Numerical study of plasmas start-up by electron cyclotron waves in NCST spherical tokamak and CN-H1 stellarator

According to the physics of tokamak start-up,this study constructs a zero-dimensional(0D)model applicable to electron cyclotron(EC)wave assisted start-up in NCST spherical torus(spherical tokamak)and CN-H1 stellarators.Using the constructed 0D model,the results obtained in this study under the same conditions are compared and validated against reference results for pure hydrogen plasma start-up in tokamak.The results are in good agreement,especially regarding electron temperature,ion temperature and plasma current.In the presence of finite Ohmic electric field in the spherical tokamak,a study on the EC wave assisted start-up of the NCST plasma at frequency of 28 GHz is conducted.The impact of the vertical magnetic field B_(v)on EC wave assisted start-up,the relationship between EC wave injection power P_(inj),Ohmic electric field E,and initial hydrogen atom density n_(H0)are explored separately.It is found that under conditions of Ohmic electric field lower than ITER(~0.3 V m^(-1)),EC wave can expand the operational space to achieve better plasma parameters.Simulating the process of28 GHz EC wave start-up in the CN-H1 stellarator plasma,the plasma current in the zerodimensional model is replaced with the current in the poloidal coil of the stellarator.Plasma startup can be successfully achieved at injection powers in the hundreds of kilowatts range,resulting in electron densities on the order of 10^(17)-10^(18)m^(-3).

Salinity fronts shape spatial patterns in zooplankton distribution in Hangzhou Bay

Ocean fronts play important roles in nutrient transport and in the shaping ecological patterns.Frontal zones in small bays are typically small in scale,have a complex structure,and they are spatially and temporally variable,but there are limited data on how biological communities respond to this variation.Hangzhou Bay,a mediumsized estuary in China,is an ideal place in which to study the response of plankton to small-scale ocean fronts,because three water masses(Qiantang River Diluted Water,Changjiang River Diluted Water,and the East China Sea current) converge here and form dynamic salinity fronts throughout the year.We investigate zooplankton communities,and temperature,salinity and chlorophyll a(Chl a) in Hangzhou Bay in June(wet perio d) and December(dry period) of 2022 and examine the dominant environmental factors that affect zooplankton community spatial variability.We then match the spatial distributions of zooplankton communities with those of salinity fronts.S alinity is the most important explanatory variable to affect zooplankton community spatial variability during both wet and dry periods,in that it contributes>60% of the variability in community structure.Furthermore,the spatial distributions of zooplankton match well with salinity fronts.During December,with weaker Qiantang River Diluted Water and a stronger secondary Changjiang River Plume,zooplankton communities occur in moderate salinity(MS,salinity range 15.6±2.2) and high salinity(HS,22.4±1.7) regions,and their ecological boundaries closely match the Qiantang River Diluted Water front.In June,different zooplankton communities occur in low salinity(LS,3.9±1.0),MS(11.7±3.6) and HS(21.3±1.9) regions.Although the LS region occurs abnormally in the central bay rather than its apex because of the anomalous influence of rising and falling tides during the sampling perio d,the ecological boundaries still match salinity interfaces.Low-salinity or brackish-water zooplankter taxa are relatively more abundant in LS or MS regions,and the biomass and abundance of zooplankton is higher in the MS region.

Tracing nitrate sources in one of the world's largest eutrophicated bays(Hangzhou Bay):insights from nitrogen and oxygen isotopes

Eutrophication caused by inputs of excess nitrogen(N) has become a serious environmental problem in Hangzhou Bay(China),but the sources of this nitrogen are not well understood.In this study,the August 2019 distributions of salinity,nutrients [nitrate(NO_(3)^(-)),nitrite,ammonium,and phosphate],and the stable isotopic composition of NO_(3)^(-)(δ^(15)N and δ^(18)O) were used to investigate sources of dissolved inorganic nitrogen(DIN) to Hangzhou B ay.Spatial distributions of nitrate,salinity,and nitrate δ^(18)O indicate that the Qiantang River,the Changjiang River,and nearshore coastal waters may all contribute nitrate to the bay.Based on the isotopic compositions of nitrate in these potential source waters and conservative mixing of nitrate in our study area,we suggest that the NO_(3)^(- )in Hangzhou B ay was likely derived mainly from soils,synthetic N fertilizer,and manure and sewage.End-member modeling indicates that in the upper half of the bay,the Qiantang River was a very important DIN source,possibly contributing more than 50% of DIN in the bay head area.In the lower half of the bay,DIN was sourced mainly from strongly intruding coastal water.DIN coming directly from the Changjiang River made a relatively small contribution to Hangzhou Bay DIN in August 2019.

