mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
The Reliability and Operational Test System of a Power Grid with Large-scale Renewable Integration

This paper proposes a reliability and operational test system named XJTU-ROTS2017, characterized by large-scale renewable power integration and long-distance transmission. The test system has 38 nodes, 63 lines, 15 transformers and 20 generators in three areas, with peak load 10,421 MW and total installed capacity 16050 MW. Electricity primarily transmits from a resource-rich area to a load area, carrying wind/solar power generation. The determination of component parameters and grid topology is based on design manuals and typical practices. The test system can be conveniently applied to reliability evaluation and operation optimization of composite power systems integrating coal/hydro/solar/wind resources. Finally, the extended applications to AC/DC hybrid power systems and interconnected power systems are discussed.
Review of Distribution Network Phase Unbalance: Scale, Causes, Consequences, Solutions, and Future Research Directions

Phase unbalance is widespread in the distribution networks in the UK, continental Europe, US, China, and other countries and regions. This paper first reviews the mass scale of phase unbalance and its causes and consequences. Three challenges arise from phase rebalancing: the scalability, data scarcity, and adaptability (towards changing unbalance over time). Solutions to address the challenges are: 1) using retrofit table, maintenance-free, automatic solutions to overcome the scalability challenge; 2) using data analytics to overcome the data-scarcity challenge; and 3) using phase balancers or other online phase rebalancing solutions to overcome the adaptability challenge. This paper categorizes existing phase rebalancing solutions into three classes: 1) load/lateral re-phasing; 2) using phase balancers; 3) controlling energy storage, electric vehicles, distributed generation, and micro-grids for phase rebalancing. Their advantages and limitations are analyzed and ways to overcome their limitations are recommended. Finally, this paper suggests future research topics: 1) long-term forecast of phase unbalance; 2) the whole-system analysis of the unbalance-induced costs; 3) the phase unbalance diagnosis for data-scarce LV networks; 4) techno-commercial solutions to exploit the flexibility from large three-phase customers for phase balancing; 5) the optimal placement of phase balancers; 6) the transition from single-phase customers to three-phase customers.
Optimization Strategy Based on Deep Reinforcement Learning for Home Energy Management

With the development of a smart grid and smart home, massive amounts of data can be made available, providing the basis for algorithm training in artificial intelligence applications. These continuous improving conditions are expected to enable the home energy management system (HEMS) to cope with the increasing complexities and uncertainties in the enduser side of the power grid system. In this paper, a home energy management optimization strategy is proposed based on deep Qlearning (DQN) and double deep Q-learning (DDQN) to perform scheduling of home energy appliances. The applied algorithms are model-free and can help the customers reduce electricity consumption by taking a series of actions in response to a dynamic environment. In the test, the DDQN is more appropriate for minimizing the cost in a HEMS compared to DQN. In the process of method implementation, the generalization and reward setting of the algorithms are discussed and analyzed in detail. The results of this method are compared with those of Particle Swarm Optimization (PSO) to validate the performance of the proposed algorithm. The effectiveness of applied data-driven methods is validated by using a real-world database combined with the household energy storage model.
Net Damping Criterion for Stability Analysis of Grid-tied VSCs in DC Voltage Control Timescale

Stability of grid-connected VSCs in DC voltage control (DVC) timescales (i.e., the frequency range of dynamics covering converter outer controls) has recently caught increased attention, while the existing approaches, such as eigenvalue analysis and dq-domain impedance analysis, have respective limitations on addressing these types of stability issues. This paper proposes an alternative net damping criterion dedicated for analyzing the DVC timescale stability in a multi-VSC system. This criterion is strictly mapped from the Nyquist stability criterion utilizing the gain margin concept, which preserves the advantages of the classical positive net damping criterion suggested by Canay [20]-allowing for decomposition analysis of a subsystem's contribution to the closed-loop stability in a single-input single-output (SISO) framework, but overcomes its deficiency of possibly erroneous prediction of system dynamic behaviors. Case studies show that the proposed criterion can correctly predict some unstable conditions (e.g.,monotonic divergence) which cannot be identified by the classical net damping criterion. Additionally, the condition for when the classical criterion is available is also pointed out, the proposed criterion can also act as a complement of the classical criterion for stability examination.
Hierarchical Dispatch Method for Integrated Heat and Power Systems Based on a Feasible Region of Boundary Variables

