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Estimating the subsolar magnetopause position from soft X-ray images using a low-pass image filter

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Earth and Planetary Physics 2024年第1期8卷 173-183页

作者： Hyangpyo kim Hyunju k.Connor Jaewoong Jung brian M.Walsh David Sibeck kip D.kuntz Frederick S.Porter Catriana k.Paw U Rousseau A.Nutter Ramiz Qudsi Rumi Nakamura Michael Collier Space Research Institute Austrian Academy of Sciences8042 GrazAustria Geophysical Institute University of Alaska FairbanksFairbanksAlaska 99775USA National Aeronautics and Space Administration(NASA)Goddard Space Flight Center GreenbeltMaryland 20771USA Astronomy Department University of Maryland College ParkCollege ParkMaryland 20742USA Center for Space Physics Boston UniversityBostonMassachusetts 02215USA Department of Physics and Astronomy Johns Hopkins UniversityBaltimoreMaryland 21218USA Howard University WashingtonDC 20059USA

The Lunar Environment heliospheric X-ray Imager(LEXI)and Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)missions will image the Earth’s dayside magneto pause and cusps in soft X-rays after their respective launches in the near future,to specify glo bal magnetic reconnection modes for varying solar wind *** suppo rt the success of these scientific missions,it is critical to develop techniques that extract the magnetopause locations from the observed soft X-ray *** this research,we introduce a new geometric equation that calculates the subsolar magnetopause position(RS)from a satellite position,the look direction of the instrument,and the angle at which the X-ray emission is *** assumptions are used in this method:(1)The look direction where soft X-ray emissions are maximized lies tangent to the magnetopause,and(2)the magnetopause surface near the subsolar point is almost spherical and thus RSis nea rly equal to the radius of the magneto pause *** create synthetic soft X-ray images by using the Open Geospace General Circulation Model(OpenGGCM)global magnetohydrodynamic model,the galactic background,the instrument point spread function,and Poisson *** then apply the fast Fourier transform and Gaussian low-pass filte rs to the synthetic images to re move noise and obtain accurate look angles for the soft X-ray pea *** the filte red images,we calculate RS and its accuracy for different LEXI locations,look directions,and solar wind densities by using the OpenGGCM subsolar magnetopause location as ground *** method estimates RS with an accuracy of10 *** accuracy improves for greater solar wind densities and during southward interplanetary magnetic *** method ca ptures the magnetopause motion during southwa rd interplaneta ry magnetic field ***,the technique will enable quantitative analysis of the magnetopause motion and help reveal the daysi

关键词： soft X-ray magnetopause reconnection low-pass filter LEXI SMILE

聚乳酸无纺布环保PDA类阻燃剂的制备与研究

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聚乳酸无纺布环保PDA类阻燃剂的制备与研究

作者： brian Branch 北京化工大学

学位级别：硕士

石油基聚合物的降解以及其火安全性能是当今世界面临的关键挑战。这是由于石油基聚合物应用广泛,在使用后难以降解,会导致严重的环境污染问题。此外,石油基聚合物大多易燃,易引发火灾对人类的生命安全造成威胁。因此解决这些问题显得相... 详细信息

