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Interval oscillation criteria for forced Emden-Fowler functional dynamic equations with oscillatory potential

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Science China Mathematics 2013年第3期56卷 561-576页

作者： ANDERSON douglas R. SAKER Samir H. Department of Mathematics and Computer Science Concordia College Department of Mathematics Faculty of Science Mansoura University

Interval oscillation criteria are established for a second-order functional dynamic equation of Emden-Fowler type with oscillatory potential by applying Riccati and generalized Riccati techniques. The results represent further improvements on those given even for differential and difference equations. Some examples are considered to illustrate the main results.

关键词： oscillation forced dynamic equations time scales functional equations Riccati technique

Solid state interfacial reactions in electrodeposited Ni/Sn couples

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International Journal of Minerals,Metallurgy and Materials 2010年第4期17卷 459-463页

作者： Wen-ming Tang An-qiang He Qi Liu douglas-G. Ivey Department of Materials Science and Engineering Hefei University of Technology Hefei 230009 China Department of Chemical and Materials Engineering University of Alberta Edmonton T6G 2G6 Canada

Ni/Sn couples, prepared by sequentially electroplating Ni layers and Sn layers on metallized Si wafers, were employed to study the microstructures and growth kinetics of Ni-Sn intermediate phases, when the Ni/Sn couples were aged at room temperature or armealed at temperatures from 150 to 225℃ for various times. The results show that the NiSn phase and Ni3Sn4 phase are formed, respectively, in the aged couples and annealed couples. The Ni3Sn4 layer is continuously distributed between the Ni and Sn sides in the annealed Ni/Sn couples. The Ni3Sn4 growth follows parabolic growth kinetics with an apparent activation energy of 39.0 kJ/mol.

关键词： electrodeposition solid state reaction diffusion microstructure kinetics

Measurement of in-bore side loads and comparison to first maximum yaw

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Defence Technology（防务技术） 2016年第2期12卷 106-112页

作者： Donald E.CARLUCCI Ryan DECKER Julio VEGA douglas RAY U.S.Army ARDEC RDAR-DSM Building 942nd FloorPicatinnyNJ 07806-5000USA U.S.Army ARDEC RDAR-EIQ-SB Building 62PicatinnyNJ 07806-5000USA

In-bore yaw of a projectile in a gun tube has been shown to result in range loss if the yaw is significant. An attempt was made to determine if relationships between in-bore yaw and projectile First Maximum Yaw(FMY) were observable. Experiments were conducted in which pressure transducers were mounted near the muzzle of a 155 mm cannon in three sets of four. Each set formed a cruciform pattern to obtain a differential pressure across the projectile. These data were then integrated to form a picture of what the overall pressure distribution was along the side of the projectile. The pressure distribution was used to determine a magnitude and direction of the overturning moment acting on the projectile. This moment and its resulting angular acceleration were then compared to the actual first maximum yaw observed in the test. The degree of correlation was examined using various statistical techniques. Overall uncertainty in the projectile dynamics was between 20% and 40% of the mean values of FMY.

关键词：偏航负载测量压力分布压力传感器发射动力学倾覆力矩角加速度统计技术

The Role of International Community in Resolving Criss in Africa: Case of Rwandan Genocide1994

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The Role of International Community in Resolving Criss in Af...

