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The mechanisms of thermal solidification agent promoting steam diversion in heavy oil reservoirs
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作者 Zhan-Xi Pang Qian-Hui Wang +2 位作者 Qiang Meng Bo Wang Dong Liu 《Petroleum Science》 SCIE EI CAS CSCD 2024年第3期1902-1914,共13页
At high cycles of steam huff&puff,oil distribution in reservoirs becomes stronger heterogeneity due to steam channeling.Thermal solidification agent can be used to solve this problem.Its solution is a lowviscosity... At high cycles of steam huff&puff,oil distribution in reservoirs becomes stronger heterogeneity due to steam channeling.Thermal solidification agent can be used to solve this problem.Its solution is a lowviscosity liquid at normal temperature,but it can be solidified above 80℃.The plugging degree is up to 99%at 250℃.The sweep efficiency reaches 59.2%,which is 7.3%higher than pure steam injection.In addition,simultaneous injection of viscosity reducer and/or nitrogen foams can further enhance oil recovery.The mechanism of this technology depends on its strong plugging ability,which changes the flowing pattern of steam to effectively mobilize remaining oil.Viscosity reducer and nitrogen foams further expand the sweep range and extends the effective period.Therefore,thermal solidification agent can plug steam channeling paths and adjust steam flowing direction to significantly enhance oil recovery at high cycles of steam huff&puff. 展开更多
关键词 Heavy oil reservoir Steam huff&puff Steam channeling Steam diversion Plugging performance Mechanism analysis
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Fracture propagation law of temporary plugging and diversion fracturing in shale reservoirs under completion experiments of horizontal well with multi-cluster sand jetting perforation
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作者 ZOU Yushi LI Yanchao +3 位作者 YANG Can ZHANG Shicheng MA Xinfang ZOU Longqing 《Petroleum Exploration and Development》 SCIE 2024年第3期715-726,共12页
This study conducted temporary plugging and diversion fracturing(TPDF)experiments using a true triaxial fracturing simulation system within a laboratory setting that replicated a lab-based horizontal well completion w... This study conducted temporary plugging and diversion fracturing(TPDF)experiments using a true triaxial fracturing simulation system within a laboratory setting that replicated a lab-based horizontal well completion with multi-cluster sand jetting perforation.The effects of temporary plugging agent(TPA)particle size,TPA concentration,single-cluster perforation number and cluster number on plugging pressure,multi-fracture diversion pattern and distribution of TPAs were investigated.A combination of TPAs with small particle sizes within the fracture and large particle sizes within the segment is conducive to increasing the plugging pressure and promoting the diversion of multi-fractures.The addition of fibers can quickly achieve ultra-high pressure,but it may lead to longitudinal fractures extending along the wellbore.The temporary plugging peak pressure increases with an increase in the concentration of the TPA,reaching a peak at a certain concentration,and further increases do not significantly improve the temporary plugging peak pressure.The breaking pressure and temporary plugging peak pressure show a decreasing trend with an increase in single-cluster perforation number.A lower number of single-cluster perforations is beneficial for increasing the breaking pressure and temporary plugging peak pressure,and it has a more significant control on the propagation of multi-cluster fractures.A lower number of clusters is not conducive to increasing the total number and complexity of artificial fractures,while a higher number of clusters makes it difficult to achieve effective plugging.The TPAs within the fracture is mainly concentrated in the complex fracture areas,especially at the intersections of fractures.Meanwhile,the TPAs within the segment are primarily distributed near the perforation cluster apertures which initiated complex fractures. 展开更多
关键词 shale temporary plugging and diversion fracturing multi-cluster sand jetting perforation distribution of temporary plugging agent fracture propagation law
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Water hammer protection for diversion systems in front of pumps in long-distance water supply projects 被引量:4
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作者 Lin Shi Jian Zhang +3 位作者 Xiao-dong Yu Sheng Chen Wen-long Zhao Xu-yun Chen 《Water Science and Engineering》 EI CAS CSCD 2023年第2期211-218,共8页
For a water supply system with long-distance diversion pipelines, in addition to the water hammer problems that occur beyond pumps, the safety of the water diversion pipeline in front of pumps also deserves attention.... For a water supply system with long-distance diversion pipelines, in addition to the water hammer problems that occur beyond pumps, the safety of the water diversion pipeline in front of pumps also deserves attention. In this study, a water hammer protection scheme combined with an overflow surge tank and a regulating valve was developed. A mathematical model of the overflow surge tank was developed, and an analytical formula for the height of the overflow surge tank was derived. Furthermore, a practical water supply project was used to evaluate the feasibility of the combined protection scheme and analyze the sensitivity of valve regulation rules. The results showed that the combined protection scheme effectively reduced the height of the surge tank, lessened the difficulties related to construction, and reduced the necessary financial investment for the project. The two-stage closing rule articulated as fast first and then slow could minimize the overflow volume of the surge tank when the power failure occurred, while the two-stage opening rule articulated as slow first and then fast could be more conducive to the safety of the water supply system when the pump started up. 展开更多
