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Application of ARIMA-RTS optimal smoothing algorithm in gas well production prediction

Petroleum 2022年第2期8卷 270-277页

作者： Yonggang Duan Huan Wang Mingqiang Wei Linjiang tan Tao Yue School of Petroleum and Natural Gas Engineering Southwest Petroleum UniversityChengdu610500China School of Mechanical and Electrical Engineering Southwest Petroleum UniversityChengdu610500China

Gas field production forecast is an important basis for decision-making in the gas *** to accurately predict the dynamic production during gas field development is an important content of reservoir engineering *** numerical simulation is the most common method for predicting oil and gas ***,it requires a lot of data to build an accurate geological model which is tedious and *** present,many scholars have used machine learning and data mining methods to predict oil and gas production,but they have not considered whether the use of increasing production measures will affect the predicted ***,ARIMA-RTS optimal smooth algorithm is the first applied to establish the prediction model of gas well *** to the historical production data,the model is processed,the production differential autoregressive integral moving average(ARIMA)model in time series is established,then ARIMA model is combined with RTS(Rauch Tung Striebel)smoothing,and the production prediction model is *** smoothing algorithm is an enhanced version of Kalman *** measurements are firstly processed by the forward filter,and then,a separate backward smoothing pass is used for obtaining the smoothing *** correctness of ARIMA-RTS model was verified with the actual production *** results show that the prediction based on ARIMA-RTS model can accurately reflect the production performance of gas *** method can effectively reduce the error caused by stimulation when *** using the ARIMA-RTS model and the ARIMA-Kalman model to predict the production of the same gas well,the prediction accuracy of ARIMA-RTS model is higher than that of ARIMA-Kalman model in production wells with *** with that of the ARIMA-Kalman model,the mean relative error fitted by the ARIMA-RTS model is reduced by 46.3%,and the relative mean square error is reduced by 56.48%.ARIMA-RTS optimal smooth algor

关键词： Production forecasting ARIMA RTS Kalman filter

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Experimental research on charging characteristics of a pressure-controlled VRLA battery in high-temperature environments

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第3期10卷 418-422页

作者： Hua ZHU Jin-jun tan Zhang-lu XU Ji-sen XU Institute of Thermal Science and Power Systems Zhejiang University Hangzhou 310027 China

Valve-regulated-lead-acid (VRLA) battery charging performed in high-temperature environments is extremely risky under overcharge conditions, and may lead to a subsequent thermal runaway. A new pressure-controlled charging method was adopted and the charging characteristics of the pressure-controlled VRLA battery in high-temperature environments were ex-perimentally studied. The concept was tested in a large temperature gradient to obtain more details about the effects of users' accustomed charging and discharging modes on battery capacity. The premature capacity loss (PCL) phenomenon under high temperature exposure was analyzed. The results showed that the capacity loss could be recovered by charging using a large current.

关键词： Valve-regulated-lead-acid (VRLA) battery Pressure-controlled charging method High-temperature environments Charging and discharging characteristics

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CHINA＇S OUTBOUND MERGERS AND ACQUISITIONS IN THE U.S.

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Frontiers of Law in China-Selected Publications from Chinese Universities 2014年第3期9卷 464-489页

作者： sheng Chen ZHANG Li 1. University of Illinois College of Law Champaign Illinois U.S.2. Lu Chau Law Firm LLP Anyang Henan China

Although scholars have long studied the acquisition by American firms of Chinese firms in China, surprisingly little research has been undertaken about Chinese firms acquiring American firms in the U.S. The significance of Chinese outbound M＆A deals in the U.S. lies in its demonstration that no all-encompassing, reductive theory can apply to all M＆A deals. This is because in each M＆A deal considerations vary widely, and these variations are the result of different acquiring firms, target firms, and jurisdictions. China＇s outbound M＆A deals in the U.S. illustrate this point well for two reasons. Firstly, most cross-border M＆A activities involve acquiring firms from developed markets and target firms from emerging markets,＂ by contrast, Chinese M＆A activities in the U.S. exemplify emerging-market firms intending to acquire firms in a developed market. Secondly, and more importantly, while the objective among American firms in acquiring Chinese firms is acquiring market share for the most part, the goals of Chinese firms, by contrast, revolve around the more advanced technology and better management offered by American firms. Because China＇s outbound M＆A activities in the U.S. is a relatively new phenomenon, this article covers some important issues in this generally untapped area based on limited cases, data, and scholarly articles that are available.