Coupling coordinated development among digital economy,regional innovation,and talent employment:A case study in the Hangzhou Metropolitan Circle,China

Coordinative development across various systems,particularly the economic,social,cultural,and human resources subsystems,is a key aspect of urban sustainability and has a direct impact on the quality of urbanization.The Hangzhou Metropolitan Circle,comprising Hangzhou City,Huzhou City,Jiaxing City,and Shaoxing City,was the first metropolitan circle approved by the National Development and Reform Commission(NDRC)as a demonstration of economic transformation in China.To evaluate the coupling coordination degree of the four cities and analyze the coordinative development in three systems(including digital economy,regional innovation,and talent employment),we collected panel data during 2015–2022 from these four cities.The development level of the three systems was evaluated by the standard deviation method and comprehensive development index.The results are as follows:(1)the level of coupling coordinated development of the three systems in the Hangzhou Metropolitan Circle was relatively low;(2)the coupling coordination degree of the four cities in the Hangzhou Metropolitan Circle showed significant regional differences,among which Hangzhou City was in the leading position,and Huzhou,Jiaxing,and Shaoxing cities made steady but slow progress in the coupling development of the three systems;and(3)the development of digital economy and talent employment needs to be strengthened.This study contributes to the coordinative development of Hangzhou Metropolitan Circle by innovatively focusing on the coupling coordination relationship among digital economy,regional innovation,and talent employment,which also meets the industrial layout of Hangzhou Metropolitan Circle.In this way,the optimal allocation and sustainable development of digital economy,regional innovation,and talent employment in the Hangzhou Metropolitan Circle can be achieved.

The 108th plenary meeting of IEC/TC 61 held in Hangzhou

Hosted by IEC,the 108th plenary meeting of IEC/TC 61 was held on June 3-7 in Hangzhou,Zhejiang province,which was supported by CHEARI Cixi Appliance Testing Service Co.,Ltd.,Zhejiang Tianxi Kitchen Appliance Co.,Ltd.,and Zhejiang Institute of Standardization.China Household Electric Appliance Research Institute(CHEARI)serves as the national mirror committee.With a focus on the framework restructuring of IEC/TC 61 and dozens of proposals related to the IEC 60335 series,the meeting was attended by Liu Ting,President of CHEARI,Qu Zongfeng,Vice President of CHEARI,Tang Jianhui,Deputy Director of Standardization Division of Zhejiang Administration for Market Regulation,Irma Rustemi,Chair of IEC/TC 61,Ma Dejun,Vice Chair of IEC/TC 61,Randi Myers,Secretary of IEC/TC 61,Christophe Boyer,Technical Officer of IEC,and over 200 experts at home and abroad.

This Is Hangzhou

Hangzhou,capital city of east China’s Zhejiang Province and the host city for the 19th Asian Games in 2023,is one of China’s top-tier cities,preceded only by such metropolises as Beijing,Shanghai,Guangzhou,and Shenzhen.Italian explorer Marco Polo(1254-1324),who visited the city in the 13th century,marveled at its prosperity and called it“the most magnificent city in the world.”

Numerical Simulation of a Two-Phase Flow with Low Permeability anda Start-Up Pressure Gradient

A new numerical model for low-permeability reservoirs is developed.The model incorporates the nonlinear characteristics of oil-water two-phase flows while taking into account the initiation pressure gradient.Related numerical solutions are obtained using a finite difference method.The correctness of the method is demonstrated using a two-dimensional inhomogeneous low permeability example.Then,the differences in the cumulative oil and water production are investigated for different starting water saturations.It is shown that when the initial water saturation grows,the water content of the block continues to rise and the cumulative oil production gradually decreases.