Fully utilizing the flexibility provided by a district heating system (DHS) can promote wind power accommodation for an electric power system (EPS). However, for privacy or communication reasons, existing power and heat dispatch methods are not suitable for practical application. In this paper, a general math formulation of the hierarchical dispatch method is proposed to coordinate EPS and DHS operators based on the feasible region of boundary variables (FRBV), and a method based on the simplicial approximation approach is proposed to obtain a conservative FRBV approximation of a DHS. A simulation based on a real 41-node DHS is constructed to determine the factors that may impact the boundaries of the FRBV, and then the performance of the simplicial approximation approach is displayed by visualizing the approximation process for the FRBV, and finally three dispatch methods are compared to show the advantages of the proposed hierarchical dispatch method.
Reduced-order Modeling and Dynamic Stability Analysis of MTDC Systems in DC Voltage Control Timescale

An equivalent source-load MTDC system including DC voltage control units, power control units and interconnected DC lines is considered in this paper, which can be regarded as a generic structure of low-voltage DC microgrids, medium-voltage DC distribution systems or HVDC transmission systems with a common DC bus. A reduced-order model is proposed with a circuit structure of a resistor, inductor and capacitor in parallel for dynamic stability analysis of the system in DC voltage control timescale. The relationship between control parameters and physical parameters of the equivalent circuit can be found, which provides an intuitive insight into the physical meaning of control parameters. Employing this model, a second-order characteristic equation is further derived to investigate system dynamic stability mechanisms in an analytical approach. As a result, the system oscillation frequency and damping are characterized in a straight forward manner, and the role of electrical and control parameters and different system-level control strategies in system dynamic stability in DC voltage control timescale is defined. The effectiveness of the proposed reduced-order model and the correctness of the theoretical analysis are verified by simulation based on PSCAD/EMTDC and an experiment based on a hardware low-voltage MTDC system platform.
郑州市成人代谢综合征流行现状及其影响因素

代谢综合征是中心性肥胖、高血糖、血压升高、血脂代谢紊乱在同一个体的聚集状态。代谢综合征可增加心血管疾病和糖尿病发病与死亡危险,开展以人群为基础的代谢综合征调查研究,对预防控制心脑血管疾病具有重要意义。目前郑州市尚无代谢综合征患病率及流行特征相关基线数据,本研究旨在了解郑州市成人代谢综合征流行现状和影响因素,为了解其长期趋势和开展综合防控工作提供基线数据和参考。
以高热为主要表现的艾滋病相关型KS 1例并文献复习

卡波西肉瘤(Kaposi's sarcoma,KS)是艾滋病相关恶性肿瘤之一,死亡率超过50%,以高热为首要表现的KS鲜见报道。现将1例以持续高热为主诉的危急重症艾滋病相关型KS患者的临床及诊治经过总结分析,并复习相关文献,以供临床参考。
铁皮石斛附生梨树不同高度与胸径农艺性状比较

目的探究喀斯特山地铁皮石斛附生梨树适宜高度和胸径条件。方法在铁皮石斛附生梨树上设置5个离地高度梯度:<60cm,60 ~80cm,80 ~ 100cm, 100 ~ 120cm,> 120cm;设置3个梨树胸径梯度:40 ~60mm,60 ~80mm, >80mm。对其农艺性状进行调查和测定,构建一般线性模型分析。结果与结论铁皮石斛附生梨树离地高度小于60cm和60cm以上,茎长和节间数存在着显著性差异,但60cm以上的3个处理之间差异不显著;不同胸径对茎长差异不大,但80mm以上的胸径与80mm以下的胸径相比,其铁皮石斛节间数的差异有显著性。结合生产实际,梨树适宜离地高度为0.6~1.5m,适宜胸径条件为80mm以上。
基于ITS2条形码的中药材牛膝及其易混品DNA分子鉴定

