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Extracellular nucleotides mediate viral central nervous system infections:Key alarmins of neuroinflammation and neurodegeneration
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作者 Raissa Leite-Aguiar Elaine Paiva-Pereira +2 位作者 Robson Coutinho-Silva Claudia Pinto Figueiredo Luiz Eduardo Baggio Savio 《Neural Regeneration Research》 2026年第5期1890-1898,共9页
Recent increases in infectious diseases affecting the central nervous system have raised concerns about their role in neuroinflammation and neurodegeneration.Viral pathogens or their products can invade the central ne... Recent increases in infectious diseases affecting the central nervous system have raised concerns about their role in neuroinflammation and neurodegeneration.Viral pathogens or their products can invade the central nervous system and cause damage,leading to meningitis,encephalitis,meningoencephalitis,myelitis,or post-infectious demyelinating diseases.Although neuroinflammation initially has a protective function,chronic inflammation can contribute to the development of neurodegenerative diseases.Mechanisms such as protein aggregation and cellular disturbances are implicated with specific viruses such as herpes simplex virus type 1 and Epstein-Barr virus being associated with Alzheimer's disease and multiple sclerosis,respectively.Extracellular nucleotides,particularly adenosine triphosphate and its metabolites are released from activated,infected,and dying cells,acting as alarmins mediating neuroinflammation and neurodegeneration.When viruses infect central nervous system cells,adenosine triphosphate is released as an alarmin,triggering inflammatory responses.This process is mediated by purinergic receptors,divided into two families:P1,which responds to adenosine,and P2,activated by adenosine triphosphate and other nucleotides.This review highlights how specific viruses,such as human immunodeficiency virus type 1,Theiler's murine encephalomyelitis virus,herpes simplex virus type 1,Epstein-Barr virus,dengue virus,Zika virus,and severe acute respiratory syndrome coronavirus 2,can initiate inflammatory responses through the release of extracellular nucleotides,particularly adenosine triphosphate,which act as critical mediators in the progression of neuroinflammation and neurodegenerative disorders.A better understanding of purinergic signaling pathways in these diseases may suggest new potential therapeutic strategies for targeting neuroinflammation to mitigate the long-term consequences of viral infections in the central nervous system. 展开更多
关键词 adenosine triphosphate DENGUE Epstein-Barr virus herpes simplex virus type 1 human immunodeficiency virus type 1 neurodegenerative diseases neurotropic infections purinergic signaling severe acute respiratory syndrome coronavirus 2 virus Zika
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Systemic IL-1β production as a consequence of corneal HSV-1 infection-contribution to the development of herpes simplex keratitis 被引量:1
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作者 Joan NíGabhann-Dromgoole Ciaran de Chaumont +6 位作者 David Shahnazaryan Siobhán Smith Conor Malone Jaythoon Hassan Cillian F.De Gascun Caroline A.Jefferies Conor C.Murphy 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2019年第9期1493-1497,共5页