关键词 Long-distance diversion pipeline Water supply Water hammer Overflow surge tank Regulating valve
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Water diversion and agricultural production:Evidence from China 被引量:1
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作者 YANG Rui XU Hang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第4期1244-1257,共14页
Water diversion can alleviate water shortages caused by the uneven distribution of water resources.China’s Southto-North Water Diversion Project(SNWD)is the largest water diversion project worldwide.Based on the pref... Water diversion can alleviate water shortages caused by the uneven distribution of water resources.China’s Southto-North Water Diversion Project(SNWD)is the largest water diversion project worldwide.Based on the prefecturelevel data of China’s Huang-Huai-Hai Plain from 2000 to 2020,this study employs an empirical strategy of Differencesin-Differences(DID)to analyze the impact of SNWD on agricultural production.The results show that SNWD has significantly increased agricultural production,measured by the agricultural value added.The estimated results of the benchmark model remain robust when the contemporaneous policy is addressed,an alternative outcome is used,subsamples are estimated,and alternative estimation techniques are employed.This study argues that the potential impact mechanism may be that SNWD significantly increases the acreage for cash crops but reduces that for grain crops.Heterogeneity analysis shows that in prefectures with high temperature or land potential,SNWD’s impact on agricultural value added is relatively low.In contrast,in areas with prolonged sunshine or high slopes,SNWD’s impact on agricultural value added is relatively large.Given the low added value of grain crops,the government should consider strengthening food security by subsidizing water supply to sustain grain production. 展开更多
关键词 South-to-North Water diversion Project agricultural production Differences-in-Differences China
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Comparative assessment of mechanical and chemical fluid diversion techniques during hydraulic fracturing in horizontal wells
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作者 Maunish S.Shah Subhash N.Shah 《Petroleum Science》 SCIE EI CAS CSCD 2023年第6期3582-3597,共16页
The application of fluid diversion during hydraulic fracturing is an evolving technology and has become popular amongst E&P operators over the past few years.The primary objective of the fluid diversion is to impr... The application of fluid diversion during hydraulic fracturing is an evolving technology and has become popular amongst E&P operators over the past few years.The primary objective of the fluid diversion is to improve hydraulic fracturing treatment by increasing stimulated reservoir volume and improving hydrocarbon recovery.This is possible by achieving any of the following objectives:creating uniform distribution of treatment slurry within the target zone;treating unstimulated and under-stimulated zones;or by increasing fracture density by creating a complex fracture network.The fluid diversion application is also helpful in decreasing the number of stages(by increasing stage length)for multi-stage plug-n-perf(PnP)fracturing treatment.It is also applied to prevent fracture-driven interactions between adjacent wells,which is currently a major issue,especially in shale.In addition,for successful refracturing treatment,the diverter application is essential for isolating the existing fractures and redirecting the treatment slurry to the desired unstimulated zones.The diversion methods can be broadly categorized into the mechanical and chemical diversion.Several established mechanical diversion techniques are frac plugs,expandable casing patches,expandable liners,swellable packers,straddle packer assembly,sand plugs,frac sleeves,perforation ball sealers,and limited entry technique.The different chemical diversion techniques are particulates,fibers,gels,surfactants,perforation pods,and composite diverting.This paper describes the current status of established mechanical and chemical diverter technologies and examines their comparative advantages and challenges.Various techniques are suitable for diverter application,but the technique is selected based on the desired objective and conditions of the wellbore and reservoir.The general guidelines for selecting diversion techniques and operational considerations are also provided in the paper.The diagnosis of diversion treatment plays an essential role in diversion technique selection and optimization of selection parameters for the subsequent treatments.Therefore,the application of conventional surface pressure monitoring techniques and advanced diagnostic tools to evaluate diversion effectiveness are briefly described.Presently no standard laboratory testing method is established for the performance evaluation of diverting agents.Therefore,researchers have implemented various laboratory methods,which are briefly summarized in the paper.Significant insight into the diversion technology and guidelines for its selection and successful implementation is provided to help engineers to increase the effectiveness of hydraulic fracturing treatments.The limitations of individual diversion techniques are clarified,which provide the future scope of research for improvement in various diversion technologies. 展开更多
