基于多数据源融合的电网故障判别与告警技术研究

针对国家电网故障判别误差率较高的问题,设计一种基于多数据源融合的电网故障判别与告警方案。利用最大离散小波变换技术和长短期记忆网络算法结合的方法提高电网故障判别与告警能力;利用最大重叠离散小波变换技术具有的扩充冗余自成正交特性对故障类型进行划分;将长短期记忆网络算法由单向进程转为双向网络,避免了反馈传输过程中的网络层无法得到合适的偏导数等梯度消失情况。试验结果表明,通过所提算法进行数据质量核查的准确度高达九成以上,表明所提研究系统对解决提升故障判别准确度的提升具有较强的实用性、优越性。

High‑Performance Silicon‑Rich Microparticle Anodes for Lithium‑Ion Batteries Enabled by Internal Stress Mitigation

Si is a promising anode material for Li ion batteries because of its high specific capacity,abundant reserve,and low cost.However,its rate performance and cycling stability are poor due to the severe particle pulverization during the lithiation/delithiation process.The high stress induced by the Li concentration gradient and anisotropic deformation is the main reason for the fracture of Si particles.Here we present a new stress mitigation strategy by uniformly distributing small amounts of Sn and Sb in Si micron-sized particles,which reduces the Li concentration gradient and realizes an isotropic lithiation/delithiation process.The Si8.5Sn0.5Sb microparticles(mean particle size:8.22μm)show over 6000-fold and tenfold improvements in electronic conductivity and Li diffusivity than Si particles,respectively.The discharge capacities of the Si_(8.5)Sn_(0.5)Sb microparticle anode after 100 cycles at 1.0 and 3.0 A g^(-1)are 1.62 and 1.19 Ah g^(-1),respectively,corresponding to a retention rate of 94.2%and 99.6%,respectively,relative to the capacity of the first cycle after activation.Multicomponent microparticle anodes containing Si,Sn,Sb,Ge and Ag prepared using the same method yields an ultra-low capacity decay rate of 0.02%per cycle for 1000 cycles at 1 A g^(-1),corroborating the proposed mechanism.The stress regulation mechanism enabled by the industry-compatible fabrication methods opens up enormous opportunities for low-cost and high-energy-density Li-ion batteries.

Stage-specific nutritional management and developmental programming to optimize meat production

Over the past few decades,genetic selection and refined nutritional management have extensively been used to increase the growth rate and lean meat production of livestock.However,the rapid growth rates of modern breeds are often accompanied by a reduction in intramuscular fat deposition and increased occurrences of muscle abnor‑malities,impairing meat quality and processing functionality.Early stages of animal development set the long‑term growth trajectory of offspring.However,due to the seasonal reproductive cycles of ruminant livestock,gestational nutrient deficiencies caused by seasonal variations,frequent droughts,and unfavorable geological locations nega‑tively affect fetal development and their subsequent production efficiency and meat quality.Therefore,enrolling live‑stock in nutritional intervention strategies during gestation is effective for improving the body composition and meat quality of the offspring at harvest.These crucial early developmental stages include embryonic,fetal,and postnatal stages,which have stage‑specific effects on subsequent offspring development,body composition,and meat quality.This review summarizes contemporary research in the embryonic,fetal,and neonatal development,and the impacts of maternal nutrition on the early development and programming effects on the long‑term growth performance of livestock.Understanding the developmental and metabolic characteristics of skeletal muscle,adipose,and fibrotic tissues will facilitate the development of stage‑specific nutritional management strategies to optimize production efficiency and meat quality.

Commissioning and operation of the cryostat for 3W1 SC wiggler

A 3W1 superconducting wiggler(SCW)with the pole gap of 68 mm was successfully tested and installed in a BEPC II storage ring in November,2019.The goal of zero liquid helium consumption was achieved,and the cryogenic system exhibited a 12%residual cooling capacity(approximately 0.69 W@4.2 K).The 3W1-SCW was set to operate at 2.49 T and has been operating for more than seven months.Three instances of magnet quenching occurred during the normal operation.The evaporated helium gas can be recycled to the helium gas recycling system when the pressure in the helium tank is higher than the parameter value(the setpoint of the pressure value is 1.2 bara).The cryogenic system can be recovered within 4 h if sufficient liquid helium is available to inject into the cryostat.

