期刊文献+
共找到442篇文章
< 1 2 23 >
每页显示 20 50 100
Unveiling simplexity:A new paradigm for understanding complex adaptive systems and driving technological innovation
1
作者 Andrea Tomassi Andrea Falegnami Elpidio Romano 《The Innovation》 2025年第9期9-10,共2页
Scientists have long sought frameworks to understand the complex systems that shape our world,from ecological dynamics to socio-technical networks.The concept of simplexity,intermittently explored for over 70 years,ha... Scientists have long sought frameworks to understand the complex systems that shape our world,from ecological dynamics to socio-technical networks.The concept of simplexity,intermittently explored for over 70 years,has now been redefined,offering a revolutionary perspective on complexity and simplicity across natural,social,and technological domains.1 This breakthrough provides insights into the interplay between simplicity and complexity,unifying disciplines and driving scientific and technological progress.In this context,information management shifts from mere storage and dissemination to dynamic strategies that shape behaviors and interactions,fostering knowledge-driven activities. 展开更多
关键词 information management concept simplexityintermittently complex adaptive systems ecological dynamics understand complex systems simplexity technological innovation complexity simplicity
原文传递
Extracellular nucleotides mediate viral central nervous system infections:Key alarmins of neuroinflammation and neurodegeneration
2
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
暂未订购
Optimal Synchronization of Higher-Order Dynamical Networks 被引量:1
3
作者 Guanrong CHEN 《Artificial Intelligence Science and Engineering》 2025年第1期31-36,共6页
This article briefly reviews the topic of complex network synchronization,with its graph-theoretic criterion,showing that the homogeneous and symmetrical network structures are essential for optimal synchronization.Fu... This article briefly reviews the topic of complex network synchronization,with its graph-theoretic criterion,showing that the homogeneous and symmetrical network structures are essential for optimal synchronization.Furthermore,it briefly reviews the notion of higher-order network topologies and shows their promising potential in application to evaluating the optimality of network synchronizability. 展开更多
关键词 complex network SYNCHRONIZATION optimal synchronizability SIMPLEX higher-order topology
在线阅读 下载PDF
Interleukin 1βreceptor and synaptic dysfunction in recurrent brain infection with Herpes simplex virus type-1
4
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
暂未订购
Herpes simplex virus 2-induced aseptic meningitis presenting with sudden deafness:A case report
5
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
暂未订购
一种基于改进Simplex噪声的虚拟地形生成方法
6
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
原文传递
Quercetin inhibits herpes simplex virus 1 replication in corneal epithelium and suppresses keratitis progression
7
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
原文传递
Compatible interaction between potato starch and wheat starch:From the perspective of microstructure and physicochemical characteristics
8
作者 Liping Yang Ruidi He +5 位作者 Kaiyue Wang Xianling Zhang Weihua Xiong Yizhou Wu Lingyan Kong Songnan Li 《Grain & Oil Science and Technology》 2025年第4期278-286,共9页
