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Strategyproof Facility Location with Limited Locations

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Journal of the Operations Research Society of China 2023年第3期11卷 553-567页

作者： Zhong-Zheng Tang chen-hao wang Meng-Qi Zhang Ying-Chao Zhao School of Science Beijing University of Posts and TelecommunicationsBeijing100876China Advanced Institute of Natural Sciences Beijing Normal UniversityZhuhai519087GuangdongChina BNU-HKBU United International College Zhuhai519087GuangdongChina Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China Caritas Institute of Higher Education Hong Kong999077China

We study the mechanism design of facility location *** problem is to design mechanisms to select a set of locations on which to build a set of facilities,aiming to optimize some system objective and achieve desirable properties based on the strategic agents'*** agents might have incentives to misreport their private locations,in order to minimize the costs(i.e.,the distance from the closest facility).We study the setting with limited locations,that is,the facilities can only be built on a given finite set of candidate locations,rather than the whole *** locating a single facility and two facilities on a real line,we propose strategyproof mechanisms with tight approximation ratios,under the objectives of minimizing the total cost and the maximum ***,we consider the problem of locating an obnoxious facility from which the agents want to stay as far away as possible,and derive tight bounds on the approximation ratio of strategyproof mechanisms.

关键词： Mechanism design Facility location Social choice

Evolutionary-assisted reinforcement learning for reservoir real-time production optimization under uncertainty

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Petroleum Science 2023年第1期20卷 261-276页

作者： Zhong-Zheng wang Kai Zhang Guo-Dong chen Jin-Ding Zhang Wen-Dong wang hao-chen wang Li-Ming Zhang Xia Yan Jun Yao School of Petroleum Engineering China University of PetroleumQingdao266580ShandongChina Qingdao University of Technology Qingdao266520ShandongChina The University of Hong Kong 999077Hong KongChina

Production optimization has gained increasing attention from the smart oilfield community because it can increase economic benefits and oil recovery *** existing methods could produce high-optimality results,they cannot be applied to real-time optimization for large-scale reservoirs due to high computational *** addition,most methods generally assume that the reservoir model is deterministic and ignore the uncertainty of the subsurface environment,making the obtained scheme unreliable for practical *** this work,an efficient and robust method,namely evolutionaryassisted reinforcement learning(EARL),is proposed to achieve real-time production optimization under ***,the production optimization problem is modeled as a Markov decision process in which a reinforcement learning agent interacts with the reservoir simulator to train a control policy that maximizes the specified *** deal with the problems of brittle convergence properties and lack of efficient exploration strategies of reinforcement learning approaches,a population-based evolutionary algorithm is introduced to assist the training of agents,which provides diverse exploration experiences and promotes stability and robustness due to its inherent *** with prior methods that only optimize a solution for a particular scenario,the proposed approach trains a policy that can adapt to uncertain environments and make real-time decisions to cope with unknown *** trained policy,represented by a deep convolutional neural network,can adaptively adjust the well controls based on different reservoir *** results on two reservoir models show that the proposed approach not only outperforms the RL and EA methods in terms of optimization efficiency but also has strong robustness and real-time decision capacity.

关键词： Production optimization Deep reinforcement learning Evolutionary algorithm Real-time optimization Optimization under uncertainty

Better use of experience from other reservoirs for accurate production forecasting by learn-to-learn method

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Petroleum Science 2024年第1期21卷 716-728页

作者： hao-chen wang Kai Zhang Nancy chen Wen-Sheng Zhou chen Liu Ji-Fu wang Li-Ming Zhang Zhi-Gang Yu Shi-Ti Cui Mei-Chun Yang China University of Petroleum(East China) 66 Changjiang West RoadQingdao West Coast New AreaQingdao266580ShandongChina University of Calgary 2500 University Dr NWCalgaryT2N 1N4AlbertaCanada Qingdao University of Technology Qingdao266071ShandongChina State Key Laboratory of Offshore Oil Exploitation Beijing100028China CNOOC Research Institute Ltd. Beijing100028China CNPC Tarim Oilfield Branch Company Korla841000XinjiangChina National Engineering Laboratory for Exploration and Development of Low-Permeability Oil and Gas Fields Xi'an710000ShaanxiChina Sinopec Matrix Co. LTDQingdao266000ShandongChina

