Task offloading mechanism based on federated reinforcement learning in mobile edge computing

With the arrival of 5G,latency-sensitive applications are becoming increasingly diverse.Mobile Edge Computing(MEC)technology has the characteristics of high bandwidth,low latency and low energy consumption,and has attracted much attention among researchers.To improve the Quality of Service(QoS),this study focuses on computation offloading in MEC.We consider the QoS from the perspective of computational cost,dimensional disaster,user privacy and catastrophic forgetting of new users.The QoS model is established based on the delay and energy consumption and is based on DDQN and a Federated Learning(FL)adaptive task offloading algorithm in MEC.The proposed algorithm combines the QoS model and deep reinforcement learning algorithm to obtain an optimal offloading policy according to the local link and node state information in the channel coherence time to address the problem of time-varying transmission channels and reduce the computing energy consumption and task processing delay.To solve the problems of privacy and catastrophic forgetting,we use FL to make distributed use of multiple users’data to obtain the decision model,protect data privacy and improve the model universality.In the process of FL iteration,the communication delay of individual devices is too large,which affects the overall delay cost.Therefore,we adopt a communication delay optimization algorithm based on the unary outlier detection mechanism to reduce the communication delay of FL.The simulation results indicate that compared with existing schemes,the proposed method significantly reduces the computation cost on a device and improves the QoS when handling complex tasks.

Progress and prospects of innovative coal-fired power plants within the energy internet

The development of electrical engineering and electronic, communications, smart power grid, and ultra-high voltage transmission technologies have driven the energy system revolution to the next generation: the energy internet. Progressive penetration of intermittent renewable energy sources into the energy system has led to unprecedented challenges to the currently wide use of coal-fired power generation technologies. Here, the applications and prospects of advanced coal-fired power generation technologies are analyzed. These technologies can be summarized into three categories:(1) large-scale and higher parameters coal-fired power generation technologies, including 620/650/700 oC ultra-supercritical thermal power and double reheat ultra-supercritical coal-fired power generation technologies;(2) system innovation and specific, highefficiency thermal cycles, which consist of renewable energy-aided coal-fired power generation technologies, a supercritical CO_2 Brayton cycle for coal-fired power plants, large-scale air-cooling coal-fired power plant technologies, and innovative layouts for waste heat utilization and enhanced energy cascade utilization;(3) coal-fired power generation combined with poly-generation technologies, which are represented by integrated gasification combined cycle(IGCC) and integrated gasification fuel cell(IGFC) technologies. Concerning the existing coal-fired power units, which are responsible for peak shaving, possible strategies for enhancing flexibility and operational stability are discussed. Furthermore, future trends for coal-fired power plants coupled with cyber-physical system(CPS) technologies are introduced. The development of advanced, coal-fired power generation technologies demonstrates the progress of science and is suitable for the sustainable development of human society.

Energy hub-based optimal planning for integrated energy systems considering part-load characteristics and synergistic effect of equipment

Integrated energy systems(lESs)represent a promising energy supply model within the energy internet.However,multi-energy flow coupling in the optimal configuration of IES results in a series of simplifications in the preliminary planning,affecting the cost,efficiency,and environmental performance of IES.A novel optimal planning method that considers the part-load characteristics and spatio-temporal synergistic effects of IES components is proposed to enable a rational design of the structure and size of IES.An extended energy hub model is introduced based on the“node of energy hub”concept by decomposing the IES into different types of energy equipment.Subsequently,a planning method is applied as a two-level optimization framework-the upper level is used to identify the type and size of the component,while the bottom level is used to optimize the operation strategy based on a typical day analysis method.The planning problem is solved using a two-stage evolutionary algorithm,combing the multiple-mutations adaptive genetic algorithm with an interior point optimization solver,to minimize the lifetime cost of the IES.Finally,the feasibility of the proposed planning method is demonstrated using a case study.The life cycle costs of the IES with and without consideration of the part-load characteristics of the components were$4.26 million and$4.15 million,respectively,in the case study.Moreover,ignoring the variation in component characteristics in the design stage resulted in an additional 11.57%expenditure due to an energy efficiency reduction under the off-design conditions.

Performance Analysis of Induced Draft Fan Driven by Steam Turbine for 1000 MW Power Units

Boiler fan is the main power consumption device in thermal power units and the induced draft fan accounted for the largest proportion. Reducing the energy consumption rate of induced draft fan is the main path to reduce the power consumption rate of thermal power units. The induce fan driven by small turbine is greatly effective for reducing the power consumption rate and the supply coal consumption rate in large thermal power plant. Take 1000 MW power units for example, the selection of steam source for steam turbine were discussed and economic performance of the unit under different steam source was compared in this paper. The result shows that compared with the motor driven method, there is about 1.6 g/kWh decrease in supply coal consumption rate driven by the fourth stage extraction steam;whereas there is about 2.5 g/kWh decrease in supply coal consumption rate driven by the fifth stage extraction steam.