关键词 Fluid diversion Diverter Diverting agents Multi-stage fracturing Hydraulic fracturing Horizontal well
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Contemporary outcomes of patients undergoing robotic-assisted radical cystectomy:A comparative analysis between intracorporeal ileal conduit and neobladder urinary diversions
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作者 Jordan M.Rich Shivaram Cumarasamy +6 位作者 Daniel Ranti Etienne Lavallee Kyrollis Attalla John P.Sfakianos Nikhil Waingankar Peter N.Wiklund Reza Mehrazin 《Asian Journal of Urology》 CSCD 2023年第4期446-452,共7页
Objective We aimed to compare perioperative and oncologic outcomes for patients undergoing robotic-assisted radical cystectomy(RARC)with intracorporeal ileal conduit(IC)and neobladder(NB)urinary diversion.Methods Pati... Objective We aimed to compare perioperative and oncologic outcomes for patients undergoing robotic-assisted radical cystectomy(RARC)with intracorporeal ileal conduit(IC)and neobladder(NB)urinary diversion.Methods Patients undergoing RARC with intracorporeal urinary diversion between January 2017 and January 2022 at the Icahn School of Medicine at Mount Sinai,New York,NY,USA were indexed.Baseline demographics,clinical characteristics,perioperative,and oncologic outcomes were analyzed.Survival was estimated with Kaplan-Meier plots.Results Of 261 patients(206[78.9%]male),190(72.8%)received IC while 71(27.2%)received NB diversion.Median age was greater in the IC group(71[interquartile range,IQR 65-78]years vs.64[IQR 59-67]years,p<0.001)and BMI was 26.6(IQR 23.2-30.4)kg/m^(2).IC group was more likely to have prior abdominal or pelvic radiation(15.8%vs.2.8%,p=0.014).American Association of Anesthesiologists scores were comparable between groups.The IC group had a higher proportion of patients with pathological tumor stage 2(pT2)tumors(34[17.9%]vs.10[14.1%],p=0.008)and pathological node stages pN2-N3(28[14.7%]vs.3[4.2%],p<0.001).The IC group had less median operative time(272[IQR 246-306]min vs.341[IQR 303-378]min,p<0.001)and estimated blood loss(250[150-500]mL vs.325[200-575]mL,p=0.002).Thirty-and 90-day complication rates were 44.4%and 50.2%,respectively,and comparable between groups.Clavien-Dindo grades 3-5 complications occurred in 27(10.3%)and 34(13.0%)patients within 30 and 90 days,respectively,with comparable rates between groups.Median follow-up was 324(IQR 167-552)days,and comparable between groups.Kaplan-Meier estimate for overall survival at 24 months was 89%for the IC cohort and 93%for the NB cohort(hazard ratio 1.23,95%confidence interval 1.05-2.42,p=0.02).Kaplan-Meier estimate for recurrence-free survival at 24 months was 74%for IC and 87%for NB(hazard ratio 1.81,95%confidence interval 0.82-4.04,p=0.10).Conclusion Patients undergoing intracorporeal IC urinary diversion had higher postoperative cancer stage,increased nodal involvement,similar complications outcomes,decreased overall survival,and similar recurrence-free survival compared to patients undergoing RARC with intracorporeal NB urinary diversion. 展开更多
关键词 ROBOTIC Radical cystectomy INTRACORPOREAL Ileal conduit Neobladder Urinary diversion Oncologic outcome
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Effectiveness of groundwater extraction in Beijing since the ingauration of the first phase of the South-to-North Water Diversion Project, China
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作者 Yuan-yuan Gao Qing-yu Sun +1 位作者 Ai-xin Wen Yan-pei Cheng 《Journal of Groundwater Science and Engineering》 2023年第3期294-307,共14页
This study assess the effectiveness of groundwater pressure extraction in Beijing since the opening of the first phase of the South-to-North Water Diversion Project,using survey and evaluation methods.Firstly,an analy... This study assess the effectiveness of groundwater pressure extraction in Beijing since the opening of the first phase of the South-to-North Water Diversion Project,using survey and evaluation methods.Firstly,an analysis of water consumption structure and the usage of diverted river water in Beijing in recent years was conducted.Secondly,the volume of groundwater pressure extraction in Beijing after the 33 project's inauguration was examined,revealing a decrease from 1.96 billion m^(3) in 2014 to 1.35 billion m^(3) in 2020.The proportion of water supply reduced from 52.3%in 2014 to 33.3%in 2020,leading to an optimized water supply structure.By the end of 2020,groundwater pressure extraction in Beijing is estimated at 446 million m3,with a substantial reduction in over-exploitation of groundwater.Groundwater resources have been effectively replenished,and the strategic reserve capacity has been enhanced.Furthermore,this study evaluates the change in groundwater levels as an indicator of the effectiveness of pressure extraction.The declining trend of groundwater levels in Beijing has been effectively mitigated,and there has been a consistent rebound in groundwater levels over the past five years. 展开更多
关键词 Beijing City South-to-North Water diversion Groundwater Over-exploitation Groundwater Pressure Extraction
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What Is the Impact of Major Diversion Attitude on Undergraduates' Learning Gains?--The Mediating Role of Course Perception
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作者 Qintao Sun Yueqi Shi 《教育技术与创新》 2023年第1期1-15,共15页