This study sought to identify potential therapeutic targets in herpes simplex keratitis(HSK) patients with active and inactive infection by investigating peripheral cytokine production. Peripheral blood mononuclear ce... This study sought to identify potential therapeutic targets in herpes simplex keratitis(HSK) patients with active and inactive infection by investigating peripheral cytokine production. Peripheral blood mononuclear cells(PBMCs) and serum were prepared from healthy controls and HSK patients during active infection or following treatment(inactive infection). Serum antibody titres were determined by ELISA. Protein expression levels were analysed by Western blot. Cytokine levels were determined by multiplex ELISA. Active corneal herpes simplex virus type 1(HSV-1) infection resulted in significantly elevated peripheral levels of IL-1β in HSK patients compared to healthy controls, and remained significantly increased following treatment. Elevated production of IL-1β in inactive patients was associated with significantly increased levels of IRF3 and STAT1, key proteins involved in promoting anti-viral immune responses. Our data suggest that inflammation persists beyond the period that it is clinically evident and that enhanced peripheral production of IL-1β may have implications for HSV-1 viral clearance in active and inactive HSK patients. 展开更多
关键词 HERPES simplex virus type 1 HERPES simplex KERATITIS inflammation peripheral immune response pathogenesis
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Total dysphagia after short course of systemic corticotherapy:Herpes simplex virus esophagitis
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作者 Isa Jetté-Cté Denise Ouellette +1 位作者 Claire Béliveau Andrew Mitchell 《World Journal of Gastroenterology》 SCIE CAS 2013年第31期5178-5181,共4页
A 72 year-old female developed a herpetic esophagitis after 3 d of oral corticotherapy for an acute exacerbation of chronic obstructive pulmonary disease,presenting as odynophagia and total dysphagia.Biospies were tak... A 72 year-old female developed a herpetic esophagitis after 3 d of oral corticotherapy for an acute exacerbation of chronic obstructive pulmonary disease,presenting as odynophagia and total dysphagia.Biospies were taken during a first esophagogastroduodenoscopy(EGD) and the patient was referred to the thoracic surgery service with a presumptive diagnosis of esophageal cancer.A second EGD was planned for dilatation,but by that time the stenosis was completely resolved.The biopsies taken during the first EGD revealed multiple herpetic viral inclusions and ulcerations without any dysplasia or neoplasia.In front of a severe esophageal stenosis,one must still exclude the usual differential diagnosis peptic stenosis and cancer.Visualization of endoscopic lesions can suggest the diagnosis but must be promptly confirmed by biopsy,viral culture or polymerase chain reaction.Although immune systemic effects of corticotherapy are well known and herpetic esophagitis occurs most frequently in immunocompromised individuals,this case emphasizes the importance of clinical awareness concerning short courses of corticotherapy for immunocompetent individuals.This article discusses the reactivation process of herpetic infection in this context and addresses its diagnostic and therapeutic issues. 展开更多
关键词 HERPES simplex ESOPHAGITIS DYSPHAGIA CORTICOSTEROIDS IMMUNOCOMPETENCE
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Infection and Immunity of Herpes Simplex Virusin the Culture System sof Lym phocytes and Monocyte-Macrophages
