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Heuristic Expanding Disconnected Graph:A Rapid Path Planning Method for Mobile Robots
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作者 Yong Tao Lian Duan +3 位作者 He Gao Yufan Zhang Yian Song Tianmiao Wang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第2期68-82,共15页
Existing mobile robots mostly use graph search algorithms for path planning,which suffer from relatively low planning efficiency owing to high redundancy and large computational complexity.Due to the limitations of th... Existing mobile robots mostly use graph search algorithms for path planning,which suffer from relatively low planning efficiency owing to high redundancy and large computational complexity.Due to the limitations of the neighborhood search strategy,the robots could hardly obtain the most optimal global path.A global path planning algorithm,denoted as EDG*,is proposed by expanding nodes using a well-designed expanding disconnected graph operator(EDG)in this paper.Firstly,all obstacles are marked and their corners are located through the map pre-processing.Then,the EDG operator is designed to find points in non-obstruction areas to complete the rapid expansion of disconnected nodes.Finally,the EDG*heuristic iterative algorithm is proposed.It selects the candidate node through a specific valuation function and realizes the node expansion while avoiding collision with a minimum offset.Path planning experiments were conducted in a typical indoor environment and on the public dataset CSM.The result shows that the proposed EDG*reduced the planning time by more than 90%and total length of paths reduced by more than 4.6%.Compared to A*,Dijkstra and JPS,EDG*does not show an exponential explosion effect in map size.The EDG*showed better performance in terms of path smoothness,and collision avoidance.This shows that the EDG*algorithm proposed in this paper can improve the efficiency of path planning and enhance path quality. 展开更多
关键词 Global path planning Mobile robot expanding disconnected graph Edge node OFFSET
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Strengthening Friendship Between China and Europe,Expanding Talent Cooperation and Exchange
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作者 DU ZHANYUAN 《China Today》 2024年第11期44-45,共2页
The CICG President Du Zhanyuan shares his insights about China-Europe talent cooperation.THE history of exchange between China and Europe is long and profound.Since the 16th century,European thinkers represented by Vo... The CICG President Du Zhanyuan shares his insights about China-Europe talent cooperation.THE history of exchange between China and Europe is long and profound.Since the 16th century,European thinkers represented by Voltaire,Bertrand Russell,and Arnold Joseph Toynbee have taken Chinese philosophy as a valuable complement to the European ideological system.China has also absorbed the ideas of European giants such as Adam Smith,Georg Wilhelm Friedrich Hegel,and Karl Marx for its transformation and progress.In recent years,exchanges and interactions between the two sides in various fields have become increasingly close. 展开更多
关键词 RUSSELL expanding ARNOLD
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Safety and efficacy of Kaffes intraductal self-expanding metal stents in the management of post-liver transplant anastomotic strictures
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作者 Chee Lim Jonathan Ng +4 位作者 Babak Sarraf Rhys Vaughan Marios Efthymiou Leonardo Zorron Cheng Tao Pu Sujievvan Chandran 《World Journal of Transplantation》 2024年第2期88-98,共11页
BACKGROUND Endoscopic management is the first-line therapy for post-liver-transplant anas-tomotic strictures.Although the optimal duration of treatment with plastic stents has been reported to be 8-12 months,data on s... BACKGROUND Endoscopic management is the first-line therapy for post-liver-transplant anas-tomotic strictures.Although the optimal duration of treatment with plastic stents has been reported to be 8-12 months,data on safety and duration for metal stents in this setting is scarce.Due to limited access to endoscopic retrograde cholan-giopancreatography(ERCP)during the coronavirus disease 2019 pandemic in our centre,there was a change in practice towards increased usage and length-of-stay of the Kaffes biliary intraductal self-expanding stent in patients with suitable anatomy.This was mainly due to the theoretical benefit of Kaffes stents allowing for longer indwelling periods compared to the traditional plastic stents.METHODS Adult liver transplant recipients aged 18 years and above who underwent ERCP were retrospectively identified during a 10-year period through a database query.Unplanned admissions post-Kaffes stent insertion were identified manually through