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Comparing surface erosion processes in four soils from the loess Plateau under extreme rainfall events

International Soil and Water Conservation Research 2021年第4期9卷 520-531页

作者： liying Sun john l.Zhou Qiangguo Cai Suxia liu Jingan Xiao Key laboratory of Water Cycle and Related land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China School of Civil and Environmental Engineering University of Technology Sydney15 BroadwayNSW 2007Australia

This research aims to improve erosion control practice in the loess Plateau,by studying the surface erosion processes,including splash,sheet/interrill and rill erosion in four contrasting soils under high rainfall intensity(120 mm h^(−1))with three-scale indoor artificial *** contrasting soils as sandy loam,sandy clay loam,clay loam and loamy clay were collected from different parts of the loess *** results showed that sediment load was significantly impacted by soil properties in all three *** rate(4.0-21.6 g m^(−2∙)min^(−1))was highest in sandy loam from the north part of the loess Plateau and showed a negative power relation with the mean weight diameter of aggregates after 20 min of rainfall *** average sediment load by sheet/interrill erosion(6.94-42.86 g m^(−2∙)min^(−1))was highest in clay loam from middle part of the loess Plateau,and the stable sediment load after 20 min showed a positive power relation with the silt content in *** average sediment load increased dramatically by rill and interrill erosion(21.03-432.16 g m^(−2∙)min^(−1)),which was highest in loamy clay from south part of the loess *** average sediment load after the occurrence of rill showed a positive power relation with clay content and a negative power relation with soil organic matter *** impacts of slope gradient on the runoff rate and sediment load also changed with soil *** critical factors varied for different processes,which were the aggregate size for splash erosion,the content of silt particles and slope gradient for sheet/interrill erosion,and the content of clay particles,soil organic matter and slope gradient for rill *** on the results of the experiments,specific erosion control practices were proposed by targeting certain erosion processes in areas with different soil texture and different distribution of slope *** findings from this study should support the improvement of erosion

关键词： Soil erosion process Particle size Surface erosion Cropland management loess Plateau

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Missed Pancreaticobiliary Malignancy: The Flaw of the Expedited Cholecystectomy

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Surgical Science 2024年第7期15卷 451-464页

作者： Dylan S. Goto larissa Fujii-lau linda l. Wong Department of Surgery John A. Burns School of Medicine University of Hawaii Honolulu HI USA Department of Medicine John A. Burns School of Medicine University of Hawaii Honolulu HI USA

Background: Early cholecystectomy has been recommended for patients with acute cholecystitis and gallstone pancreatitis. However, patients with pancreaticobiliary malignancy may present acutely with similar symptoms. We hypothesize that the diagnoses of these malignancies may potentially be delayed as an unintended consequence of expedited cholecystectomies. This study reviews a cohort of patients who underwent pancreaticoduodenectomy (PD) to identify those who underwent a separate cholecystectomy before their PD. Methods: We retrospectively reviewed 162 PDs performed between 2012 and 2022. Data collected included: demographics, disease etiology and the presence of cholelithiasis. We identified patients who had a previous cholecystectomy and the time elapsed before PD as well as procedures done during the interval. We reported detailed case summaries on those patients who had a cholecystectomy within 1 year of PD. Results: In the entire cohort, mean age was 65 years, 54% were males, and 83% had a malignant reason for PD. Thirty-one patients had cholelithiasis with 23 (14%) patients having had previous cholecystectomy. Six patients had cholecystectomy within 1 year of PD. They had the following malignancies: ampullary—3, pancreas—1, cholangiocarcinoma—1 and neuroendocrine—1. Four of these patients had expedited cholecystectomy on their index hospital admission and were later found to have a periampullary malignancy with further work up. Conclusions: Pancreaticobiliary malignancies can be difficult to diagnose, and surgeons should not overlook these potential diagnoses when considering expedited cholecystectomy. Future studies in large cohorts are needed to identify high risk candidates who should undergo more detailed testing to exclude malignancy before proceeding with cholecystectomy.

关键词： Cholecystectomy Periampullary Malignancy Pancreas Malignancy Pancreaticoduodenectomy

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Bravo (wireless) ambulatory esophageal pH monitoring: How do day 1 and day 2 results compare?