To assess whether a development strategy will be profitable enough,production forecasting is a crucial and difficult step in the *** development history of other reservoirs in the same class tends to be studied to make predictions ***,the permeability field,well patterns,and development regime must all be similar for two reservoirs to be considered in the same *** results in very few available experiences from other reservoirs even though there is a lot of historical information on numerous reservoirs because it is difficult to find such similar *** paper proposes a learn-to-learn method,which can better utilize a vast amount of historical data from various ***,the proposed method first learns how to learn samples before directly learning rules in ***,by utilizing gradients from networks with independent parameters and copied structure in each class of reservoirs,the proposed network obtains the optimal shared initial parameters which are regarded as transferable information across different *** on that,the network is able to predict future production indices for the target reservoir by only training with very limited samples collected from reservoirs in the same *** cases further demonstrate its superiority in accuracy to other widely-used network methods.

关键词： Production forecasting Multiple patterns Few-shot learning Transfer learning

Solitary necrotic nodules of the liver with"ring"-like calcification:A case report

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World Journal of Clinical Cases 2022年第21期10卷 7409-7414页

作者： Jin-Peng Bao Hu Tian hao-chen wang Cong-Cong wang Bo Li Department of General Surgery The First Affiliated Hospital of Shandong First Medical University&Shandong Provincial Qianfoshan HospitalJinan 250014Shandong ProvinceChina Department of Gastroenterology Shandong First Medical UniversityJinan 250024Shandong ProvinceChina Department of General Surgery Shandong Provincial Qianfoshan HospitalShandong UniversityJinan 250100Shandong ProvinceChina

BACKGROUND Solitary necrotic nodule of the liver(SNNL)is a rare benign lesion with a complete necrotic core and a clear fibrous capsule containing elastic *** present the case of a patient with a radiographic computed tomography(CT)finding of"ring"-like annular calcification within the lesion and postoperative pathologic diagnosis of necrotic nodules wrapped by dense fibers in liver tissue,as well as the patient's subsequent management and *** SUMMARY A 38-year-old Chinese woman with a history of systemic lupus erythematosus treated with prednisone and hydroxychloroquine,without any symptoms,was found to have hepatic space-occupying lesions by imaging examination at a health examination.A subsequent CT scan suggested a space-occupying lesion of the liver with annular calcification,which was not defined to be benign or *** that,a laparoscopic hepatic space-occupying resection was *** postoperative pathological diagnosis was necrotic nodules wrapped by dense fibers in the liver tissue,and the final diagnosis was *** patient had an uneventful postoperative *** There is a"ring"-like calcification in *** patient had a history of systemic lupus erythematosus,without a history of parasite infection,trauma,or ***,whether the etiology and pathological changes of SNNL are related to rheumatic immune diseases remains to be investigated.

关键词： Solitary necrotic nodules of the liver Annular calcification Rheumatic immune disease Laparoscopic hepatic space-occupying resection Case report

Unexpected delayed reversal of rocuronium-induced neuromuscular blockade by sugammadex:A case report and review of literature

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World Journal of Clinical Cases 2022年第35期10卷 13138-13145页

作者： hao-chen wang cheng-Wei Lu Tzu-Yu Lin Ya-Ying Chang Department of Anesthesiology Far-Eastern Memorial HospitalNew Taipei City 220Taiwan Department of Mechanical Engineering Yuan Ze UniversityChung-Li 320Taiwan International Program in Engineering for Bachelor Yuan Ze UniversityChung-Li 320Taiwan