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作者 Ji Xiaohui(季晓辉) Yao Kun(姚 ) Zhou Yaoxi(周瑶玺) Zhang Ming(张 明) Wang Minglun(王明伦) Cao Zhihui(曹志惠) Sun Banghua(孙邦华) Li Huandi(李焕娣) Ding Runing(丁如宁) Chen Shenbao(陈慎宝) 《The Journal of Biomedical Research》 CAS 1999年第2期98-102,共5页
The study was made by the method of experimental infection using cultured cells in vitro. The characteristic of HSV infection of the cells and the effects of immunity factors on the infection were analyzed by cytopath... The study was made by the method of experimental infection using cultured cells in vitro. The characteristic of HSV infection of the cells and the effects of immunity factors on the infection were analyzed by cytopathic effect, double antibodies sandwich ELISA for immunoglobulin yield, hemolytic plaque assay for specific SRBC antibody forming cells, microcytopathy assay for viral titer, IFA for viral antigen and PCR for viral DNA.The results were as follows: ①A series of models of HSV infection were established, including the model of HSV 1 persistent infection of Raji cells, the model of acute and cytocidal HSV 1 infection of HSB\-2 cells, the models of temporary persistent HSV 1 infection of LPS stimulated U\-\{937\} cells and murine peritoneal macrophages and the models of inhibitions both of IgG synthesis and specific SRBC antibody production by HSV 1 infection of human tonsillar lymphocytes activated by PWM stimulating. ②According to the characteristic of HSV infection of lymphocyte and monocyte macrophage, it was reasonable that stimulating with antigen, mitogen, LPS, or inflammatory factors might make lymphocytes and/or monocyte macrophages become permissive cells of replicative HSV infection, or might activate the latent virus, resulting in HSV dissemination by blood circulation. ③It was proved that IFN α, IFN γ, TNF, M CSF, GM CSF and IL 3 have an inhibitory effect on HSV replication in lymphocyte and monocyte macrophage, respectively and reversed the replicative enhancement activity of LPS, suggesting that applications of these immunity factors favour lymphocytes and monocyte macrophages with a resistance to HSV replicative infection and with an inhibition of latent virus reactivation in vivo, and therefore, it might be helpful for preventing the virus from dissemination by blood circulation.\; 展开更多
关键词 herpes simplex virus LYMPHOCYTE monocyte macrophage INFECTION IMMUNITY
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Cooperative Therapeutic Effects of Herpes Simplex Virus Thymidine Kinase Gene/Ganciclovir System and Chemotherapeutic Agents on Prostate Cancer in vitro
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作者 邢毅飞 肖亚军 +4 位作者 鲁功成 曾甫清 赵军 熊平 冯玮 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2006年第5期610-613,共4页
The killing effects of herpes simplex virus thymidine kinase gene/ganciclovir (HSV-tk/GCV) approach by the addition of several commonly clinical chemotherapeutic agents on hormone refractory prostate cancer (HRPC)... The killing effects of herpes simplex virus thymidine kinase gene/ganciclovir (HSV-tk/GCV) approach by the addition of several commonly clinical chemotherapeutic agents on hormone refractory prostate cancer (HRPC) cells PC-3m were investigated. After transferring of the HSV-tk gene into PC-3m cells, mRNA and protein expression of HSV-tk was detected by reverse-transcript polymerase chain reaction (RT-PCR) and strept avidin-biotin complex (SABC) im- munohistochemical method. The killing effect of GCV, cisplatin (CDDP), etoposide (VP-16), vincristine (VCR), methotrexate (MTX), 5-fluorouracil (5-Fu), and suramin on PC-3m cells was evaluated by morphological assessment analysis, trypan blue exclusion assay and MTT assay respectively. Additionally, the cooperative effect of HSV-tk/GCV system combined with the above agents on the target cancer cells was determined by MTT. Furthermore, apoptosis and necrosis induced by GCV plus 5-Fu or suramin was analyzed by flow cytometry (FCM). The results showed that that there was HSV-tk mRNA and protein expression in pDR2-tk plasmid transduced PC-3m cell. Combination of GCV with VP-16, VCR, 5-Fu or suramin led to an enhanced cellular killing effect, but with CDDP resulted in a reduced one and with MTX in an approximate one. FCM revealed that synergistic use of GCV and 5-fu or suramin resulted in a rather large proportion of apoptosis and necrosis with the apoptosis index being 36.38 % and 35.51%, and the proportion of necrosis being 33.05 % and 28.87 %, respectively. In conclusion, HSV-tk/CGV approach by addition of certain clinical available chemotherapeutic drugs brings on statistically significant enhanced cell killing over single-agent treatment. Our results highlight the potential for such new combination therapies for future treatments of HRPC. 展开更多
关键词 prostatic neoplasms herpes simplex virus thymidine kinase gene GANCICLOVIR CHEMOTHERAPY gene therapy
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Effects of herpes simplex virus thymidine kinase/acyclovir system on growth of human pulmonary adenocarcinoma A549 cell line in vitro and in vivo
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作者 何祥梁 何东华 +4 位作者 郭先健 钱桂生 黄桂君 陈维忠 李淑萍 《Journal of Medical Colleges of PLA(China)》 CAS 2002年第3期227-231,共5页
Objective: To observe the effect of anciclovir (ACV) treatment on tumors induced by inoculation of TK gene-transfected human pulmonary adenocarcinoma A549 cells in nude mice. Methods: A recombinant plasmid containing ... Objective: To observe the effect of anciclovir (ACV) treatment on tumors induced by inoculation of TK gene-transfected human pulmonary adenocarcinoma A549 cells in nude mice. Methods: A recombinant plasmid containing TK gene was constructed and transfected into A549 cells by electroporation. The sensitivity of the transgenic cells (A549-TK) to ACV was examined by MTT assay in vitro and for in vivo observation, inoculation of A549-TK and A-549 cells into nude mice was separately performed to induce tumor growth, the response of which to ACV treatment was observed, and the tumor tissues were pathologically examined. Results: A recombinant plasmid containing TK gene was successfully constructed and transfected into A549 cells. The sensitivity of A549-TK cells to ACV was 43 times higher than that of A549 cells. The tumors induced by A549-TK cells showed no significant increase in size after ACV treatment (P>0. 05) , and light microscopy revealed local tissue necrosis, karyoklasis, and nuclei disappearance. Conclusion: A549-TK cells acquires sensitivity to ACV both in vitro and in vivo, and ACV can inhibit the growth of tumors induced by A549-TK cell inoculation in nude mice. 展开更多
关键词 pulmonary carcinoma herpes simplex virus thymine kinase gene gene therapy ACYCLOVIR nude mice
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Streptococcus pneumoniae and Herpes Simplex Virus-1 Central Nervous System Co-Infection
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作者 António Martins Cláudio Silva +4 位作者 Fernando Silva Lúcia Ribeiro António José Cruz Filipa Ceia Lurdes Santos 《Advances in Infectious Diseases》 CAS 2023年第1期47-53,共7页
