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Detection of Nonlinear Behavior Induced by Hard Limiting in Voltage Source Converters in Wind Farms Based on Higher-order Spectral Analysis

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Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 630-645页

作者： Zetian zheng Shaowei huang Qiangsheng Bu Chen Shen Jun yan State Key Laboratory of Power Systems Department of Electrical EngineeringTsinghua UniversityBeijing 100084China State Grid Jiangsu Electric Power Co. Ltd.Research InstituteNanjingChina

In recent years, sub-synchronous oscillation accidents caused by wind power integration have received extensive attention. The recorded constant-amplitude waveforms can be induced by either linear or nonlinear oscillation mechanisms. Hence, the nonlinear behavior needs to be distinguished prior to choosing the analysis method. Since the 1960s, the higher-order statistics(HOS) theory has become a powerful tool for the detection of nonlinear behavior(DNB) in production quality control wherein it has mainly been applied to mechanical condition monitoring and fault diagnosis. This study focuses on the hard limiters of the voltage source converter(VSC) control systems in the wind farms and attempts to detect the nonlinear behavior caused by bi-or uni-lateral saturation hard limiting using the HOS analysis. First, the conventional describing function is extended to obtain the detailed frequency domain information on the bi-and uni-lateral saturation hard limiting. Furthermore, the bi-and tri-spectra are introduced as the HOS, which are extended into bi-and tri-coherence spectra to eliminate the effects of the linear parts on the harmonic characteristics of hard limiting in the VSC control system, respectively. The effectiveness of the HOS in the DNB and the classification of the hard-limiting types is proven, and its detailed derivation and estimation procedure is presented. Finally, the quadratic and cubic phase coupling in the signals is illustrated, and the performance of the proposed method is evaluated and discussed.

关键词： Bi-coherence spectrum detection of nonlinear behavior hard limiting higher-order statistics tri-coherence spectrum voltage source converter wind farms.

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Analysis and monitoring of drug therapy in a patient with peptic ulcer complicated by infection:A case report

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World Journal of Clinical Cases 2024年第8期12卷 1530-1535页

作者： yan-Ping Gou Yue huang Li Chen Wei zheng Yun-Hua zheng The Second People’s Hospital of Meishan City&Renshou County People’s Hospital Meishan 620500Sichuan ProvinceChina Quality Evaluation and Medical Record Management The Affiliated Hospital of Southwest Jiaotong University&The Third People's Hospital of ChengduChengdu 610000Sichuan ProvinceChina Patriotic Health Campaign Qionglai City Health BureauChengdu 610000Sichuan ProvinceChina

BACKGROUND The role of primary-level medical pharmacists in medical institutions in China is limited;therefore,it is necessary to explore the role of pharmacists in the process of drug treatment.CASE SUMMARY A Chinese pharmacist participated in the complete treatment of a patient with a duodenal ulcer.The rationale for drug treatment was evaluated,and adjustments were made to the antacid and anti-infective regimen,as well as the dose and frequency of administration.Body temperature,routine blood examination,and adverse drug reactions were strictly monitored.During treatment,the pharmacist recommended anti-infective therapy with ampicillin-sulbactam,which effectively controlled the infection.Additionally,the pharmacist suggested changing famotidine to lansoprazole for acid suppression and gastroprotective treatment,combined with Chinese patent medicine such as Kangfuxin Liquid.This is the first case report of a pharmacist in primary-level medical institutions adjusting drug use for patients with duodenal ulcer and pulmonary infection.CONCLUSION A pharmacist participated in the treatment process,provided individualized medication adjustment,and achieved good clinical results.

