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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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A Stroke-Limitation AMD Control System with Variable Gain and Limited Area for High-Rise Buildings
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作者 Zuo-Hua Li Qing-Gui Wu +1 位作者 Jun Teng Chao-Jun Chen 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第1期865-884,共20页
Collisions between a moving mass and an anti-collision device increase structural responses and threaten structural safety.An active mass damper(AMD)with stroke limitations is often used to avoid collisions.However,a ... Collisions between a moving mass and an anti-collision device increase structural responses and threaten structural safety.An active mass damper(AMD)with stroke limitations is often used to avoid collisions.However,a strokelimited AMD control system with a fixed limited area shortens the available AMD stroke and leads to significant control power.To solve this problem,the design approach with variable gain and limited area(VGLA)is proposed in this study.First,the boundary of variable-limited areas is calculated based on the real-time status of the moving mass.The variable gain(VG)expression at the variable limited area is deduced by considering the saturation of AMD stroke.Then,numerical simulations of a stroke-limited AMD control system with VGLA are conducted on a high-rise building structure.These numerical simulations show that the proposed approach has superior strokelimitation performance compared with a stroke-limited AMD control system with a fixed limited area.Finally,the proposed approach is validated through experiments on a four-story steel frame. 展开更多
关键词 High-rise buildings active control stroke limitations variable gain variable limited area
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Exploring device physics of perovskite solar cell via machine learning with limited samples
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作者 Shanshan Zhao Jie Wang +8 位作者 Zhongli Guo Hongqiang Luo Lihua Lu Yuanyuan Tian Zhuoying Jiang Jing Zhang Mengyu Chen Lin Li Cheng Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第7期441-448,共8页
Perovskite solar cells(PsCs)have developed tremendously over the past decade.However,the key factors influencing the power conversion efficiency(PCE)of PSCs remain incompletely understood,due to the complexity and cou... Perovskite solar cells(PsCs)have developed tremendously over the past decade.However,the key factors influencing the power conversion efficiency(PCE)of PSCs remain incompletely understood,due to the complexity and coupling of these structural and compositional parameters.In this research,we demon-strate an effective approach to optimize PSCs performance via machine learning(ML).To address chal-lenges posed by limited samples,we propose a feature mask(FM)method,which augments training samples through feature transformation rather than synthetic data.Using this approach,squeeze-and-excitation residual network(SEResNet)model achieves an accuracy with a root-mean-square-error(RMSE)of 0.833%and a Pearson's correlation coefficient(r)of 0.980.Furthermore,we employ the permu-tation importance(PI)algorithm to investigate key features for PCE.Subsequently,we predict PCE through high-throughput screenings,in which we study the relationship between PCE and chemical com-positions.After that,we conduct experiments to validate the consistency between predicted results by ML and experimental results.In this work,ML demonstrates the capability to predict device performance,extract key parameters from complex systems,and accelerate the transition from laboratory findings to commercialapplications. 展开更多
关键词 Perovskite solar cell Machine learning Device physics Performance prediction limited samples
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Data-driven methods for predicting the representative temperature of bridge cable based on limited measured data
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作者 WANG Fen DAI Gong-lian +2 位作者 HE Chang-lin GE Hao RAO Hui-ming 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第9期3168-3186,共19页