Co-infections of the central nervous system (CNS) caused by bacterial and viral pathogens are considered to be rare. Herpes simplex virus type-1 (HSV-1) reactivation following Streptococcus pneumoniae infection is wel... Co-infections of the central nervous system (CNS) caused by bacterial and viral pathogens are considered to be rare. Herpes simplex virus type-1 (HSV-1) reactivation following Streptococcus pneumoniae infection is well described but most cases are related to oral or cutaneous lesions or in respiratory samples. HSV-1 CNS reactivation after Streptococcus pneumoniae meningitis is a very rare event and may have significant morbidity and mortality. In this case report, we describe a 71-year-old female patient that presented with a history of abdominal pain and confusion/disorientation that had tonic-clonic seizures while in the Emergency Department. The diagnostic work-up confirmed CNS co-infection caused by Streptococcus pneumoniae and HSV-1. Of note, beyond age, the patient had no known risk factors for both entities and recovered fully after antibiotic and antiviral therapy. This case underlines that clinicians must be aware of CNS co-infection despite being a rare diagnosis. This should be suspected particularly in patients who present an unusual clinical course of CNS infection. 展开更多
关键词 Streptococcus pneumoniae Herpes simplex Virus Type 1 Central Nervous system CO-INFECTION
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A Computational Comparison of Basis Updating Schemes for the Simplex Algorithm on a CPU-GPU System
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作者 Nikolaos Ploskas Nikolaos Samaras 《American Journal of Operations Research》 2013年第6期497-505,共9页
The computation of the basis inverse is the most time-consuming step in simplex type algorithms. This inverse does not have to be computed from scratch at any iteration, but updating schemes can be applied to accelera... The computation of the basis inverse is the most time-consuming step in simplex type algorithms. This inverse does not have to be computed from scratch at any iteration, but updating schemes can be applied to accelerate this calculation. In this paper, we perform a computational comparison in which the basis inverse is computed with five different updating schemes. Then, we propose a parallel implementation of two updating schemes on a CPU-GPU System using MATLAB and CUDA environment. Finally, a computational study on randomly generated full dense linear programs is preented to establish the practical value of GPU-based implementation. 展开更多
关键词 simplex Algorithm BASIS INVERSE GRAPHICS Processing Unit MATLAB Compute UNIFIED Device Architecture
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Interleukin 1βreceptor and synaptic dysfunction in recurrent brain infection with Herpes simplex virus type-1
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作者 Roberto Piacentini Claudio Grassi 《Neural Regeneration Research》 SCIE CAS 2025年第2期416-423,共8页