目的利用糖体rRNA基因内转录间隔区(ITS2)序列,对牛膝及其易混品进行鉴定分析。方法提取牛膝及其易混品的DNA,使用ITS2通用引物进行PCR扩增并测序,拼接校对并去除低质量碱基获得目的序列,利用MEGA 7.0对目的序列进行分析比对,计算种内、种间遗传距离,利用邻接法(NJ)构建系统聚类树,同时应用ITS2数据库网站预测其ITS2二级结构。结果牛膝的ITS2序列长度为193 bp,与所有易混品种间遗传距离为0.178 ~0.958。 NJ树显示牛膝单独聚一支,另外牛膝有明显ITS2二级结构特征,可与其易混品明显区分。结论ITS2序列能够有效地区分牛膝与其易混品,为牛膝的用药安全提供技术保障。
Flame retardant synergy between interfacial and bulk carbonation in glass fiber reinforced polypropylene

Glass fiber reinforced polypropylene (GF-PP) composites have high flammability on account of wick effectwhich leads to accelerated flow of the polymer melt along the glass fibers (GF) surface to the flame zone. In this study, dipentaerythritol (DPER), a charring agent,was adsorbed on the GF surface through the hydrogen bond between silane coupling agent and DPER. DPER has a synergistic effectwith the intumescent flame retardants (IFR) added in the composites,which can induce interfacial carbonization on the surface of GF, thus transforming the intrinsic smooth GF surface into roughness one. In this way, the negative effect of the wick effect in flame retardancy is weakened.Moreover, the char residues remained on the surface of GF can bring an improved adhesion between GF and char residues formed in the resin so that a more stable barrier char layer is formed. The PP composites with 20 wt% modified glass fiber (M-GF) and 30 wt% IFR can achieve the UL-94V-0, and its limiting oxygen index (LOI) value increased from 16.5% to 29.5%. Simultaneously, the heat release rate (HRR), total heat release (THR) and total smoke release (TSR) decreased significantly, and the peak of heat release rate (PHRR) reduced 60.6% compared with GF-PP.
Influence of solvent on ion conductivity of polybenzimidazole proton exchange membranes for vanadium redox flow batteries

Polybenzimidazole (PBI) is a kind of proton transport membrane material, and its ion conductivity is a key factor affecting its application in vanadium redox flow batteries (VRFBs). The casting solvent of PBI has a significant influence on the acid doping level of PBI membranes which is closely related to ionic conductivity. In this paper, 3,3'-diaminobenzidine (DABz) and 4,4'-Dicarboxydiphenylether (DCDPE) were used as raw materials by solution condensation to prepare the PBI with ether bond groups. The chemical structure of PBI was determined by ~1H NMR and FT-IR, and the prepared PBI had good solubility which can be dissolved in a variety of solvents. The PBI proton exchange membranes were prepared by solution coating with 5 different solvents of N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), 1-methyl-2- pyrrolidone (NMP), methane sulfonic acid (MSA). The effects of different solvents on the ion conductivity and physicochemical properties were discussed in detail. The results showed that the PBI membrane prepared by using MSA as solvent (the PBI + MSA membrane) exhibits high water uptake, acid doping level and low vanadium ion permeability. The VRFB assembled with the PBI + MSA membrane exhibited higher coulombic efficiency (CE) 99.87% and voltage efficiency (VE) 84.50% than that of the commercial Nafion115 membrane at 100 mA·cm–2, and after 480 cycles, the EE value can still be maintained at 83.73%. The self-discharge time of a single battery was recorded to be as long as 1000 h. All experimental data indicated that MSA is the best solvent for casting PBI membrane.
Preparation of graphene oxide/natural rubber composites by latex cocoagulation: Relationship between microstructure and reinforcement