关键词： Ampicillin-sulbactam Famotidine Lansoprazole Kangfuxin Liquid Chinese pharmacist Case report

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The Multiple Roles of Autophagy in Neural Function and Diseases

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Neuroscience Bulletin 2024年第3期40卷 363-382页

作者： yan-yan Li zheng-Hong Qin Rui Sheng Department of Pharmacology and Laboratory of Aging and Nervous Diseases Jiangsu Key laboratory of Neuropsychiatric DiseasesCollege of Pharmaceutical Sciences of Soochow UniversitySuzhou 215123China

Autophagy involves the sequestration and delivery of cytoplasmic materials to lysosomes,where proteins,lipids,and organelles are degraded and recycled.According to the way the cytoplasmic components are engulfed,autophagy can be divided into macroautophagy,microautophagy,and chaperone-mediated autophagy.Recently,many studies have found that autophagy plays an important role in neurological diseases,including Alzheimer's disease,Parkinson's disease,Huntington's disease,neuronal excitotoxicity,and cerebral ischemia.Autophagy maintains cell homeostasis in the nervous system via degradation of misfolded proteins,elimination of damaged organelles,and regulation of apoptosis and inflammation.AMPK-mTOR,Beclin 1,TP53,endoplasmic reticulum stress,and other signal pathways are involved in the regulation of autophagy and can be used as potential therapeutic targets for neurological diseases.Here,we discuss the role,functions,and signal pathways of autophagy in neurological diseases,which will shed light on the pathogenic mechanisms of neurological diseases and suggest novel targets for therapies.

关键词： Autophagy Neurodegenerative diseases Cerebral ischemia AMPK mTOR Beclin 1 TP53 Endoplasmic reticulum stress

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Modulated symbol-based one-time pad secure transmission scheme using physical layer keys

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Science China(Information Sciences) 2024年第1期67卷 221-239页

作者： Xiaoyan HU zheng WAN Kaizhi huang Liang JIN Mengyao yan Yajun CHEN Jinmei yanG Information Engineering University Purple Mountain Laboratories for Network and Communication Security

This paper proposes a novel modulated symbols-based one-time pad(SOTP) secure transmission scheme using physical layer keys.Unlike classical physical layer key generation and exclusive OR(XOR)encryption in the discrete binary space,we design a framework for modulated symbols-based one-time pad(OTP) encryption,where the cryptographic primitive and mathematical model of SOTP is given to build a practical cryptographic protocol.Compared with existing physical layer encryption(PLE) schemes,we provide rigorous proof that the framework can meet perfect secrecy and correctness requirements.In addition,we provide a specific scheme of physical layer OTP secure transmission for quadrature amplitude modulation(QAM) and phase-shift keying(PSK) symbols based on physical layer keys.This scheme realizes the unification of bit encryption and symbol encryption,which can adaptively select the quantization level according to the signal-to-noise ratio(SNR) to minimize the symbol error rate(SER).Further,we analyze the performance quantitatively and derive the closed-form expressions of SER,which indicates that the proposed scheme has a lower SER.Finally,simulation results verify that the proposed symbol-wise OTP secure transmission scheme can achieve perfect secrecy and high reliability.

关键词： physical layer security one-time pad wireless channel physical layer encryption perfect secrecy

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Computerized tomography-guided therapeutic percutaneous puncture catheter drainage-combined with somatostatin for severe acute pancreatitis: An analysis of efficacy and safety

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World Journal of Gastrointestinal Surgery 2024年第1期16卷 59-66页

作者： Xue-Lan zheng Wan-Ling Li yan-Ping Lin Ting-Long huang Department of Critical Care Medicine The Second Affiliated Hospital of Fujian Medical UniversityQuanzhou 362000Fujian ProvinceChina CT Room The Second Affiliated Hospital of Fujian Medical UniversityQuanzhou 362000Fujian ProvinceChina