With the promotion of potatoes as a staple food,the challenge lies in integrating them into traditional staple grain-based diets.As the primary component of grains,starch plays a crucial role,and its interactions with... With the promotion of potatoes as a staple food,the challenge lies in integrating them into traditional staple grain-based diets.As the primary component of grains,starch plays a crucial role,and its interactions with other heterogeneous starches could significantly influence their functional properties.Therefore,this study aimed to explore the role of substitution ratio(SR,0–100%)of potato starch(PS)in the compatibility with wheat starch(WS)from the perspective of microstructure and physicochemical characteristics using the simplex-centroid method.Results of scaning electron microscopy(SEM)revealed the network structure in SR 30%of PS possessed the smallest size and the most compact gel structure.A higher SR of PS increased the solubility and swelling power of the blended WS and improved its freeze-thaw stability.Peak viscosity and gel hardness of the blended WS exhibited an increasing trend as the SR of PS increased.With the increasing SR of PS,the blended WS exhibited an increased tanδvalue with decreased viscous and elastic moduli.There is a non-additive effect between PS and WS,which should be responsible for their difference between experimental and theoretical values.These findings could provide a new direction for understanding the compatibility interactions between different starches,and provide a theoretical guidance for the development of PS-based foods with desirable properties. 展开更多
关键词 Potato starch Wheat starch Simplex centroid Rheological properties VISCOSITY HARDNESS
在线阅读 下载PDF
Comprehensive Brain-wide Mapping of Afferent and Efferent Nuclei Associated with the Heart in the Mouse
9
作者 Haiying Liu Xin Huang +7 位作者 Ruixin Xia Xin Zhao Zimeng Li Qian Liu Congye Li Honghui Mao Wenting Wang Shengxi Wu 《Neuroscience Bulletin》 2025年第10期1743-1760,共18页
Normal heart function depends on complex regulation by the brain,and abnormalities in the brain‒heart axis affect various diseases,such as myocardial infarction and anxiety disorders.However,systematic tracking of the... Normal heart function depends on complex regulation by the brain,and abnormalities in the brain‒heart axis affect various diseases,such as myocardial infarction and anxiety disorders.However,systematic tracking of the brain regions associated with the input and output of the heart is lacking.In this study,we injected retrograde transsynaptic pseudorabies virus(PRV)and anterograde transsynaptic herpes simplex virus(HSV)into the left ventricular wall of mice to identify the whole-brain regions associated with the input to and output from the heart.We successfully detected PRV and HSV expression in at least 170 brain subregions in both male and female mice.Sex differences were discovered mainly in the hypothalamus and medulla,with male mice exhibiting greater correlation and hierarchical clustering than female mice,indicating reduced similarity and increased modularity of virus expression patterns in male mice.Further graph theory and multiple linear regression analysis of different injection timelines revealed that hub regions of PRV had highly similar clusters,with different brain levels,suggesting a top-down,hierarchically transmitted neural control pattern of the heart.Hub regions of HSV had scattered clusters,with brain regions gathered in the cortex and brainstem,suggesting a bottom-up,leapfrog,multipoint neural sensing pattern of the heart.Both patterns contain many hub brain regions that have been previously overlooked in brain‒heart axis studies.These results provide brain targets for future research and will lead to deeper insight into the brain mechanisms involved in specific heart conditions. 展开更多
关键词 HEART BRAIN Herpes simplex virus Pseudorabies virus Graph theory
原文传递
Localization of Acoustic Emission Source in Rock Using SMIGWO Algorithm
10
作者 Jiong Wei Fuqiang Gao +2 位作者 Jinfu Lou Lei Yang Xiaoqing Wang 《International Journal of Coal Science & Technology》 2025年第2期42-51,共10页