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Isolating Host Environment by Booting Android from OTG Devices

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Chinese Journal of Electronics 2018年第3期27卷 617-624页

作者： XUE Yuan ZHANG Xiaosong YU Xiao ZHANG Yaoyuan tan Yu'an LI Yuanzhang School of Computer Science and Technology Beijing Institute of Technology Department of Computer Science and Technology Tangshan University Research Center of Massive Language Information Processing and Cloud Computing Application

With the integration of smartphone into daily life, end users store a large amount of sensitive information into Android device. For protecting the sensitive information, a method of multi-booting Android OS from On-The-Go(OTG) device is proposed to meet the requirements of end users in different scenarios. The proposed method utilizes system domain isolation to guarantee the security of sensitive information on different Android *** difference with other solutions is that our proposed solution does not add additional components to Android OS,which makes the overhead of Android runtime has been effectively controlled. A prototype of the proposed method is implemented and deployed into the real android device to evaluate the effectiveness, the efficiency and the performance overhead. The experiment results show that the performance overhead is reasonable and our method can effectively mitigate the risk of sensitive information leakage when booting different Android instance in the same Android device.

关键词： Android security Privacy protection System domain isolation Multi-booting

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Two-stage acceleration of interstellar ions driven by high-energy lepton plasma flows

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Science China(Physics,Mechanics & Astronomy) 2015年第10期58卷 76-80页

作者： CUI YunQian sheng ZhengMing LU QuanMing LI YuTong ZHANG Jie Beijing National Laboratory of Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Scottish Universities Physics Alliance Department of Physics University of Strathclyde Key Laboratory for Laser Plasmas (Mo E) and Department of Physics and Astronomy Shanghai Jiao Tong University IFSA Collaborative Innovation Center Shanghai Jiao Tong University School of Earth and Space Sciences University of Science and Technology of China

We present the particle-in-cell(PIC) simulation results of the interaction of a high-energy lepton plasma flow with background electron-proton plasma and focus on the acceleration processes of the protons. It is found that the acceleration follows a two-stage process. In the first stage, protons are significantly accelerated transversely(perpendicular to the lepton flow) by the turbulent magnetic field "islands" generated via the strong Weibel-type instabilities. The accelerated protons shows a perfect inverse-power energy spectrum. As the interaction continues, a shockwave structure forms and the protons in front of the shockwave are reflected at twice of the shock speed, resulting in a quasi-monoenergetic peak located near 200 Me V under the simulation parameters. The presented scenario of ion acceleration may be relevant to cosmic-ray generation in some astrophysical environments.

关键词： particle acceleration Fermi acceleration collisionless shock lepton plasma flow

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Ultrathin and Flexible CNTs/MXene/Cellulose Nanofibrils Composite Paper for Electromagnetic Interference Shielding

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Nano-Micro Letters 2019年第4期11卷 276-292页

作者： Wentao Cao Chang Ma Shuo tan Mingguo Ma Pengbo Wan Feng Chen Department of Orthopedics Shanghai Tenth People’s HospitalTongji University School of MedicineShanghai 200072People’s Republic of China Engineering Research Center of Forestry Biomass Materials and Bioenergy Beijing Key Laboratory of Lignocellulosic ChemistryCollege of Materials Science and TechnologyBeijing Forestry UniversityBeijing 100083People’s Republic of China Center of Advanced Elastomer Materials State Key Laboratory of Organic-Inorganic CompositesBeijing University of Chemical TechnologyBeijing 100029People’s Republic of China

