Enhancing Autonomy Capability in Regional Power Grids:A Strategic Planning Approach with Multiple Autonomous Evaluation Indexes

After the integration of large-scale DistributedGeneration(DG)into the distribution network,the randomness and volatility of its output result in a reduction of spatiotemporal alignment between power generation and demand in the distribution network,exacerbating the phenomenon of wind and solar power wastage.As a novel power system model,the fundamental concept of Regional Autonomous Power Grids(RAPGs)is to achieve localized management and energy autonomy,thereby facilitating the effective consumption of DGs.Therefore,this paper proposes a distributed resource planning strategy that enhances the autonomy capabilities of regional power grids by considering multiple evaluation indexes for autonomy.First,a regional Energy Storage(ES)configuration strategy is proposed.This strategy can select a suitable reference value for the upper limit of ES configuration based on the regional load andDGoutput to maximize the elimination of source load deviations in the region as the upper limit constraint of ES capacity.Then,a control strategy for regional ES is proposed,the charging and discharging reference line of ES is set,and multiple autonomy and economic indexes are used as objective functions to select different proportions of ES to control the distributed resources of the regional power grid and establish evaluation indexes of the internal regional generation and load power ratio,the proportion of power supply matching hours,new energy consumption rate and tie line power imbalance outside the region to evaluate changes in the regional autonomy capabilities.The final simulation results showthat in the real regional grid example,the planning method in the planning year in the region of the overall power supply matching hour ratio and new energy consumption rate increased by 3.9%and 4.8%on average,and the power imbalance of the tie line decreased by 7.8%on average.The proposed planning approach enables the maximization of regional autonomy while effectively smoothing the fluctuation of power exchange between the regional grid and the higher-level grid.This presents a rational and effective planning solution for the regional grid,facilitating the coordinated development between the region and the distribution network.

Combined Optimal Dispatch of Thermal Power Generators and Energy Storage Considering Thermal Power Deep Peak Clipping and Wind Energy Emission Grading Punishment

Peak load and wind energy emission pressure rise more as wind energy penetration keeps growing,which affects the stabilization of the PS(power system).This paper suggests integrated optimal dispatching of thermal power generators and BESS(battery energy storage system)taking wind energy emission grading punishment and deep peak clipping into consideration.Firstly,in order to minimize wind abandonment,a hierarchical wind abandonment penalty strategy based on fuzzy control is designed and introduced,and the optimal grid-connected power of wind energy is determined as a result of minimizing the peak cutting cost of the system.Secondly,considering BESS and thermal power,the management approach of BESS-assisted virtual peak clipping of thermal power generators is aimed at reducing the degree of deep peak clipping of thermal power generators and optimizing the output of thermal power generators and the charging and discharging power of BESS.Finally,Give an example of how this strategy has been effective in reducing abandonment rates by 0.66% and 7.46% individually for different wind penetration programs,and the daily average can reduce the peak clipping power output of thermal power generators by 42.97 and 72.31 MWh and enhances the effect and economy of system peak clipping.

Optimal Scheduling Strategy of Source-Load-Storage Based onWind Power Absorption Benefit

In recent years,the proportion of installed wind power in the three north regions where wind power bases are concentrated is increasing,but the peak regulation capacity of the power grid in the three north regions of China is limited,resulting in insufficient local wind power consumption capacity.Therefore,this paper proposes a two-layer optimal scheduling strategy based on wind power consumption benefits to improve the power grid’s wind power consumption capacity.The objective of the uppermodel is tominimize the peak-valley difference of the systemload,which ismainly to optimize the system load by using the demand response resources,and to reduce the peak-valley difference of the system load to improve the peak load regulation capacity of the grid.The lower scheduling model is aimed at maximizing the system operation benefit,and the scheduling model is selected based on the rolling schedulingmethod.The load-side schedulingmodel needs to reallocate the absorbed wind power according to the response speed,absorption benefit,and curtailment penalty cost of the two DR dispatching resources.Finally,the measured data of a power grid are simulated by MATLAB,and the results show that:the proposed strategy can improve the power grid’s wind power consumption capacity and get a large wind power consumption benefit.