The Grey Wolf Optimization(GWO)algorithm is acknowledged as an effective method for rock acoustic emission localization.However,the conventional GWO algorithm encounters challenges related to solution accuracy and con... The Grey Wolf Optimization(GWO)algorithm is acknowledged as an effective method for rock acoustic emission localization.However,the conventional GWO algorithm encounters challenges related to solution accuracy and convergence speed.To address these concerns,this paper develops a Simplex Improved Grey Wolf Optimizer(SMIGWO)algorithm.The randomly generating initial populations are replaced with the iterative chaotic sequences.The search process is optimized using the convergence factor optimization algorithm based on the inverse incompleteГfunction.The simplex method is utilized to address issues related to poorly positioned grey wolves.Experimental results demonstrate that,compared to the conventional GWO algorithm-based AE localization algorithm,the proposed algorithm achieves a higher solution accuracy and showcases a shorter search time.Additionally,the algorithm demonstrates fewer convergence steps,indicating superior convergence efficiency.These findings highlight that the proposed SMIGWO algorithm offers enhanced solution accuracy,stability,and optimization performance.The benefits of the SMIGWO algorithm extend universally across various materials,such as aluminum,granite,and sandstone,showcasing consistent effectiveness irrespective of material type.Consequently,this algorithm emerges as a highly effective tool for identifying acoustic emission signals and improving the precision of rock acoustic emission localization. 展开更多
关键词 Acoustic emission Source localization Iterative chaotic mapping Simplex method Grey wolf optimizer algorithm
在线阅读 下载PDF
Viral eye:Emerging insights into corneal and ocular surface viral infections
11
作者 Marco Zeppieri Matteo Capobianco +7 位作者 Alessandro Avitabile Federico Visalli Cosimo Mazzotta Mutali Musa Rosa Giglio Daniele Tognetto Caterina Gagliano Francesco Cappellani 《World Journal of Virology》 2025年第4期56-66,共11页
Viral infections of the ocular surface significantly contribute to morbidity and visual impairment globally.The herpes simplex virus(HSV),adenovirus,cytomegalovirus(CMV),and human papillomavirus(HPV)are predominant pa... Viral infections of the ocular surface significantly contribute to morbidity and visual impairment globally.The herpes simplex virus(HSV),adenovirus,cytomegalovirus(CMV),and human papillomavirus(HPV)are predominant pathogens impacting the cornea and conjunctiva,resulting in recurrent illness,epidemic outbreaks,and virus-associated neoplasia.Progress in virology,immunology,and molecular diagnostics has enhanced comprehension of host–virus interactions and introduced novel therapeutic opportunities.A narrative literature review was performed utilizing PubMed,Scopus,and Web of Science,encompassing papers published from 2000 to 2025,with a specific focus on research from 2020 onwards.Eligible publications were peer-reviewed clinical and experimental investigations,together with reviews that focused on epidemiology,etiology,diagnostic methodologies,and therapeutic alternatives.Research indicates that HSV keratitis is the predominant infectious cause of corneal blindness in high-income nations,although adenovirus persists in instigating epidemics of keratoconjunctivitis in the absence of licensed antiviral treatments.CMV keratitis,previously confined to immunocompromised persons,is now acknowledged in immunocompetent patients as a causative agent of corneal endotheliitis.HPV is associated with ocular surface squamous neoplasia,especially in areas with elevated ultraviolet exposure and high human immunodeficiency virus prevalence.Innovative molecular diagnostics,innovative antiviral agents,immunomodulatory approaches,and immunization initiatives signify significant progress that could enhance preventative and therapeutic results. 展开更多
关键词 Herpes simplex keratitis Cytomegalovirus keratitis Adenoviral conjunctivitis Viral eye infections Ocular surface squamous neoplasia
暂未订购
Oncolytic HSV-1 expressing GM-CSF and IL-12 enhances anti-tumor efficacy in immunocompetent murine melanoma model