Graphene oxide (GO) has recently attracted substantial interest as a possible reinforcing agent for next generation rubber composite materials. In this research, GO was incorporated in natural rubber (NR) composites through latex co-coagulation technique. The microstructures of GO/NR compositeswere characterized through a combination of transmission electron microscope, scanning electron microscope, X-ray diffraction, Fourier transform infrared spectroscopy, and Differential scanning calorimeter. The results showed that highly exfoliated GO sheetswere finely dispersed into NR rubber matrixwith strong interface interaction between GO and NR. The mechanical properties of the GO/NR composites were further evaluated. The results showed that the tensile strength, tear strength and modulus can be significantly improved at a content of less than 2 phr. Especially, GOexhibited specific reinforce mechanisminNR due to the stress-induced crystallization effects of NR. The stress transfer from the NR to the GO sheets and the hindrance of GO sheets to the stress-induced crystallization of NR were further displayed in stress–strain behavior of GO/NR composites. These enhanced properties were attributed to the high surface area of GO sheets and highly exfoliated microstructures of GO sheets in NR.
Metastable state of gas hydrate during decomposition: A novel phenomenon

Natural gas hydrates are solid compoundswith cage-like structures formed by gas and water. An intriguing phenomenonthat gas hydrates candissociate at a lowrate belowthe ice freezing pointhas been viewed as themetastability of hydrate. The mechanisms of hydrate metastability have been widely studied, and many mechanisms were proposed involving the self-preservation effect, supercooled water-gas-hydrate metastable equilibrium, and supersaturated liquid–gas-hydrate systemetc. Themetastable state of hydrate could be of crucial significance in the kinetics of hydrate formation and decomposition, heat and mass transfer during gas production processes, and the application of hydrate-based technique involving desalination, energy storage and transportation, and gas separation and sequestration. Few researches have systematically considered this phenomenon, and its mechanism remains unclear. In this work, various mechanisms and hypothesis explaining the metastable state of gas hydrates were introduced and discussed. Further studies are still required to reveal the intrinsic nature of this metastable state of gas hydrate, and this work could give some implications on the existing theory and current status of relevant efforts.
超声造影诊断儿童脾梗死2例

病例1系支原体肺炎诊断明确,积极抗感染治疗下仍发热不退,根据感染后引起血液的高凝指标,需警惕血栓性疾病尤其脾梗死的发生。常规超声检查及彩色多普勒、能量多普勒及B-Flow技术无法将脾梗死与正常脾脏回声区分,将声诺维静脉造影用于该患儿,结果明确提示脾中极梗死的存在,与增强CT结果相符;经过2个多月的保守治疗后,多次常规超声检查不能清楚显示脾梗死的范围改变,超声造影的随访结果再次明确脾梗死范围明显缩小,从而避免了该儿童患者随访中CT的重复检查。病例2存在非典型的临床症状,白细胞计数增高,常规超声提示脾脏肿大,回声改变及血流异常,但临床症状、血常规和普通超声检查均无法将脾脏感染灶与脾梗死鉴别。静脉超声造影提供了一个简洁、快速的诊断方法,其结果明确可靠,与增强CT完全相符,再次说明在儿童的脾梗死诊断和随访中,应用静脉超声造影作为首选影像学检查方法,可以替代多次增强CT检查,从而减少射线损伤,适宜在儿科领域推广应用。
妊娠合并心脏病专题讨论-妊娠合并肺动脉高压的关注要点

妊娠合并肺动脉高压(pulmonary arterial hypertension,PAH),也称肺高血压,病死率可高达17%~ 56%,世界卫生组织(WHO)将任何原因导致的PAH列为Ⅳ级风险,孕期严重心血管事件发生风险40%~100%,属妊娠禁忌,而临床实际工作中,妊娠合并PAH并不罕见,是导致孕产妇死亡的重要原因之一,针对此类病例的孕产期保健工作,需要关注原发疾病及妊娠导致的一系列母体变化,个体化及细节管理非常重要。
产后出血风险评估工具和预警系统的效用评价