electronic and scanned medical records.The main outcome was the incidence of complications when stents were left indwelling for 3 months vs 6 months.Stent efficacy was calculated via rates of stricture recurrence between patients that had stenting courses for≤120 d or>120 d.RESULTS During the study period,a total of 66 ERCPs with Kaffes insertion were performed in 54 patients throughout their stenting course.In 33 ERCPs,the stent was removed or exchanged on a 3-month interval.No pancreatitis,perfor-ations or deaths occurred.Minor post-ERCP complications were similar between the 3-month(abdominal pain and intraductal migration)and 6-month(abdominal pain,septic shower and embedded stent)groups-6.1%vs 9.1%respectively,P=0.40.All strictures resolved at the end of the stenting course,but the stenting course was variable from 3 to 22 months.The recurrence rate for stenting courses lasting for up to 120 d was 71.4%and 21.4%for stenting courses of 121 d or over(P=0.03).There were 28 patients that were treated with a single ERCP with Kaffes,21 with removal after 120 d and 7 within 120 d.There was a significant improvement in stricture recurrence when the Kaffes was removed after 120 d when a single ERCP was used for the entire stenting course(71.0%vs 10.0%,P=0.01).CONCLUSION Utilising a single Kaffes intraductal fully-covered metal stent for at least 4 months is safe and efficacious for the management of post-transplant anastomotic strictures. 展开更多
关键词 Liver transplantation CHOLANGIOPANCREATOGRAPHY Endoscopic retrograde CONSTRICTION PATHOLOGIC Self expandable metallic stents Bile duct diseases CHOLESTASIS
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The expanding amyloid family:Structure,stability,function,and pathogenesis
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作者 Michael R Sawaya 《四川生理科学杂志》 2024年第1期106-106,共1页
The hidden world of amyloid biology has suddenly snapped into atomic-level focus,revealing over 80 amyloid protein fibrils,both pathogenic and functional.Unlike globular proteins,amyloid proteins flatten and stack int... The hidden world of amyloid biology has suddenly snapped into atomic-level focus,revealing over 80 amyloid protein fibrils,both pathogenic and functional.Unlike globular proteins,amyloid proteins flatten and stack into unbranched fibrils.Stranger still,a single protein sequence can adopt wildly different two-dimensional conformations,yielding distinct fibril polymorphs. 展开更多
关键词 AMYLOID PATHOGENESIS expanding
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Lateral earth pressure of granular backfills on retaining walls with expanded polystyrene geofoam inclusions under limited surcharge loading 被引量:1
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作者 Kewei Fan Guangqing Yang +2 位作者 Weilie Zou Zhong Han Yang Shen 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第4期1388-1397,共10页
Existing studies have focused on the behavior of the retaining wall equipped with expanded polystyrene(EPS)geofoam inclusions under semi-infinite surcharge loading rather than limited surcharge loading.In this paper,t... Existing studies have focused on the behavior of the retaining wall equipped with expanded polystyrene(EPS)geofoam inclusions under semi-infinite surcharge loading rather than limited surcharge loading.In this paper,the failure mode and the earth pressure acting on the rigid retaining wall with EPS geofoam inclusions and granular backfills(henceforth referred to as EPS-wall),under limited surcharge loading are investigated through two-and three-dimensional model tests.The testing results show that different from the sliding of almost all the backfill in the EPS-wall under semi-infinite surcharge loading,only an approximately triangular backfill slides in the wall under limited surcharge loading.The distribution of the lateral earth pressure on the EPS-wall under limited surcharge loading is non-linear,and the distribution changes from the increase of the wall depth to the decrease with the increase of the limited surcharge loading.An approach based on the force equilibrium of a differential element is developed to predict the lateral earth pressure behind the EPS-wall subjected to limited surcharge loading,and its performance was fully validated by the three-dimensional model tests. 展开更多
关键词 Retaining wall expanded polystyrene(EPS)geofoam Limited surcharge loading Lateral earth pressure Model test Prediction
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Even Closer China-Philippines Relations China and the Philippines have shown commitment to managing differences and expanding cooperation,which fosters more confidence in the ongoing stability of bilateral relations over the next six years
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作者 Dai Fan 《China Report ASEAN》 2023年第1期45-47,共3页