As the rapid development of portable and wearable devices,different electromagnetic interference(EMI)shielding materials with high efficiency have been desired to eliminate the resulting radiation ***,limited EMI shielding materials are successfully used in practical applications,due to the heavy thickness and absence of sufficient strength or ***,an ultrathin and flexible carbon nanotubes/MXene/cellulose nanofibrils composite paper with gradient and sandwich structure is constructed for EMI shielding application via a facile alternating vacuum-assisted filtration *** composite paper exhibits outstanding mechanical properties with a tensile strength of 97.9±5.0 MPa and a fracture strain of 4.6±0.2%.Particularly,the paper shows a high electrical conductivity of 2506.6 S m?1 and EMI shielding effectiveness(EMI SE)of 38.4 dB due to the sandwich structure in improving EMI SE,and the gradient structure on regulating the contributions from reflection and *** strategy is of great significance in fabricating ultrathin and flexible composite paper for highly efficient EMI shielding performance and in broadening the practical applications of MXene-based composite materials.

关键词： MXene Carbon nanotubes Cellulose nanofibrils Mechanical property Electromagnetic interference shielding

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Objective Omega vortex identification method

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Journal of Hydrodynamics 2019年第3期31卷 455-463页

作者： Jian-ming Liu Yi-sheng Gao Yi-qian Wang Chaoqun Liu School of Mathematics and Statistics Jiangsu Normal University Xuzhou 221116 China Department of Mathematics University of Texas at Arlington Arlington 76019 Texas USA School of Aerospace Engineering Tsinghua University Beijing 100084 China

A new vortex identification method (Liu et al. 2016) was proposed to represent the rotation relative strength and capture and visualize the vortices in our previous study. The basic idea of the Ω method is that a ratio of the vorticity squared over the summation of the vorticity squared and the deformation squared should be used to measure the relative rotation strength. However, the vorticity tensor norm is not objective. Thus, a moving observer will observe different vortex structures in a moving reference frame, which will make confusions about the real vortex structures. In the present study, by the definitions of the net spin tensor and the net vorticity vector, an objective Ω vortex identification method is presented with examples to verify that the vortex structures retain in a moving reference frame.

关键词： Vortex identification the Ω method objectivity turbulence visualization turbulence

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Towards designing high mechanical performance low-alloyed wrought magnesium alloys via grain boundary segregation strategy:A review

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Journal of Magnesium and Alloys 2024年第5期12卷 1774-1791页

作者： Zhi Zhang Jinshu Xie Jinghuai Zhang Xu-sheng Yang Ruizhi Wu Key Laboratory of Superlight Material and Surface Technology Ministry of EducationCollege of Materials Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001China State Key Laboratory of Ultra-Precision Machining Technology Department of Industrial and Systems EngineeringThe Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina Hong Kong Polytechnic University Shenzhen Research Institute Shenzhen 518060China

Low-alloyed magnesium(Mg)alloys have emerged as one of the most promising candidates for lightweight ***,their further application potential has been hampered by limitations such as low strength,poor plasticity at room temperature,and unsatisfactory *** address these challenges,grain refinement and grain structure control have been identified as crucial factors to achieving high performance in low-alloyed Mg *** effective way for regulating grain structure is through grain boundary(GB)*** review presents a comprehensive summary of the distribution criteria of segregated atoms and the effects of solute segregation on grain size and growth in Mg *** analysis encompasses both single element segregation and multi-element co-segregation behavior,considering coherent interfaces and incoherent ***,we introduce the high mechanical performance low-alloyed wrought Mg alloys that utilize GB segregation and analyze the potential impact mechanisms through which GB segregation influences materials *** upon these studies,we propose strategies for the design of high mechanical performance Mg alloys with desirable properties,including high strength,excellent ductility,and good formability,achieved through the implementation of GB *** findings of this review contribute to advancing the understanding of grain boundary engineering in Mg alloys and provide valuable insights for future alloy design and optimization.