Major diversion is an important part of the large-category student enrollment and training model.The degree to which undergraduates recognize the logic of the major diversion system,their satisfaction with the diverte... Major diversion is an important part of the large-category student enrollment and training model.The degree to which undergraduates recognize the logic of the major diversion system,their satisfaction with the diverted major,and their major identity after diversion all influence their subsequent learning process and outcomes.The questionnaire survey of undergraduates in this study discovered that major diversion attitude has a significant positive effect on undergraduates'learning gains;the mediating effect test discovered that course perception plays a partially mediating role between major diversion attitude and learning gains.Therefore,under the large-category student enrollment and training model,it is necessary to improve the major diversion system in terms of formulation,major selection guidance,and major identity promotion.Furthermore,strengthening the logical connection and content coupling of different types of courses,dealing with the proportion,priority,and sequence of courses,optimizing the allocation of course resources,and reasonably planning and setting courses all play an important role in improving undergraduate learning gains. 展开更多
关键词 the large-category enrollment and training major diversion attitude course perception learning gains
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Relationship between diversion colitis and quality of life in rectal cancer 被引量:15
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作者 Dong Nyoung Son Dong Jin Choi +5 位作者 Si Uk Woo Jin Kim Bo Ra Keom Chul Hwan Kim Se Jin Baek Seon Hahn Kim 《World Journal of Gastroenterology》 SCIE CAS 2013年第4期542-549,共8页
AIM:To investigated the incidence of diversion colitis(DC) and impact of DC symptoms on quality of life(QoL) after ileostomy reversal in rectal cancer.METHODS:We performed a prospective study with 30 patients who unde... AIM:To investigated the incidence of diversion colitis(DC) and impact of DC symptoms on quality of life(QoL) after ileostomy reversal in rectal cancer.METHODS:We performed a prospective study with 30 patients who underwent low anterior resection and the creation of a temporary ileostomy for the rectal cancer between January 2008 and July 2009 at the Department of Surgery,Korea University Anam Hospital.The participants totally underwent two rounds of the examinations.At first examination,endoscopies,tissue biopsies,and questionnaire survey about the symptom were performed 3-4 mo after the ileostomy creations.At second examination,endoscopies,tissue biopsies,and questionnaire survey about the symptom and QoL were performed 5-6 mo after the ileostomy reversals.Clinicopathological data were based on the histopathological reports and clinical records of the patients.RESULTS:At the first examination,all of the patients presented with inflammation,which was mild in 15(50%) patients,moderate in 11(36.7%) and severe in 4(13.3%) by endoscopy and mild in 14(46.7%) and moderate in 16(53.3%) by histology.At the second examination,only 11(36.7%) and 17(56.7%) patients had mild inflammation by endoscopy and histology,respectively.There was no significant difference in DC grade between the endoscopic and the histological findings at first or second examination.The symptoms detected on the first and second questionnaires were mucous discharge in 12(40%) and 5(17%) patients,bloody discharge in 5(17%) and 3(10%) patients,abdominal pain in 4(13%) and 2(7%) patients and tenesmus in 9(30%) and 5(17%) patients,respectively.We found no correlation between the endoscopic or histological findings and the symptoms such as mucous discharge,bleeding,abdominal pain and tenesmus in both time points.Diarrhea was detected in 9 patients at the second examination;this number correlated with the severity of DC(0%,0%,66.7%,33.3% vs 0%,71.4%,23.8%,4.8%,P = 0.001) and the symptom-related QoL(r =-0.791,P < 0.001).CONCLUSION:The severity of DC is related to diarrhea after an ileostomy reversal and may adversely affect QoL. 展开更多
关键词 diversion COLITIS Quality of life DIARRHEA ILEOSTOMY RECTAL cancer
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Diversion colitis and pouchitis: A mini-review 被引量:11
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作者 Kentaro Tominaga Kenya Kamimura +3 位作者 Kazuya Takahashi Junji Yokoyama Satoshi Yamagiwa Shuji Terai 《World Journal of Gastroenterology》 SCIE CAS 2018年第16期1734-1747,共14页
Diversion colitis is characterized by inflammation of the mucosa in the defunctioned segment of the colon after colostomy or ileostomy. Similar to diversion colitis, diversion pouchitis is an inflammatory disorder occ... Diversion colitis is characterized by inflammation of the mucosa in the defunctioned segment of the colon after colostomy or ileostomy. Similar to diversion colitis, diversion pouchitis is an inflammatory disorder occurring in the ileal pouch, resulting from the exclusion of the fecal stream and a subsequent lack of nutrients from luminal bacteria. Although the vast majority of patients with surgically-diverted gastrointestinal tracts remain asymptomatic, it has been reported that diversion colitis and pouchitis might occur in almost all patients with diversion. Surgical closure of the stoma, with reestablishment of gut continuity, is the only curative intervention available for patients with diversion disease. Pharmacologic treatments using short-chain fatty acids, mesalamine, or corticosteroids are reportedly effective for those who are not candidates for surgical reestablishment; however, there are no established assessment criteria for determining the severity of diversion colitis, and no management strategies to date. Therefore, in this mini-review, we summarize and review various recently-reported treatments for diversion disease. We are hopeful that the information summarized here will assist physicians who treat patients with diversion colitis and pouchitis, leading to better case management. 展开更多