Melatonin attenuates hepatic ischemia-reperfusion injury in rats by inhibiting NF-κB signaling pathway

Background:The sterile inflammatory response is one of the key mechanisms leading to hepatic ischemia-reperfusion injury.Melatonin has been shown to prevent organ injuries,but its roles in the inflammatory response after hepatic ischemia-reperfusion injury have not been fully explored,especially in late ischemia-reperfusion injury.The present study aimed to investigate the roles and possible mechanisms of melatonin in the inflammatory response after hepatic ischemia-reperfusion injury.Methods:Sixty Sprague-Dawley rats were randomly divided into a sham group,ischemia-reperfusion injury group(I/R group),and melatonin-treated group(M+I/R group).The rats in the I/R group were subjected to 70%hepatic ischemia for 45 min,followed by 5 or 24 h of reperfusion.The rats in the M+I/R group were injected with melatonin(10 mg/kg,intravenous injection)15 min prior to ischemia and immediately before reperfusion.Serum and samples of ischemic liver lobes were harvested for future analysis,and the 7-day survival rate was assessed after hepatic ischemia-reperfusion surgery.Results:In comparison with the I/R group,the M+I/R group showed markedly decreased expression levels of inflammatory cytokines(IL-6 and TNF-α)and numbers of apoptotic hepatocytes(P<0.05).Immunoblotting showed that the expression levels of IL-6,p-NF-κBp65/t-NF-κBp65 and p-IκB-α/t-IκB-αin the M+I/R group were significantly lower than those in the I/R group,and immunofluorescence staining showed that the expression level of p-NF-κBp65 in the M+I/R group was lower than that in the I/R group(P<0.05).The 7-day survival rates were 20%in the I/R group and 50%in the M+I/R group(P<0.05).Conclusions:Melatonin downregulated the activity of the NF-κB signaling pathway in the early and late stages of hepatic ischemia-reperfusion injury,alleviated the inflammatory response,protected the liver from ischemia-reperfusion injury,and increased the survival rate.

Superconducting multipole wiggler with large magnetic gap for HEPS-TF

A 16-pole superconducting multipole wiggler with a large gap of 68 mm was designed and fabricated to serve as a multipole wiggler for HEPS-TF.The wiggler consists of 16 pairs of NbTi superconducting coils with a period length of 170 mm,and its maximum peak field is 2.6 Tesla.In magnet design,magnet poles were optimized.Furthermore,the Lorentz force on the coils and electromagnetic force between the upper and lower halves were computed and analyzed along with the stored energy and inductance at different currents.To enhance the critical current of the magnet coil,all the pole coils selected for the magnet exhibited excellent performance,and appropriate prestress derived from the coil force analysis was applied to the pole coils during magnet assembly.The entire magnet structure was immersed in 4.2-K liquid helium in the cryostat cooled solely by four two-stage cryocoolers,and the performance test of the superconducting wiggler was appropriately completed.Based on the measured results,the first and second field integrals on the axis of the superconducting wiggler were significantly improved at different field levels after the compensation of the corrector coils.Subsequently,the wiggler was successfully installed in the storage ring of BEPCII operation with beams.

川西地区川主庙剖面泡砂岩中流体运移规律研究

流体的运移方向及规律是研究油气运移方式及路径的重要内容,只有对流体运移方向及规律建立起运移模型,从而更有效指导油气勘探。此次研究区为马林岩向斜北西翼的名山组泡砂岩层,岩性特征为砂岩层与泥岩层交替出现的互层,向斜翼部以砖红色中–厚层砂岩为主,夹薄层泥岩;向斜核部的位置泥岩层以砖红色泥岩为主,夹粉砂岩和细砂岩。由于名山组泡砂岩孔隙流体在向斜内部的运移模式还没有不太清楚,通过对泥岩层裂缝充填物特征研究和元素分析,了解裂缝与流体之间的关系,进行流体运移痕迹研究,得出流体运移期次和运移规律,从而来建立流体在向斜泥岩层中的运移模型。研究表明,该区泥岩层中裂缝整体较发育,流体运移呈现出规律性:向斜翼部地层应力较小,裂缝发育较少,流体做顺层方向运移;向斜中部所受应力较大,裂缝分布呈蜘蛛网状,流体沿着蜘蛛网状通道运移;核部地层应力大且集中,裂缝发育呈十字状,流体沿十字状裂缝通道运移。