Dynamic evaluation of a scaled-down heat pipe-cooled system during start-up/shut-down processes using a hardware-in-the-loop test approach

Micro-mobile heat pipe-cooled nuclear power plants are promising candidates for distributed energy resource power genera-tors and can be flexibly deployed in remote places to meet increasing electric power demands.However,previous steady-state simulations and experiments have deviated significantly from actual micronuclear system operations.Hence,a transient analysis is required for performance optimization and safety assessment.In this study,a hardware-in-the-loop(HIL)approach was used to investigate the dynamic behavior of scaled-down heat pipe-cooled systems.The real-time features of the HIL architecture were interpreted and validated,and an optimal time step of 500 ms was selected for the thermal transient.The power transient was modeled using point kinetic equations,and a scaled-down thermal prototype was set up to avoid mod-eling unpredictable heat transfer behaviors and feeding temperature samples into the main program running on a desktop PC.A series of dynamic test results showed significant power and temperature oscillations during the transient process,owing to the inconsistency of the rapid nuclear reaction rate and large thermal inertia.The proposed HIL approach is stable and effective for further studying of the dynamic characteristics and control optimization of solid-state small nuclear-powered systems at an early prototyping stage.

Land Surface Temperature Change in Hangzhou Urban Area in Recent 20 Years Based on Landsat Image

Since the reform and opening-up in 1978, the urbanization level of our country has been continuously improved and the urban development has made great progress. However, with the rapid expansion of urban construction land, the population density and building density have been greatly increased, resulting in the urban heat island effect, which has negative impact on the urban thermal environment and restricts the high-quality development of urbanization. This paper focuses on how the urban surface thermal environment of Hangzhou changes in 20 years. In this paper, the characteristics of land surface temperature (LST) in Hangzhou urban area from 2000 to 2020 were studied by using Landsat images. The radiative transfer equation method is used to retrieve the land surface temperature, and the retrieval results are analyzed. The results show that: 1) the land surface temperature in Hangzhou city area has a slight upward trend in the past 20 years;2) the area of high temperature area is expanding;3) the land surface temperature in the city center area has decreased significantly in the past 20 years, while the ground temperature in other areas around the city center has increased significantly.

Classification,Protection and Sustainable Utilization of Living Heritage Bridges Based on Value Evaluation:A Case Study of Hangzhou

Living heritage bridge is a part of living heritage,which not only plays a traffic function in today's society,but also has historical,cultural and artistic value of heritage bridge,and has gradually become an important part of world heritage protection.In this paper,the living heritage bridges in Hangzhou are taken as samples,which are divided into four categories:“use value”,“landscape value”,“social and cultural value”and“historical value”.Different protection schemes are put forward for different types of bridges,aiming at classifying and protecting the living heritage bridges in Hangzhou and providing reference for the protection of living heritage bridges in China.

WTA ‘Xianghu Dialogue' 2022 Opens in Hangzhou

From February 24 to 25,World Tourism Alliance(WTA)"Xianghu Dialogue"2022 was held in Hangzhou,Zhejiang Province,under the theme of"Harmonious Symbiosis:A New Paradigm for a New Tourism"to build consensus and promote cooperation.

基于遥感的海域环境变化监测分析

以杭州湾海域和连云港周边海域为研究对象,基于Landsat-5、Landsat-9的多光谱和热红外数据,对研究区的海域岸线和温度场信息进行提取,分析海域岸线变迁和温度分布变化特征。结果显示,研究区的海域岸线变化均较显著;海域温度在核电站运行前较为均匀,无明显温度分异,核电站运行后,因温排水排放,核电站周边海域温度出现明显分异;Landsat-9热红外数据温度反演结果可靠,可用于监测温排水对海域环境的影响。

