province were screened for viral serological markers using commercially available radioimmunoassay (RIA) and enzyme linked immunosorbent assay (ELISA) kits. Serum HBV DNA load was determined by real-time detection PCR. A type-specific primer based the nested-PCR method was employed in the HBV genotyping. The genotype results obtained were confirmed by direct sequencing of nested PCR amplicons of the pre-S region. Ten samples of each genotype (B and C) were sequenced. RESULTS: The survey on a cohort of 125 HBV carriers in and around Hangzhou City, Zhejiang Province showed the existence of HBV genotypes A (0.8%), B (48%), C (40.8%), D (0.8%), mixed B and C (9.6%) and an absence of E and F genotypes. Distribution of HBV genotypes in patients with liver diseases revealed a statistically insignificant higher prevalence of genotype B in mild chronic hepatitis (CH). Among the three genotypes B, C and mixed B/C infections 11 (73.3%), 3 (20%) and 1 (6.7%), (P< 0.05), respectively in subjects with moderate CH, genotype B was significantly predominant. The infection patterns for genotypes B, C and B/C mixed in (i) liver c

关键词： hepatitis B virus chronic hepatitis B liver cirrhosis hepatocellular carcinoma hepatitis B e antigen hepatitis B virus DNA load viremia hepatitis B genotypes liver function tests alanine transaminase aspartate transaminase real-time detection PCR

来源：

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

SYNTHESIS AND BIOSYNTHESIS OF β-LACTAM ANTIBIOTICS

引用

中国抗生素杂志 1985年第2期10卷 114-124页

作者： edward Abraham England Sir William Dunn School of pathology University of Oxford

In 1928 Fleming observed the antibacterial action of penicillin at ***’s Hospital, London, on a plate seeded with staphylococci that had been contaminated with a strain of penicillium *** than ten years later H. W. Florey and E. Chain and their colleagues at Oxford University showed that crude preparations of penicillin had chemotherapeutic properties which seemed at the time to be almost miraculous. This marked the beginning of investigations that were to lead to the widespread use of β-lactam antibiotics in medicine.

关键词： LACTAM ANTIBIOTICS SYNTHESIS AND BIOSYNTHESIS OF

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

The immunological underpinnings of vaccinations to prevent cvtomegalovirus disease

引用

Cellular & Molecular Immunology 2015年第2期12卷 170-179页

作者： A. Louise McCormick edward S. Mocarski Laboratory of Biochemical Pharmacology Department of Pediatrics Emery University Atlanta GA USA Department of Microbiology and Immunology and Emery Vaccine Center Emery University Atlanta GA USA

A universal cytomegalovirus （CMV） vaccination promises to reduce the burden of the developmental damage that afflicts up to 0.5% of live births worldwide. An effective vaccination that prevents transplacental transmission would reduce CMV congenital disease and CMV-associated still births and leave populations less susceptible to opportunistic CMV disease. Thus, a vaccination against this virus has long been recognized for the potential of enormous health-care savings because congenital damage is life-long and existing anti-viral options are limited. Vaccine researchers, industry leaders, and regulatory representatives have discussed the challenges posed by clinical efficacy trials that would lead to a universal CMV vaccine, reviewing the links between infection and disease, and identifying settings where disrupting viral transmission might provide a surrogate endpoint for disease prevention. Reducing the complexity of such trials would facilitate vaccine development. Children and adolescents are the targets for universal vaccination, with the expectation of protecting the offspring of immunized women. Given that a majority of females worldwide experience CMV infection during childhood, a universal vaccine must boost natural immunity and reduce transmission due to reactivation and re-infection as well as primary infection during pregnancy. Although current vaccine strategies recognize the value of humoral and cellular immunity, the precise mechanisms that act at the placental interface remain elusive. Immunity resulting from natural infection appears to limit rather than prevent reactivation of latent viruses and susceptibility to re-infection, leaving a challenge for universal vaccination to improve upon natural immunity levels. Despite these hurdles, early phase clinical trials have achieved primary end points in CMV seronegative subjects. Efficacy studies must be expanded to mixed populations of CMV-naive and naturally infected subjects to understand the overall

关键词： congenital disease prevention re-infection vaccine

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：