产后出血(PPH)是导致孕产妇死亡的首要原因。充分评估PPH的高危风险,并建立有效的PPH预警系统,可早期发现并积极处理高危因素或潜在隐患,在一定程度上预防PPH,最大程度地降低严重产后出血(SPPH)发生率,减少孕产妇死亡。本文针对现有PPH评估工具及PPH预警系统进行回顾分析,对比各种评价指标及预警在PPH防治中的效用与价值。分娩过程是一个时时变化、需要时时评估的动态过程,静态单一的PPH评估工具时效性和效用均较低,需整合各种高危因素,综合、动态地进行评估,完善PPH预警。因目前诸多PPH预警评价体系中并无统一的管理方案,现应用较多的英国改良产科早期预警系统及孕产妇早期综合预警两个系统的标准之间也存在着一定差异,故而预警指标并不能完全取代临床判断,需结合临床,综合分析、个体化诊疗。
Clinical observation on the effect of acupuncture and moxibustion combined with rehabilitation training on post-stroke shoulder hand syndrome

Objective:To compare the clinical effects of body acupuncture,moxibustion,and body acupuncture plus moxibustion in the treatment of post-stroke shoulder hand syndrome (SHS).Methods:A total of 90 SHS patients after stroke were randomly divided into the body acupuncture group,the moxibustion group,and the body acupuncture plus moxibustion group,with 30 cases in each.On the basis of rehabilitation and routine treatment,the patients in different groups were treated with body acupuncture,moxibustion,and body acupuncture plus moxibustion respectively.Treatment was given once a day,5 times a week,and 4 weeks in all.The visual analogue scale (VAS) scores,edema grading scores,and simplified Fugl-Meyer assessment (FMA) scores were evaluated before and after treatment,and the therapeutic effects of patients were evaluated as well.Results:After treatment,the VAS and edema grading scores of the three groups were all lower and the FMA scores were all higher than those before treatment,with statistically significant differences (all P<0.05).The VAS and edema grading scores of the acupuncture plus moxibustion group were lower and the FMA score was higher than those of the body acupuncture group and the moxibustion group,with statistically significant differences (all P<0.05).The total effective rate of the acupuncture plus moxibustion group was 96.7%,higher than 80.0% of the body acupuncture group and 83.3% of the moxibustion group,with statistically significant differences (both P<0.05).Conclusion:Body acupuncture,moxibustion,and body acupuncture plus moxibustion are all effective for post-stroke SHS,while the effect of acupuncture plus moxibustion is the best in relieving the pain and swelling,and improving effectively the joint movement of post-stroke SHS patients,which should be popularized in clinical practice.
Solution combustion synthesis and electrochemical properties of yttrium-doped LiMnPO_4/C cathode materials for lithium ion batteries

Phospho-olivine pristine LiMnPO_4/C and yttrium-substituted LiMn_(1-x)Y_xPO_4/C (x = 0,0.01,0.03,0.05)were synthesized by a solution combustion method.The effects of Y-doped on structure,morphology and electrochemical performances were investigated.From powder X-ray diffraction pattern,all substituted materials adopt an identical structure to that of the LiMnPO_4 olivine structure,suggesting that the yttrium ion was well incorporated into the crystal lattice,without any changes in the host crystal structure.The electrochemical impedance spectroscopy provides clearly that yttrium-substituting reduces the charge transfer impedance and improves the lithium ion diffusion through the structure.When x = 0.01,the material shows an excellent capacity and stability during charge/discharge process.The initial specific discharge capacity can reach up to 156.84 mAh/g at C/20,with a coulombic efficiency of about 96.11%,which is 14% higher than that of the pristine material.The results confirm that the cyclic stability and the electrochemical performances of LiMnPO_4/C are highly improved by Y-doping.
Extraction of scandium from red mud by acid leaching with CaF_2 and solvent extraction with P507