杭州电竞中心结构设计重难点概述

杭州电竞中心内圈主体结构采用钢框架-支撑结构,外圈采用“大倾角梭形斜柱+多段钢折梁框架”,是集承重与抗侧力于一体的结构体系,屋盖采用车辐式索承网格自平衡结构形式。详细介绍了地下结构、中央场馆结构的设计要点,门厅处利用建筑造型空间设计为多段钢折梁与跨层桁架相结合的结构形式;室内二层至三层楼面设计一浮空弧形人行桥,截面形式为薄壁钢箱梁,桥宽2.2m,跨度57m,采用“上挂下支”的稳定结构形式。对整体结构进行了静力弹性、动力弹塑性、振动台试验、典型节点有限元、整体稳定以及局部稳定等系列分析与试验。结果表明:结构在静力荷载和地震作用下强度和刚度均满足规范要求;典型节点极限承载力为荷载设计值的4.17倍;结构整体稳定性安全系数为3.79;斜柱局部稳定安全系数为2.52。合理的设计保证了结构的安全、经济和实用性。

后亚运杭州文化强市探析

杭州第十九届亚洲运动会是继北京奥运会后,中国又一次承办的国际综合性体育赛事。杭州成功举办第十九届亚运会,向世界展现了中国文化自信,同时也为杭州建设文化强市带来新思考。那么在亚运会结束后如何保留其所留下的亚运会遗产以及如何合理运用、促进文旅结合、加强文化交流是杭州、浙江、中国需要考虑的重要问题。文章从杭州亚运会彰显中华文化魅力、全力做好后亚运杭州文化遗产保护与开发、推动后亚运杭州文化产业创新发展、加强后亚运杭州文化交流与国际传播四个方面对后亚运杭州建设文化强市进行了探析。

杭州湾北部凤鲚雌、雄繁殖群体的渔业生物学特征

为掌握杭州湾北部凤鲚雌、雄繁殖群体组成及渔业生物学特征,于2018、2019、2020年5—8月凤鲚汛期采集凤鲚样品,利用幂函数、列联表卡方分析等方法对凤鲚雌、雄繁殖群体的全长、体质量和性腺发育状况等进行研究。结果显示,杭州湾北部凤鲚雌性繁殖群体全长分布为113~233mm,优势全长组为130~150mm和170~200mm(总和73.2%);雄性繁殖群体全长为88~204mm,优势全长组为110~140mm(总和66.0%)。雌性体质量分布为3.6~29.7g,优势体质量组为6.0~10.0g和14.0~20.0g(总和64.2%);雄性体质量分布为1.3~16.2g,优势体质量组为2.0~8.0g(总和90.0%)。雌性全长(L)与体质量(m)关系式为m=0.518×10^(-5)L2.874(r^(2)=0.978,n=984),雄性全长与体质量关系式为m=1.033×10^(-5)L^(2.692)(r^(2)=0.957,n=661)。雌、雄性比为1.49∶1,雌性个体数显著多于雄性个体数(P<0.05)。雌性个体性腺发育以Ⅳ、Ⅴ期为主,性腺发育达Ⅳ期及以上的性成熟个体全长主要集中于140~150mm和170~200mm,雄性个体性腺发育以Ⅲ、Ⅳ期为主,性腺发育达Ⅳ期及以上的性成熟个体全长主要集中于110~150mm。摄食等级以0和1级为主,个体数占比高达95.8%,空胃率仅为69.2%。研究表明,杭州湾北部凤鲚雌性繁殖群体由多个世代群体组成,并在繁殖期内维持一定的摄食水平。

基于POI数据的杭州市公共服务设施空间分布研究

基于杭州市六类公共服务设施的POI数据,采用最近邻指数、标准差椭圆和核密度分析等地理空间分析方法,分析了杭州市公共服务设施的空间分布特征,得出以下结论:(1)杭州市六类公共服务设施均有在主城区高度集聚的特征。(2)六类设施布局方向均为西北-东南向,公共交通设施的辐射范围最广,方向性最突出。(3)公共服务设施分布均存在明显的中心-边缘结构特征,但不同类设施分布存在差异。