Several experimental evidence suggests a link between brain Herpes simplex virus type-1 infection and the occurrence of Alzheimer’s disease.However,the molecular mechanisms underlying this association are not complet... Several experimental evidence suggests a link between brain Herpes simplex virus type-1 infection and the occurrence of Alzheimer’s disease.However,the molecular mechanisms underlying this association are not completely understood.Among the molecular mediators of synaptic and cognitive dysfunction occurring after Herpes simplex virus type-1 infection and reactivation in the brain neuroinflammatory cytokines seem to occupy a central role.Here,we specifically reviewed literature reports dealing with the impact of neuroinflammation on synaptic dysfunction observed after recurrent Herpes simplex virus type-1 reactivation in the brain,highlighting the role of interleukins and,in particular,interleukin 1βas a possible target against Herpes simplex virus type-1-induced neuronal dysfunctions. 展开更多
关键词 herpes simplex virus type 1 interleukin MICROGLIA NEUROINFLAMMATION synaptic dysfunction
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Herpes simplex virus 2-induced aseptic meningitis presenting with sudden deafness:A case report
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作者 Yuan-Cheng Liu Shih-Hsuan Hsiao Peir-Rong Chen 《World Journal of Clinical Cases》 SCIE 2025年第8期22-25,共4页
BACKGROUND Aseptic meningitis is defined as meningeal inflammation caused by various etio-logies with negative cerebrospinal fluid(CSF)bacterial culture.The most common etiologies are viruses[enteroviruses,arboviruses... BACKGROUND Aseptic meningitis is defined as meningeal inflammation caused by various etio-logies with negative cerebrospinal fluid(CSF)bacterial culture.The most common etiologies are viruses[enteroviruses,arboviruses,and herpes simplex virus type 2(HSV-2)].Aseptic meningitis can have various presentations,including sensori-neural deafness.While sensorineural deafness from mumps meningoencephalitis has been reported,cases of HSV-2-induced hearing loss are rare.Herein,we re-port a case of HSV-2-induced meningitis that presented with sudden deafness.CASE SUMMARY A 68-year-old man experienced a profound sudden onset of left-sided hearing loss for one day.Pure-tone audiograms demonstrated sudden left-sided sensorineural hearing loss(thresholds 80-90 dB).After treatment with high-dose steroids for 1 week,he experienced an acute consciousness change with left hemiparesis.The laboratory data showed no significant abnormalities.Brain computed tomography without contrast and magnetic resonance imaging revealed no intracranial hemo-rrhage or obvious brain lesion.The CSF analysis and the Multiplex PCR panels showed HSV-2 positivity.Hence,under the diagnosis of herpes meningoenceph-alitis,acyclovir was prescribed and his symptoms gradually resolved.CONCLUSION This case report further demonstrates that a viral infection could be a cause of sudden sensorineural hearing loss. 展开更多
关键词 Aseptic meningitis Type 2 herpes simplex Sudden sensorineural hearing loss IMMUNOCOMPROMISED Cerebrospinal fluid Case report
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一种基于改进Simplex噪声的虚拟地形生成方法
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作者 沈博 张健钦 +1 位作者 马帅豹 文政 《系统仿真学报》 北大核心 2025年第10期2605-2612,共8页
针对传统虚拟地形生成方法存在的计算复杂度高、生成速度慢、真实感不足等问题,提出了一种基于改进Simplex噪声的虚拟地形生成方法。利用Simplex噪声计算效率高、硬件开销低、随机性更自然等优势,构建基础地形模板;引入分形算法,通过多... 针对传统虚拟地形生成方法存在的计算复杂度高、生成速度慢、真实感不足等问题,提出了一种基于改进Simplex噪声的虚拟地形生成方法。利用Simplex噪声计算效率高、硬件开销低、随机性更自然等优势,构建基础地形模板;引入分形算法,通过多频率、多振幅的噪声叠加增强地形细节层次;结合湍流算法,增加随机扰动和复杂性,从而进一步提高地形的自然感和多样性。仿真结果表明:该方法在地形生成效率、真实感,以及多样性方面均优于传统生成方法。 展开更多
关键词 虚拟地形 simplex噪声 分形算法 湍流算法 改进simplex
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Quercetin inhibits herpes simplex virus 1 replication in corneal epithelium and suppresses keratitis progression