BACKGROUND Rocuronium,a nondepolarizing muscle relaxant,is usually administered during general anesthesia to facilitate endotracheal intubation and keep patients immobile during the ***,the selective reversal agent of rocuronium,fully reverses the neuromuscular blockade(NMB)at the end of *** reports show that sugammadex rapidly achieves a ratio of train-offour(TOF),a quantitative method of neuromuscular monitoring,of 0.9 which ensures adequate recovery for safe ***,very rare patients with neuromuscular diseases may respond poorly to *** SUMMARY A 69-year-old female presented with abdominal fullness and nausea,and was diagnosed with *** underwent gastric peroral endoscopic myotomy under general anesthesia with rocuronium(0.7 mg/kg).At the end of surgery,sugammadex 3.6 mg/kg was administered when TOF showed 2 ***,the TOF ratio recovered to 0.65 in 30 *** was awake but could not fully open her *** tidal volume during spontaneous breathing was *** additional doses of sugammadex(up to 7.3 mg/kg)in the following 3 h,the TOF ratio was 0.9,and the endotracheal tube was smoothly *** excluding possible mechanisms underlying the prolonged recovery course,we speculated our patient may have had an undiagnosed neuromuscular disease,hinted by her involuntary movement of the tongue and ***,her poor renal function and history of delayed recovery from general anesthesia may be related to the long duration of *** In our case,both prolonged rocuronium-induced NMB and poor response to sugammadex were *** optimize the dose of rocuronium,perioperative TOF combined with other neuromuscular monitoring is suggested.

关键词： Sugammadex Train-of-four Rocuronium Neuromuscular blockade General anesthesia Case report

Application of interface material and effects of oxygen gradient on the performance of single-chamber sediment microbial fuel cells(SSMFCs)

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Journal of Environmental Sciences 2019年第1期31卷 163-168页

作者： Chin-Tsan wang Thangavel Sangeetha Wei-Mon Yan Wen-Tong Chong Lip-Huat Saw Feng Zhao Chung-Ta Chang chen-hao wang Department of Mechanical and Electro-Mechanical Engineering National I-Lan University Department of Energy and Refrigerating Air-Conditioning Engineering National Taipei University of Technology Department of Mechanical Engineering University of Malaya Jalan Universiti Lee Kong Chian Faculty of Engineering and Science UTAR CAS Key Laboratory of Urban Pollutant Conversion Institute of Urban Environment Chinese Academy of Science Institute of Materials Science and Engineering National Taiwan University of Science and Technology

Single-chamber sediment microbial fuel cells(SSMFCs) have received considerable attention nowadays because of their unique dual-functionality of power generation and enhancement of wastewater treatment performance. Thus, scaling up or upgrading SSMFCs for enhanced and efficient performance is a highly crucial task. Therefore, in order to achieve this goal, an innovative physical technique of using interface layers with four different pore sizes embedded in the middle of SSMFCs was utilized in this *** results showed that the performance of SSMFCs employing an interface layer was improved regardless of the pore size of the interface material, compared to those without such layers. The use of an interface layer resulted in a positive and significant effect on the performance of SSMFCs because of the effective prevention of oxygen diffusion from the cathode to the anode. Nevertheless, when a smaller pore size interface was utilized, better power performance and COD degradation were observed. A maximum power density of 0.032 mW/m^2 and COD degradation of 47.3% were obtained in the case of an interface pore size of 0.28 μm. The findings in this study are of significance to promote the future practical application of SSMFCs in wastewater treatment plants.

关键词： Single sediment microbial fuel cells Interface layer Dissolved oxygen Pore size Oxygen diffusion Diffusion coefficient

Competition between Stepwise Polarization Switching and Chirality Coupling in Ferroelectric GeS Nanotubes

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Chinese Physics Letters 2023年第4期40卷 80-84页

作者：王浩臣王智灏陈宣言魏苏淮朱文光张燮 School of Physical Sciences University of Science and Technology of ChinaHefei 230026China Beijing Computational Science Research Center Beijing 100193China

Ferroelectricity of group-Ⅳ chalcogenides MX(M = Ge,Sn;X = Se,S) monolayers has been extensively ***,how the ferroelectricity evolves in their one-dimensional nanotubes remains largely *** an accurate deep-learning interatomic potential of first-principles precision,we uncover a general stepwise mechanism for polarization switching in zigzag and chiral Ge S nanotubes,which has an energy barrier that is substantially lower than the one associated with the conventional one-step switching *** switching barrier(per atom) gradually decreases with increasing the number of intermediate steps and converges to a value that is almost independent of the tube *** the chiral Ge S nanotubes,the switching path of polarization with chirality coupling is preferred at less intermediate *** study unveils novel ferroelectric switching behaviors in one-dimensional nanotubes,which is critical to coupling ferroelectricity and chirality.