一种实验用自动计量存储式电子秤系统的设计与制作

以氧化钙-氢氧化钙储能实验为例,分析了质量检测过程中用时长、效率低、准确度差等问题,从实际应用出发,设计了一种实验用可自动计量存储的电子秤系统,实现了被测物体的质量自动、实时、准确地测量和存储。通过多次实验得出系统的测试相对误差小于1.2%,满足一般实验的测试要求。该系统优化了准确度、提高了实验人员的工作效率,在长时间、变质量检测实验中具有较好的应用性和推广性。

Research Progress on Antidepressant Therapeutic Biomarkers of Xiaoyaosan

Depression is one of the most prevalent and serious mental disorders with a significant burden of disease.Xiaoyaosan(XYS),a well-known Chinese formula,has been widely used in the treatment of depression.Both clinical studies and animal experiments have indicated that XYS has an obvious antidepressant activity.How to select objective pharmacodynamic markers for traditional Chinese medicine(TCM)treatments based on clinical metabolites,linking pathogenic genes,and drug targets,is a bottleneck problem in the modernization of TCM.To address this issue,we sorted out clinical metabonomics experiments of XYS in treating depression,constructed a metabolic profile of therapeutic biomarkers,and deduced metabolic biomarker-protein interactions networks.The therapeutic biomarkers found for XYS were involved in neurotransmitter synthesis,energy metabolism,and gut microbial metabolism.This study aims to provide a scientific basis for the clinical diagnosis of depression and evaluate the efficacy of XYS in its treatment.

A Network Pharmacology Approach to Decipher the Mechanisms of Anti-depression of Xiaoyaosan Formula

Objective: Depression is one of the prevalent and prominent complex psychiatric diseases, and the number of depressed patients has been on the rise globally during the recent decades.Xiaoyaosan, as a famous Chinese herbal formula, has been widely used in depression patients for a long time.However, the therapeutic mechanisms remain uncertain because of the difficulty of depression pathophysiology and the lack of bioinformatic approach to understand the molecular connection.Materials and Methods: In this thesis, we applied a network pharmacology approach to explain the potential mechanisms between Xiaoyaosan and depression involved in oral bioavailability screening, drug-likeness assessment, caco-2 permeability, blood–brain barrier target recognition, and network analysis.Results: Sixty-six active compounds in Xiaoyaosan formula with favorable pharmacokinetic profiles are predicted as active compounds for antidepression treatment.Network analyses showed that these 66 compounds target 40 depression-associated proteins including especially HTR2A, NR3C1, monoamine oxidase inhibitor B, XDH, and CNR2.These proteins are mainly involved in the neuroactive ligand–receptor interaction, serotonergic synapse, cAMP signaling pathways, and calcium signaling pathways.Conclusion: The integrated network pharmacology method can provide a new approach for understanding the pathogenesis of depression and uncovering the molecular mechanisms of Xiaoyansan, which will also facilitate the application of traditional Chinese herbs in modern medicine.

Design of digital controller for HEPS corrector power supply

Purpose In order to realize the control of current closed loop in HEPS corrector power supply,a digital control board is designed.Methods The control board uses the latest FPGA to realize digital processing and uses two different AD chips to realize current and voltage sampling,respectively.In order to achieve high-precision closed-loop control,an effective closed-loop control program is designed.Results The controller has been widely used in HEPS projects,and its control effect has been proved.Conclusions In order to realize control and reduce power cost,the controller is designed.The testing experiments show that the controller has excellent performance,reliable operation and low cost.