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作者 Yubin Yu Sihao Liu +2 位作者 Qinghua Liu Xiuping Liu Kaili Wu 《Virologica Sinica》 2025年第4期647-657,共11页
Quercetin is a natural compound with potent antiviral effects;however,its role in the treatment of herpes simplex keratitis(HSK)remains underexplored.Here,we investigated the antiviral effects of quercetin against her... Quercetin is a natural compound with potent antiviral effects;however,its role in the treatment of herpes simplex keratitis(HSK)remains underexplored.Here,we investigated the antiviral effects of quercetin against herpes simplex virus 1(HSV-1).By examining different phases of viral infection in human corneal epithelial cells(HCECs),we found that 30μmol/L quercetin inhibits HSV-1 replication primarily by disrupting viral attachment.RNA-sequencing and subsequent analyses revealed that the nuclear factor E2-related factor 2(Nrf2)was upregulated by quercetin in a dose-dependent manner.Knocking down Nrf2 partially compromised quercetin's antiviral effect.Importantly,topical application of 100μmol/L quercetin alleviated HSK severity in mice,reduced viral titers in tears,and inhibited VP16 expression in the cornea and trigeminal ganglia.These findings demonstrate the antiviral effect of quercetin against HSV-1 and provide a foundation for mechanistic studies to elucidate its therapeutic potential in HSK. 展开更多
关键词 QUERCETIN Herpes simplex virus type 1(HSV-1) Herpes simplex keratitis(HSK) Nrf2 ANTIVIRAL
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基于Simplex算法的高压直流输电分段变速率VDCOL研究 被引量:9
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作者 冯明 李兴源 +2 位作者 李妮 王超 洪潮 《四川大学学报(工程科学版)》 EI CAS CSCD 北大核心 2015年第4期162-167,共6页
为了改善高压直流系统的故障后的恢复性能,在研究低压限流单元(voltage dependent current order limiter,VDCOL)对直流系统无功功率消耗和电压稳定性影响的基础上,提出了一种分段变速率低压限流单元(piecewise-variable-rate VDCOL,PVR... 为了改善高压直流系统的故障后的恢复性能,在研究低压限流单元(voltage dependent current order limiter,VDCOL)对直流系统无功功率消耗和电压稳定性影响的基础上,提出了一种分段变速率低压限流单元(piecewise-variable-rate VDCOL,PVR-VDCOL)的控制方法,该方法通过将电压下降或恢复过程划分为几个不同的阶段,并在每个阶段根据电压水平的不同而设置不同的功率恢复速率。推导了控制器初值的计算公式,制定了利用Simplex算法优化控制器参数的流程,并重点分析了分段数目对控制器性能的影响及其确定方法。在PSCAD/EMTDC中对提出的PVR-VDCOL和传统线性VDCOL的控制效果进行了对比仿真,并对不同分段数目下的仿真结果进行了对比分析,仿真结果表明提出的PVR-VDCOL能够有效改善直流系统的恢复性能。 展开更多
关键词 高压直流输电 低压限流单元 电压稳定 simplex算法
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甘肃窑街中侏罗世植物化石Coniopteris simplex的原位孢子特征研究 被引量:6
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作者 辛存林 魏明 +2 位作者 陈世伟 孟健 都卫东 《地质科学》 CAS CSCD 北大核心 2012年第1期211-220,共10页
通过大量的实验分析,揭示了Coniopteris simplex的原位孢子特征,甘肃窑街盆地中侏罗世Coniopteris simplex原位孢子的基本特征可以概括为:孢子为四面体形,极面观为三角形至圆三角形,顶角钝圆,三边线内凹;体积小,极面观直径为25~38μm,... 通过大量的实验分析,揭示了Coniopteris simplex的原位孢子特征,甘肃窑街盆地中侏罗世Coniopteris simplex原位孢子的基本特征可以概括为:孢子为四面体形,极面观为三角形至圆三角形,顶角钝圆,三边线内凹;体积小,极面观直径为25~38μm,平均约30μm;三射线平直或微弯,其长度为半径的2/3~3/4,宽度较窄,具唇状边缘。外壁近于光滑,但具多条不规则的褶皱;无周壁;孢子的颜色以黄褐色为主。明确了Cyathidites minor可能是Coniopterissimplex孢子,后者为前者的母体植物。 展开更多
关键词 Coniopteris simplex 原位孢子 中侏罗世 甘肃窑街
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基于Simplex算法的VSC-HVDC控制参数优化 被引量:15
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作者 郭春义 赵成勇 +2 位作者 李广凯 饶宏 黎小林 《电力自动化设备》 EI CSCD 北大核心 2010年第9期13-17,共5页
以电压源换流器高压直流输电(VSC-HVDC)的稳态模型为基础,根据VSC功率传输方程的直角坐标形式,采用逆系统方法和PI控制相结合的方法设计了VSC的有功功率和无功功率独立调节的VSC-HVDC控制系统。基于非线性单纯形Simplex算法,对PI控制参... 以电压源换流器高压直流输电(VSC-HVDC)的稳态模型为基础,根据VSC功率传输方程的直角坐标形式,采用逆系统方法和PI控制相结合的方法设计了VSC的有功功率和无功功率独立调节的VSC-HVDC控制系统。基于非线性单纯形Simplex算法,对PI控制参数进行优化。PSCAD/EMTDC下的仿真结果表明,通过参数优化,VSC-HVDC控制目标的最大误差百分比低于1.5%;同时也证明所设计的控制系统能独立控制有功功率和无功功率。 展开更多
关键词 电压源换流器 高压直流输电 控制系统 simplex算法 PI参数优化