关键词： ferroelectric steps coupling

Fractionation of Heavy Metals in Soils as Affected by Soil Types and Metal Load Quantity

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Pedosphere 2002年第4期12卷 309-319页

作者： ZHOU DONGMEI, chen HUAIMAN, hao XIUZHEN and wang YUJUNInstitute of Soil Science, the Chinese Academy of Sciences, Nanjing 210008 (China) Institute of Soil Science the Chinese Academy of Sciences Nanjing 210008

Two series of soil subsamples, by spiking copper (Cu), lead (Pb), zinc (Zn) and cadmium (Cd) in an orthogonal design, were prepared using red soil and brown soil, respectively. The results indicated that heavy metal fractions in these soil subsamples depended not only on soil types, but also on metal loading quantity as well as on interactions among metals in soil. Lead and Cu in red soil appeared mostly in weakly specifically adsorbed (WSA), Fe and Mn oxides bound (OX), and residual (RES) fractions. Zinc existed in all fractions except organic bound one, and Cd was major in water soluble plus exchangeable (SE) one. Different from the results of red soil, Pb and Cu was present in brown soil in all fractions except organic one, but over 75% of Zn and 90% of Cd existed only in SE fraction. Meanwhile, SE fraction for any metal in red soil was lower than that in brown soil and WSA and OX fractions were higher. It is in agreement with low cation exchange capacity and large amounts of metal oxides included in red soil. Metal fractions in soil, especially for water soluble plus exchangeable one, were obviously influenced by other coexisting metals. The SE fraction of heavy metals increased with increasing loading amounts of metals in red soil but not obviously in brown soil, which suggest that metal availability be easily affected by their total amounts spiked in red soil. In addition, more metals in red soil were extracted with 0.20 mol L-1 NH4Cl (pH 5.40) than that with 1.0 mol L-1 Mg(NO3)2 (pH 7.0), but the reverse happened in brown soil, implicating significantly different mechanisms of metal desorption from red soil and brown soil.

关键词： fraction heavy metal interaction ionic impulsion soil

Role of iron ore in enhancing gasification of iron coke:Structural evolution,influence mechanism and kinetic analysis

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 58-69页

作者： Jie wang Wei wang Xuheng chen Junfang Bao Qiuyue hao Heng Zheng Runsheng Xu School of Chemistry and Materials Science Hubei Engineering UniversityXiaogan 432000China Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081China Institue of Ironmaking Technology Baosteel Central Research InstituteShanghai 201999China State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

The utilization of iron coke provides a green pathway for low-carbon *** uncover the influence mechanism of iron ore on the behavior and kinetics of iron coke gasification,the effect of iron ore on the microstructure of iron coke was ***,a comparative study of the gasification reactions between iron coke and coke was conducted through non-isothermal thermogravimetric *** findings indicate that compared to coke,iron coke exhibits an augmentation in micropores and specific surface area,and the micropores further extend and *** provides more adsorption sites for CO_(2) molecules during the gasification process,resulting in a reduction in the initial gasification temperature of iron *** the heating rate in non-isothermal gasification can enhance the reactivity of iron *** metallic iron reduced from iron ore is embedded in the carbon matrix,reducing the orderliness of the carbon structure,which is primarily responsible for the heightened reactivity of the carbon *** kinetic study indicates that the random pore model can effectively represent the gasification process of iron coke due to its rich pore ***,as the proportion of iron ore increases,the activation energy for the carbon gasification gradually decreases,from 246.2 kJ/mol for coke to 192.5 kJ/mol for iron coke 15wt%.

关键词： low-carbon ironmaking iron coke gasification structural evolution kinetic model