关键词 diversion COLITIS diversion POUCHITIS ILEITIS Inflammatory BOWEL disease
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A numerical study on water diversion ratio of the Changjiang(Yangtze)estuary in dry season 被引量:19
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作者 李路 朱建荣 +1 位作者 吴辉 王彪 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2010年第3期700-712,共13页
We studied the flood, ebb and tidal averaged along (net) water diversion ratio (WDR) during dry season in the Changjiang (Yangtze) estuary, China, along with the effects of northerly wind, river discharge, tide and th... We studied the flood, ebb and tidal averaged along (net) water diversion ratio (WDR) during dry season in the Changjiang (Yangtze) estuary, China, along with the effects of northerly wind, river discharge, tide and their interactions on WDR using the improved version of three-dimensional numerical model ECOM. Using data for annual mean wind speed and river discharge during January, we determined that the flood, ebb, net WDR values in the North Branch of the estuary were 3.48%, 1.68%,-4.06% during spring tide, and 4.82%, 2.34%,-2.79% during neap tide, respectively. Negative net WDR values denote the transport of water from the North Branch into the South Branch. Using the same data, the corresponding ratios were 50.09%, 50.92%, 54.97%, and 52.33%, 50.15%, 43.86% in the North Channel and 38.56%, 44.78%, 103.96%, and 36.92%, 43.17%, 60.97% in the North Passage, respectively. When northerly wind speed increased, landward Ekman transport was enhanced in the North Branch, increasing the flood WDR, while the ebb WDR declined and the net WDR exhibited a significant decrease. Similarly, in the North Channel, the flood WDR is increased, the ebb WDR reduced, and the net WDR showed a marked decrease. In the North Passage, the flood WDR also increased while the ebb and net WDR declined. As the river discharge increased, the flood and ebb WDR of the North Branch increased slightly and the net WDR increased markedly. In the North Channel the flood and ebb WDR changed very slightly, while the net WDR declined during spring tides and increased during neap tides. The WDR in the North Passage changed slightly during flood and ebb tides while the net WDR showed a marked increase. The WDR values of different bifurcations and the responses to northerly wind, river discharge, and tide are discussed in comparison with variations in river topography, horizontal wind-induced circulation, and tidal-induced residual current. 展开更多
关键词 water diversion ratio northerly wind river discharge TIDE the Changjiang (Yangtze) estuary
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Spatio-temporal distribution of phytoplankton in the Danjiangkou Reservoir, a water source area for the South-to-North Water Diversion Project (Middle Route), China 被引量:12
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作者 殷大聪 郑凌凌 宋立荣 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2011年第3期531-540,共10页
One of the water source areas of the South-to-North Water Diversion Project is the Danjiangkou Reservoir (DJKR). To understand seasonal variation in phytoplankton composition, abundance and distribution in the DJKR ... One of the water source areas of the South-to-North Water Diversion Project is the Danjiangkou Reservoir (DJKR). To understand seasonal variation in phytoplankton composition, abundance and distribution in the DJKR area before water diversion, as well as to estimate potential risks of water quality after water diversion, we conducted an investigation on phytoplankton in the DJKR from August 2008 to May 2009. The investigation included 10 sampling sites, each with four depths of 0.5, 5, 10, and 20 m. In this study, 117 taxa belonging to 76 genera were identified, consisting of diatoms (39 taxa), green algae (47 taxa), blue-green algae (19 taxa), and others (12 taxa). Annual average phytoplankton abundance was 2.01×10^6 ind./L, and the highest value was 14.72 ×10^6 ind/L (at site 3 in August 2008). Phytoplankton abundance in front of the Danjiangkou Dam (DJKD) was higher than that of the Danjiang Reservoir Basin. Phytoplankton distribution showed a vertical declining trend from 0.5 m to 20 m at most sites in August 2008 (especially at sites of 1, 2, 4 and 10), but no distinct pattern in other sampling months. In December 2008 and March 2009, Stephanodiseus sp. was the most abundant species, amounting to 55.23% and 72.34%, respectively. We propose that high abundance ofStephanodiscus sp. may have contributed greatly to the frequent occurrence of Stephanodiscus sp. blooms in middle-low reaches of the Hanjiang River during the early spring of 2009. In comparison with previous studies conducted from 1992 to 2006, annual average phytoplankton density, green algae and blue-green algae species, as well as major nutrient concentrations increased, while phytoplankton diversity indices declined. This indicates a gradual decline in water quality. More research should be conducted and countermeasures taken to prevent further deterioration of water quality in the DJKR. 展开更多
关键词 Danjiangkou Reservoir PHYTOPLANKTON South-to-North Water diversion Project EUTROPHICATION
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Impact of the eastern water diversion from the south to the north project on the saltwater intrusion in the Changjiang Estuary in China 被引量:10
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作者 XU Kun ZHU Jianrong GU Yuliang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2012年第3期47-58,共12页