石油基聚合物的降解以及其火安全性能是当今世界面临的关键挑战。这是由于石油基聚合物应用广泛,在使用后难以降解,会导致严重的环境污染问题。此外,石油基聚合物大多易燃,易引发火灾对人类的生命安全造成威胁。因此解决这些问题显得相当紧迫,需要我们提出能够同时平衡材料环保与阻燃性能的创新解决方案。对于聚合物的降解问题,一种潜在的解决方案是利用和开发同时具有生物安全性和可生物降解的生物基聚合物。然而,相较于石油基聚合物,这些替代品往往在某些方面有性能缺陷（如力学性能et al）。因此,对这些生物基聚合物的研究需要同时兼顾其环境友好的优点并改善其对应性能的缺陷。而在阻燃性能方面,传统的阻燃剂（如含卤阻燃剂）,已被证明具有良好的阻燃效果,但由于其会产生毒副产物,存在环境与健康隐患,因此将开发新型安全无卤的磷系阻燃剂以代替传统的卤系阻燃剂。本研究通过将聚多巴胺（PDA）和磷系阻燃剂应用在聚乳酸（PLA）无纺布,为解决上述问题做出了一定贡献。通过实验发现,PDA涂层与磷系化合物的同时应用可显著提高PLA织物的阻燃性能,且涂层同样具有较高的生物安全性且对环境影响较小。此外,这项工作还凸现了PDA涂层可在PLA中快速高效应用的潜力。主要成果如下:本论文的第一部分是聚多巴胺和磷基化合物THPO作为关键阻燃剂的应用。通过喷雾共沉积方法将THPO引入到聚多巴胺基质中。这种方法显著增强了涂层织物的耐火性。极限氧指数（LOI）从对照织物的18%增加到27.5%。此外,UL-94测试的损坏长度从9.5厘米减少到7.5厘米。值得注意的是,熔体滴落性能得到增强,在测试过程中没有观察到火焰滴落。此外,热重分析显示THPO促进了适度的炭形成。仅存在聚多巴胺涂层时,样品的总烟雾产生量和烟雾产生速率均显着降低,导致Fig RA值从22.2 k W/m2s降低至14.7 k W/m2s;进一步凸显了该方法的有效性。抗紫外线测试显示,20小时内涂层样品的质量平均损失1.5%,而对照PLA织物的质量损失超过15%。本研究的第二部分重点是使用聚多巴胺作为功能涂层和聚磷酸铵（APP）作为磷基阻燃剂,在PLA织物表面形成称为PDA-Cu-APP的金属络合物。这种创新方法证明了进一步增强了织物的耐火性能,熔体滴落性能得到改善,在UL-94垂直燃烧测试中未观察到熔滴。极限氧指数（LOI）从对照PLA的18%显着增加至29.2%。此外,热重分析表明,炭残留物从对照PLA织物的1.5%增加到9.0%。Fig RA值从22.2 k W/m2s降低至14.7 k W/m2s,降低了33%。涂层中的PDA组分显着提高了抗紫外线性能,降低了质量损失率,紫外老化后涂层织物的拉伸强度是对照PLA织物的4倍。总之,本研究将生物基聚多巴胺涂层与磷基阻燃剂相结合以增强PLA织物的防火安全性,保持了环境可持续性目标的可行性。这些发现为未来开发生物基聚合物材料阻燃解决方案的研究提供了有效的途径。

关键词：阻燃剂聚多巴胺聚乳酸聚磷酸铵三(羟甲基)膦氧化物无纺布

Finding the magnetopause location using soft X-ray observations and a statistical inverse method

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Earth and Planetary Physics 2024年第1期8卷 184-203页

作者： Gonzalo Cucho-Padin Hyunju Connor Jaewoong Jung brian Walsh David G.Sibeck Space Weather Laboratory NASA Goddard Space Flight CenterGreenbeltMDUSA Department of Physics The Catholic University of AmericaWashingtonDCUSA Geospace Physics Laboratory NASA Goddard Space Flight CenterGreenbeltMDUSA Astronomy Department University of Maryland College ParkCollege ParkMDUSA Center for Space Physics Department of Mechanical EngineeringBoston UniversityBostonMAUSA

Variability in the location and shape of the dayside magnetopause is attributed to magnetic reconnection,a fundamental process that enables the transfer of mass,energy,and momentum from the solar wind into the *** spatial and temporal properties of the magnetopause,under varying solar and magnetospheric conditions,remain largely unknown because empirical studies using in-situ observations are challenging to *** wide field-of-view(FOV)imaging is the only means to simultaneously observe the spatial distribution of the plasma properties over the vast dayside magnetospheric region and,subsequently,quantify the energy transport from the interplanetary medium into the terrestrial *** upcoming missions,ESA/CAS SMILE and NASA’s LEXI will provide wide-field imagery of the dayside magnetosheath in soft X-rays,an emission generated by charge exchange interactions between high charge-state heavy ions of solar wind origin and exospheric neutral ***-cadence two-dimensional observations of the magnetosheath will allow the estimation of dynamic properties of its inner boundary,the magnetopause,and enable studies of its response to changes in the solar wind dynamic pressure and interplanetary magnetic field *** work introduces a statistically-based estimation approach based on inverse theory to estimate the spatial distribution of magnetosheath soft X-ray emissivities and,with this,identify the location of the magnetopause over the Sun−Earth *** do so,we simulate the magnetosheath structure using the MHD-based OpenGGCM model and generate synthetic soft X-ray images using LEXI’s orbit and attitude *** results show that 3-D estimations using the described statistically-based technique are robust against Poisson-distributed shot noise inherent to soft X-ray ***,our proposed methodology shows that the accuracy of both three-dimensional(3-D)estimation and the magnetopause standoff distance calculation hi