关键词： Magnesium alloys Grain boundary segregation High strength High plasticity High formability

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Projected heat wave increasing trends over China based on combined dynamical and multiple statistical downscaling methods

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Advances in Climate Change Research 2023年第5期14卷 758-767页

作者： Ming ZHANG Zhong-Yang GUO Guang-Tao DONG Jian-Guo tan Key Laboratory of Geographic Information Science(Ministry of Education) East China Normal UniversityShanghai 200241China School of Geographic Sciences East China Normal UniversityShanghai 200241China Key Laboratory of Spatial-Temporal Big Data Analysis and Application of Natural Resources in Megacities Ministry of Natural Resources of ChinaShanghai 200241China Shanghai Climate Center Shanghai 200030China Key Laboratory of Cities'Mitigation and Adaptation to Climate Change in Shanghai China Meteorological AdministrationShanghai 200030China Shanghai Meteorological IT Support Center Shanghai 200030China China Meteorological Administration Urban Meteorology Key Laboratory Beijing 100089China

Extensive investigations on the projection of heat waves(HWs)were conducted on the basis of coarse-resolution global climate models(GCMs).However,these investigations still fail to characterise the future changes in HWs regionally over *** dynamical downscaling with a horizontal resolution of 25 km×25 km was employed on the basis of GCM-HadCM3 to provide reliable projections on HWs over the Chinese mainland,and six statistical downscaling methods were used for bias correction under RCP4.5 and RCP8.5 *** multi-method ensemble(MME)of the top three dynamical downscaling methods with good performance was used to project future *** showed that PRECIS primarily replicated the detailed spatiotemporal pattern of ***,PRECIS overestimated the HWs in the Northwest and Southeast and expanded the areas of HWs in the Northeast and *** statistical downscaling methods(quantile mapping,CDF-t and quantile delta mapping)demonstrated good performance in improving PRECIS simulation for reproducing *** contrast,parametric-based trend-preserving approaches such as scaled distribution mapping and ISI-MIP are outperformed by the three aforementioned methods in downscaling HWs,particularly in the high latitudes of *** on MME projections,at the end of the 21st century,the national average of the number of HW days each year,the length of the longest HW event in the year and the extreme maximum temperature in HW will increase by 3 times,1 time and 1.3℃,respectively,under the RCP4.5 scenario,whilst that under the RCP8.5 scenario will increase by 8 times,3 times and 3.7℃,respectively,relative to *** Northwest is regionally projected to suffer long and hot HWs,whilst the South and Southeast will experience frequent consecutive ***,HWs projected by the combined dynamical and statistical downscaling method are highly reliable in projecting HWs over China.

关键词： Dynamical downscaling Statistical downscaling Heat waves Climate change

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Pharmacotherapy for the core symptoms of autism spectrum disorder

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2024年第11期25卷 956-971页

作者： Peiying tan Xiaolin SHEN Lizhang ZENG Xuchu WENG Hongyan GENG Key Laboratory of Brain Cognition and Education SciencesMinistry of EducationSouth China Normal UniversityGuangzhou510631China Institute for Brain Research and Rehabilitation and Guangdong Key Laboratory of Mental Health and Cognitive ScienceSouth China Normal UniversityGuangzhou510631China

Autism spectrum disorder(ASD)is a range of neurodevelopmental diseases characterized by social dysfunction and stereotypic *** etiology of ASD remains largely unexplored,resulting in a diverse array of described clinical manifestations and varying degrees of ***,there are no drugs approved by a supervisory organization that can effectively treat the core symptoms of *** and adolescence are crucial stages for making significant achievements in ASD treatment,necessitating the development of drugs specifically for these *** on the drug targets and mechanisms of action,it can be found that atypical psychotropic medications,anti-inflammatory and antioxidant medications,hormonal medications,ion channel medications,and gastrointestinal medications have shown significant improvement in treating the core symptoms of ASD in both children and *** addition,comparisons of drugs within the same category regarding efficacy and safety have been made to identify better alternatives and promote drug *** further evaluation of the effectiveness and safety of these medications is needed,they hold great potential for widespread application in the clinical treatment of the principal symptoms of ASD.

关键词： Autism spectrum disorder(ASD) Core symptom Pharmacotherapy Repetitive behaviors Social dysfunction

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