The south to the north project (WDP) on the saltwater intrusion in the Changjiang Estuary is studied by the improved three-dimensionai (3D) numerical model.The net unit width flux in the Changjiang Estuary as well as ... The south to the north project (WDP) on the saltwater intrusion in the Changjiang Estuary is studied by the improved three-dimensionai (3D) numerical model.The net unit width flux in the Changjiang Estuary as well as the sectional salt flux is calculated in the North Branch (NB),the South Branch (SB),the North Channel (NC),the South Channel (SC),the North Passage (NP) and the South Passage (SP),respectively.The net seaward water flux in the SB is reduced,and the net water flux spilling over from the NB to the SB is enhanced after the eastern WDP.Under the mean river discharge condition in the dry season,the net salt flux spilling over from the NB to the SB is increased by 2.09 t/s and 0.52 t/s during the spring and neap tides,respectively,due to the eastern WDP.The saltwater intrusion in the Changjiang Estuary is enhanced by the eastern WDP.Compared with that during the spring tide,the net water diversion ratio during the neap tide in the NC is smaller,and thus the enhancement of the saltwater intrusion by the eastern WDP is smaller in the NC,and larger in the NP and the SP.The tidally averaged surface salinity at the water intakes of the Dongfengxisha Reservoir,the Chenhang Reservoir and the Qingcaosha Reservoir rises both during the spring and neap tides. 展开更多
关键词 eastern water diversion from the south to the north project saltwater intrusion Changjiang Estuary numerical calculation the water resource
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Extracorporeal continuous portal diversion plus temporal plasmapheresis for “small-for-size” syndrome 被引量:4
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作者 Peng Hou Chao Chen +2 位作者 Yu-Liang Tu Zi-Man Zhu Jing-Wang Tan 《World Journal of Gastroenterology》 SCIE CAS 2013年第33期5464-5472,共9页
AIM:To investigate the effect of plasmapheresis via the portal vein for"small-for-size"syndrome(SFSS)aided by extracorporeal continuous portal diversion(ECPD).METHODS:Extensive or total hepatectomy in the pi... AIM:To investigate the effect of plasmapheresis via the portal vein for"small-for-size"syndrome(SFSS)aided by extracorporeal continuous portal diversion(ECPD).METHODS:Extensive or total hepatectomy in the pig is usually adopted as a postoperative liver failure(PLF)or SFSS model.In this study,animals which underwent85%-90%hepatectomy were randomized into either the Systemic group(n=7)or the Portal group(n=7).In the Systemic group,all pigs received temporal plasmapheresis(PP)via the extracorporeal catheter circuit(systemic to systemic circulation)from 24 to 30 h posthepatectomy(PH);in the Portal group,all pigs received ECPD to divert partial portal vein flow(PVF)to the systemic circulation after hepatectomy,then converted to temporal PP from 24 to 30 h PH,and subsequently converted to ECPD again until 48 h PH.In the Portal group,the PVF was preserved at 3.0-3.3 times that of the baseline value,similar to that following 70%hepatectomy,which was regarded as the optimal PVF to the hypertrophic liver remnant.At 48 h PH,all pigs were re-opened and the portal vein pressure(PVP),PVF,and HAF(hepatic artery flow)were measured,and then diversion of the portal venous flow was terminated.After1 h the PVP,PVF,and HAF were re-measured.The portal hemodynamic changes,liver injury,liver regeneration and bacterial/lipopolysaccharide(LPS)translocation were evaluated in the two groups.RESULTS:The PVP in the Portal group was significantly lower than that in the Systemic group during the time period from 2 to 49 h PH(P<0.05).Serum alanine aminotransferase(ALT),total bilirubin(TB)and ammonia were significantly reduced in the Portal group compared with the Systemic group from 24 to 48 h PH(P<0.05).The Portal group may have attenuated sinusoidal endothelial injury and decreased the level of HA compared with the Systemic group.In the Systemic group,there was significant sinusoidal dilation,hydropic changes in hepatocytes and hemorrhage into the hepatic parenchyma,and the sinusoidal endothelial lining was partially destroyed and detached into the sinusoidal space.CD31immunostaining revealed significant destruction of the endothelial lining.In the Portal group,there was no intraparenchymal hemorrhage and the sinusoidal endothelial cells and hepatocytes were well preserved.CD31immunostaining was mild which indicated less destruction of the endothelial lining.HA was significantly decreased in the Portal group compared with the Systemic group from 2 to 48 h PH.The rate of liver remnant regeneration was elevated,while apoptosis was attenuated in the Portal group compared with the Systemic group.Thymidine kinase activity was much higher in the Portal group than in the Systemic group at 48 h PH.The PCNA index was significantly increased and the apoptotic index was significantly decreased in the Portal group compared with the Systemic group.Bacterial translocation and endotoxin,as well as the inflammatory response,were significantly attenuated in the Portal group compared with the Systemic group.LPS,tumor necrosis factor-and interleukin-6 levels were all significantly decreased in the Portal group compared with the Systemic group from 24 to48 h PH,while bacterial DNA level was significantly decreased from 2 to 48 h PH.CONCLUSION:PP plus ECPD via the portal vein can attenuate toxic load and hyperperfusion injury,and should be undertaken instead of PP via the systemic circulation in SFSS or PLF. 展开更多
关键词 Small-for-size syndrome POSTOPERATIVE liver failure EXTRACORPOREAL PORTAL diversion PLASMAPHERESIS HEPATECTOMY