格律体译诗策略探析——以李正栓英译《杭州回舫》为例

译诗要像诗。诗歌具有区别于其他文本的特征,在此基础上,诗歌意境和意蕴得以实现。多年来,中国译者倾心于格律体译诗,李正栓就是其中的典型译者。他倡导以诗译诗、韵体译诗、力求忠实对等。我们借助李正栓翻译原则对其《杭州回舫》英译本进行分析,并通过翻译运用的具体方法,结合汉英语言差异和中英诗表现语言具体性的不同方式,对格律体译诗的策略方法进行思考,并提出保留意象、翻译补偿、借助英语句法优势三种翻译策略或方法。

杭州地区大气臭氧浓度垂直分布

利用国产双池型电化学反应臭氧探空仪在杭州开展为期1年(2021年12月~2022年11月)观测,分析了该地区臭氧廓线垂直分布、臭氧柱总量以及对流层臭氧柱含量特征,并评估AIRS和MLS反演的臭氧廓线产品以及AIRS、OMIDOAS和TROPOMI反演的臭氧柱总量产品.结果表明,臭氧探空仪与地面原位臭氧分析仪观测结果具有高一致性.杭州地区臭氧垂直结构呈显著月变化特征,5月在上对流层-下平流层区域(12~16km高度范围)呈现高浓度臭氧的下传结构.4~9月在边界层附近1.5km高度以下观测到高浓度臭氧含量层.边界层内臭氧含量夏季最高,垂直变化不明显;其次是春季、秋季和冬季,均表现为随高度增加而增大.臭氧探空廓线与卫星反演臭氧垂直廓线吻合较好,在对比高度范围内相对偏差大多<10%.杭州地区臭氧柱总量和对流层柱含量平均值分别为302.1DU和40.5DU,呈明显季节变化特征.臭氧柱总量和对流层柱含量最高的季节分别为春季和夏季,5月对流层臭氧柱含量最高.臭氧探空柱总量与AIRS、OMI DOAS和TROPOMI反演臭氧柱总量一致性较好,相关系数分别为0.78、0.88和0.76.

基于组合权重的文一路地下空间开发适宜性评价

对地下空间开发适宜性进行科学、合理的评价,是避免地下空间资源浪费,保证其健康可持续发展的前提。基于地形地貌、工程地质、水文地质、不良地质作用和建设现状构建地下空间开发适宜性评价指标体系,通过数值模拟确定盾构隧道施工的影响范围,完成建设现状评价指标分级量化;分别采用层次分析法和熵权法计算评价指标主观和客观权重,通过博弈论确定组合权重。在此基础上,利用综合指数法对杭州市文一路地下空间开发适宜性进行评价。通过评价结果对比分析和学院路地下工程实例,验证了评价模型的可靠性,为地下空间开发规划提供指导和借鉴。

杭州湾北岸现代潮滩沉积物粒度特征及其对古海平面的指示意义

对杭州湾北岸3处现代潮滩沉积物进行高精度粒度分析,查找研究区潮滩不同微相的粒度特征和差异,提取基于粒度分析的潮滩微相识别敏感指标,并将其应用到该区域的全新世钻孔潮滩沉积物中,识别钻孔潮滩沉积微相,据此建立研究区全新世早期的海平面曲线。研究表明:杭州湾北岸现代高潮滩盐沼沉积物粘土含量明显高于高潮滩下部和中潮滩,而砂含量与之相反;高潮滩盐沼平均粒径等粒度参数明显小于中、高潮滩的粒度参数;盐沼沉积物粒度频率曲线峰态宽缓,明显区别于高潮滩下部和中潮滩。上述现代潮滩微相粒度敏感指标可成功应用到钻孔潮滩沉积微相划分中,并建立了该区域全新世早期海平面曲线。曲线显示,9700~8700 cal a BP期间海平面上升约11.6 m,海平面上升速率可达1.2 cm/a。现代潮滩不同位置沉积物粒度参数的规律性差异可作为潮滩微相识别的有效指标,为古潮滩沉积微相识别和古海平面重建提供参考依据。