作者： douglas GAKUMBA 外交学院

学位级别：硕士

Rwanda is a small land locked country in Eastern Africa bordered by neighbors of ***, Uganda, Burundi and Tanzania. It was relatively unknown before deadly violencebreak out in1994. It came into the international attention when over one million Tutsis andpolitically moderate Hutus were butchered in just one hundred days, making the Rwandangenocide the fastest, most well-organized killing spree of the twentieth century. In1994on April6th, a Hutu President Juvenal Habyarimana, and all others on board werekilled when the airplane he was travelling with was shot down by a ground missile whilelanding at Kigali airport. He was from the meeting in Arusha, Tanzania. The massacre ofRwanda’s minority Tutsi which was prepared well in advance by Hutu extremist began hoursafter the president’s deaths. On7April ten Belgian UN peacekeepers were killed. By doingthis the extremist who seemed to have done their assignment well, knew the UN would giveup the peacekeeping mission and pull out from Rwanda, and they were right. Within the following three months by using local garden equipment like machetes, hoes,pangs and other low-tech arms, the Hutus slaughtered over one million Tutsis in an attempt tofinish them all. The well prepared and coordinated government attempt to cruelly finish theTutsi population obviously meets the definition of genocide adopted by the UN GeneralAssembly in1948. By signing the convention, members of the UN have committedthemselves to prevent and punish the crime of genocide. If parties who have signed theGenocide Convention have committed to prevent and punish the crime of genocide, why didthe international community just watched when the Rwandan genocide was happening? This thesis will analyze the response of the international community with more attention tothe United Nations and the United States, to the Rwandan genocide. Why the UNpeacekeepers already in Rwanda did give up? Why did the US, the world’s most powerfulcountry in the world refus

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Neurosurgical treatment for addiction: lessons from an untold story in China and a path forward

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National Science Review 2020年第3期7卷 702-712页

作者： Shuo Ma Chencheng Zhang Ti-fei Yuan douglas Steele Valerie Voon Bomin Sun Department of Functional Neurosurgery Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai Key Laboratory of Psychotic Disorders Shanghai Mental Health CenterShanghai Jiao Tong University School of Medicine Co-innovation Center of Neuroregeneration Nantong University Division of Imaging Science and Technology Medical School University of Dundee Department of Psychiatry University of Cambridge

Addiction is a major public-health crisis associated with significant disability and mortality. Although various pharmacological and behavioral treatments are currently available, the clinical efficacy of these treatments is limited. Given this situation, there is a growing interest in finding an effective neurosurgical treatment for addiction. First, we discuss the use of ablative surgery in treating addiction. We focus on the rise and fall of nucleus accumbens ablation for addiction in China. Subsequently, we review recent studies that have explored the efficacy and safety of deep-brain-stimulation treatment for addiction. We conclude that neurosurgical procedures, particularly deep-brain stimulation, have a potentially valuable role in the management of otherwise intractable addictive disorders. Larger well-controlled clinical trials, however, are needed to assess clinical efficacy and safety. We end by discussing several key issues involved in this clinical field and identifying some areas of progress.

关键词： drug addiction psychosurgery ablative surgery deep-brain stimulation medical ethics

Free-Trade Agreements in a Model of Trade, Migration and Politics

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Frontiers of Economics in China-Selected Publications from Chinese Universities 2018年第1期13卷 15-31页

作者： John douglas Wilson Ilkay Yilmaz Department of Economics Michigan State University East Lansing M1 48824 USA Department of Economics Mersin University Ciftlikkoy Yenisehir 33342 Mersin Turkey

This paper uses a probabilistic voting model to investigate voting for a free-trade agreement between a labor-abundant country and a capital-abundant country. Migration from the labor-abundant country to the capital-abundant country increases the probability of a free-trade agreement, with lower migration costs leading to more migration and a higher free-trade probability. On the other hand, if a lower probability of free trade is caused by an increased voter bias against free-trade candidates, then there is less migration. A dynamic extension of the model is also investigated.

关键词： free trade migration Heckscher-Ohlin labor-abundant capital-abundant

Potential distributional shifts in North America of allelopathic invasive plant species under climate change models

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Plant Diversity 2022年第1期44卷 11-19页

作者： Anson Wang Anthony E.Melton douglas ESoltis Pamela SSoltis Department of Biology University of FloridaGainesvilleFL32611USA Florida Museum of Natural History University of FloridaGainesvilleFL32611USA Genetics Institute University of FloridaGainesvilleFL32610USA Biodiversity Institute University of FloridaGainesvilleFL32611USA