Cable-stayed bridges have been widely used in high-speed railway infrastructure.The accurate determination of cable’s representative temperatures is vital during the intricate processes of design,construction,and mai... Cable-stayed bridges have been widely used in high-speed railway infrastructure.The accurate determination of cable’s representative temperatures is vital during the intricate processes of design,construction,and maintenance of cable-stayed bridges.However,the representative temperatures of stayed cables are not specified in the existing design codes.To address this issue,this study investigates the distribution of the cable temperature and determinates its representative temperature.First,an experimental investigation,spanning over a period of one year,was carried out near the bridge site to obtain the temperature data.According to the statistical analysis of the measured data,it reveals that the temperature distribution is generally uniform along the cable cross-section without significant temperature gradient.Then,based on the limited data,the Monte Carlo,the gradient boosted regression trees(GBRT),and univariate linear regression(ULR)methods are employed to predict the cable’s representative temperature throughout the service life.These methods effectively overcome the limitations of insufficient monitoring data and accurately predict the representative temperature of the cables.However,each method has its own advantages and limitations in terms of applicability and accuracy.A comprehensive evaluation of the performance of these methods is conducted,and practical recommendations are provided for their application.The proposed methods and representative temperatures provide a good basis for the operation and maintenance of in-service long-span cable-stayed bridges. 展开更多
关键词 cable-stayed bridges representative temperature gradient boosted regression trees(GBRT)method field test limited measured data
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Leaf nitrogen resorption is more important than litter nitrogen mineralization in mediating the diversity–productivity relationship along a nitrogen-limited temperate forest succession chronosequence 被引量:2
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作者 Peng Zhang Xiao-Tao Lü +2 位作者 Guangze Jin Zhili Liu Mai-He Li 《Forest Ecosystems》 SCIE CSCD 2023年第1期132-140,共9页
The resorption of nutrients by plants before litter fall and the mineralization of nutrients from plant litter by soil processes are both important pathways supporting primary productivity. While the positive relation... The resorption of nutrients by plants before litter fall and the mineralization of nutrients from plant litter by soil processes are both important pathways supporting primary productivity. While the positive relationship between plant biodiversity and primary productivity is widely accepted for natural ecosystems, the roles of nutrient resorption and mineralization in mediating that relationship remains largely unknown. Here, we quantified the relative importance of nitrogen(N) resorption and N mineralization in driving plant community N investment and the correlation between species diversity and community productivity along an N-limited successional chronosequence of the mixed broadleaved–Korean pine(Pinus koraiensis) forest in northeastern China. Leaf N resorption efficiency(NRE) at the community level increased significantly along the successional chronosequence,whereas litter N mineralization rate decreased significantly. Leaf NRE was more important than litter N mineralization rate in driving the diversity–productivity relationship. However, higher leaf NRE led to less N mineralization as succession progressed along the chronosequence. Our results highlight the importance of the N resorption pathway rather than the N mineralization pathway for forest N acquisition with community succession,and they provide mechanistic insights into the positive effects of biodiversity on ecosystem functioning. In future forest management practices, we recommend appropriate application of N fertilizer to mitigate the adverse effects of N-poor soil on seedling regeneration during late succession and thus maintain the sustainable development of temperate forest ecosystems. 展开更多
关键词 Community composition DIVERSITY Ecosystem functioning N cycling N limited Niche complementarity Trade-off
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Access to novel anti-diabetic agents in resource limited settings:A brief commentary
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作者 Poobalan Naidoo Kiolan Naidoo +1 位作者 Sumanth Karamchand Rory F Leisegang 《World Journal of Diabetes》 SCIE 2023年第7期939-941,共3页