12
作者 Han Xiao Qiran Yin +4 位作者 Jia Liu Hengrui Hu Jiang Li Manli Wang Zhihong Hu 《Virologica Sinica》 2025年第6期977-988,共12页
Oncolytic virus therapy is a promising strategy for cancer treatment.Herpes simplex virus type 1(HSV-1)has been successfully used in oncolytic virotherapy.In the present research,we applied an HSV-1 synthetic genomics... Oncolytic virus therapy is a promising strategy for cancer treatment.Herpes simplex virus type 1(HSV-1)has been successfully used in oncolytic virotherapy.In the present research,we applied an HSV-1 synthetic genomics platform to construct two oncolytic viruses,oHSV-1.1 and oHSV-1.2.oHSV-1.1 had the virulence gene ICP34.5 and ICP47 deleted for attenuation,and oHSV-1.2 was additionally armed with murine granulocyte macrophage-colony stimulating factor(GM-CSF)and interleukin-12(IL-12).The oncolytic viruses were evaluated in vitro and in an immunocompetent murine melanoma model.The animal experiments confirmed that both oncolytic viruses displayed antitumor efficacy,including inhibiting tumor growth and prolonging overall survival.Compared with oHSV-1.1,oHSV-1.2 demonstrated superior tumor growth suppression and enhanced antitumor efficacies,as evidenced by increased tumor cell apoptosis,cytotoxic T cells and macrophages infiltration,IFN-γ production,and upregulation of inflammatory-related gene expression.Our research highlights the potential of oncolytic HSV-1 expressing both GM-CSF and IL-12 for melanoma therapy,and provides a promising strategy for further development of oncolytic virotherapy. 展开更多
关键词 Herpes simplex virus typeⅡ(HSV-1) Oncolytic virus Synthetic genomics MELANOMA GM-CSF IL-12
原文传递
Ubiquitously expressed transcript isoform 2(UXT-V2)restricts HSV-2 replication by targeting glycoprotein B for degradation through ubiquitin-proteasome pathway
13
作者 Chuntian Li Yuncheng Li +6 位作者 Ranqing Cheng Miaomiao Li Mudan Zhang Zhiyuan Zhu Ping Yang Qinxue Hu Yalan Liu 《Virologica Sinica》 2025年第5期778-792,共15页
Herpes simplex virus 2(HSV-2)is a major pathogen causing neonatal herpes and increasing the risk of human immunodeficiency virus 1(HIV-1)infection.However,the mechanisms underlying host restriction of HSV-2 infection ... Herpes simplex virus 2(HSV-2)is a major pathogen causing neonatal herpes and increasing the risk of human immunodeficiency virus 1(HIV-1)infection.However,the mechanisms underlying host restriction of HSV-2 infection are still not fully understood.The ubiquitously expressed transcript isoform 2(UXT-V2),anα-type prefoldin protein,functions as a versatile transcription factor associated with numerous human tumors,but its role in viral infection remains unclear.In this study,we found that ectopic expression of UXT-V2 significantly inhibited HSV-2 replication,while knockout of endogenously expressed UXT-V2 promoted HSV-2 proliferation.Further analysis revealed that UXT-V2 restricts HSV-2 replication independent of its role in regulating NF-κB.In the context of HSV--2 infection or in viral glycoprotein B(gB)-transfected cells,UXT-V2 facilitates K48-linked ubiquitination of gB,leading to its degradation via the proteasome pathway,thereby inhibiting viral replication.Furthermore,we identified that UXT-V2 interacts with gB,recruiting the E3 ligase TRIM21 to facilitate K48-linked ubiquitination of gB.HSV-2,in turn,reduces the abundance of UXT-V2 proteins both in vitro and in mice,highlighting the complexity of HSV-2-host interactions.Collectively,our findings,for the first time,demonstrate an anti-HSV-2 role of UXT-V2,unveiling a novel host immune defense mechanism involved in regulating glycoprotein homeostasis. 展开更多
关键词 Herpes simplex virus 2(HSV-2) UXT-V2 Glycoprotein B(gB) UBIQUITINATION
原文传递
Antiviral immune responses in human reproductive tract:Pathogenic mechanisms and therapeutic implications
14
