双循环新格局下重庆市城镇化发展动力与实现路径

源于时代之变而构筑的双循环新发展格局是市场经济条件下多尺度空间输出理论与劳动地域大分工的“叠加”,为新型城镇化发展带来新的动力源泉。为了揭示这种影响,首先将科技创新和制度改革这2个城镇化发展动力外生变量内生化,构建基于“四维驱动力模型+创新力+制度力”的城镇化动力因子分析框架,结合主成分回归模型对2000年以来重庆市城镇化发展动力进行分析,并据此引入波特的“钻石模型”对其城镇化发展路径进行系统思考。结果表明：1）纳入动力因子体系的创新力和制度力对重庆市城镇化发展产生显著的正向驱动效应,其中创新力表现最为明显。2）重庆市城镇化发展是“六维力”共同作用的结果,但市场力和行政力依然是最主要的驱动力;其次是创新力、内源力和外向力,其中创新力对城镇化发展的驱动效应已在阶段2(2010—2018年)超越行政力的作用效应;最后是制度力;间接反映重庆市城镇化本身是一个内生作用的过程,构筑“以国内大循环为主体、国内国际双循环相互促进”新发展格局具有客观必然性和前瞻性。3）基于波特“钻石模型”分析指出：重庆市存在增长极体量小、市场购买力不足、产品低端化、同质化现象严重等问题,并据此从发展高级生产要素、创造...     

基于不同摩擦系数水平的滑移隔震体系的相对输入能量与绝对输入能量的差异性分析

定义了能量变化率指标,以简谐激励作用下的滑移隔震结构为例,探讨了摩擦系数对滑移隔震结构能量变化率指标的影响,通过对这些能量指标的研究,分析了系统的相对输入能量和绝对输入能量的差异性随摩擦系数的变化规律,为后续研究提供理论依据。     

河南夏季高温日数的时空分布特征及500 hPa环流型

对河南省40个代表站1961-2005年夏季≥35℃高温日数进行经验正交函数(EOF)展开分析,结果显示,前3个典型场基本能反映河南夏季高温日数分布的主要特征,前3个模态的累积方差贡献率达85%.据此,得出河南夏季≥35℃高温日数的时空分布类型为全省一致型、西北至东南差异型和西南至东北差异型.第一模态对应的时间系数序列的变化幅度最大,第二模态对应的时间系数序列的变化幅度比前一个时间序列要小.第一模态的时间系数演变显示,河南夏季高温日数平均呈减少趋势,且存在2～4 a、8～14 a的周期变化,目前河南夏季高温日数正处于偏多状态中.应用逐日20时500 hPa ECMWF北半球格点资料,对1991-2005年河南典型的大面积持续高温下的环流形势进行普查、分类,分别求各种类型下的环流平均场,从而得到河南省高温的两种环流型,即贝加尔湖高压型和副热带高压型.     

新公式计算岩层真厚度的Excel算法

使用软件1,将岩层序号、导线的方位和倾角、岩层的倾向、倾角和两层面切割导线处的读数分别输入A、F、G、H、I、J、K列,先后分别沿M、N列从第2行单元格开始拖动鼠标,岩层真厚度数据和累积厚度即刻计算出来,进一步可计岩组或岩性段的真厚度;将导线的序号、方位、倾角、长度分别输入W、X、Y、Z列,先后分别沿AB、AC、AD、AE、AF、AG、AH列,从第2行单元格开始拖动鼠标,导线的水平投影长度、纵座标增量及其累积值、横座标增量及其累积值、高程增量及其累积值即刻计算出来。使用软件2,在输入原始数据的同时,结果便计算出来。     

Assessment of boundary-element method for modelling a free-floating sloped wave energy device. Part 1: Numerical modelling

The boundary-element method has been widely used as a design tool in the offshore and ship building industry for more than 30 years. Its application to wave energy conversion is, however, more recent. This paper deals with the numerical modelling of a free-floating sloped wave energy device. The power take-off mechanism of the device consists of an immersed tube with a piston sliding inside. The modelling is done using the boundary-element method package WAMIT. The model is first worked out for the case where the axis of the tube is vertical. It is then derived for the tube inclined and successfully verified against numerical benchmark data. A companion paper presents results of a detailed comparison with a physical model study.     