On January 3,2023,China welcomed the first visit in the new year by a foreign head of state,Philippine President Ferdinand Marcos Jr.The visit was also the president’s first official state visit to a country outside ... On January 3,2023,China welcomed the first visit in the new year by a foreign head of state,Philippine President Ferdinand Marcos Jr.The visit was also the president’s first official state visit to a country outside ASEAN since he took office in June 2022,which demonstrated the great importance the two countries attach to their bilateral relations.The three-day visit was fruitful despite a tight schedule. 展开更多
关键词 expanding VISIT BILATERAL
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Key Factors to Consider When Introducing a New Vaccine in Low-Income Settings: Lessons from Malawi Expanded Program on Immunization
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作者 Samuel Mpinganjira Kimberly Konono +5 位作者 Joseph Mwaka Adidja Amani Habtamu Anteneh Michael Ngigi Boston Zimba Atupele Kapito 《World Journal of Vaccines》 CAS 2024年第1期1-23,共23页
Introduction: As new vaccines become available, countries must assess the relevance to introduce them into their vaccination schedules. Malawi has recently introduced several new vaccines and plans to introduce more. ... Introduction: As new vaccines become available, countries must assess the relevance to introduce them into their vaccination schedules. Malawi has recently introduced several new vaccines and plans to introduce more. This study was conducted to identify key factors that need to be considered when deciding to introduce a new vaccine and current challenges faced by low and middle income countries using Malawi as an example. Methodology: The study employed a desk review approach, examining published literature from various sources such as PubMed, Medline, and Google Scholar. Policy documents from organizations like the World Health Organization, GAVI the Alliance, and the Ministry of Health for Malawi were also included. A total of 99 articles and documents on new vaccine introduction, challenges of immunization, policy documents in immunization and health systems strengthening were included. The review focused on addressing five key areas critical to new vaccine introduction namely: the need for a vaccine, availability of the vaccine, safety and effectiveness of the vaccine, demand for the vaccine, and the prudent use of public or private funds. Results: Malawi considered the burden of cervical cancer and the significance of malaria in the country when introducing the HPV and malaria vaccines. The country opted for vaccines that can be handled by the cold chain capacity and available human resources. Despite that malaria vaccine and Typhoid Conjugate Vaccine trials were done in country, there are limited vaccine safety and efficacy trials conducted in Malawi, leading to a reliance on WHO-prequalified vaccines. Demand for newly introduced vaccines varied, with high demand for Oral Cholera Vaccine during a cholera outbreak, while demand for COVID-19 vaccines decreased over time. Although cost-effectiveness studies were limited in the country, 2 studies indicated that Typhoid Conjugate Vaccine and malaria vaccine would be cost effective. All these have been implemented despite having challenges like lack of accurate surveillance data, inadequate cold chain capacity, limited safety and efficacy vaccine clinical trials, political influence, and limited funding. Conclusion: Despite several challenges Malawi set a good example of the careful considerations required before introducing a new vaccine. The process involves data review, priority setting, precise planning, and consultation with stakeholders. Low-income countries should invest in vaccine safety, efficacy, and cost-effectiveness trials. 展开更多
关键词 VACCINE Introduction Implementation expanded Program on Immunization LOW-INCOME STAKEHOLDERS
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Nursing Care and Causative Analysis of Grade IV Capsular Contracture Following Breast Cancer Expander Implantation
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作者 Rong Chen Nan Zhang Huiting Zhang 《Advances in Breast Cancer Research》 CAS 2024年第1期1-9,共9页