The prevalence of diabetes mellitus is increasing in resource limited settings.Simultaneously,there has been an increase in the number of novel therapies for the management of diabetes mellitus.However,use of novel an... The prevalence of diabetes mellitus is increasing in resource limited settings.Simultaneously,there has been an increase in the number of novel therapies for the management of diabetes mellitus.However,use of novel antidiabetic therapies is limited because of major market access challenges in resource limited settings.Niching products to those patients with the highest absolute risk for major adverse cardiovascular outcomes,and thus most likely to benefit from the therapy,are less likely to have negative budget impact for funders.To improve access,and reduce morbidity and mortality,requires alignment amongst key stakeholders including patient advocacy groups,health care professional councils,national departments of health,the pharmaceutical industry,treasury and finance departments. 展开更多
关键词 Type 2 diabetes mellitus Novel anti-diabetic agents Resource limited settings ACCESS
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Exclusive Fibula Osteosynthesis for Treating Open Fractures Gustillo I-III B of the Distal Half of the Leg Bones in a Resources-Limited Setting
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作者 Georges Kuyigwa Toha Paul Munguakonkwa Budema +2 位作者 Ona Longombe Ahuka Akinja Bitum Uwonda Jean Marie Vianney Kabangu Tshimbila 《Open Journal of Orthopedics》 2023年第3期108-121,共22页
Introduction: Management of open leg bones fractures is a challenging health issue for the surgeon, particularly true in resource-limited settings. In this study, we evaluate exclusive fibular osteosynthesis in the tr... Introduction: Management of open leg bones fractures is a challenging health issue for the surgeon, particularly true in resource-limited settings. In this study, we evaluate exclusive fibular osteosynthesis in the treatment of open fractures of the distal half of the leg bones as a therapeutic option in our context. Methods: This is a prospective, experimental, multicenter study of 30 open fractures of the distal half of the leg bones treated with exclusive fibula osteosynthesis, conducted in 3 hospitals in the DRC from January 1, 2013 to September 30, 2016. Results: The age range of 20 to 40 years grouped 22 (73.4%) patients, the sex ratio was 1:1 and the unemployed were the most involved with 16 (53.3%) cases. The Gustilo II, I, III B and III A types represented 40%, 33.3%, 20% and 6.7%, respectively. The fractures were located in the distal third in 12 (40%) cases, in the middle third in 11 (36.7%) cases, and in both malleoli in 7 cases (23.3%). Osteosynthesis of the fibula by screw plate was applied in 22 (73.3%) patients and pinning in 8 (26.7%). Satisfactory reduction of the tibial fracture site was achieved in 29 (96.7%) cases and 100% bone healing was achieved within an average of 10 weeks. Four (13.3%) loss of alignment, 1 (3.3%) infection, 1 (3.3%) skin necrosis and 2 (6.7%) ankle stiffness complicated our fractures. Conclusion: Exclusive osteosynthesis of the fibula as a common technique for fractures of the distal half of the leg bones allowed us to reduce, immobilize and consolidate the tibial fracture in the required time and to preserve the mobility of the ankle. 展开更多
关键词 Fibular Exclusive Osteosynthesis Open Tibial Fractures Resources limited Settings Tibial Fracture Consolidation
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A Recursive Algorithm for Offspring's Genotype Frequency of Selfing Population on Multiple Alleles with Limited Loci 被引量:2
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作者 陈奇 李大林 《Agricultural Science & Technology》 CAS 2010年第6期26-27,41,共3页
This paper studies the offspring's genotype frequency of the selfing population on multiple alleles with limited loci.A recursive algorithm is given for it.It is discovered that the genotype frequency of homozygous g... This paper studies the offspring's genotype frequency of the selfing population on multiple alleles with limited loci.A recursive algorithm is given for it.It is discovered that the genotype frequency of homozygous gene of limited loci increases by generations.Relative increment reduces by generations and the genotype frequency tends to a definite value finally.The genotype frequency of limited loci with hybrid gene tends to 0 finally.But it is possibility that the genotype frequency increases in previous generations then reduces later.It is found that the number of the hybrid gene are more,the speeds tending to 0 are quicker. 展开更多
关键词 limited loci Multiple alleles SELFING POPULATION Genotype frequency
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Temperature Characteristics of Bilayer Thin-Film Devices Under Organic Interface Limited Current Conduction