Performance of Hepatitis Delta Virus(HDV)RNA Testing for the Diagnosis of Active HDV Infection:Systematic Review and Meta-analysis

Background and Aims:Hepatitis delta virus(HDV)is a defective virus and causes severe liver disease.Several HDV RNA assays have been developed,however the diagnostic efficacy remains unclear.This systematic review and metaanalysis aims to evaluate the diagnostic accuracy of HDV RNA assays to aid in the diagnosis of active hepatitis D.Methods:The PubMed,Embase,and Cochrane Library databases were systematically searched from the beginning to June 31,2022.Information on the characteristics of the literature and data on sensitivity,specificity,and area under curve(AUC)of the receiver operating characteristic(ROC)were extracted.Stata 14.0 was used for meta-analysis of the combined sensitivity,specificity,positive likelihood ratio,and negative likelihood ratio.Results:A total of 10 studies were included in the meta-analysis.The summary sensitivity,specificity,positive likelihood ratio,negative likelihood ratio,and diagnostic odds ratio of HDV RNA assays for HDV diagnosis were 0.92(95%CI:0.87-0.95),0.90(95%CI:0.86-0.93),7.74(95%CI:5.31-11.29),0.10(95%CI:0.06-0.18)and 99.90(95%CI:47.08-211.99),respectively.The AUC of the pooled ROC curve was 0.95(95%CI:0.92-0.96).Conclusions:The results show that HDV RNA assays had high diagnostic performance.However,that is limited by the number and quality of studies.Standard protocols for the development of assays by manufacturers and larger studies on the use of the assays are needed.

基于规律成簇的间隔短回文重复序列及其相关蛋白技术检测乙型肝炎病毒共价闭合环状DNA方法的建立

目的建立一种基于规律成簇的间隔短回文重复序列及其相关蛋白(CRISPR/Cas13a)的乙型肝炎病毒(HBV)共价闭合环状DNA(HBV cccDNA)检测方法。方法提取2017年6月至2020年10月于首都医科大学附属北京佑安医院就诊的4例乙型肝炎患者肝脏总DNA后,使用HindⅢ内切酶和质粒安全性ATP依赖DNA酶(PSAD)分别进行酶切;根据松弛环状DNA(rcDNA)和cccDNA的结构差异,设计特异性扩增HBV cccDNA的引物,对酶切后的产物进行滚环扩增(RCA)和PCR扩增;并筛选crRNA,建立基于CRISPR/Cas13a技术的HBV cccDNA检测新方法。结果利用α-1-抗胰蛋白酶(A1AT)和HBV表面抗原(HBsAg)引物对双重酶切后的产物进行扩增,验证产物中HBV基因组的存在;利用HBV cccDNA和HBV rcDNA引物对PSDA酶切后的产物扩增,验证了产物中只存在HBV cccDNA;利用RCA后的阳性样本作为模板梯度稀释,然后进行PCR扩增转录后使用CRISPR/Cas13a检测,计算出检测下限为10拷贝/μl。结论本研究建立了RCA-PCR-CRISPR-Cas13a的新型检测方法,可对HBV cccDNA进行高灵敏度和高特异性检测,为乙型肝炎患者抗病毒治疗评估、治疗终点的确定以及调整治疗方案提供了有效的监测手段。

Combined Effects of Stretching and Nanofillers on the Crystalline Structure and Mechanical Properties of Polypropylene and Single-walled Carbon Nanotube Composite Fibers

The combined effects of stretching and single-walled carbon nanotubes （SWCNTs） on crystalline structure and mechanical properties were systematically investigated in melt-spun polypropylene （PP） fibers prepared at two different draw ratios. The dispersion, alignment of the SWCNT bundles and interfacial crystalline structure in the composite fibers are significantly influenced by the stretching force during the melt spinning. The nanohybrid shish kebab （NHSK） superstructure where extended PP chains and aligned SWCNT bundle as hybrid shish and PP lamellae as kebab has been successfully obtained in the composite fibers prepared at the high draw ratio and the related formation mechanism is discussed based on the results of morphological observations and 2d-SAXS patterns. Large improvement in tensile strength and modulus has been realized at the high draw ratio due to the enhanced orientation and dispersion of SWCNT bundles as well as the formation of NHSK.