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基于Downhill-Simplex算法的观测数据与作物生长模型同化方法研究 被引量:6
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作者 孙琳丽 景元书 +4 位作者 马玉平 俄有浩 邹艳东 邢开瑜 吴玮 《中国农业气象》 CSCD 北大核心 2012年第4期555-566,共12页
以夏玉米叶面积指数(LAI)、贮存器官干重(WSO)、地上总干重(TAGP)以及土壤水分含量(SM)为结合点,建立了基于Downhill-Simplex算法的作物生长模型WOFOST同化多种地面观测数据的一般方法或流程:开展观测数据与作物生长模型同化方法的正确... 以夏玉米叶面积指数(LAI)、贮存器官干重(WSO)、地上总干重(TAGP)以及土壤水分含量(SM)为结合点,建立了基于Downhill-Simplex算法的作物生长模型WOFOST同化多种地面观测数据的一般方法或流程:开展观测数据与作物生长模型同化方法的正确性验证→利用Downhill-Simplex算法进行WOFOST模型的敏感性分析→选择敏感参数组合→通过优化效果确定待优化参数→利用新的观测数据对待优化参数进行优化,从而实现了观测数据与作物生长模型的同化,提升了模型的模拟能力。同化过程中遴选出的WOFOST模型的待优化参数主要包括比叶面积、最大CO2同化速率、初始地上部总干物重、根深最大日增量和初始土壤有效水等。 展开更多
关键词 观测数据同化 作物生长模型 Downhill—simplex算法 敏感性分析
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SIMPLEX算法与其他算法收敛特性的比较 被引量:4
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作者 李斌 陈听宽 崔凝 《华北电力大学学报(自然科学版)》 CAS 北大核心 2004年第3期51-55,共5页
编制了 SIMLPEX 程序。通过两个典型的流动传热问题,验证了程序的正确性,并将 SIMLPEX 与SIMPLE,SIMPLEC,SIMPLER 算法的收敛特性进行了比较。结果表明,不同算法的收敛特性与具体问题有关;SIMPLEX 算法虽能减少迭代次数,但由于求解过程... 编制了 SIMLPEX 程序。通过两个典型的流动传热问题,验证了程序的正确性,并将 SIMLPEX 与SIMPLE,SIMPLEC,SIMPLER 算法的收敛特性进行了比较。结果表明,不同算法的收敛特性与具体问题有关;SIMPLEX 算法虽能减少迭代次数,但由于求解过程中增加了 de,dn 方程组的求解,使达到收敛耗用的 CPU 时间增加,对于某些问题 SIMPLEX 耗用的 CPU 时间要少于 SIMPLER,但通常情况下多于SIMPLE 和 SIMPLEC;SIMPLE 算法通过选择合适的松弛因子,可以使其计算耗用的 CPU 时间少于其他算法不采用收敛加速技术时耗用的 CPU 时间。 展开更多
关键词 传热学 simplex算法 收敛特性 流动传热
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BOTDR系统应用Simplex编码的信号快速处理方法 被引量:2
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作者 李达 张燕君 付兴虎 《光电工程》 CAS CSCD 北大核心 2014年第1期29-35,共7页
本文提出了一种将Simplex编码调制去噪技术与叠加平均去噪技术相结合的方法—S叠加算法。该方法是将S编码与叠加平均算法混合使用,在去噪效果相同的情况下,S叠加算法可以大幅度减少叠加次数,缩短了信号处理时间,同时,降低了随着Simplex... 本文提出了一种将Simplex编码调制去噪技术与叠加平均去噪技术相结合的方法—S叠加算法。该方法是将S编码与叠加平均算法混合使用,在去噪效果相同的情况下,S叠加算法可以大幅度减少叠加次数,缩短了信号处理时间,同时,降低了随着Simplex编码长度的增加对信号解调带来的困难;对分布式光纤传感系统进行数学建模,并在此模型的基础上进行了数值分析,数据表明,S叠加算法可以大幅度减少信号的处理时间,证明了该方法的正确性和有效性。 展开更多
关键词 Brillouin散射 叠加平均 simplex编码
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基于Simplex算法对马奶啤酒发酵控制优化及品质分析 被引量:1
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作者 王威 武运 +4 位作者 古丽娜孜 张亚南 吴浩天 田歌 华雨 《食品工业科技》 CAS CSCD 北大核心 2017年第4期191-196,共6页
以马奶啤酒为考察对象,通过控制单因素实验确定四个单因素,判断步长,利用Simplex算法确定马奶啤酒发酵控制参数,结果表明:接种总量8%(干酪乳杆菌∶马克思克鲁维酵母菌=1∶2),发酵温度35℃,发酵时间48 h,蔗糖添加量9%及麦芽汁添加量30%... 以马奶啤酒为考察对象,通过控制单因素实验确定四个单因素,判断步长,利用Simplex算法确定马奶啤酒发酵控制参数,结果表明:接种总量8%(干酪乳杆菌∶马克思克鲁维酵母菌=1∶2),发酵温度35℃,发酵时间48 h,蔗糖添加量9%及麦芽汁添加量30%为最佳发酵参数,此条件下的综合p H为3.30±0.02,酒精度为5.4%±0.2%vol,感官评分为79±1.4。感官指标,理化指标及卫生指标均符合《GB 19302-2010发酵乳》国标。马奶啤酒发酵控制的研究为新疆地区马乳及其制品的多样性提供了理论与实践基础。 展开更多
关键词 马奶啤酒 simplex算法 发酵控制参数 品质分析
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An Inequality Concerning the Center of Simplex's Circumscribed Sphere 被引量:12
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作者 苏化明 《Chinese Quarterly Journal of Mathematics》 CSCD 1992年第2期49-51,共3页
Let A={A_1, A_2,…, A_(n+1)} be a simplex in E^n which its center O of circumscribed sphere is in inside of A. If R and R_i are radiuses of A_i respectively (A_i={A_1, A_2,…, A_(i-1), O, A_(i+1),…,A_(n+1)} ,i=1,2,…... Let A={A_1, A_2,…, A_(n+1)} be a simplex in E^n which its center O of circumscribed sphere is in inside of A. If R and R_i are radiuses of A_i respectively (A_i={A_1, A_2,…, A_(i-1), O, A_(i+1),…,A_(n+1)} ,i=1,2,…,n+1),then we have The equality holds if and only if A is a regular simplex. 展开更多
关键词 center and radius of circumscribed sphere of simplex volume of simplex Cayley-Menger determinant
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