Modeling of Large-Scale Hydrogen Storage System Considering Capacity Attenuation and Analysis of Its Efficiency Characteristics

In the existing power system with a large-scale hydrogen storage system,there are problems such as low efficiency of electric-hydrogen-electricity conversion and single modeling of the hydrogen storage system.In order to improve the hydrogen utilization rate of hydrogen storage system in the process of participating in the power grid operation,and speed up the process of electric-hydrogen-electricity conversion.This article provides a detailed introduction to the mathematical and electrical models of various components of the hydrogen storage unit,and also establishes a charging and discharging efficiency model that considers the temperature and internal gas partial pressure of the hydrogen storage unit.These models are of great significance for studying and optimizing gas storage technology.Through these models,the performance of gas storage units can be better understood and improved.These studies are very helpful for improving energy storage efficiency and sustainable development.The factors affecting the charge-discharge efficiency of hydrogen storage units are analyzed.By integrating the models of each unit and considering the capacity degradation of the hydrogen storage system,we can construct an efficiency model for a large hydrogen storage system and power conversion system.In addition,the simulation models of the hydrogen production system and hydrogen consumption system were established in MATLAB/Simulink.The accuracy and effectiveness of the simulation model were proved by comparing the output voltage variation curve of the simulation with the polarization curve of the typical hydrogen production system and hydrogen consumption system.The results show that the charge-discharge efficiency of the hydrogen storage unit increases with the increase of operating temperature,and H2 and O2 partial voltage have little influence on the charge-discharge efficiency.In the process of power conversion system converter rectification operation,its efficiency decreases with the increase of temperature,while in the process of inverter operation,power conversion system efficiency increases with the increase of temperature.Combined with the efficiency of each hydrogen storage unit and power conversion system converter,the upper limit of the capacity loss of different hydrogen storage units was set.The optimal charge-discharge efficiency of the hydrogen storage system was obtained by using the Cplex solver at 36.46%and 66.34%.

Interface Engineering of Titanium Nitride Nanotube Composites for Excellent Microwave Absorption at Elevated Temperature

Currently,the microwave absorbers usually suffer dreadful electromagnetic wave absorption(EMWA)performance damping at elevated temperature due to impedance mismatching induced by increased conduction loss.Consequently,the development of high-performance EMWA materials with good impedance matching and strong loss ability in wide temperature spectrum has emerged as a top priority.Herein,due to the high melting point,good electrical conductivity,excellent environmental stability,EM coupling effect,and abundant interfaces of titanium nitride(TiN)nanotubes,they were designed based on the controlling kinetic diffusion procedure and Ostwald ripening process.Benefiting from boosted heterogeneous interfaces between TiN nanotubes and polydimethylsiloxane(PDMS),enhanced polarization loss relaxations were created,which could not only improve the depletion efficiency of EMWA,but also contribute to the optimized impedance matching at elevated temperature.Therefore,the TiN nanotubes/PDMS composite showed excellent EMWA performances at varied temperature(298-573 K),while achieved an effective absorption bandwidth(EAB)value of 3.23 GHz and a minimum reflection loss(RLmin)value of−44.15 dB at 423 K.This study not only clarifies the relationship between dielectric loss capacity(conduction loss and polarization loss)and temperature,but also breaks new ground for EM absorbers in wide temperature spectrum based on interface engineering.

A Distributed Photovoltaics Ordering Grid-Connected Method for Analyzing Voltage Impact in Radial Distribution Networks

In recent years,distributed photovoltaics(DPV)has ushered in a good development situation due to the advantages of pollution-free power generation,full utilization of the ground or roof of the installation site,and balancing a large number of loads nearby.However,under the background of a large-scale DPV grid-connected to the county distribution network,an effective analysis method is needed to analyze its impact on the voltage of the distribution network in the early development stage of DPV.Therefore,a DPV orderly grid-connected method based on photovoltaics grid-connected order degree(PGOD)is proposed.This method aims to orderly analyze the change of voltage in the distribution network when large-scale DPV will be connected.Firstly,based on the voltagemagnitude sensitivity(VMS)index of the photovoltaics permitted grid-connected node and the acceptance of grid-connected node(AoGCN)index of other nodes in the network,thePGODindex is constructed to determine the photovoltaics permitted grid-connected node of the current photovoltaics grid-connected state network.Secondly,a photovoltaics orderly grid-connected model with a continuous updating state is constructed to obtain an orderly DPV grid-connected order.The simulation results illustrate that the photovoltaics grid-connected order determined by this method based on PGOD can effectively analyze the voltage impact of large-scale photovoltaics grid-connected,and explore the internal factors and characteristics of the impact.