关键词： magnetopause soft X-ray tomography

Psychiatric comorbidities in epilepsy:population co-occurrence,genetic correlations and causal effects

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General Psychiatry 2024年第1期37卷 103-111页

作者： Viktor H Ahlqvist Christina Dardani Paul Madley-Dowd Harriet Forbes Jessica Rast Caichen Zhong Renee M Gardner Christina Dalman kristen Lyal cRAIG Newschaffer Torbjorn Tomson Michael Lundberg Daniel Berglind Neil M Davies brian k Lee Cecilia Magnusson Dheeraj Rai Department of Global Public Health Karolinska InstitutetStockholmSweden Medical Research Council Integrative Epidemiology Unit Bristol Medical SchoolUniversity of BristolBristolUK Centre for Academic Mental Health Population Health SciencesBristol Medical SchoolUniversity of BristolBristolUK Faculty of Epidemiology and Population Health London School of Hygiene and Tropical MedicineLondonUK A.J.Drexel Autism Institute Drexel UniversityPhiladelphiaPAUSA Department of Epidemiology and Biostatistics School of Public HealthDrexel UniversityPhiladelphiaPAUSA College of Health and Human Development Pennsylvania State UniversityState CollegePAUSA Department of Clinical Neuroscience Karolinska InstitutetStockholmSweden Centre for Epidemiology and Community Medicine Region StockholmStockholmSweden k.G Jebsen Center for Genetic Epidemiology Department of Public Health and NursingNorwegian University of Science and TechnologyTrondheimNorway Division of Psychiatry University Collge LondonLondonUK Department of Statistical Sciences University Cllge LondonLondonK NIHR Biomedical Research Centre University of BristoBristolUK Avon and Wiltshire Partnership NHS Mental Health TrustBristolUK

Background Psychiatric comorbidities are common in patients with *** for the co-occurrence of psychiatric conditions and epilepsy remain poorly *** We aimed to triangulate the relationship between epilepsy and psychiatric conditions to determine the extent and possible origins of these *** Using nationwide Swedish health registries,we quantified the lifetime prevalence of psychiatric disorders in patients with *** then used summarydata from genome-wide association studies to investigate whether the identified observational associations could be attributed to a shared underlying genetic aetiology using cross-trait linkage disequilibrium score ***,we assessed the potential bidirectional relationships using two-sample Mendelian *** In a cohort of 7628495 individuals,we found that almost half of the 94435 individuals diagnosed with epilepsy were also diagnosed with a psychiatric condition in their lifetime(adjusted lifetime prevalence,44.09%;95%confidence interval(Cl)43.78%to 44.39%).We found evidence for a genetic correlation between epilepsy and some neurodevelopmental and psychiatric *** example,we observed a genetic correlation between epilepsy and attention-deficit/hyperactivity disorder(r,=0.18,95%Cl 0.09 to 0.27,p<0.001)—a correlation that was more pronounced in focal epilepsy(r=0.23,95%CI 0.09 to 0.36,p<0.001).Findings from Mendelian randomisation using common genetic variants did not support bidirectional effects between epilepsy and neurodevelopmental or psychiatric *** Psychiatric comorbidities are common in patients with *** correlations may partially explain some comorbidities;however,there is little evidence of a bidirectional relationship between the genetic liability of epilepsy and psychiatric *** findings highlight the need to understand the role of environmental factors or rare genetic variations in the origins of psy

关键词： epilepsy Psychiat lifetime

Insula and the Immune System:More than mere Co-existence?