Acceptor-Donor-Acceptor Conjugated Oligomers Based on Diketopyrrolopyrrole and Thienoacenes with Four, Five and Six Rings for Organic Thin-film Transistors

Three acceptor-donor-acceptor （A-D-A） conjugated oligomers, i.e., O1, 02 and 03, have been synthesized using diketopyrrolopyrrole （DPP） as an electron-acceptor unit, and naphtho[1,2-b：5,6-b＇]dithiophene （NDT）, anthra[1,2-b：5,6- b＇]dithiophene （ADT） or dithieno[3,2-b：Y,2＇-b＇]naphtbo[1,2-b：5,6-b＇]dithiophene （DTNDT） as electron-donor unit. These oligomers exhibit identical highest occupied molecular orbital （HOMO） and lowest unoccupied molecular orbital （LUMO） energy levels, which were ca. -5.1 and -3.3 eV, respectively. Upon thermal annealing, all three oligomers formed thin films with ordered microstructures, and their organic thin film transistors （OTFTs） exhibited p-type transport behavior. The mobility was increased with an extension of the size of D-units. 03 showed the best OTFT performance with the mobility of up to 0.20 cm2·V-1 ·s-1. The film quality of 03 was improved by adding 1 wt% poly（methylmethacrylate） （PMMA）. In consequence, the mobility of the O3-based devices was further enhanced to 0.30 cm2·V-1 ·s-1.

Design of control algorithm for accelerator magnet power supply with large time constant load

Objective High Energy Photon Source-Test Facility(HEPS-TF)is a pre-research project for the construction of high energy synchrotron radiation source in the 12th five-year plan period.The purpose is to research the key technology and develop the key equipment of high energy synchrotron radiation source.Superconducting 3W1 magnet is the first self-developed superconducting wiggler magnet in China,and it is also one of the key research topics of HEPS.The author has completed a new digital closed-loop control algorithm for the superconducting 3W1 magnet with large load time constant and the nonlinear characteristics of inductance increasing with current,namely three-branch structure algorithm.In the face of the rapid development of high energy accelerator technology,the application of intelligent technology has become an inevitable development trend in the field of accelerator magnet power supply technology.Although the digital control of accelerator magnet power supply has been widely used,it is the first time to apply the new closed-loop control algorithm to realize fast adjustment and precision tracking in accelerator superconducting magnet power supply in China.Method According to the nonlinear characteristics of inductance and output current of superconducting magnet,a new digital closed-loop control algorithm for the load of superconducting magnet power supply with large time constant is proposed.Conclusion This algorithm is quite different from the traditional algorithm and can attain the independent tracking and adjust-ment of the control target.Finally,by testing the ripple,error and stability of superconducting 3W1 magnet power supply,the correctness,practicability and reliability of power supply system as well as the digital control algorithm are verified.The results provide a new idea for the control of accelerator magnet power supply.

The design of the superconducting wiggler power supply system for HEPS-TF

Purpose This paper describes the design of power supply system for superconducting wiggler in the project of high energy photon source-test facility.It includes three sets of high precision DC stabilized current power supplies for superconducting magnet excitation and three sets of quench protection assembly(QPA).A special magnetic load which has a very large time constant is studied in this paper.In this paper,a stable superconducting excitation power supply is developed,which can adjust the response quickly under the condition of very large load time constant.Meanwhile,the energy dissipation circuit of the QPA is integrated into the power supply in an active quenching protection mode to accelerate the energy release of the superconducting magnet and protect the superconducting magnet.Method The main circuit topology,control algorithm,quenching protection circuit and interlocking logic function are designed for the superconducting magnet with large inductance.The upper computer controls the switch of the three main power circuits through the serial port,sets the output current and adjusts the parameters according to the load.Conclusion Through a series of scientific and rigorous experiments,the rationality of superconducting wiggler magnet power supply scheme is demonstrated.The output current stability test and output voltage ripple test of the power supply meet or exceed the requirements of the magnet system.