Objective: By observing the treatment and nursing care of a patient with Grade IV capsular contracture following breast cancer expander implantation and subsequent Stage II reconstruction, we aim to analyze the reason... Objective: By observing the treatment and nursing care of a patient with Grade IV capsular contracture following breast cancer expander implantation and subsequent Stage II reconstruction, we aim to analyze the reasons for the formation of capsular contracture after Stage I expander implantation and prevent its recurrence following Stage II reconstruction. Methods: In May 2020, the patient noticed an increase in the size of a breast mass. In August, she underwent AC-THP neoadjuvant chemotherapy, followed by a “right breast-conserving nipple-areolar subglandular excision + right axillary lymph node dissection + expander implantation” surgery in November 2020. Radiation therapy began in January 2021. During radiation therapy, the patient experienced severe breast hardening, distortion, tenderness, and was diagnosed with Grade IV capsular contracture. To relieve the capsular contracture, the patient underwent a “contracted capsule incision and release procedure + removal of the right breast expander + right breast implantation” surgery in July 2021. Postoperatively, measures were taken to prevent incision infection, emphasizing aseptic techniques, ensuring smooth negative pressure drainage, reducing skin flap tension, monitoring skin flap blood supply, actively preventing subcutaneous effusion and hematoma, and applying appropriate compression dressings. Results: The patient was discharged after the removal of the drainage tube. During the postoperative follow-up at 3 and 6 months, there was no recurrence of capsular contracture, and the breast appeared full, upright, and relatively soft. There were no complications such as hematoma, infection, breast implant rupture, breast sagging, or displacement. The patient had a good outcome without additional financial or surgical burdens. Conclusion: The occurrence of Grade IV capsular contracture in the patient is generally related to infection after Stage I expander implantation, improper compression dressing, excessive saline injection causing content infiltration, and radiation therapy. Therefore, it is recommended to enhance the intraoperative and postoperative prophylactic use of antibiotics after Stage I expander implantation. Intermittent saline injection after surgery, with the amount of saline gradually increasing rather than filling all at once, is advisable. This helps the breast tissue gradually adapt to expansion, reducing the risk of capsular contracture. Postoperatively, patients should be instructed to wear pressure garments and breast elastic bandages while intensifying breast monitoring during radiation therapy and increasing postoperative follow-up. 展开更多
关键词 Breast Cancer Capsular Contracture expander Implantation
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Expanding Food Security
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作者 GODFREY OLUKYA 《ChinAfrica》 2023年第3期40-41,共2页
China and FAO assist Uganda to become self-sufficent in food production, and serve as the food basket of the region Eighty percent of Uganda’s economy depends on agriculture, according to the Uganda Bureau of Statist... China and FAO assist Uganda to become self-sufficent in food production, and serve as the food basket of the region Eighty percent of Uganda’s economy depends on agriculture, according to the Uganda Bureau of Statistics. For this reason, Frank Tumwebaze, Uganda’s minister of agriculture, animal industry and fisheries, said in an interview recently that since the majority of the country’s population is involved in agriculture. 展开更多
关键词 INTERVIEW AGRICULTURE expanding
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Compression properties of cost-efficient porous expanded clay reinforced AA7075 syntactic foams fabricated by industrial-oriented die casting technology
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作者 İsmail Cem Akgün Çağın Bolat Ali Gökşenli 《China Foundry》 SCIE EI CAS CSCD 2024年第1期60-70,共11页
In today’s manufacturing industries,hard competition between rival firms makes it compulsory for researchers to design lighter and cheaper machine components due to the megatrends of cost-effectiveness and anti-pollu... In today’s manufacturing industries,hard competition between rival firms makes it compulsory for researchers to design lighter and cheaper machine components due to the megatrends of cost-effectiveness and anti-pollution.At this point,aluminum syntactic foams(ASFs)are new-generation engineering composites and come into the upfront as a problem-solver.Owing to their features like low density,sufficient elongation,and perfect energy absorption ability,these advanced foams have been considerably seductive for many industrial sectors nowadays.In this study,an industrial-oriented automatic die casting technology was used for the first time to manufacture the combination of AA7075/porous expanded clay(PEC).Micro evaluations(optical and FESEM)reveal that there is a homogenous particle distribution in the foam samples,and inspections are compatible with the other ASF studies.Additionally,T6 aging heat treatment was operated on one half of the produced foams to explore the probable impact of aging on the compressive responses.Attained results show that PEC particles can be an alternative to expensive hollow spheres used in the previous works.Besides,a favorable relationship is ascertained between the aging treatment and mechanical properties such as compression strength and plateau strength. 展开更多