The extraction of Sc by acid leaching with CaF_2 and solvent extraction with P507 from red mud was proposed.The influence of acid leaching and solvent extraction on recovery of Sc was investigated.The CaF_2 can obviously improve the leaching efficiency of Sc and reduce the acid consumption.The leaching efficiency of Sc increases from 74% to 92% and the dosage of acid reduces under suitable conditions by adding 5% CaF_2.The minerals in red mud can easily be decomposed and leached into the acid solution with CaF_2 through analysis of XRD pattern.The particles of red mud become smaller and multihole.The Sc can be selectively extracted with 10% P507 at the pH value of 0.1 from the acid leaching solution.More than 98% of Sc and less than 10% of Al and Fe are extracted.The Sc_2O_3 with purity of 99% is obtained after the process of reverse extraction with NaOH,H_2SO_4 dissolution,precipitation by oxalic acid and roasting at 750 °C.
Systematic study of the dependence of magnetic and structural properties of Nd_2Fe_(14)B powders on the average particle size

A systematic study of the magnetic and structural properties dependence on the particle size was realized.For this,commercial NdFeB powder was separated into five different mean particle sizes using sieves.Besides,from the original powder,eleven samples were also produced by mechanical milling assisted by surfactant,using various milling times.A total of sixteen samples were studied by scanning electron microscopy (SEM),X-ray diffraction (XRD),vibrating sample magnetometry (VSM),and Mossbauer spectrometry (MS).The particle sizes of the samples vary from the micrometer to the nanometer scale.The crystallite size decreases with decreasing particle size.XRD result indicates that the Nd_2Fe_(14)B phase is found in all the samples,and the presence of this phase is also corroborated by MS using six sextets for fitting their spectra,with an additional singlet corresponding to the Nd_(1.1)Fe_4B_4 phase.The mean hyperfine magnetic field increases with increasing particle size because the magnetic dipolar interaction between the magnetic moment of the particles increases with particle size.From the VSM measurements the magnetic energy density (BH)_(max) values were calculated for different particle sizes,and their maximum value of 34.45 MGOe is obtained for the sample with the particle size of 60 µm.
Theoretical prediction of radiation-enhanced diffusion behavior in nickel under self-ion irradiation

The enhanced diffusion in materials under irradiation plays an important role in the long-term microstructural evolution.In this work,the self-ion irradiation in nickel was used as a model system to study the effect of radiation-enhanced diffusion on the implanted ion profiles.Initially,the depth profiles of vacancies and implanted ions for nickel self-ion irradiation with ion energies up to 15 MeV were computed by the high-efficiency Monte Carlo code IM3D(Irradiation of Materials in 3D).The results are in good agreement with those predicted by SRIM(Stopping and Range of Ions in Matter).Then,diffusion coefficients as functions of temperature and damage rate were obtained,and the depth-dependent diffusion coefficients at various temperatures and damage rates were also illustrated.For this purpose,we used a temperature-dependent effective sink concentration for nickel,which was estimated from the available experimental investigations on the damage structures of irradiated nickel.At length,case studies on the time evolution of implanted ion profiles under the condition of nickel selfirradiation were performed and discussed based on Fick's second law.The results help to understand the fundamental diffusion properties in ion irradiation,especially under higher-dose irradiation.
Co_2B_2O_5 as an anode material with high capacity for sodium ion batteries

In this work,a flake-structured Co_2B_2O_5 material was obtained by a simple sol-gel method and researched for use in sodium ion batteries firstly.When serving as anode material for sodium ion batteries,it exhibits the high initial reversible capacity of 466 mAh·g~(-1) at a current density of 100 mA·g~(-1).Through the recombination of carbon nanotubes (CNTs),the composite Co_2B_2O_5/CNTs delivers the initial reversible capacity of 464 mAh·g~(-1),and 324 mAh·g~(-1) is obtained after 60 cycles under the current density of 100 mA·g~(-1).When under the current density of 1000 mA·g~(-1),a capacity of 236 mAh·g~(-1) is obtained for Co_2B_2O_5/CNTs while 160 mAh·g~(-1) for Co_2B_2O_5.Moreover,the sodium storage behavior of Co_2B_2O_5 is identified by kinetic analysis.The higher Na~+ capacitive contribution of Co_2B_2O_5/CNTs could account for the enhanced rate performance.The results indicate that Co_2B_2O_5 is a promising anode material for sodium ion batteries.