Predictive studies play a crucial role in the study of biological invasions of terrestrial plants under possible climate change *** species are recognized for their ability to modify soil microbial communities and influence ecosystem ***,we focused on six species of allelopathic flowering plants-Ailanthus altissima,Casuarina equisetifolia,Centaurea stoebe ***,Dioscorea bulbifera,Lantana camara,and Schinus terebinthifolia-Xhat are invasive in North America and examined their potential to spread further during projected climate *** used Species Distribution Models(SDMs)to predict future suitable areas for these species in North America under several proposed future climate *** and Maxent were used to develop SDMs,estimate current distributions,and predict future areas of suitable climate for each *** with the greatest predicted suitable climate in the future include the northeastern and the coastal northwestern regions of North *** size estimations demonstrate the possibility of extreme range loss for these invasives in the southeastern United States,while new areas may become suitable in the northeastern United States and southeastern *** findings show an overall northward shift of suitable climate during the next few decades,given projected changes in temperature and *** results can be utilized to analyze potential shifts in the distribution of these invasive species and may aid in the development of conservation and management plans to target and control dissemination in areas at higher risk for potential future invasion by these allelopathic species.

关键词： Allelopathy Invasive species Species distribution models Ecological niche models Invasion impacts Multi-species assessment

Management of pancreaticobiliary disease using a new intra-ductal endoscope:The Texas experience

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World Journal of Gastroenterology 2009年第11期15卷 1353-1358页

作者： douglas S Fishman Paul R Tarnasky Sandeep N Patel Isaac Raijman Texas Children’s Hospital Section of Pediatric Gastroenterology and NutritionBaylor College of Medicine6621 Fannin StreetHoustonTX 77030United States Digestive Health Associates Methodist Pavilion II 221 West Colorado Blvd.DallasTX 75208-2359United States Division of Gastroenterology and Nutrition The University of Texas Health Science Center at San Antonio7703 Floyd Curl Drive San AntonioTX 78229-3900United States Digestive Associates of Houston 6620 Main Street.HoustonTX 77030United States

AIM:To evaluate a new single-operator mini-endoscope, Spyglass,for its performance,feasibility and safety in the management of pancreaticobiliary disease. METHODS:In a multicenter retrospective analysis of patients undergoing intraductal endoscopy,we evaluated 128 patients(71 men,mean age 57.6 years).Indications were therapeutic(TX)in 72(56%) and diagnostic(DX)in 56(44%). RESULTS:Peroral endoscopy was performed in 121 and percutaneous in *** indications included CBD stones in 41,PD stones in six,and biliary strictures in *** indications included abnormal LFT’s in 15, abnormal imaging in 38 and cholangiocarcinoma staging in *** of the stone(s)was considered good in 31,fair in six,and poor in four. Advancement of the electrohydraulic lithotripsy probe was not possible in three patients and proper targeting of the lesion was partial in four patients.A holmium laser was used successfully in three *** clearance was achieved in 37 patients after one procedure and in four patients after two *** of biliary strictures was modified in 20/29 and confirmed to be malignant in 10/*** the modified patients,no diagnosis was available in *** demonstrated malignancy in 8/17 and non-malignancy in *** pathology by imaging studies and abnormal LFT’s was modified in 43/63(66%).Staging of cholangiocarcinoma demonstrated multicentric cholangiocarcinoma in 2/*** was no morbidity associated with the use of Spyglass. CONCLUSION:Spyglass Spyscopeis a first generation, single operator miniature endoscope that can evaluate and treat various biliary and pancreatic tract diseases.

关键词： Intra-ductal endoscopy Choledochoscopy Cholangiopancreatoscopy Endoscopic retrogradecholangiopancreatography Biliary disease Sclerosingcholangitis Cholangiocarcinoma Lithotripsy Pancreaticdisease Spyglass

Research integrity in forensic anthropology

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Forensic Sciences Research 2021年第3期6卷 285-291页

作者： douglas H.Ubelaker National Museum of Natural History Smithsonian InstitutionWashingtonDCUSA

Research represents the driving force for change and advancement in the forensic sciences[1].Of course,forensic science features casework and the application of our scientific knowledge to medicolegal ***,that scienti... 详细信息

关键词： knowledge legal driving