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Entanglement diversion and quantum teleportation of entangled coherent states 被引量:5
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作者 蔡新华 郭杰荣 +1 位作者 聂建军 贾金平 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第3期488-491,共4页
The proposals on entanglement diversion and quantum teleportation of entangled coherent states are presented. In these proposals, the entanglement between two coherent states, |α〉 and |-α〉, with the same amplitu... The proposals on entanglement diversion and quantum teleportation of entangled coherent states are presented. In these proposals, the entanglement between two coherent states, |α〉 and |-α〉, with the same amplitude but a phase difference of π is utilized as a quantum channel. The processes of the entanglement diversion and the teleportation are achieved by using the 50/50 symmctric beam splitters, the phase shifters and the photodetectors with the help of classical information. 展开更多
关键词 entangled coherent state entanglement diversion quantum teleportation detection of photon
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Rock mechanical problems and optimization for the long and deep diversion tunnels at Jinping Ⅱ hydropower station 被引量:5
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作者 Shiyong Wu Ge Wang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE 2011年第4期314-328,共15页
According to site-specific environments such as high water pressures, high in-situ stresses and strong rockbursts, the design scheme of the long and deep diversion tunnels at Jinping II hydropower station was optimize... According to site-specific environments such as high water pressures, high in-situ stresses and strong rockbursts, the design scheme of the long and deep diversion tunnels at Jinping II hydropower station was optimized to ensure construction safety. New drainage tunnels were considered. Furthermore, lining structures and grouting pressures were modified during the excavation of tunnels. The construction scheme was updated dynamically based on the complex geological conditions. For instances, the diversion tunnels were first excavated by drilling and blasting method at the first stage of construction, and then by the combination method of tunnel boring machine (TBM) and drilling and blasting, and finally by drilling and blasting method. Through optimized scheme and updated construction scheme, the excavation of diversion tunnel #1 was successfully completed in June, 2011. This paper summarizes the key issues in rock mechanics associated with the construction of the long and deep diversion tunnels at Jinping II hydropower station. The experiences of design and construction obtained from this project could provide reference to similar projects. 展开更多
关键词 Jinping II hydropower station diversion tunnels optimized design construction method GROUTING
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Botulinum toxin for chronic anal fissure after biliopancreatic diversion for morbid obesity 被引量:4
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作者 Serafino Vanella Giuseppe Brisinda +3 位作者 Gaia Marniga Anna Crocco Giuseppe Bianco Giorgio Maria 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第10期1021-1027,共7页
AIM: To study the effect of botulinum toxin in patients with chronic anal fissure after biliopancreatic diversion (BPD) for severe obesity. METHODS: Fifty-nine symptomatic adults with chronic anal fissure developed af... AIM: To study the effect of botulinum toxin in patients with chronic anal fissure after biliopancreatic diversion (BPD) for severe obesity. METHODS: Fifty-nine symptomatic adults with chronic anal fissure developed after BPD were enrolled in an open label study. The outcome was evaluated clinically and by comparing the pressure of the anal sphincters before and after treatment. All data were analyzed in univariate and multivariate analysis. RESULTS: Two months after treatment, 65.4% of the patients had a healing scar. Only one patient had mild incontinence to flatus that lasted 3 wk after treatment, but this disappeared spontaneously. In the multivariate analysis of the data, two registered months after the treatment, sex (P = 0.01), baseline resting anal pressure (P = 0.02) and resting anal pressure 2 mo after treatment (P < 0.0001) were significantly related to healing rate.CONCLUSION: Botulinum toxin, despite worse results than in non-obese individuals, appears the best alternative to surgery for this group of patients with a high risk of incontinence. 展开更多
关键词 Botulinum toxin Anal diseases Anal fis- sure Severe obesity Bariatric surgery Biliopancreatic diversion
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Totally intracorporeal robot-assisted urinary diversion for bladder cancer(part 2).Review and detailed characterization of the existing intracorporeal orthotopic ileal neobladder 被引量:5
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作者 Hugo Otaola-Arca Kulthe Ramesh Seetharam Bhat +2 位作者 Vipul R.Patel Marcio Covas Moschovas Marcelo Orvieto 《Asian Journal of Urology》 CSCD 2021年第1期63-80,共18页