关键词 die casting porous materials metal matrix sytanctic foams expanded clay compressive deformation
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Expandable endoprostheses in skeletally immature patients:Where we are
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作者 RecepÖztürk 《World Journal of Orthopedics》 2024年第4期312-317,共6页
Approximately 45 percent of malignant bone tumors are seen under the age of 16 and one of the important results of growth plate sacrification in patients with immature skeletons is limb inequality.Until the early 1990... Approximately 45 percent of malignant bone tumors are seen under the age of 16 and one of the important results of growth plate sacrification in patients with immature skeletons is limb inequality.Until the early 1990s,the treatment options for these patients were rotationplasty or amputation.Multimodal approaches that combine imaging,chemotherapy,and surgical techniques have enabled the development of limb-preserving methods with satisfactory results.In order to overcome inequality problems,expandable prostheses have been developed in the 1980s.Extendable endoprosthesis replacements have been improved over the years and are now an established and safe alternative.Noninvasive prostheses appear to be advantageous compared to minimally invasive expandable prostheses that require multiple surgical procedures,but the complication rate remains high.Therefore,although expandable prostheses are not the definitive answer to the treatment of bone sarcomas in skeletally immature children,they are still a suitable interim choice until full adulthood is achieved.Due to reported high complication rates,the procedures require significant experience and are recommended for use only in specialized cancer centers. 展开更多
关键词 Bone sarcoma expandable endoprostheses Limb salvage surgery NONINVASIVE Minimal-invasive INVASIVE Extendible endoprostheses
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Study of Rice Husks and Expanded Polystyrene Composites for Construction Applications
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作者 Edem Chabi Valéry Kouandété Doko +2 位作者 Sena Peace Hounkpè Paul Damien Amadji Emmanuel Olodo 《Open Journal of Civil Engineering》 2024年第3期456-468,共13页
In the current context of environmental challenges, this study focuses on developing innovative and eco-friendly composites using rice husk and recycled expanded polystyrene. This dual-responsibility approach valorize... In the current context of environmental challenges, this study focuses on developing innovative and eco-friendly composites using rice husk and recycled expanded polystyrene. This dual-responsibility approach valorizes a by-product like rice husk, often considered waste, and reuses polystyrene, a plastic waste, thereby contributing to CO2 emission reduction and effective waste management. The manufacturing process involves dissolving recycled polystyrene into a solvent to create a binder, which is then mixed with rice husk and cold-compacted into composite materials. The study examines the impact of two particle sizes (fine and coarse) and different proportions of recycled polystyrene binder. The results show significant variations in the mechanical characteristics of the composites, with Modulus of Rupture (MOR) values varying from 2.41 to 3.47 MPa, Modulus of Elasticity (MOE) ranging from 223.41 to 1497.2 MPa, and Stiffness Coefficient (K) from 5.04 to 33.96 N/mm. These characteristics demonstrate that these composites are appropriate for various construction applications, including interior decoration, panel claddings, and potentially for furniture and door manufacturing when combined with appropriate coatings. This study not only highlights the recycling of agricultural and plastic waste but also provides a localized approach to addressing global climate change challenges through the adoption of sustainable building materials. 展开更多
关键词 Rice Husk Recycled expanded Polystyrene Eco-Friendly Composites Waste Valorization Sustainable Construction
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The Methods of Expanding Vegetable Trade Between China and EU
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作者 张丽琼 《科技信息》 2009年第33期I0175-I0175,共1页
Expanding the export of vegetable to EU is an important way to improve china's trade competitive ability. This article analyzes the characteristics of EU's vegetable trade and raises some suggestions.