Two-Stage Planning of Distributed Power Supply and Energy Storage Capacity Considering Hierarchical Partition Control of Distribution Network with Source-Load-Storage

Aiming at the consumption problems caused by the high proportion of renewable energy being connected to the distribution network,it also aims to improve the power supply reliability of the power system and reduce the operating costs of the power system.This paper proposes a two-stage planning method for distributed generation and energy storage systems that considers the hierarchical partitioning of source-storage-load.Firstly,an electrical distance structural index that comprehensively considers active power output and reactive power output is proposed to divide the distributed generation voltage regulation domain and determine the access location and number of distributed power sources.Secondly,a two-stage planning is carried out based on the zoning results.In the phase 1 distribution network-zoning optimization layer,the network loss is minimized so that the node voltage in the area does not exceed the limit,and the distributed generation configuration results are initially determined;in phase 2,the partition-node optimization layer is planned with the goal of economic optimization,and the distance-based improved ant lion algorithm is used to solve the problem to obtain the optimal distributed generation and energy storage systemconfiguration.Finally,the IEEE33 node systemwas used for simulation.The results showed that the voltage quality was significantly improved after optimization,and the overall revenue increased by about 20.6%,verifying the effectiveness of the two-stage planning.

Establish a “China model” of Pension Security Inquiry Analysis

From a global perspective, local awareness and People Standard in three ways, conditions to establish and improve a social security system covering urban and rural areas has matured its localization requirements have become more evident. Therefore, to explore the social security system with Chinese characteristics model, not only is the key to solve China＇s current social conflicts, as well as building a socialist harmonious society and a necessary step in the inevitable choice. Globalization and global governance movement accelerated economic globalization, social security, face the opportunities and challenges, China should establish a “China model” of pension security.

Rheological properties of a multiscale granular system during mixing of cemented paste backfill:A review

The technology of cemented paste backfill(CPB)is an effective method for green mining.In CPB,mixing is a vital process aiming to prepare a paste that meets the non-stratification,non-segregation,and non-bleeding requirements.As a multiscale granular system,homogenization is one of the challenges in the paste-mixing process.Due to the high shearing,high concentration,and multiscale characteristics,paste exhibits complex rheological properties in the mixing process.An overview of the mesomechanics and structural evolution is presented in this review.The effects of various influencing factors on the paste's rheological properties were investigated,and the rheological models of the paste were outlined from the macroscopic and mesoscopic levels.The results show that the mechanical effects and structural evolution are the fundamental factors affecting the rheological properties of the paste.Existing problems and future development trends are presented to change the practice where the CPB process comes first and the theory lags.

Effect of variations in the polar and azimuthal angles of coarse particles on the structure of drainage channels in thickened beds

The 3D reconstruction and quantitative characterization of drainage channels and coarse tailings particles in a bed were conducted in this study.The influence of variations in the azimuthal angle(θ)and polar angle(φ)of coarse particles on drainage channel structure was analyzed,and the drainage mechanism of the bed was studied.Results showed that water discharge in the bed reduced the size of pores and throat channels,increasing slurry concentration.The throat channel structure was a key component of the drainage process.Theφandθof particles changed predominantly along the length direction.The changes inφhad a cumulative plugging effect on the drainage channel and increased the difficulty of water discharge.The rake and rod formed a shear ring in the tailings bed with shear,and theθdistribution of particles changed from disorderly to orderly during the rotation process.The drainage channel was squeezed during the shearing process with the change inθ,which broke the channel structure,encouraged water discharge in the bed,and facilitated a further increase in slurry concentration.The findings of this work are expected to offer theoretical guidance for preparing high-concentration underflow in the tailings thickening process.

Review of Black Start on New Power System Based on Energy Storage Technology

With the continuous development of new energy generation technology and the increasingly complex power grid environment,the traditional black start scheme cannot meet the requirements of today’s power grid in order to ensure the stable operation of the power system can be restored quickly in the face of large power outages,so a more complete black start scheme needs to be developed to cope with the new power system.With the development of energy storage technology,the limitations of the traditional black-start scheme can be solved by new energy farms with energy storage configuration.Therefore,this paper investigates the problems faced by black-start,the key technologies of energy storage assisted new energy black-start,and introduces the research related to new energy black-start technology to provide reference for future research and application of new energy black-start.

2019新型冠状病毒信息库

2019年12月在中国武汉开始爆发的新型肺炎已造成全球25个国家/地区的31516人感染、638人死亡(截止2020年2月7日16时),引起该肺炎的病毒被世界卫生组织命名为2019新型冠状病毒(2019-nCoV)。为促进2019-nCoV数据共享应用并及时向全球公众提供病毒的相关信息,国家生物信息中心(CNCB)/国家基因组科学数据中心(NGDC)建立了2019新型冠状病毒信息库(2019nCoVR,https://bigd.big.ac.cn/ncov)。该信息库整合了来自德国全球流感病毒数据库、美国国家生物技术信息中心、深圳(国家)基因库、国家微生物科学数据中心及CNCB/NGDC等机构公开发布的2019-nCoV核苷酸和蛋白质序列数据、元信息、学术文献、新闻动态、科普文章等信息,开展了不同冠状病毒株的基因组序列变异分析并提供可视化展示。同时,2019nCoVR无缝对接CNCB/NGDC的相关数据库,提供新测序病毒株系的基因组原始测序数据、组装后序列的在线汇交、管理与共享、国际数据库同步发布等数据服务。本文对2019nCoVR数据汇交、管理、发布及使用等进行全面阐述,以方便用户了解该信息库各项功能及数据状况,为加速开展病毒的分类溯源、变异演化、快速检测、药物研发以及新型肺炎的精准预防与治疗等研究提供重要基础。