Return period and risk calculations for ocean wave energy applications

The statistical behavior of wave energy at a site strongly depends on the wave characteristics. Wave energy converters fail to produce energy when there are no sufficiently available wave heights. Hence, evaluation of return periods and risk values of the minimum wave height becomes important for wave energy studies. A time index representing the minimum wave height is proposed here for ocean wave applications. Persistence plays a significant role in the calculation of return period and risk. Although ignoring the serial independence makes calculations easy, it leads to overestimations of the real status. In this paper, return periods and risk values are compared with each other by taking into consideration independent and dependent situations. Application of the study is achieved for the stations located in the Pacific Ocean and Gulf of Mexico.     

Observations of wave pump efficiency

Currently available data on wave pump efficiency is reviewed. The obtainable efficiency is an important consideration in the design of practical devices for the extraction of wave energy and the analysis of natural systems (e.g., coral flats and rip currents). We find that the peak efficiency is 0.5 for very steep (∼ 40–45°) ramps where the waves break over the top of the ramp. For flatter (< 30°) ramps, the breaking process is more gradual and the peak efficiency is less than 0.1. We have identified natural atoll lagoon systems where the flushing is wave driven and successfully modeled it as driven by a wave pump. The same is the case for rip currents. For both of these natural systems, the pump efficiency is around 0.035. In addition a numerical swash model is used to estimate wave pump efficiency and is seen to match the experimental results for natural systems or breaking wave scenario.     

我国绦虫一新记录属(钩吻属)及其一种记述

从730条海水鱼体内采得73种绦虫和其他寄生虫(线虫、吸虫等)。其中一种绦虫共有27条标本,经鉴定为假叶目Pseudophyllidea三枝钩科Triaenophoridae钩吻属Anchistrocephalus。本属为国内新记录,宿主马面鲀为本属新宿主。     

Numerical simulation of seepage flow field in groundwater source heat pump system and its influence on temperature field

Energy utilization in the aquifers is a new technology closely related to development of heat pump technique. It is significant for the flow distribution to be predicted in the aquifer surrounding the Groundwater Source Heat Pump System (GSHPS). The authors presented a new concept of "flow transfixion" by analyzing general features of aquifers, and then discussed interaction of the flow transfixion with the heat transfixion, which has practical significance to projects. A numerical model of groundwater flow was established based on the basic tenets of water-heat transferring in the aquifer. On this basis the flow field and the temperature field of GSHPS for a site in Shenyang City were numerically simulated. The basis of the flow transfixion was obtained; it was discussed for the influence of the flow transfixion on the heat transfixion. To a certain extent, the study offers some reference for the projects' design of GSHP in the studied area.     

日粮水平对周期性变温模式下刺参生长和能量收支的影响

变温对不同水生生物生长的影响有所不同,对部分种类具有明显的促进作用,而由于种类或温度设置等差异,研究结果各有差异.刺参(Apostichopus japonicus)在生长和生理水平上对一定程度上的符合自然水域温度波动曲线的周期性变温具有积极响应,作者研究在2个变温平均温度(均温15,18 ℃),5个日粮水平(饥饿;0.3%初始体重;0.6%初始体重;0.9%初始体重;1.4%初始体重)下刺参幼参的生长、摄食和能量收支.结果表明,在饱食条件下,刺参在变温条件下生长率高于相应的恒温对照,(15±3) ℃下差异达到显著水平.在各日粮条件下,(15±3) ℃下刺参的生长率均高于(18±3) ℃下对应日粮组.随日粮水平的升高,食物吸收率(FI)和食物转化率(FCE)显著升高.食物转化率变温组均大于恒温处理组,且在均温15 ℃下变温组显著高于恒温组(P<0.05).在能量分配模式中呼吸能占比例最大,且随变温均温升高而显著增加,是造成不同温度下刺参生长率变化的主要因素之一.在(15±3) ℃和(18±3) ℃下,刺参以能量表示的维持日粮值分别为0.39%和0.51%,与相关资料报道的恒温状态下维持日粮相比,一定程度上的变温并不会提高刺参的维持代谢.