关键词 欧盟 对外贸易 蔬菜 市场分析
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Native Expanding <i>Merremia boisiana</i>Is Not More Allelopathic than Its Non-Expanding Congener <i>M. vitifolia</i>in the Expanded Range in Hainan 被引量:4
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作者 Qiaoqiao Huang Yide Shen +3 位作者 Xiaoxia Li Zhiwei Fan Mingguang Li Hanting Cheng 《American Journal of Plant Sciences》 2013年第4期774-779,共6页
Exotic invaders may possess novel biochemical weapons that native plants do not have, and these novel biochemical weapons may be more allelopathic than those from native plants to other native competitors. During rang... Exotic invaders may possess novel biochemical weapons that native plants do not have, and these novel biochemical weapons may be more allelopathic than those from native plants to other native competitors. During range expansion, native species also encounter many new plant competitors. Thus, allelochemicals from native expanding species may also be more novel and allelopathic than those from non-expanding species to other plant competitors in the expanded range. We test this hypothesis using the native expanding Merremia boisiana and its non-expanding congener M. vitifolia in year 2012 inthe expanded range inHainan. In petridish bioassays, we found that aqueous extracts of M. boisiana leaves were often less inhibitory or more stimulatory to seed germination and seedling growth of five vegetable species than those of M. vitifolia leaves. In pot culture, we also found that aqueous leaf extracts of the two congeners could both inhibit the growth of a naturally co-occurring plant Paederia scanden, but their effects did not differ from each other. These results indicate that while allelopathy may contribute to the competitive ability of M. boisiana, it may not act as a novel weapon explaining its success in the expanded range in Hainan. 展开更多
关键词 ALLELOPATHY Expansion Invasion Merremia boisiana NATIVE expanding Species Novel Weapons
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Strain rate dependency and fragmentation pattern of expanding warheads 被引量:5
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作者 John F.MOXNES Anne K.PRYTZ +3 位作者 Фyvind FR?YLAND Stian SKRIUDALEN Steinar BФRVE Gard ФDEGARDSTUEN 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2015年第1期1-9,共9页
For the characterization of the behaviors of a metal material in events like expanding warheads, it is necessary to know its strength and ductility at high strain rates, around 104e105/s. The flyer plate impact testin... For the characterization of the behaviors of a metal material in events like expanding warheads, it is necessary to know its strength and ductility at high strain rates, around 104e105/s. The flyer plate impact testing produces the uniform stress and strain rates but the testing is expensive. The Taylor test is relatively inexpensive but produces non-uniform stress and strain fields, and the results are not so easily inferred for material modeling. In the split-Hopkinson bar(SHB), which may be used in compression, tension and torsion testing, the strain rates never exceeds 103/s. In the present work, we use the expanding ring test where the strain rate is 104e105/s. A streak camera is used to examine the expanding ring velocity, and a water tank is used to collect the fragments. The experimental results are compared with the numerical simulations using the hydrocodes AUTODYN, IMPETUS Afea and a regularized smooth particle(RSPH) software. The number of fragments increases with the increase in the expansion velocity of the rings. The number of fragments is similar to the experimental results. The RSPH software shows much the same results as the AUTODYN where the Lagrangian solver is used for the ring. The IMPETUS Afea solver shows a somewhat different fragmentation characteristic due to the node splitting algorithm that induces pronounced tensile splitting. 展开更多
关键词 WARHEAD FRAGMENTATION SIMULATION Fracture model expanding ring
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Preventive Countermeasures for "Immiserizing Growth in Expanding Economies" in China's Rural Areas in the New Era 被引量:2
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作者 PANG Yong-hong,WANG Fang-fang,LIU You-bin School of Trade and Administration,Chongqing University,Chongqing 400030,China 《Asian Agricultural Research》 2011年第9期1-5,共5页