Dynamic economic evaluation of hundred megawatt-scale electrochemical energy storage for auxiliary peak shaving

With the rapid development of wind power,the pressure on peak regulation of the power grid is increased.Electro-chemical energy storage is used on a large scale because of its high efficiency and good peak shaving and valley fill-ing ability.The economic benefit evaluation of participating in power system auxiliary services has become the focus of attention since the development of grid-connected hundred megawatt-scale electrochemical energy storage systems(ESS).Based on the relationship between power and capacity in the process of peak shaving and valley filling,a dynamic economic benefit evaluation model of peak shaving assisted by hundred megawatt-scale electrochemi-cal ESS considering the equivalent life of the battery is proposed.The model considers the investment cost of energy storage,power efficiency,and operation and maintenance costs,and analyzes the dynamic economic benefits of dif-ferent energy storage technologies participating in the whole life cycle of the power grid.Then,according to the cur-rent ESS market environment,the auxiliary service compensation price,peak-valley price difference and energy stor-age cost unit price required to make the energy storage technology achieve the balance of payments are calculated,and the economic balance points of different energy storage types are clarified.Finally,based on the measured data of different provincial power grids,the economies of six energy storage types applied to three provincial power grids are compared and analyzed,and the rationality and effectiveness of the relevant models proposed are verified.The work has theoretical guiding significance for the economic benefit evaluation of hundred megawatt-scale electro-chemical energy storage.Highlights 1 A proportional relationship between grid filling power and capacity demand is proposed.It is used to determine the energy storage configuration for auxiliary peak shaving.2 A dynamic economic evaluation model considering energy storage investment and maintenance costs,electric-ity profit,and auxiliary service compensation is proposed.3 In the three provincial power grids,the economics of 6 hundred megawatt-scale electrochemical energy stor-ages are compared and analyzed.4 Auxiliary service compensation,time of day rate,and energy storage cost that enable energy storage to reach an economic equilibrium point are determined.

Research on the Properties of Periodic Solutions of Beverton⁃Holt Equation

Fractional linear maps have played a key role in mathematical biology,population dynamics,and other research areas.In this paper,a special kind of Ricatti map is studied in detail in order to determine the asymptotical behaviors of fixed points and periodic solutions.Making use of composition operation of maps and the methods of dynamical systems and qualitative theory,fixed points or periodic orbits are expressed precisely,average value of periodic solution is estimated concretely,and several different bounds are obtained for periodic solutions of the Beverton⁃Holt map when both intrinsic growth rate and carrying capacity change periodically.In addition,some sufficient conditions are given about the attenuation of periodic solution of the non⁃autonomous Beverton⁃Holt equation.Compared with present works in literature,our results about bounds of periodic solutions are more precise,and our proofs about the attenuation of periodic solution are more concise.

Experimental study of channel electron multiplier

Background Channel electron multiplier(CEM)can be used to measure extremely few charged particles,such as electrons and ions.The CEM is widely used in particle detection,so it is very important to study their performance parameters.Purposes Test and analyze the performance parameters of the CEM,such as resistance,gain,and pulse output for a single entrance photoelectron.Methods The heated tantalum filament is used as a stable and adjustable planar electron source to test the performance of the CEM in the analog mode.The performance parameters of the CEM in the pulse counting mode are tested by using the ultraviolet LED to excite the gold photocathode to generate a single photoelectron.Results and conclusions The gain of the CEM in the analog mode can reach more than 106 and the gain in the pulse counting mode can be two orders of magnitude higher.The curved helical channel has a greater advantage than the ordinary straight channel,which is conducive to weakening the ion feedback phenomenon.

数据驱动的公共卫生安全

在现代社会中,数据已成为重要的生产要素和国家基础性战略资源,是维护国家生物安全与社会稳定的利器[1].正确处理和利用数据,有助于我们及时、快速、有效地发现和解决问题,进一步维护社会的和谐稳定发展.在公共卫生安全领域,公共卫生安全事件成为21世纪人类生存面临的非传统安全威胁之一,特别是新发再发传染病对全球公共卫生和社会经济安全构成严重威胁[2,3].