Development and application of knowledge-based subject group integration platforms:A case study of Shanghai Institute of Ceramics,CAS

Purpose:According to the different requirements of research group users,we established the knowledge-based subject group integration platforms of Shanghai Institute of Ceramics,the Chinese Academy of Sciences(abbreviated as SIC CAS hereinafter),which were designed and constructed to better meet the needs of CAS research groups for their development,collaboration and communication.Design/methodology/approach:We first identified the requirements of users via preliminary investigation,and then chose CASI1 P,iLibrary and XKE technology,respectively as the building tools compatible with the major demands of users.These steps helped us complete the layout design of SIC CAS integration platforms,as well as its knowledge organization and integration.Findings:According to the need of users,we applied three types of platform construction technologies to five SIC integration platforms,and formulated standard norms for the further construction process,which could provide useful reference for a sustainable development for the extensive construction in CAS institutes.Research limitations:In order to make the SIC integration platforms more intelligent and have more functions,we need to enlarge the scale of the Platforms and upgrade the building tools for the platform construction.Practical implications:The nature of SIC sub-project integration platforms is to construct a content-sensitive environment which can embed knowledge services and knowledge applications seamlessly into scientific activities,so the Platform is expected to be a useful tool to help researchers better understand the recent development of the research field and form collaborations with their peers.Originality/value:SIC integration platforms are the only pilot construction that used 3different platform technologies in the first batch of knowledge-based subject group integration platforms of the Chinese Academy of Sciences.The construction is user-centered throughout the whole process,namely,from the technology selection,content construction to the sustainable development of the platforms,which are all based on user requirements.During this process,we have not only established sustainable mechanisms for both the personalized feedback and security management of the institutional knowledge of SIC CAS,but also formed a service team for the sustainable development of SIC integration platforms.

骨巨细胞瘤软组织内复发两例报道及文献复习(英文)

We investigated the clinical features of soft-tissue recurrence in giant cell tumor of bone (GCTB). Among 106 cases with GCTB in our hospital, there were 2 cases occurring soft-tissue recurrence which histories were reported. These two soft-tissue recurrences occurred with the interval of 6.9 years and 2.5 years respectively from primary diagnosis. The clinical presentation was nonspecific masses in soft tissue. Radiographic ossification was not found at periphery or within the masses. Through pathological examination peripheral ossification was found in 1 case and malignant transformation occurred in the other case. Through retrieving and reviewing literatures in PubMed, 19 cases of soft-tissue recurrence with detailed materials were collected and analyzed. Soft-tissue recurrence of GCTB is a rare episode which reflects its locally aggressive nature, the reasons of which are tumor cells implantation and tumor residual. Ossification at periphery or in the masses can be considered as a pathognomonic character of this episode in radiographic and pathohistological examination. The prevention lies in determining tumor extension preoperatively, proper non-tumor manipulations, removing the tumor and irrigating operative wound as completely as possible.

Energy Planning of Beijing Towards Low-carbon,Clean and Efficient Development in 2035

Energy transition towards clean,efficient energy supply has been a common sense of the government and public in China.However,lacking reasonable planning will lead to undisciplined development,resource waste,and excessive investment.In this context,this paper investigates potential pathways of Beijing energy transition towards a high-level low-carbon,clean and efficient energy system in 2035 with an extended energysocpe model.Firstly,based on available data,future energy demands are predicted by a newly proposed hybrid forecasting method,which combines the traditional regression model,grey model,and support vector machine model with an entropy-based weighted factor.Secondly,the superstructure-based optimization model is employed to investigate the system configuration and operation strategy of the future Beijing energy system.Finally,the uncertainty impact of electricity price,natural gas price,hydrogen price,and the capital expenditures of electrolyzer and steam methane reforming for hydrogen applications are studied.The forecasting results show that all walks of life will witness a continuously increasing energy demand in multiple sectors of Beijing towards 2035.The planning results suggest that the imported electricity and natural gas will dominate the energy supply of Beijing in 2035 with a contribution of 86%of the energy resources consumption of 384 TWh.Moreover,the energy system presents a high end-use electrification level of 65%and high penetration of efficient technologies,which supply 119 TWh via combined heat and power,26 TWh via heat pump and 95 TWh via district heating network.The energy use of various sectors of energy resources,technologies and end-use are closely related.Hydrogen will have an increased penetration in the private mobility sector,but the locally generated hydrogen is mainly from steam methane reforming technology.