BACKGROUND Severe acute pancreatitis(SAP),a condition with rapid onset,critical condition and unsatisfactory prognosis,poses a certain threat to human health,warranting optimization of relevant treatment plans to improve treatment efficacy.AIM To evaluate the efficacy and safety of computerized tomography-guided the-rapeutic percutaneous puncture catheter drainage(CT-TPPCD)combined with somatostatin(SS)in the treatment of SAP.METHODS Forty-two SAP patients admitted to The Second Affiliated Hospital of Fujian Medical University from June 2020 to June 2023 were selected.On the basis of routine treatment,20 patients received SS therapy(control group)and 22 patients were given CT-TPPCD plus SS intervention(research group).The efficacy,safety(pancreatic fistula,intra-abdominal hemorrhage,sepsis,and organ dysfunction syndrome),abdominal bloating and pain relief time,bowel recovery time,hospital stay,inflammatory indicators(C-reactive protein,interleukin-6,and pro-calcitonin),and Acute Physiology and Chronic Health Evaluation(APACHE)II score of both groups were evaluated for comparison.RESULTS Compared with the control group,the research group had a markedly higher total effective rate,faster abdominal bloating and pain relief and bowel recovery,INTRODUCTION Pancreatitis,an inflammatory disease occurring in the pancreatic tissue,is classified as either acute or chronic and is associated with high morbidity and mortality,imposing a socioeconomic burden[1,2].The pathogenesis of this disease involves early protease activation,activation of nuclear factor kappa-B-related inflammatory reactions,and infiltration of immune cells[3].Severe acute pancreatitis(SAP)is a serious condition involving systemic injury and subsequent possible organ failure,accounting for 20%of all acute pancreatitis cases[4].SAP is also characterized by rapid onset,critical illness and unsatisfactory prognosis and is correlated with serious adverse events such as systemic inflammatory response syn-drome and acute lung injury,threatening the health of pa

关键词： Computerized tomography guidance Therapeutic percutaneous puncture catheter drainage Somatostatin Severe acute pancreatitis Efficacy and safety

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Regulation role of miR-204 on SIRT1/VEGF in metabolic memory induced by high glucose in human retinal pigment epithelial cells

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International Journal of Ophthalmology(English edition) 2024年第7期17卷 1232-1237页

作者： Qiao-Ling Lai Ting Xie Wei-Dong zheng yan huang Department of Ophthalmology Renmin Hospital of Wuhan UniversityWuhan 460060Hubei ProvinceChina Department of Ophthalmology The First Affiliated Hospital of Fujian Medical UniversityFuzhou 350004Fujian ProvinceChina Department of Ophthalmology&Optometry Fujian Medical UniversityFuzhou 350004Fujian ProvinceChina

AIM:To examine the regulatory role of microRNA-204(miR-204)on silent information regulator 1(SIRT1)and vascular endothelial growth factor(VEGF)under highglucose-induced metabolic memory in human retinal pigment epithelial(hRPE)cells.METHODS:Cells were cultured with either normal(5 mmol/L)or high D-glucose(25 mmol/L)concentrations for 8d to establish control and high-glucose groups,respectively.To induce metabolic memory,cells were cultured with 25 mmol/L D-glucose for 4d followed by culture with 5 mmol/L D-glucose for 4d.In addition,exposed in 25 mmol/L D-glucose for 4d and then transfected with 100 nmol/L miR-204 control,miR-204 inhibitor or miR-204 mimic in 5 mmol/L D-glucose for 4d.Quantitative reverse transcription-polymerase chain reaction(RT-qPCR)was used to detect miR-204 mRNA levels.SIRT1 and VEGF protein levels were assessed by immunohistochemical and Western blot.Flow cytometry was used to investigate apoptosis rate.RESULTS:It was found that high glucose promoted miR-204 and VEGF expression,and inhibited SIRT1 activity,even after the return to normal glucose culture conditions.Upregulation of miR-204 promoted apoptosis inhibiting SIRT1 and increasing VEGF expression.However,downregulation of miR-204 produced the opposite effects.CONCLUSION:The study identifies that miR-204 is the upstream target of SIRT1and VEGF,and that miR-204 can protect hRPE cells from the damage caused by metabolic memory through increasing SIRT1 and inhibiting VEGF expression.