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World Journal of Gastroenterology 2007年第30期13卷 4091-4095页

作者： Matthew l Bechtold Jason-Scott l Holly Klaus Thaler john B Marshall Division of Gastroenterology University of Missouri Hospital and Clinics Columbia MO 65212 United States General Surgery University of Missouri Hospital and Clinics Columbia MO 65212 United States

AIM： To investigate if differences exist for patients＇ gastroesophageal reflux as measured by the Bravo ambulatory esophageal pH system between d 1 and d 2.METHODS： A retrospective study of 27 consecutive adult patients who underwent Bravo esophageal pH monitoring was performed. Patients underwent EGD under Ⅳ conscious sedation prior to Bravo placement. Acid reflux variables and symptom scores for d 1 were compared to d 2.RESUlTS： The mean doses of fentanyl and midazolam were 90.4 μg and 7.2 mg, respectively. D 1 results were significantly more elevated than d 2 with respect to total time pH 〈 4, upright position reflux, and mean number of long refluxes. No statistical difference was noted between the two days for supine position reflux, number of refluxes, duration of longest reflux, episodes of heartburn, and symptom score.CONClUSION： Patients undergoing Bravo esophageal pH monitoring in association with EGD and moderate conscious sedation experience significantly more acid reflux on d i compared to d 2. The Ⅳ sedation may be responsible for the increased reflux on d 1. Performed this way, 48-h Bravo results may not be entirely representative of the patients＇ true GE reflux profile.

关键词： Esophageal pH monitoring Bravo Gastroeso- phageal reflux disease Reflux pH testing

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温度对热处理气氛可燃极限的影响

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金属热处理 2011年第10期36卷 105-108页

作者： dwyer john Hansel James G.Philips Tom Chen Wayne 侯学涛空气产品公司宾夕法尼亚洲艾伦敦18195美国 Air Products三福中国台湾空气产品公司天津

讨论了热处理气氛中常用气体成分的可燃极限,分析了上下可燃极限与温度的关系。提出了一个应用CAFT理论推断气氛可燃极限的方法,同时解释了温度对热处理炉安全操作的影响。

关键词：热处理可燃极限发生式气氛燃烧3要素可燃范围绝热火焰温度计算值化学计量

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Tolerance to individual and joint effects of arsenic and Bacillus thuringiensis subsp, israelensis or lysinibacillus sphaericus in Culex mosquitoes

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Insect Science 2014年第4期21卷 477-485页

作者： Christina l. Mogren William E. Walton john T. Trumble Department of Entomology University of California Riverside CA 92521 USA

Arsenic contamination of global water supplies has come to the forefront in policy decisions in recent decades. However, the effects of arsenic on lower trophic levels of insects inhabiting contaminated ecosystems are not well understood. One approach to document both acute and sublethal effects of toxicants like arsenic is to assay them in combination with microbial pathogens to evaluate shifts in survival curves of the test organisms. larvae of Culex quinquefasciatus and Culex tarsalis were reared in water containing 0 or 1 000μg/l of arsenate or arsenite. Fourth instars were then exposed to a range of doses of Bacillus thuringiensis subsp, israelensis （Bti） or lysinibacillus sphaericus （ls）, with shifts in lethal concentrations determined. Arsenic accumulation in 4th instars was also quantified, and a relative growth index （RGI） calculated for the treatments and compared to controls. larvae of both species accumulated between 4 447 ± 169 ng As/g and 6 983 4- 367 ng As/g, though RGI values indicated accumulation did not affect growth and development. In all cases, the lC50＇s and lC90＇s of Cx. quinquefasciatus exposed jointly with arsenic and Bti/ls were higher than Cx. tarsafis. Cx. tarsafis reared in arsenite showed a significant reduction in their Bti lC90 values compared to the control, indicating a sublethal effect of Bti. When exposed jointly with ls, arsenite was more toxic than arsenate in Cx. tarsalis. Overall, these results indicate tolerance of these Culex species to arsenic exposures, and why this may occur is discussed.

关键词： arsenate arsenite Bsph Bti Culex tarsalis Culex quinquefasciatus

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Professionalization and the Training of University Administrators in China:A Comparative Perspective

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Frontiers of Education in China 2013年第2期8卷 303-320页

作者： GENG Yiqun john l.YEAGER Institute of Communication Studies Communication University of ChinaBeijing 100024China School of Education University of PittsburghPittsburghPA 15260USA

Compared to the training of higher education management professionals in the US,the training of their counterparts in China is relatively modest,with few programs offered at the graduate ***,few concrete solutions have been proposed for tackling the challenge of preparing managerial professionals for the sound development of higher educational institutions in *** on existing theories and practices associated with professionalization and findings from the literature and data collected from universities both in China and the US,this paper examines the training of higher education professionals from a comparative perspective in the two *** the intention of identifying the characteristics of“best practices”for the training and education of institutional executives,in an effort to provide possible suggestions for the future development of higher management training in China,the paper will discuss the topic from two perspectives:short-term in-service training programs and formal PhD and EdD programs.