表面氢键网络诱导的富含表面氧空位的BiOCl合成以及光催化研究

从原子尺度上设计合成氧空位是深入了解氧化物催化氧化技术的关键.在这项研究中,氧空位可以通过构建表面氢键网络从而被限域在催化剂的表面.这种有趣的氢键网络是由富含羟基的Bi OCl和磷酸分子所构建.氢键网络的存在可以选择性削弱表面金属-氧键结合能,从而大大降低表面氧空位的形成能.这种限域在表面的氧空位可以用来详细地区分两种经典催化体系中与一氧化氮(NO)氧化有关的体相氧和表面氧的贡献.理论计算与实验表明,体相氧空位可以通过加快晶格O扩散从而促进热催化NO氧化,而表面氧空位则在光活化表面分子氧去除NO方面更加有效.这项研究表明合理地设计缺陷是实现理想化学反应的关键,同时为高性能的光催化剂设计用于污染物控制开辟了新的思路.

Do not let precision medicine be kidnapped

Obama＇s precision medicine initiative made the medical community boil over after the initiative＇s release. Precision medicine has been advocated by the majority of scientists and doctors. However, some experts have questioned this concept. This article does not oppose precision medicine. However, the incentive of vigorously promoting precision medicine at present is a concern.

Barriers and countermeasures in developing traditional Chinese medicine in Europe

Traditional Chinese medicine （TCM） is one of the unique cultural treasures of Chinese; it represents a significant feature and prominent advantage of the healthcare cause in China. Data in this paper were from World Health Organization, Chinese Bureau of Statistics, China National Knowledge Infrastructure, and PubMed. In recent years, TCM has established a solid foundation in Europe, which made great strides in legislation, education, research, and international exchange, and has enjoyed a vast development space in the continent. Now, TCM is embracing unprecedented development opportunities in Europe. At the same time, the stiff international competition poses a grave threat to China＇s TCM industry. With multiple cultural, legal, and institutional challenges, as well as talent shortages in the way, TCM is now facing many difficulties in Europe. To fully prepare and enact active and vigorous steps to seize opportunities, we should have a clear picture about the serious challenges hampering TCM development in Europe. The TCM development at overseas markets has shifted from a spontaneous trade activity into a national strategy spearheaded by the government and participated in by multiple stakeholders. We should make a systematic, comprehensive, and sustainable push in fields such as TCM therapy, healthcare, education, research, culture, and industry development. The ultimate goal is to bring TCMs to the global market and allow them to play a role in safeguarding public health along with modern medicines.

Asymmetric Access of γ-Amino Acids and γ-Amino Phosphonic Acid Derivatives via Copper-Catalyzed Enantioselective and Regioselective Hydroamination

γ-Aminobutyric acid is a major inhibitory neurotransmitter in the mammalian central nervous system that plays a substantial role in brain disorders.γ-Amino phosphonic acid is a unique surrogate of both natural and unnatural γ-amino acid.Because of their unique biological activity,γ-amino acid and γ-amino phosphonic acid derivatives have attracted considerable attention.However,an efficient and straightforward method for constructing chiral γ-substituted-γ-amino acid and γ-amino phosphonic acid derivatives remains a long-standing challenge.Herein,a highly efficient,versatile,and universal Cucatalyzed asymmetric hydroamination of cinnamyl esters,cinnamyl phosphonates,and cinnamyl phosphine oxides is presented for accessing γ-amino acid andγ-amino phosphonic acid derivatives in good yields with high levels of enantiocontrol and regioselectivity.

Hydrothermal synthesis,characterization and nonlinear optical effect of orthorhombic phase Ca_(2)B_(6)O_(11)·H2O

Hydrothermal treatment of calcium oxide and boric acid mixtures at temperaturesbetween 234 ℃ and 300 ℃ has produced a colorless, transparent, orthorhombic compound Ca2B6O11 · H2O. Of the seven known members of the series of hydrated dicalcium hexaborate containing boron-oxygen six-membered ring anionic group (B3O8)7, only the title compound has been found to have the nonlinear optical effect. The second harmanic generation (SHG) effect of its crystal is larger than that of KH2PO4 (KDP). The reflection spectrum has shown that this compound has no absorption in the experimental wavelength range (800-240 nm). Its crystal structure is favorable for generating the nonlinear optical effect.

Thermal-optic tuning cascaded double ring optical sensor based on wavelength interrogation

Based on the Vernier effect of the cascaded double ring resonator(CDRR) sensor,a sensor consisting of a microfluidic control system,a sensing ring,and a reference ring with a micro-heater for thermal tuning is proposed in this paper.In wavelength interrogation,a broadband spectrometer or a large tunable range laser is not required.The shift of the output spectrum caused by the refractive index change of the sample is converted into the change of the electric power by the thermal tuning heater.Due to the Vernier effect,the sensitivity of the sensor is 20 times higher than that of the single ring.The spectral envelope of the thermal-optic tuning of the sensor was fitted by a Gaussian function in the wavelength range of8 nm.The experimental results showed that the sensitivity was 33.703 W/RIU,and the limit of detection was 1.34×10-5 RIU.