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Neuroscience Bulletin 2022年第10期38卷 1271-1273页

作者： Panagiotis kerezoudis Charles L.Howe long-Jun Wu brian N.Lundstrom Jamie J.Van Gompel Department of Neurologic Surgery Mayo ClinicRochesterMNUSA Department of Neurology Mayo ClinicRochesterMNUSA

Does the Brain Regulate the Immune System?While long considered to be separate entities,increasing evidence has demonstrated that thebrain and theperipheral immune system interact through bidirectional feedback[1].The brain hosts a vibrant immune environment(*** and perivascular macrophages)that is responsible for maintaining the integrity of the central nervous system[2].In addition,the brain is the central regulator of the rest of the body and its homeostasis.

关键词： Immune homeostasis Ins

1967~2033 nm波段硅基可调谐外腔半导体激光器设计与仿真

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中国激光 2024年第6期51卷 74-83页

作者：万浩然杨禹霖乔忠良李翔 Jia Xu brian Sia 余文军翁登群李再金李林陈浩赵志斌薄报学高欣曲轶刘重阳汪宏张宇牛智川海南师范大学物理与电子工程学院海南省激光技术与光电子功能材料重点实验室半导体激光海南省国际联合研究中心海南海口571158 新加坡南洋理工大学电气与电子工程学院新加坡639798 新加坡南洋理工大学淡马锡实验室新加坡637553 中国科学院半导体研究所半导体超晶格国家重点实验室北京100083 长春理工大学高功率半导体激光器国家重点实验室吉林长春130022

2μm波长附近可调谐半导体激光器在分子光谱学和光通信领域中有广阔的应用前景。基于绝缘体上硅(SOI)平台,对2μm波长附近可调谐半导体激光器的外腔部分进行了设计优化。分析了不同尺寸光波导的模式损耗特性、单个微环谐振腔受总线波导... 详细信息

2μm波长附近可调谐半导体激光器在分子光谱学和光通信领域中有广阔的应用前景。基于绝缘体上硅(SOI)平台,对2μm波长附近可调谐半导体激光器的外腔部分进行了设计优化。分析了不同尺寸光波导的模式损耗特性、单个微环谐振腔受总线波导耦合间距的作用以及总线波导光反馈终端对外腔半导体激光器性能的影响。并提出了一种具有高工艺兼容度的多模环形光波导光反馈结构。所设计的可调谐半导体激光器硅基外腔可通过环形波导上的镍铬合金微加热器进行0.1 nm/k的高精度调谐,对单个微加热器施加3.2 V电压时,调谐范围可达66 nm(1967~2033 nm)。

关键词：硅光集成可调谐外腔半导体激光器环形谐振腔光波导终端

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Harpephyllum caffrum stimulates glucose uptake,abates redox imbalance and modulates purinergic and glucogenic enzyme activities in oxidative hepatic injury

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Asian Pacific Journal of Tropical Biomedicine 2022年第1期12卷 9-19页

作者： kolawole A.Olofinsan Ochuko L.Erukainure Beseni k.brian Md.Shahidul Islam Department of Biochemistry School of Life SciencesUniversity of KwaZulu-Natal(Westville Campus)Durban 4000South Africa Department of Pharmacology University of the Free StateBloemfontein 9300South Africa

Objective:To investigate the antioxidative and antidiabetic effects of Harpephyllum caffrum bark infusion as well as its effects on glucogenic and nucleotide hydrolyzing enzyme activities in FeSO4-induced oxidative stress in rat hepatic ***:Harpephyllum caffrum infusion was prepared from dried plant materials(40 g)infused in boiling water(400 mL)for 20 min at room *** antioxidative and inhibitory activities against carbohydrate digestive enzymes of the infusion were determined using established *** liver tissues of rats were used for glucose uptake assay and to evaluate the infusion’s effect on endogenous antioxidant,glucogenic,and nucleotide hydrolyzing enzyme activities in FeSO4-induced hepatic ***:The Harpephyllum caffrum infusion significantly reduced ferric iron(FRAP)and free radicals(OH•and DPPH)in a dose-dependent *** inhibitedα-amylase andα-glucosidase activities and increased glucose uptake in hepatic ***4 significantly decreased glutathione concentration,catalase,and superoxide dismutase activities while increasing malondialdehyde level,glycogen phosphorylase,fructose-1,6-bisphosphatase,and adenosine triphosphatase ***,treatment with Harpephyllum caffrum infusion reversed FeSO4-induced *** of the infusion revealed the presence of catechol,O-pyrocatechuic acid,mequinol,maltol,and glycoside ***:The Harpephyllum caffrum infusion demonstrates antidiabetic and antioxidative potentials in in vitro models of type 2 diabetes as depicted by its ability to inhibit carbohydrate digestive enzymes,mitigate oxidative imbalance,and regulate glucogenic and nucleotide hydrolyzing enzyme activities in oxidative hepatic injury.