Objective:To review the most used intracorporeal orthotopic ileal neobladder(ICONB)after radical cystectomy for bladder cancer and create a unified compendium of the different alternatives,including new consistent ima... Objective:To review the most used intracorporeal orthotopic ileal neobladder(ICONB)after radical cystectomy for bladder cancer and create a unified compendium of the different alternatives,including new consistent images.Methods:We performed a non-systematic review of the literature with the keywords“bladder cancer”,“urinary diversion”,“radical cystectomy”,and“neobladder”.Results:Forty studies were included in the analysis.The most frequent type of ICONB was the modified Studer“U”neobladder(70%)followed by the Hautmann“W”modified neobladder(7.5%),the“Y”neobladder(5%),and the Padua neobladder(5%).The operative time to perform a urinary diversion ranged from 124 to 553 min.The total estimated blood loss ranged from 200 to 900 mL.The rate of positive surgical margins ranged from 0%to 8.1%.Early minor and major complication rates ranged from 0%to 100%and from 0%to 33%,respectively.Late minor and major complication rates ranged from 0%to 70%and from 0%to 25%,respectively.Conclusion:The most frequent types of ICONB are Studer“U”neobladder,Hautmann“W”neobladder,“Y”neobladder,and the Padua neobladder.Randomized studies comparing the performance of the different types of ICONB,the performance in an intra or extracorporeal manner,or the performance of an ICONB versus ICIC are lacking in the literature.To this day,there are not sufficient quality data to determine the supremacy of one technique.This manuscript represents a compendium of the most used ICONB with detailed descriptions of the technical aspects,operative and perioperative outcomes,and new consistent images of each technique. 展开更多
关键词 Bladder cancer Ileal orthotopic neobladder Intracorporeal urinary diversion Robot-assisted radical cystectomy Surgical technique
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Real-time flood forecasting of Huai River with flood diversion and retarding areas 被引量:6
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作者 Li Zhijia Bao Hongjun +2 位作者 Xue Cangsheng Hu Yuzhong Fang Hong 《Water Science and Engineering》 EI CAS 2008年第2期10-24,共15页
A combination of the rainfall-runoff module of the Xin’anjiang model, the Muskingum routing method, the water stage simulating hydrologic method, the diffusion wave nonlinear water stage method, and the real-time err... A combination of the rainfall-runoff module of the Xin’anjiang model, the Muskingum routing method, the water stage simulating hydrologic method, the diffusion wave nonlinear water stage method, and the real-time error correction method is applied to the real-time flood forecasting and regulation of the Huai River with flood diversion and retarding areas. The Xin’anjiang model is used to forecast the flood discharge hydrograph of the upstream and tributary. The flood routing of the main channel and flood diversion areas is based on the Muskingum method. The water stage of the downstream boundary condition is calculated with the water stage simulating hydrologic method and the water stages of each cross section are calculated from downstream to upstream with the diffusion wave nonlinear water stage method. The input flood discharge hydrograph from the main channel to the flood diversion area is estimated with the fixed split ratio of the main channel discharge. The flood flow inside the flood retarding area is calculated as a reservoir with the water balance method. The faded-memory forgetting factor least square of error series is used as the real-time error correction method for forecasting discharge and water stage. As an example, the combined models were applied to flood forecasting and regulation of the upper reaches of the Huai River above Lutaizi during the 2007 flood season. The forecast achieves a high accuracy and the results show that the combined models provide a scientific way of flood forecasting and regulation for a complex watershed with flood diversion and retarding areas. 展开更多
关键词 flood forecasting and regulation Xin’anjiang model Muskingum method water stage simulating hydrologic method diffusion wave nonlinear water stage method flood diversion and retarding area Huai River
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Optimization and coordination of South-to-North Water Diversion supply chain with strategic customer behavior 被引量:4
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作者 Zhi-song CHEN Hui-min WANG 《Water Science and Engineering》 EI CAS 2012年第4期464-477,共14页
The South-to-North Water Diversion (SNWD) Project is a significant engineering project meant to solve water shortage problems in North China. Faced with market operations management of the water diversion system, th... The South-to-North Water Diversion (SNWD) Project is a significant engineering project meant to solve water shortage problems in North China. Faced with market operations management of the water diversion system, this study defined the supply chain system for the SNWD Project, considering the actual project conditions, built a decentralized decision model and a centralized decision model with strategic customer behavior (SCB) using a floating pricing mechanism (FPM), and constructed a coordination mechanism via a revenue-sharing contract. The results suggest the following: (1) owing to water shortage supplements and the excess water sale policy provided by the FPM, the optimal ordering quantity of water resources is less than that without the FPM, and the optimal profits of the whole supply chain, supplier, and external distributor are higher than they would be without the FPM; (2) wholesale pricing and supplementary wholesale pricing with SCB are higher than those without SCB, and the optimal profits of the whole supply chain, supplier, and external distributor are higher than they would be without SCB; and (3) considering SCB and introducing the FPM help increase the optimal profits of the whole supply chain, supplier, and external distributor, and improve the efficiency of water resources usage. 展开更多
关键词 South-to-North Water diversion supply chain strategic customer behavior floatingpricing mechanism
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