On the basis of defining the concept of "immiserizing growth in expanding economies",through analysing the status quo of economy in China's rural areas in the new era,this paper aims to find out the fact... On the basis of defining the concept of "immiserizing growth in expanding economies",through analysing the status quo of economy in China's rural areas in the new era,this paper aims to find out the factors responsible for economic weakness of China's rural residents.It analyses the impact of market consuming economy on growth economy,and points out the phenomenon of "immiserizing growth in expanding economies" which may be triggered by China's rapid rural economic growth as follows:first,the income disparity between urban and rural residents increases ceaselessly,the commodity prices continuously soar,and the rural residents' market consuming capacity is short;second,the wealth concentrates highly and the majority of farmers' income is low.Thus we put forward the countermeasures and proposals for preventing "immiserizing growth in expanding economies" in rural areas as follows:we should reform household registration system so that the rural residents have the right to migrate freely,and farmers' status is promoted;we should coordinate urban-rural development,strengthen agriculture and rural infrastructure building and achieve impartial allocation of public resources;we should carry out redistribution on income scientifically and effectively,consolidate rural social security system,bridge urban-rural income gap,transform the comparative advantage into competitive advantage,so as to circumvent "immiserizing growth in expanding economies". 展开更多
关键词 Immiserizing GROWTH in expanding ECONOMIES SOCIAL
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Effects of expanding zone parameters of vacuum dust suction mouth on flow simulation results 被引量:8
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作者 章易程 杨春朝 +3 位作者 Chris Baker 陈默 邹翔 戴万林 《Journal of Central South University》 SCIE EI CAS 2014年第6期2547-2552,共6页
Based on the parametric analysis of the expanding zone of the vacuum dust suction mouth,the flow in the vacuum dust suction mouth was simulated by computational fluid dynamics(CFD)software,Fluent.The effects of the ex... Based on the parametric analysis of the expanding zone of the vacuum dust suction mouth,the flow in the vacuum dust suction mouth was simulated by computational fluid dynamics(CFD)software,Fluent.The effects of the expanding zone parameters on flow simulation were analyzed.The results show that simulation effects depend on threshold values of the expanding zone parameters of the dust suction mouth,and the threshold values of the expanding zone can be obtained according to the different structures of the vacuum dust suction mouth and be selected as the geometric parameters in calculating,and also corners of the expanding zone make unobvious difference in calculation accuracy and in computational efficiency compared with no corner.The simulation results provide practical guidance to the flow simulation on the dust suction mouth. 展开更多
关键词 dust suction mouth expanding zone threshold analysis computational fluid dynamics
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Efficacy and safety of standard and anti-reflux self-expanding metal stent: A systematic review and meta-analysis of randomized controlled trials 被引量:2
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作者 Sudha Pandit Hrishikesh Samant +1 位作者 James Morris Steven J Alexander 《World Journal of Gastrointestinal Endoscopy》 CAS 2019年第4期271-280,共10页