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作者 杨青森 彭应全 +4 位作者 邢宏伟 李训栓 袁建挺 马朝柱 赵明 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2008年第6期1075-1080,共6页
Temperature characteristics are important for the performance of organic thin film devices. On the basis of the hopping theory of Miller-Abrahams,an analytical model of charge transport for bilayer organic devices und... Temperature characteristics are important for the performance of organic thin film devices. On the basis of the hopping theory of Miller-Abrahams,an analytical model of charge transport for bilayer organic devices under the organicorganic interface limited current conduction is developed. The dependence of current, field,and carrier distribution in bilayer organic devices with the structure of "injection electrode/Layer Ⅰ/Layer Ⅱ/collection electrode" on temperature are numerically analyzed. We conclude that, for a given applied voltage, when temperature is raised, the voltage of LayerⅠ will increase,and the field will be higher. Meanwhile, the voltage of Layer Ⅲ will decrease, the field will become weaker accordingly,and the current of the device will increase. 展开更多
关键词 organic-organic interface limited temperature characteristics numerical analysis
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Study on Limited Filamentous Sludge Bulking Test in A/O Activated Sludge Process
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作者 万玉山 孙凌峰 +2 位作者 贾春霞 李娜 雷春生 《Agricultural Science & Technology》 CAS 2014年第9期1620-1623,共4页
[Objective] This study aimed to make use of the limited filamentous sludge bulking characteristics to purify water quality and save energy. [Method] The effects of dissolved oxygen (DO) on sludge bulking were explor... [Objective] This study aimed to make use of the limited filamentous sludge bulking characteristics to purify water quality and save energy. [Method] The effects of dissolved oxygen (DO) on sludge bulking were explored by changing the DO con- centration in the aerobiotic pool of NO system from the low load (0.25 kg COD/(kg MLSS.d)) and the medium to high load (0.55 kgCOD/(kg MLSSod)). [Result] In the NO activated sludge system, when the sludge load was 0.25 kg COD/(kg MLSS.d), DO=1.5 mg/L, the sludge index was at around 250, while when the sludge load- ing was 0.55 kg COD/(kg MLSS.d), DO=1.5 mg/L, the sludge index was close to 300, occurring the limited filamentous bulking. The bulked sludge still showed high removal rates to COD, SS, nitrogen and phosphorus. [Conclusion] It could improve the oxygen transfer rate and reduce the aeration rate at low DO conditions to achieve energy-saving. 展开更多
关键词 A/O process limited filamentous sludge bulking Sludge load Energy saving
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新西兰品种权保护的域外扩张及我国的因应之策——兼评“Zespri Group Limited v Gao&Ors”案 被引量:1
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作者 李秀丽 《中国种业》 2020年第4期1-5,共5页
以“Zespri Group Limited v Gao&Ors”案判决书为研究视角,认为在侵权和损失认定方面,法官通过法律原则、国内外判例与学理学说的运用并通过解释立法目的,创造性地运用国内法律,影响其国外利益格局。该案将成为国内法域外适用向植... 以“Zespri Group Limited v Gao&Ors”案判决书为研究视角,认为在侵权和损失认定方面,法官通过法律原则、国内外判例与学理学说的运用并通过解释立法目的,创造性地运用国内法律,影响其国外利益格局。该案将成为国内法域外适用向植物新品种保护领域渗透的标志性事件。为维护我国自身利益,建议进一步做好植物新品种保护制度自身建设,加强植物新品种保护制度和植物遗传资源保护制度之间的协调。 展开更多
关键词 “Zespri GROUP limited V Gao&Ors”案 域外效力适用 植物品种权 遗传资源保护
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LIMITED MEMORY BFGS METHOD BY USING LINEAR INDEPENDENT SEARCH DIRECTIONS
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作者 倪勤 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2001年第2期236-239,共4页
The degree of numerical linear independence is proposed and discussed. Based on this linear independence theory, a modified limited memory BFGS method is deve loped. Similar to the standard limited memory method, thi... The degree of numerical linear independence is proposed and discussed. Based on this linear independence theory, a modified limited memory BFGS method is deve loped. Similar to the standard limited memory method, this new method determines the new update by applying the updating formula m times to an initial positive diagonal matrix using the m previous pairs of the change in iteration and gradient. Besides the most recent pair of the change, which guarantees the quadratic termination, the choice of the other ( m -1) pairs of the change in the new method is dependent on the degree of numerical linear independence of previous search directions. In addition, the numerical linear independence theory is further discussed and the computation of the degree of linear independence is simplified. Theoretical and numerical results show that this new modified method improves efficiently the standard limited memory method. 展开更多