关键词： Harpephyllum caffrum Antioxidant Oxidative injury Carbohydrate dysmetabolism

Changes in Lipoprotein Lipase in the Heart Following Diabetes Onset

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Engineering 2023年第1期20卷 19-25页

作者： Chae Syng Lee Yajie Zhai brian Rodrigues Faculty of Pharmaceutical Sciences University of British ColumbiaVancouverBC V6T 1Z3Canada

Due to its constant pumping and contraction, the heart requires a substantial amount of energy, with fatty acids (FAs) providing a major part of its adenosine triphosphate (ATP). However, the heart is incapable of making this substrate and attains its FAs from multiple sources, including the action of lipoprotein lipase (LPL). LPL is produced in cardiomyocytes and subsequently secreted to its heparan sulfate proteoglycan (HSPG) binding sites on the plasma membrane. To then move LPL to the endothelial cell (EC) lumen, glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1) attaches to interstitial LPL and transfers it to the vascular lumen, where the LPL is ready to perform its function of breaking down circulating triglycerides (TG) into FAs. The endo-β-glucuronidase heparanase (Hpa) is unique in that it is the only known mammalian enzyme to cleave heparan sulfate (HS), thereby promoting the abovementioned release of LPL from the cardiomyocyte HSPG. In diabetes, it has been suggested that changes in how the heart generates energy are responsible for the development of diabetic cardiomyopathy (DCM). Following moderate diabetes, with the reduction in glucose utilization, the heart increases its LPL activity at the vascular lumen due to an increase in Hpa action. Although this adaptation might be beneficial to compensate for the underutilization of glucose by the heart, it is toxic over the long term, as harmful lipid metabolite accumulation, along with augmented FA oxidation and thus oxidative stress, leads to cell death. This coincides with the loss of a cardioprotective growth factor—namely, vascular endothelial growth factor B (VEGFB). This review discusses interconnections between Hpa, LPL, and VEGFB and their potential implications in DCM. Given that mechanism-based therapeutic care for DCM is unavailable, understanding the pathology of this cardiomyopathy, along with the contribution of LPL, will help us advance its clinical ma

关键词： Cardiac metabolism Lipopr otein lipase Heparanase Vascular endothelial growth factor Diabetic car diomyopathy

Biochar applications influence soil physical and chemical properties,microbial diversity,and crop productivity:a meta-analysis

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Biochar 2022年第1期4卷 1055-1071页

作者： Hardeep Singh brian k.Northup Charles W.Rice P.V.Vara Prasad Department of Agronomy Kansas State University2002 Throckmorton Plant Sciences Center1712 Claflin RoadManhattanKS 66506USA United States Department of Agriculture-Agricultural Research Service Grazinglands Research LaboratoryEl-RenoOK 73036USA

Biochar is a widely known soil *** we synthesize the available information on influence of biochar application on different soil properties and crop productivity using *** data on influence of biochar applications on different soil physical,chemical,microbial properties,and crop productivity were extracted from literature and statistically *** on selection criteria,59 studies from the literature published between 2012 and 2021 were selected for the *** were developed between effect size of biochar application on different soil properties and crop *** of biochar increased soil pH,cation exchange capacity,and organic carbon by 46%,20%,and 27%,respectively,with greater effects in coarse and fine-textured *** on chemical properties were variable among biochar prepared from different *** physical properties,biochar application reduced bulk densities by 29%and increased porosity by 59%.Biochar prepared at higher pyrolytic temperatures(>500℃)improved bulk density and porosity to greater extents(31%and 66%,respectively).Biochar prepared at lower pyrolytic temperatures(long-term field experiments to provide better explanations for changes in biochar properties as it undergoes aging,its longer-term effects on soil properties,and timing of re-application of different biochars.

关键词： Biochar Crop productivity Microbial diversity Soil physical properties Soil chemical properties