BACKGROUND Self-expanding metal stents are the main palliative treatment modality for unresectable esophageal cancer. Gastroesophageal reflux is a common adverse outcome after placement of esophageal stent for cancer ... BACKGROUND Self-expanding metal stents are the main palliative treatment modality for unresectable esophageal cancer. Gastroesophageal reflux is a common adverse outcome after placement of esophageal stent for cancer involving the gastroesophageal junction and the gastric cardia. Anti-reflux stents with valve have been designed to prevent the acid reflux. The superiority of anti-reflux stent over standard stent in preventing gastroesophageal reflux has not been established well. This study compares the anti-reflux stent and the standard stent in terms of their efficacy to prevent acid reflux.AIM To compare the standard and the anti-reflux stents in terms of their efficacy,safety, and complications.METHODS The meta-analysis included 8 randomized clinical trials(RCTs) to compare pooled outcomes of total 395 patients. Primary outcomes include improvement in reflux symptoms and dysphagia score. Secondary outcomes include complications of stent migration, occlusion, and bleeding.RESULTS A total of eight RCTs were included in the meta-analysis. Compared to the standard stent, the anti-reflux stent showed a trend towards reduction in the dysphagia score without reaching a statistical significance [Standardized mean difference(SMD):-0.33(-0.71, 0.05); P = 0.09, I2: 37%]. There was no statistical difference in the gastrointestinal reflux(GER) scores between the two types of stents [SMD:-0.17(-0.78, 0.45); P = 0.008, I2: 74%]. Compared to standard stent,anti-reflux stent showed no difference in the risk of stent migration [OR: 1.37(0.66, 2.83); P = 0.40, I2: 0 %], bleeding [OR: 1.43(0.40, 5.13); P = 0.59, I2: 0 %], and obstruction [OR: 1.66(0.60, 4.60); P = 0.33, I2: 0 %].CONCLUSION Traditional self-expanding standard esophageal stent and anti-reflux stent with valve are similar in terms of outcomes and complications. 展开更多
关键词 Self expanding metal STENT Anti-reflux STENT RANDOMIZED controlled trial ESOPHAGEAL STENT META-ANALYSIS
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Homotopy analysis solutions for the asymmetric laminar flow in a porous channel with expanding or contracting walls 被引量:7
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作者 X.-H. Si L.-C. Zheng +1 位作者 X.-X. Zhang Y. Chao 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2011年第2期208-214,共7页
In this paper, the asymmetric laminar flow in a porous channel with expanding or contracting walls is investigated. The governing equations are reduced to ordinary ones by using suitable similar transformations. Homot... In this paper, the asymmetric laminar flow in a porous channel with expanding or contracting walls is investigated. The governing equations are reduced to ordinary ones by using suitable similar transformations. Homotopy analysis method (HAM) is employed to obtain the expres- sions for velocity fields. Graphs are sketched for values of parameters and associated dynamic characteristics, especially the expansion ratio, are analyzed in detail. 展开更多
关键词 Homotopy analysis method · expanding or contracting wall · Asymmetric laminar flow · Porous channel · Expansion ratio
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Theoretical Analysis on Thermal Choking in Expanding RBCC Duct 被引量:1
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作者 吴亚可 何国强 刘佩进 《Defence Technology(防务技术)》 SCIE EI CAS 2010年第4期234-240,共7页
A one-dimensional theoretical model was adopted in this paper to describe and analyze the flow in an expanding RBCC(rocket based combined cycle)duct.It can be concluded that the expanding angle,heating amount and dist... A one-dimensional theoretical model was adopted in this paper to describe and analyze the flow in an expanding RBCC(rocket based combined cycle)duct.It can be concluded that the expanding angle,heating amount and distribution of heating play crucial roles on the thermal choking.They mainly influence the acceleration of flow,the position of choking throat and the total pressure loss.In order to fulfill the transition of subsonic flow to supersonic flow in the expanding RBCC duct,the heating amount has to change from a bigger value to a smaller one along the duct.When the thermal choking occurs in the RBCC duct,the moderate expanding angle,proper heating amount and distribution of heating are necessary for the best performance of RBCC combustor.Adopting the RBCC duct with smaller expanding angles anterior and bigger expanding angles posterior has positive effects on the thermal choking and flexibility of selecting heating method,and can restrain the negative effect of the combustion on the inlet also. 展开更多
关键词 propulsion system of aviation & aerospace RBCC expanding duct one-dimensional analysis thermal choking
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