关键词 unconstrained optimization limited memory method BFGS method degree of linear independence
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Application of internal fixation of steel-wire limited loop in early Achilles tendon rupture 被引量:10
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作者 Zhe Chen Jia-Sen Wei +3 位作者 Zhao-Yang Hou Jiong Hu Yan-Guang Cao Qi-Xin Chen 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2013年第11期902-907,共6页
Objective:To explore the clinical effect and safety of internal fixation of steel-wire limited loop in early Achilles tendon rupture.Methods:Seventy-six patients respectively with early transected and avulsed types of... Objective:To explore the clinical effect and safety of internal fixation of steel-wire limited loop in early Achilles tendon rupture.Methods:Seventy-six patients respectively with early transected and avulsed types of Achilles tendon rupture were selected and treated with internal fixation of steel-wire limited loop.The patients began to take exercise for their lower limbs through continous passive motion as early as possible after surgical repair,and the loops were removed after 3-5 months.Six months later,the condition of complications including Achilles tendon re-rupture,wound fistula,wound infection and skin necrosis,cutaneous sensation in sural nerve dominance region,time back to preinjury work or learning as well as time to physical activities were observed.One year later,the therapeutic effect was evaluated,and the maximum circumferences of bilateral legs and raptured plane circumferences of Achilles tendon were measured.Results:The wound of all patients healed well,no complications like Achilles tendon re-rupture,wound fistula,wound infection and skin necrosis occured,and the cutaneous sensation in sural nerve dominance region was normal.The mean time back to preinjury work or learning as well as to pysical activities of all patients were respectively 10 and 22 weeks.Seventy out of 76 patients(92.1%) achieved an excellent effect,and 6(7.9%) good effect.The excellent and good rate came up to 100%.The maximum circumference in the affected leg decreased to 2 mm averagely compared with the offside,while the ruptured plane circumferences of Achilles tendon in the affected side increased to 2.2 mm compared with the offside.Conclusions:Kor early Achilles tendon rupture,internal fixation of steel-wire limited loop can recover the ankle function better,return to the preinjury state in the shortest lime,and has few complications. 展开更多
关键词 ACHILLES TENDON rupture Steel-wire limited LOOP Internal fixation ANKLE function
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Combined treatment of phacoemulsification and single-port limited pars plana vitrectomy in acute angle-closure glaucoma 被引量:11
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作者 Ha Jeong Noh Seong Taeck Kim 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2019年第6期974-979,共6页
AIM: To evaluate the efficacy of combined treatment of phacoemulsification(PE) and micro-incisional single-port transconjunctival limited pars plana vitrectomy(PPV) in acute angle-closure glaucoma(AACG).METHODS: A ret... AIM: To evaluate the efficacy of combined treatment of phacoemulsification(PE) and micro-incisional single-port transconjunctival limited pars plana vitrectomy(PPV) in acute angle-closure glaucoma(AACG).METHODS: A retrospective study included 26 patients who underwent PE diagnosed with AACG. Among them, 16 patients(16 eyes) underwent PE alone, 10 patients(10 eyes) underwent combined limited vitrectomy and PE. Then we compared intraocular pressure(IOP), anterior chamber angle, anterior chamber depth, central corneal thickness and corneal endothelial cell count before and after surgery, and effective PE time during cataract surgery.RESULTS: Effective PE time was shorter in the combined surgery group than in the single surgery group(P=0.040). There was no statistically significant difference in IOP and best-corrected visual acuity between the two groups postoperatively. At 6 mo postoperatively, there was no difference in the anterior chamber angle, anterior chamber depth, and central corneal thickness between two groups, but corneal endothelial cell count was higher in the combined surgery group than in the single surgery group(P=0.046). No complication such as vitreoretinal disease, endophthalmitis, bullous keratopathy was noted.CONCLUSION: Combined micro-incisional single-port transconjunctival limited PPV and PE are more effective and safer than PE alone because of less operation time and fewer complications for management of AACG. 展开更多