Flexible regulation engineering of titanium nitride nanofibrous membranes for efficient electromagnetic microwave absorption in wide temperature spectrum

Simultaneous development of well impedance matching and strong loss capability has become a mainstream method for achieving outstanding electromagnetic microwave absorption(EMWA)performances over wide temperature range.However,it is difficult to pursue both due to the mutual restraint of relationship between impedance matching and loss capability about temperature.Here,we propose a flexible regulation engineering of titanium nitride(TiN)nanofibrous membranes(NMs,TNMs),which could be distributed uniformly in the polydimethylsiloxane(PDMS)matrix and contributed to the formation of abundant local conductive networks,generating the local conductive loss and enhancing the loss ability of EMWs.Moreover,when the TNMs are used as functional units and dispersed in the matrix,the corresponding composites exhibit an outstanding anti-reflection effect on microwaves.As hoped,under the precondition of good impedance matching,local conductive loss and polarization loss together improve the loss capacity at room temperature,and polarization loss can compensate the local conductive loss to acquire effective dielectric response at elevated temperature.Benefiting from the reasonably synergistic loss ability caused by flexible regulation engineering,the corresponding composites exhibit the perfect EMWA performances in a wide temperature range from 298 to 573 K.This work not only elaborates the ponderable insights of independent membrane in the composition-structure-function connection,but also provides a feasible tactic for resolving coexistence of well impedance matching and strong loss capability issues in wide temperature spectrum.

音乐治疗在提升女犯情绪智力水平中的应用

对上海市女子监狱200名女犯运用音乐治疗对其情绪智力进行团体干预,结果显示,实验组女犯干预后的情绪智力水平显著高于实验前(p<0.001),且显著高于未干预的对照组(p<0.001)。由此证明:音乐治疗能显著提升服刑女犯的情绪智力水平,音乐团体辅导活动存在立即辅导效应与持续性效应;所设计的音乐治疗团体辅导方案切实可行,具有很强的可复制性和推广性,可以作为提升服刑女犯情绪智力的团体辅导进行使用。

MeRIP-PF:An Easy-to-use Pipeline for High-resolution Peak-finding in MeRIP-Seq Data

RNA modifications, especially methylation of the N6 position of adenosine （A）--m6A, rep- resent an emerging research frontier in RNA biology. With the rapid development of high-throughput sequencing technology, in-depth study of m6A distribution and function relevance becomes feasible. However, a robust method to effectively identify m6A-modified regions has not been available yet. Here, we present a novel high-efficiency and user-friendly analysis pipeline called MeRIP-PF for the signal identification of MeRIP-Seq data in reference to controls. MeRIP-PF provides a statistical P-value for each identified m6A region based on the difference of read distribution when compared to the con- trols and also calculates false discovery rate （FDR） as a cut offto differentiate reliable m6A regions from the background. Furthermore, MeRIP-PF also achieves gene annotation ofm6A signals or peaks and produce outputs in both XLS and graphical format, which are useful for further study. MeRIP-PF is implemented in Perl and is freely available at http：//software.big.ac.cn/MeRIP-PF.html.

Low-Temperature Synthesis of Crystalline Inorganic/Metallic Nanocrystal-Halloysite Composite Nanotubes

We have demonstrated a facile approach for the low-temperature synthesis of crystalline inorganic/metallic nanocrystal-halloysite composite nanotubes by employing the bulk controlled synthesis of inorganic/metallic nanocrystals on halloysite nanotubes.The halloysite clay nanotubes can adsorb the target precursor and induce inorganic/metallic nanocrystals to grow in situ.The crystalline phase and morphology of the composite clay nanotubes is tunable.By simply tuning the acidity of the titania sol,the crystalline titania-clay nanotubes with tunable crystalline phases of anatase,a mixture of anatase and rutile or rutile are achieved.The approach is general and has been extended to synthesize the representative perovskite oxide(barium and strontium titanate)-halloysite composite nanotubes.Metallic nickel nanocrystal can also be grown on the surface of halloysite nanotubes at low temperature.The traditional thermal treatment for crystallite transformation is not required,thus intact contour of halloysite nanotubes and the crystallinity structure of halloysite nanotubes can be guaranteed.The combined properties from inorganic/metallic nanocrystal(high refractive index,high dielectric constant and catalytic ability)and the halloysite clay nanotubes are promising for applications such as photonic crystals,high-k-gate dielectrics,photocatalysis and purification.