关键词： human retinal pigment epithelial metabolic memory microRNA-204 silent information regulator 1 vascular endothelial growth factor high-glucose

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Effect of lens surgery on health-related quality of life in preschool children with congenital ectopia lentis

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International Journal of Ophthalmology(English edition) 2024年第1期17卷 66-72页

作者： yan-Qiao huang Qian-Zhong Cao Yi-Yao Wang Yi-Jing Zhou Dan-Ying zheng State Key Laboratory of Ophthalmology Zhongshan Ophthalmic CenterSun Yat-sen UniversityGuangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangdong Provincial Clinical Research Center for Ocular DiseasesGuangzhou 510060Guangdong ProvinceChina

AIM:To evaluate the effect of lens surgery on health-related quality of life(HRQoL)of preschool children with congenital ectopia lentis(CEL).METHODS:A prospective self-controlled study was conducted in Zhongshan Ophthalmic Center.Children aged from 5 to 7y whom were diagnosed with CEL and underwent phacoemulsification with scleral-fixated posterior chamber intraocular lens implantation and their parents were enrolled in this study.All of them completed the child and proxy(parental)PedsQL™4.0 before and after the surgery.Their preoperative scores were compared to their postoperative ones.Subgroup analyses were performed based on gender and preoperative bilateral presenting visual acuity of the children.RESULTS:Thirty-two children with CEL successfully underwent surgery without any complications,among whom 8 had monocular surgery and 24 had binocular surgery.Preoperative and postoperative questionnaires were completed by 32 child-parent pairs.Surgical intervention could significantly improve the vision of affected children(P<0.001).The medians of physical,psychosocial and total health scores self-reported by the children were 68.75(62.50,81.25),65.00(60.00,80.00)and 67.39(60.87,78.26)preoperatively and were 93.75(87.50,100.00),90.00(83.33,96.67)and 89.13(85.32,95.65)postoperatively.The preoperative scores of the affected children were significantly lower in all scales than age-matched healthy children(P<0.001).All the postoperative scores were significantly higher than the preoperative scores in affected children and their parents(P<0.001).In the physical functioning evaluation,the preoperative score reported by parents of girls was higher than parents of boys(P=0.041),and the postoperative score of girls was higher than that of boys(P=0.036).CONCLUSION:CEL is associated with significantly worse quality of life in preschool children.Surgical intervention can significantly improve the HRQoL in affected children from both personal and family perspective.

关键词： congenital ectopia lentis surgical intervention health-related quality of life preschool children

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High-Order Decoupled and Bound Preserving Local Discontinuous Galerkin Methods for a Class of Chemotaxis Models

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Communications on Applied Mathematics and Computation 2024年第1期6卷 372-398页

作者： Wei zheng yan Xu School of Mathematical Sciences University of Science and Technology of ChinaHefei230026AnhuiChina

In this paper,we explore bound preserving and high-order accurate local discontinuous Galerkin(LDG)schemes to solve a class of chemotaxis models,including the classical Keller-Segel(KS)model and two other density-dependent problems.We use the convex splitting method,the variant energy quadratization method,and the scalar auxiliary variable method coupled with the LDG method to construct first-order temporal accurate schemes based on the gradient flow structure of the models.These semi-implicit schemes are decoupled,energy stable,and can be extended to high accuracy schemes using the semi-implicit spectral deferred correction method.Many bound preserving DG discretizations are only worked on explicit time integration methods and are difficult to get high-order accuracy.To overcome these difficulties,we use the Lagrange multipliers to enforce the implicit or semi-implicit LDG schemes to satisfy the bound constraints at each time step.This bound preserving limiter results in the Karush-Kuhn-Tucker condition,which can be solved by an efficient active set semi-smooth Newton method.Various numerical experiments illustrate the high-order accuracy and the effect of bound preserving.

