实景演出的灯光特点及技术发展趋势

基于实践经验及应用案例,总结归纳户外大型实景演出的灯光特点、灯光技术发展趋势等。     

Olivine-norite rock detected by the lunar rover Yutu-2 likely crystallized from the SPA-impact melt pool

Chang’E-4 landed in the South Pole-Aitken (SPA) basin, providing a unique chance to probe the composition of the lunar interior. Its landing site is located on ejecta strips in Von Kármán crater that possibly originate from the neighboring Finsen crater. A surface rock and the lunar regolith at 10 sites along the rover Yutu-2 track were measured by the onboard Visible and Near-Infrared Imaging Spectrometer in the first three lunar days of mission operations. In situ spectra of the regolith have peak band positions at 1 and 2 μm, similar to the spectral data of Finsen ejecta from the Moon Mineralogy Mapper, which confirms that the regolith''s composition of the landing area is mostly similar to that of Finsen ejecta. The rock spectrum shows similar band peak positions, but stronger absorptions, suggesting relatively fresh exposure. The rock may consist of 38.1 ± 5.4% low-Ca pyroxene, 13.9 ± 5.1% olivine and 48.0 ± 3.1% plagioclase, referred to as olivine-norite. The plagioclase-abundant and olivine-poor modal composition of the rock is inconsistent with the origin of the mantle, but representative of the lunar lower crust. Alternatively, the rock crystallized from the impact-derived melt pool formed by the SPA-impact event via mixing the lunar crust and mantle materials. This scenario is consistent with fast-cooling thermal conditions of a shallow melt pool, indicated by the fine to medium-sized texture (<3 mm) of the rock and the SPA-impact melting model [Icarus 2012; 220: 730–43].     

Diagnosis of CO2 dynamics and fluxes in global coastal oceans

Global coastal oceans as a whole represent an important carbon sink but, due to high spatial–temporal variability, a mechanistic conceptualization of the coastal carbon cycle is still under development, hindering the modelling and inclusion of coastal carbon in Earth System Models. Although temperature is considered an important control of sea surface pCO₂, we show that the latitudinal distribution of global coastal surface pCO₂ does not match that of temperature, and its inter-seasonal changes are substantially regulated by non-thermal factors such as water mass mixing and net primary production. These processes operate in both ocean-dominated and river-dominated margins, with carbon and nutrients sourced from the open ocean and land, respectively. These can be conceptualized by a semi-analytical framework that assesses the consumption of dissolved inorganic carbon relative to nutrients, to determine how a coastal system is a CO₂ source or sink. The framework also finds utility in accounting for additional nutrients in organic forms and testing hypotheses such as using Redfield stoichiometry, and is therefore an essential step toward comprehensively understanding and modelling the role of the coastal ocean in the global carbon cycle.     

Rapid phenotypic evolution with shallow genomic differentiation during early stages of high elevation adaptation in Eurasian Tree Sparrows

Known as the ‘third polar region’, the Qinghai-Tibet Plateau represents one of the harshest highland environments in the world and yet a number of organisms thrive there. Previous studies of birds, animals and humans have focused on well-differentiated populations in later stages of phenotypic divergence. The adaptive processes during the initial phase of highland adaptation remain poorly understood. We studied a human commensal, the Eurasian Tree Sparrow, which has followed human agriculture to the Qinghai-Tibet Plateau. Despite strong phenotypic differentiation at multiple levels, in particular in muscle-related phenotypes, highland and lowland populations show shallow genomic divergence and the colonization event occurred within the past few thousand years. In a one-month acclimation experiment investigating phenotypic plasticity, we exposed adult lowland tree sparrows to a hypoxic environment and did not observe muscle changes. Through population genetic analyses, we identified a signature of polygenic adaptation, whereby shifts in allele frequencies are spread across multiple loci, many of which are associated with muscle-related processes. Our results reveal a case of positive selection in which polygenic adaptation appears to drive rapid phenotypic evolution, shedding light on early stages of adaptive evolution to a novel environment.     

差别定价的产业用地供应策略对产业结构升级的影响——基于中国277个城市的实证分析

“以地谋发展”模式下,地方政府主导土地配置,采取“低工业、高商住”的产业用地出让策略,实现了产业结构升级和经济增长的目标。然而,中国经济转型期,曾经推动产业结构升级的供地策略可能不再适应新时期发展要求。本文从理论出发,剖析地方政府供地逻辑,分析差别定价的产业用地供应策略在不同经济发展水平下对产业结构升级的影响差异,提出相应假说,基于门槛回归模型,并利用2011—2016年中国277个城市产业用地供应数据进行实证检验。结果表明,产业用地价格差异对产业结构升级的影响会随经济发展水平不同呈非线性关系,随着经济发展水平的提高,差别定价的产业用地供应策略对产业结构升级的影响效应将由正转负;产业用地供应向商住用地倾斜而产生的产业用地结构错配会显著抑制产业结构升级;提高土地出让市场化程度,降低土地财政依赖则有利于提升产业结构。据此本文建议,地方政府在制定产业用地供应策略时,要充分考虑所处的社会经济环境,而在参与土地市场活动时,要明确自身干预经济的局限性,更多地培育有效市场,注重提高土地市场化程度,避免过度依赖土地财政。     

基于BP算法的股价预测模型实证分析

从技术分析的角度分析股票市场,采用BP神经网络对股票价格进行预测,提出了将股票市场的基础数据指标和技术指标相结合,作为神经网络输入的候选变量,筛选出影响股票价格涨跌的变量,从而建立起神经网络模型。最后用MATLABB编程手段对沃尔玛公司的交易资料进行实证分析。     

民营高科技企业现有政策体系实施流程的成本分析

本文从政策传播的角度出发,对民营高科技企业现有政策体系实施流程进行了成本分析,将成本划分为内容成本、时间成本、集群成本和关系成本。通过将政策体系实施流程成本化,是深入探讨我国民营高科技企业政策激励的关键基础。     

电子商务条件下的供应链管理研究

本文介绍了牛鞭效应的概念和起因,通过分析电子商务环境下的供应链管理所具有的新特点,本文认为,基于电子商务的供应链管理有益于减少牛鞭效应的不良影响。同时,文章提出了新的供应链管理的实施方案,以及基于电子商务的供应链管理的优势所在。     

动态联盟企业合作伙伴的选择评判分析

首先建立动态联盟企业合作的评价指标体系;接着应用AHP改进法求合作伙伴的权重,应用粗集理论的模式识别方法对数据信息去除冗余条件属性和进行决策规则简化。在此基础上应用灰色关联理论对合作伙伴的选择进行评价,并作为神经网络的输入数据,通过隐含学习和训练,输出神经网络拟合值,对评价结果进行验证和排序;最后使用MATLAB6.5对算例进行分析,验证其可行性。