关键词： professionalization higher education management training administrators

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Combining multiple imperfect data sources for small area estimation:a Bayesian model of provincial fertility rates in Cambodia

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Statistical Theory and Related Fields 2019年第2期3卷 178-185页

作者： Junni l.Zhang john Bryant Guanghua School of Management Center for Statistical Science and Center for Data SciencePeking UniversityBeijingPeople’s Republic of China Bayesian Demography limited ChristchurchNew Zealand

Demographic estimation becomes a problem of small area estimation when detaileddisaggregation leads to small cell *** usual difficulties of small area estimation are compounded when the available data sources contain measurement *** present a Bayesianapproach to the problem of small area estimation with imperfect data *** overall modelcontains separate submodels for underlying demographic processes and for measurement *** unknown quantities in the model,including coverage ratios and demographic rates,are estimated jointly via Markov chain Monte Carlo *** approach is illustrated usingthe example of provincial fertility rates in Cambodia.

关键词： Measurement error Bayesian hierarchical model coverage errors fertility Cambodia small area estimation

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Comparative Study of Faculty Evaluation of Teaching Practice between Chinese and *** of Higher Education

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Frontiers of Education in China 2011年第2期6卷 200-226页

作者： Qianyi CHEN john l.YEAGER Office of Admissions and Financial Aid University of PittsburghPittsburghPA 15260USA School of Education University of PittsburghPittsburghPA 15260USA

Along with the“massification”of higher education in China since the late 1990s,the issue of quality and excellence appeared at the top of China's higher education *** faculty evaluation of teaching is one of the major approaches adopted by China's higher education sector to pursue quality and excellence,it is valuable to examine the effectiveness of faculty evaluation of teaching practices adopted by the Chinese higher education institutions(HEIs).Study of current literature reveals some similarities and differences between the faculty evaluation of teaching policies and practices between Chinese and American higher education *** paper examines the specific practices adopted by some top-tier Chinese HEIs and American elite colleges and universities,summarizes and analyzes the major differences and similarities of faculty evaluation of teaching practices between these two countries'top-tier HEIs,and discusses the applicability of the American models to the Chinese setting of higher ***,a set of best practices regarding faculty evaluation of teaching are proposed for Chinese HEIs.

关键词： faculty evaluateon of teaching Project 985 universities student ratings peer evaluation self-evaluation

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Rapid accessibility evaluation for ballistic lunar capture via manifolds: A Gaussian process regression application

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Astrodynamics 2022年第4期6卷 375-397页

作者： Sandeep K.Singh john l.Junkins Manoranjan Majji Ehsan Taheri Department of Aerospace Engineering Texas A&M UniversityCollege StationTX 77843USA Department of Aerospace Engineering Auburn UniversityAuburnAL 36849USA

In this study,a supervised machine learning approach called Gaussian process regression(GPR)was applied to approximate optimal bi-impulse rendezvous maneuvers in the cis-lunar *** demonstrate the use of the GPR approximation of the optimal bi-impulse transfer to patch points associated with various invariant manifolds in the cis-lunar *** proposed method advances preliminary mission design operations by avoiding the computational costs associated with repeated solutions of the optimal bi-impulsive lambert transfer because the learned map is computationally *** approach promises to be useful for aiding in preliminary mission *** use of invariant manifolds as part of the transfer trajectory design offers unique features for reducing propellant consumption while facilitating the solution of trajectory optimization *** ballistic capture coasts are also very attractive for mission guidance,navigation,and control robustness.A multi-input single-output GPR model is presented to represent the fuel costs(in terms of theΔV magnitude)associated with the class of orbital transfers of interest *** developed model is also proven to provide efficient *** multi-resolution use of local GPRs over smaller sub-domains and their use for constructing a global GPR model are also *** of the unique features of GPRs is that they provide an estimate of the quality of approximations in the form of covariance,which is proven to provide statistical consistency with the optimal trajectories generated through the approximation *** numerical results demonstrate our basis for optimism for the utility of the proposed method.

关键词： Gaussian process regression supervised learning invariant manifolds ballistic transfers Bayesian inference

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Tissue engineering for neuromuscular disorders of the gastrointestinal tract

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World Journal of Gastroenterology 2012年第47期18卷 6918-6925页

作者： Kenneth l Koch Khalil N Bitar john E Fortunato Khalil N Bitar Section on Gastroenterol-ogy Department of Medicine Wake Forest University School ofMedicine Winston-Salem NC 27101 United States Wake Forest Institute for Regenerative Medicine Wake Forest School of Medicine Winston-Salem NC 27101United States

The digestive tract is designed for the optimal processing of food that nourishes all organ *** esophagus,stomach,small bowel,and colon are sophisticated neuromuscular tubes with specialized sphincters that transport ingested food-stuffs from one region to *** contractions move ingested solids and liquids from the esophagus into the stomach;the stomach mixes the ingested nutrients into chyme and empties chyme from the stomach into the *** to-and-fro movement of the small bowel maximizes absorption of fat,protein,and *** contractions are necessary for colon function and defecation.

关键词： Neuromuscular disorders Gastrointestinal tract Dysfunction Esophagus Stomach Small bowel Colon

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