关键词 limited VITRECTOMY PHACOEMULSIFICATION acute ANGLE-CLOSURE glaucoma
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Limited resection for duodenal gastrointestinal stromal tumors:Surgical management and clinical outcome 被引量:11
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作者 Jens Hoeppner Birte Kulemann +2 位作者 Goran Marjanovic Peter Bronsert Ulrich Theodor Hopt 《World Journal of Gastrointestinal Surgery》 SCIE CAS 2013年第2期16-21,共6页
AIM:To analyze our experience in patients with duodenal gastrointestinal stromal tumors(GIST) and review the appropriate surgical approach.METHODS:We retrospectively reviewed the medical records of all patients with d... AIM:To analyze our experience in patients with duodenal gastrointestinal stromal tumors(GIST) and review the appropriate surgical approach.METHODS:We retrospectively reviewed the medical records of all patients with duodenal GIST surgically treated at our medical institution between 2002 and 2011.Patient files,operative reports,radiological charts and pathology were analyzed.For surgical therapy open and laparoscopic wedge resections and segmental resections were performed for limited resection(LR).For extended resection pancreatoduodenectomy was performed.Age,gender,clinical symptoms of the tumor,anatomical localization,tumor size,mitotic count,type of resection resectional status,neoadjuvant therapy,adjuvant therapy,risk classification and follow-up details were investigated in this retrospective study.RESULTS:Nine patients(5 males/4 females) with a median age of 58 years were surgically treated.The median follow-up period was 45 mo(range 6-111 mo).The initial symptom in 6 of 9 patients was gastrointestinal bleeding(67%).Tumors were found in all four parts of the duodenum,but were predominantly located in the first and second part of the duodenum with each 3 of 9 patients(33%).Two patients received neoadjuvant medical treatment with 400 mg imatinib per day for 12 wk before resection.In one patient,the GIST resection was done by pancreatoduodenectomy.The 8 LRs included a segmental resection of pars 4 of the duodenum,5 wedge resections with primary closure and a wedge resection with luminal closure by Roux-Y duodeno-jejunostomy.One of these LRs was done minimally invasive;seven were done in open fashion.The median diameter of the tumors was 54 mm(14-110 mm).Using the Fletcher classification scheme,3/9(33%) tumors had high risk,1/9(11%) had intermediate risk,4/9(44%) had low risk,and 1/9(11%) had very low risk for aggressive behaviour.Seven resections showed microscopically negative transsection margins(R0),two showed positive margins(R1).No patient developed local recurrence during follow-up.The one patient who underwent pancreatoduodenectomy died due to progressive disease with hepatic metastasis but without evidence of local recurrence.Another patient died in complete remission due to cardiac disease.Seven of the nine patients are alive disease-free.CONCLUSION:In patients with duodenal GIST,limited surgical resection with microscopically negative margins,but also with microscopically positive margins,lead to very good local and systemic disease-free survival. 展开更多
关键词 GASTROINTESTINAL STROMAL tumor DUODENUM Surgery limited RESECTION SURVIVAL
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PERFORMANCE ANALYSIS OF POLLING SYSTEMS WITH LIMITED SERVICE 被引量:12
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作者 Zhao Dongfeng Li Bihai Zheng Sumin(Department of Information and Electronic Science, Yunnan University, Kunming 650091) 《Journal of Electronics(China)》 1998年第1期43-49,共7页
This paper analyzes a queue mode] of the polling system with limited service (K=1) in discrete time. By the imbedded Markov chain theory and the probability generating function method, the mean values of queue length ... This paper analyzes a queue mode] of the polling system with limited service (K=1) in discrete time. By the imbedded Markov chain theory and the probability generating function method, the mean values of queue length and message waiting time are explicitly obtained. Also, we give the simulation results. The results obtained by H. Tagai (1985) are revised. 展开更多
关键词 POLLING system limited SERVICE DISCRETE TIME
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Effect of Limited Single Irrigation on Yield of Winter Wheat and Spring Maize Relay Intercropping 被引量:10
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作者 ZHANG Bu-Chong HUANG Gao-Bao LI Feng-Min 《Pedosphere》 SCIE CAS CSCD 2007年第4期529-537,共9页