作者 Kim-Ling Chin Nurhafiza Zainal 《Asian Pacific Journal of Tropical Medicine》 2025年第2期67-76,共10页
Viral reproductive tract infections(VRTIs)are a significant global health concern with severe consequences,including infertility,chronic pelvic pain,and increased risk of HIV transmission.Complex interplay between pat... Viral reproductive tract infections(VRTIs)are a significant global health concern with severe consequences,including infertility,chronic pelvic pain,and increased risk of HIV transmission.Complex interplay between pathogens and the host immune system plays a critical role in the pathogenesis and treatment of VRTIs.This review aims to provide a comprehensive overview of the multifaceted roles of the immune system in both contributing to and combating VRTIs.The review will also address the consequent perturbations in immune homeostasis and the implications for disease manifestation and progression.The interrelation between systemic immunity and local immune responses is discussed,providing insights into the challenges and breakthroughs in managing these infections.By providing a comprehensive overview of the mechanisms,implications,and therapeutic strategies associated with viral reproductive tract infections and immune dysfunction,this review also informs future research and clinical practice in this important area of reproductive health. 展开更多
关键词 Viral reproductive tract infections(VRTIs) Immune response Human papillomavirus(HPV) Herpes simplex virus(HSV) Cytomegalovirus(CMV) Human immunodeficiency virus(HIV) Zika virus(ZIKV) Hepatitis B virus(HBV) Hepatitis C virus(HCV)
暂未订购
基于Simplex算法的高压直流输电分段变速率VDCOL研究 被引量:9
15
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
在线阅读 下载PDF
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
16
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
在线阅读 下载PDF
混合直流输电系统的参数优化方法 被引量:20
17
作者 郭春义 刘文静 +3 位作者 赵成勇 黄晓明 陆翌 裘鹏 《电力系统自动化》 EI CSCD 北大核心 2015年第11期96-102,共7页
混合直流输电系统结合了传统电网换相换流器(LCC)和电压源换流器(VSC)的优点,具有广泛的应用前景。文中针对整流侧为LCC换流站、逆变侧为VSC换流站的混合直流输电系统,介绍了单极型、伪双极型、双极型3种不同混合直流结构的特点及应用... 混合直流输电系统结合了传统电网换相换流器(LCC)和电压源换流器(VSC)的优点,具有广泛的应用前景。文中针对整流侧为LCC换流站、逆变侧为VSC换流站的混合直流输电系统,介绍了单极型、伪双极型、双极型3种不同混合直流结构的特点及应用场合。考虑到混合直流输电系统的主电路参数和控制系统参数对系统的运行特性都有直接的影响,提出了一种可以同步优化主电路和控制系统参数的方法。首先,重点阐述了系统参数中直流平波电抗器L和直流电容器C的参数设计原则,然后基于Simplex算法对LC参数以及两侧控制器比例-积分的参数进行了优化。在电磁暂态仿真软件PSCAD/EMTDC下搭建了混合直流输电系统的模型,仿真结果表明,使用Simplex算法对系统参数进行优化后,其运行特性将得到改善,从而验证了所提出的参数设计优化方法的有效性。 展开更多
关键词 电网换相换流器 电压源换流器 混合直流输电 拓扑结构 参数优化设计 Simplex算法
在线阅读 下载PDF
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
18
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
在线阅读 下载PDF
采用APD检测的编码瑞利BOTDA系统性能 被引量:11
19
作者 李永倩 杨润润 张立欣 《红外与激光工程》 EI CSCD 北大核心 2017年第3期119-125,共7页
瑞利布里渊光时域分析系统具有单光源、单端工作、非破坏的优点,为了解决系统信噪比与空间分辨率之间的矛盾,将编码技术应用到瑞利布里渊光时域分析系统中,可以在保持空间分辨率不变的前提下提高系统信噪比。提出了基于雪崩光电二极管... 瑞利布里渊光时域分析系统具有单光源、单端工作、非破坏的优点,为了解决系统信噪比与空间分辨率之间的矛盾,将编码技术应用到瑞利布里渊光时域分析系统中,可以在保持空间分辨率不变的前提下提高系统信噪比。提出了基于雪崩光电二极管检测和Simplex编码的瑞利布里渊光时域分析系统,系统中的随机散粒噪声功率和信号功率有关,而热噪声功率主要取决于雪崩光电二极管光电检测器的性能、与信号功率无关。由系统中与两种噪声相关的电流波动的方差和Simplex码的编解码规则可得编码系统的均方误差,由此推导了系统信噪比和编码增益公式。随着编码长度的增加,编码增益会逐渐增大并在某一编码长度后趋于稳定,因此系统存在最佳编码长度,最终推导了最佳编码长度公式,并对信噪比和最佳编码长度进行了MATLAB仿真。仿真结果表明,在基于Simplex码的瑞利布里渊光时域分析系统中,当脉冲基底1阶边带产生的瑞利散射光功率为0.5mW时,随编码长度的增加,编码增益逐渐增大并趋于稳定值6.69 dB,系统的最佳编码长度为63 bit。 展开更多
关键词 受激布里渊散射 分布式光纤传感器 Simplex编码 瑞利散射
原文传递
基于几何特征参数控制的翼型设计方法研究 被引量:6
20
作者 张森 席德科 李华星 《工程热物理学报》 EI CAS CSCD 北大核心 2019年第5期1058-1064,共7页
给出了基于双椭圆弧的中弧线方程式,并推导了由茹可夫斯基翼型公式拓展得到的厚度分布方程式,通过将指定的厚度分布均匀布置在中弧线上得到了一种新的翼型设计方法.该方法通过8个参数控制翼型的型线,其中4个参数具有明确的几何意义,其余... 给出了基于双椭圆弧的中弧线方程式,并推导了由茹可夫斯基翼型公式拓展得到的厚度分布方程式,通过将指定的厚度分布均匀布置在中弧线上得到了一种新的翼型设计方法.该方法通过8个参数控制翼型的型线,其中4个参数具有明确的几何意义,其余4个参数可局部调整翼型的型线.利用Modefrontier优化平台将翼型设计程序与气动性能预测程序集成在一起,实现了翼型的优化设计,并以E387翼型为参考设计了一款翼型.结果显示,新翼型的气动性能相对于参考翼型有了显著的提升。研究表明,本文提出的翼型设计方法能够帮助设计者主动的对翼型的几何特征参数进行精准控制,并更好的理解设计过程,弥补了现有的翼型设计方法在主动进行几何特征参数控制上的不足。 展开更多
关键词 翼型设计 Xfoil Modefrontier SIMPLEX 优化设计
原文传递
上一页 1 2 23 下一页 到第
使用帮助 返回顶部