关键词： Chemotaxis models Local discontinuous Galerkin(LDG)scheme Convex splitting method Variant energy quadratization method Scalar auxiliary variable method Spectral deferred correction method

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Microscale spherical TiO_(2)powder prepared by hydrolysis of TiCl_(4)solution:Synthesis and kinetics

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Particuology 2024年第1期84卷 60-71页

作者： Peiyi yan Ying Zhang Shili zheng School of Rare Earths University of Science and Technology of ChinaHefei230026China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou341119China Key Laboratory of Green Process and Engineering National Engineering Research Center of Green Recycling for Strategic Metal ResourcesInstitute of Process EngineeringChinese Academy of SciencesBeijing100190China State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization Panzhihua617000China

Hydrolysis of TiCl_(4)solution is capable of preparing microscale TiO_(2)particles.This research studied the synthesis of microscale spherical TiO_(2)powders and the hydrolysis kinetics.The effects of the flow field generated by different agitators and baffles in the crystallizer,the initial free acid concentration,the initial equivalent TiO_(2)concentration,and the temperature on the hydrolysis progress and powder morphology were systematically studied.The results show that the flow field in a crystallizer can significantly affect the morphology and particle size of the powders,and the axial flow can improve the sphericity of the powders.The increased free HCl and equivalent TiO_(2)concentrations in the pregnant solution inhibit the forward hydrolysis reaction,prolong the time to reach equilibrium,and reduce the yield.An appropriate temperature matching the compositions of the pregnant solution is crucial for the powder morphology and size.Powders with sizes ranging from around 5 um-40μm can be tuned under controlled flow field,solution compositions,and temperature conditions.In addition,the Cheng and Wunderlich modified Avrami equation was used for the crystallization kinetic modeling.The effects of the free HCl concentration,equivalent TiO_(2)concentration,and hydrolysis temperature are reflected in the reaction rate constant and active nuclei reduction index.Increasing the free HCl and equivalent TiO_(2)concentrations will reduce the reaction rate constant and accelerate the deactivation of the active nuclei,thus increasing the final powder size,while increasing the temperature will lead to the opposite results.

关键词： TiCl_(4) Hydrolysis Microscale TiO_(2) Spherical Kinetics

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Difference in microstructural characteristics of stamp-charged coke and gravity-charged coke with approximate macroscopic performance

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Journal of Iron and Steel Research(International) 2024年第5期31卷 1050-1062页

作者： Chong Zou zheng-yan huang Jian-yun Li Bin Li Shi-wei Liu Yuan She School of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an710311ShaanxiChina Technical Center of Shandong Iron and Steel Co. Ltd.(Laiwu Branch)Jinan271104ShandongChina

The microstructural characteristics including optical texture,porosity and pore structure and chemical structure of stamp-charged coke(SCC)and gravity-charged coke(GCC)with similar conventional macro-indicators were investigated,and the properties including micro-strength,reactivity of coke matrix and that after alkali enrichment were comparatively studied by various characterization methods.The anisotropic structure of SCC is composed of high content of fine mosaic texture,while the content of medium mosaic texture,coarse texture and fibrous texture is low.The statistical average shows that the fine mosaic average of SCC(24.89%)is 3.78 times the GCC average(6.58%),and the coarse mosaic average(1.24%)is only about 1/3 of the GCC average(3.43%).The porosity of SCC is lower than that of GCC,but tamping process does not lead to the fact that the number of closed pores of SCC is significantly lower than that of GCC.Although the structure of SCC is compact,its pore number is large and the pore wall is thin.Pores of coke with diameter less than 150 nm seem unaffected by tamping process.The aromatic structure of SCC was less ordered than that of GCC,which was speculated to be related to the addition of more low metamorphic coal in coking.The microscopic strength and structural strength of SCC are lower than those of GCC.The reactivity of coke matrix is affected by the specific surface area,but it is not the determining factor of its macro-reactivity.The improvement in dissolution reactivity of coke after potassium enrichment is independent of coke type.

关键词： Stamp-charged coke Optical texture Porosity Microstructure Reactivity

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