A field experiment was conducted during the 2002/2003 cropping season of winter wheat (Triticum aestivum) and spring maize (Zea mays) to evaluate the effect of limited single drip irrigation on the yield and water... A field experiment was conducted during the 2002/2003 cropping season of winter wheat (Triticum aestivum) and spring maize (Zea mays) to evaluate the effect of limited single drip irrigation on the yield and water use of both crops under relay intercropping in a semi-arid area of northwestern China. A controlled 35 mm single irrigation, either early or late, was applied to each crop at a certain growth stage. Soil water, leaf area, final grain yield and yield components such as the thousand-grain weight, length of spike, fertile spikelet number, number of grains per spike, and grain weight per spike were measured, and water use efficiency and leaf area index were calculated for the irrigated and non-irrigated relay intercropping treatments and sole cropping controls. The results showed that yield, yield components, water use efficiency, and leaf area index in the relay intercropping treatments were affected by limited single drip irrigation during various growth stages of wheat and maize. The total yields in the relay intercropping treatment irrigated during the heading stage of wheat and the heading and anthesis stage of maize were the highest among all the treatments, followed by that irrigated during the anthesis stage of wheat and silking stage of maize; so was the water use efficiency. Significant differences occurred in most yield components between the irrigated and non-irrigated relay-intercropping treatments. The dynamics of the leaf area index in the relay-intercropped or solely cropped wheat and maize showed a type of single-peak pattern, whereas that of the relay intercropping treatments showed a type of double-peak pattern. Appropriately, limited single irrigation and controlled soil water content level could result in higher total yield, water use efficiency, and leaf area index, and improved yield components in relay intercropping. This practice saved the amount of water used for irrigation and also increased the yield. Therefore, heading stage of wheat and heading and anthesis stage of maize were suggested to be the optimum limited single irrigation time for relay-intercropped wheat and maize in the semi-arid area. 展开更多
关键词 leaf area index limited single irrigation water use efficiency winter wheat and spring maize relay intercropping yield and yield components
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Optimal Power Allocation with Limited Feedback of Channel State Information in Multi-User MIMO Systems 被引量:7
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作者 Kusi Ankrah Bonsu Weiwei Zhou +1 位作者 Su Pan Yan Yan 《China Communications》 SCIE CSCD 2020年第2期163-175,共13页
In this paper,an expression for the user’s achievable data rate in the multi-user multiple-input multiple-output(MU-MIMO)system with limited feedback(LF)of channel state information(CSI)is derived.The energy efficien... In this paper,an expression for the user’s achievable data rate in the multi-user multiple-input multiple-output(MU-MIMO)system with limited feedback(LF)of channel state information(CSI)is derived.The energy efficiency(EE)is optimized through power allocation under quality of service(QoS)constraints.Based on mathematical equivalence and Lagrange multiplier approach,an energy-efficient unequal power allocation(EEUPA)with LF of CSI scheme is proposed.The simulation results show that as the number of transmitting antennas increases,the EE also increases which is promising for the next generation wireless communication networks.Moreover,it can be seen that the QoS requirement has an effect on the EE of the system.Ultimately,the proposed EEUPA with LF of CSI algorithm performs better than the existing energy-efficient equal power allocation(EEEPA)with LF of CSI schemes. 展开更多
关键词 energy efficiency unequal power allocation limited feedback MU-MIMO QoSguarantee and precoding
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The height-width ratio limited value for rubber bearing isolated structure computed by uniform design method 被引量:7
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作者 王铁英 王焕定 +1 位作者 张永山 刘文光 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2007年第1期36-40,共5页
Rubber isolation is the most mature control technology in practical application, and is widely used by short rigid buildings. However, many high isolation buildings have been built around the world in recent years, wh... Rubber isolation is the most mature control technology in practical application, and is widely used by short rigid buildings. However, many high isolation buildings have been built around the world in recent years, which do not follow the existing criterions and codes. Many researchers began to research the special problems caused by larger height-width ratio isolation structures. The overturning effect of high height-width ratio structures with rubber bearing is firstly studied. Considering the main factors, such as the height-width ratio of structures, type of site, the designed basic acceleration of ground motion and the decouple factor in horizon, computing experiment is defined with the Uniform Design Method, which is also known as designing isolation structure. The forces of the bearing under edge of structures based on the position of the rubber bearing are calculated. The result indicates that the rubber bearings will lose its functionality under very high tension and compressing force of earthquake motion in horizon and vertical, when the height-width ratio is over a certain value. Thus, based on the calculation result of isolation structures defined in the uniform design method, regression analysis is conducted, and also the rubber edge force regression formula are gotten, which has higher correlation and smaller standard deviation. This formula can be used to roughly calculate whether the pull force occurs at the edge of the building. By the edge bearings of isolation structure minimum force formula, the height-width ratio limited value of the isolation structure is deducted when rubber bearing has minimum force of zero. 展开更多
关键词 isolation structures the uniform design method regression analysis height-width ratio limited value
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Exogenous application of glycine betaine improved water use efficiency in winter wheat(Triticum aestivum L.) via modulating photosynthetic efficiency and antioxidative capacity under conventional and limited irrigation conditions 被引量:3
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作者 Nazir Ahmed Yushi Zhang +3 位作者 Ke Li Yuyi Zhou Mingcai Zhang Zhaohu Li 《The Crop Journal》 SCIE CAS CSCD 2019年第5期635-650,共16页
Improving water use efficiency(WUE)is an important subject in agricultural irrigation for alleviating the scarcity of water resources in semiarid regions of the North China Plain.Moreover,glycine betaine(GB)is one of ... Improving water use efficiency(WUE)is an important subject in agricultural irrigation for alleviating the scarcity of water resources in semiarid regions of the North China Plain.Moreover,glycine betaine(GB)is one of the most effective compatible solutes synthesized naturally in plants for enhancing stress tolerance under abiotic stress,but little information is available on the involvement of GB in regulating crop WUE under field conditions.This study was conducted to explore the role of exogenously applied GB in improving WUE and plant physiological and biochemical responses inwinterwheat subjected to conventional or limited irrigation during the 2015–2016 and 2016–2017 growing seasons.Exogenous application of GB significantly enhanced antioxidant enzyme activities and reduced the accumulation ofmalondialdehyde and hydrogen peroxide under limited irrigation conditions.Furthermore,GB-treated plantsmaintained higher leaf relative water content andmembrane stability,which led to higher chlorophyll content and gas exchange attributes for better intrinsic and instantaneouswater use efficiencies compared to control plants under limited irrigation conditions.GB-treated plants had higher indole-acetic acid and zeatin riboside levels but lower ABA levels compared to control plants under conventional and limited irrigation conditions.Additionally,GB enhanced the grain filling rate and duration,grain number per spike,and final grainweight,which resulted in higher grain yield compared to the control.Interestingly,GB significantly improved the integrative and photosynthetic WUE under conventional and limited irrigation conditions,although GB treatment did not markedly affect total water consumption.These results suggest the involvement of GB in improving WUEs in winter wheat by modulating hormonal balance,membrane stability,photosynthetic performance and antioxidant systems to maintain higher grain yield under conventional and limited irrigation conditions. 展开更多
关键词 Winter wheat GLYCINE BETAINE Water use efficiency limited irrigation PHOTOSYNTHETIC performance Antioxidant systems
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