基于Bernese软件对卫星定轨实时计算

利用GPS广播星历计算卫星坐标是GPS实时定位中的重要部分,卫星轨道精度对GPS定位结果有很大影响。依据Bernese卫星定轨流程,利用Fortran语言实现了卫星轨道处理程序,并通过实例对计算得到的卫星轨道坐标与Bernese5.0软件处理的广播星历和精密星历得到结果进行比较分析,误差均小于±2.5m,程序定位效果良好,证实了自编程序的可行性。     

基于Matlab的大地测量计算程序设计

MATLAB是一个今年来发展起来的高性能的用于科学计算分析的编程软件,它把科学计算、结果的可视化和编程集中在一个使用方便的环境中,不仅功能强,而且使用方便,易于掌握,因此,在MATLAB的基础上进行了常用大地测量计算的程序设计,将测量中经常用到的计算使用MATLAB实现,使我们计算数据更加方便。     

CAD 环境下基于 AutoLISP 语言的程序开发

论述了在AutoLISP语言基础上进行坐标提取和展点程序流程设计,并用AutoLISP语言实现这些功能,操作简单易行。同时,对所编程序进行分析介绍,并提出其主要功能及优点。     

Scientific data and their release of Chang＇E-1 and Chang＇E-2

The Chang＇E-1 and Chang＇E-2 missions have successfully obtained a huge amount of ltmar scientific data, through the seven onboard instruments including a CCD stereo camera, a laser altimeter, an interference imag- ing spectrometer, an X-ray spectrometer, a microwave radiometer, a high-energy particle detector and a solar-wind ion detector. Most of the Chang＇E data are now publicly available to the science community, and this article serves as an official guide on how these data are classified and organized, and how they can be retrieved from http：//159.226.88.59：7779/CE1OutENGWeb/. This article also presents the detailed specifications of various instru- ments and gives examples of research progress made based on these instruments.     

1：5万区矿调地球化学样品的分析质量监控

从改变溶样方式和改进分析方法入手,结合样品特性,对西南天山哈拉齐地区地球化学样品中19种元素的分析方法配套方案进行了优化;建立健全包括“人、机、料、法、环、测”6个方面的质量管理系统;开发建设了包含7个模块的实验室信息管理系统（LIMS）,使质量管理走向信息化、规范化;通过准确度、精密度、重复性检验、异常点、外部监控样等内外部控制方法,采取多种手段,形成原因查找及改进的监控体系图,建成完善的1：5万区矿调地球化学样品分析质量监控体系,为西南天山哈拉齐地区地球化学找矿和基础研究提供准确的地球化学信息。     

低碳试点城市的减碳效果及机制研究

评估低碳试点城市的减碳效果和机制路径,可以为中国实现碳达峰及碳中和目标提供重要的实践参考和依据。本文运用2007—2018年中国城市面板数据,构建多期双重差分模型并通过稳健性测试,全面考察了低碳试点政策对碳排放的影响及作用机制。研究发现：① 与非试点城市相比,低碳试点政策显著地降低了城市碳排放强度和碳排放总量;其中,试点城市的碳排放强度对比下降了4.7%,碳排放总量对比下降了7.3%。② 基于城市低碳生产、低碳生活与低碳行政三维主体行为的理论机制分析和实证研究表明：从城市低碳生产维度,生产能源节约、技术进步与推行绿色建筑解释了低碳试点政策减碳效果的60.14%;从居民低碳生活维度,生活能源节约解释了低碳试点政策减碳效果的22.17%;从低碳行政维度,缩减行政支出解释了低碳试点政策减碳效果的17.29%。③ 低碳试点城市的减碳行为具有显著的异质效应。低碳城市试点不仅加快了中国的减碳进程,也为世界控制碳排放以及缓解气候变化提供了具有中国特色的解决方案。     

Potential impact of albedo incorporation in boreal forest sector climate change policy effectiveness

Forests have an important role to play in climate change mitigation through carbon sequestration and wood supply. However, the lower albedo of mature forests compared to bare land implies that focusing only on GHG accounting may lead to biased estimates of forestry's total climatic impacts. An economic model with a high degree of detail of the Norwegian forestry and forest industries is used to simulate GHG fluxes and albedo impacts for the next decades. Albedo is incorporated in a carbon tax/subsidy scheme in the Norwegian forest sector using a partial, spatial equilibrium model. While a price of EU€100/tCO₂e that targets GHG fluxes only results in reduced harvests, the same price including albedo leads to harvest levels that are five times higher in the first five years, with 39% of the national productive forest land base being cleared. The results suggest that policies that only consider GHG fluxes and ignore changes in albedo will not lead to an optimal use of the forest sector for climate change mitigation.

Policy relevance

Bare land reflects a larger share of incoming solar energy than dense forest and thus has higher albedo. Earlier research has suggested that changes in albedo caused by management of boreal forest may be as important as carbon fluxes for the forest's overall global warming impacts. The presented analysis is the first attempt to link albedo to national-scale forest climate policies. A policy with subsidies to forest owners that generate carbon sequestration and taxes levied on carbon emissions leads to a reduced forest harvest. However, including albedo in the policy alongside carbon fluxes yields very different results, causing initial harvest levels to increase substantially. The inclusion of albedo impacts will make harvests more beneficial for climate change mitigation as compared to a carbon-only policy. Hence, it is likely that carbon policies that ignore albedo will not lead to optimal forest management for climate change mitigation.     

Estimated supply of RED credits 2011–2035

Previous attempts to estimate the supply of greenhouse gas emission reductions from reduced emissions from deforestation (RED) have generally failed to incorporate policy developments, country-specific abilities and political willingness to supply offsets for developed countries’ emissions. To address this, we estimate policy-appropriate projections of creditable emission reductions from RED. Two global forest carbon models are used to examine major assumptions affecting the generation of credits. The results show that the estimated feasible supply of RED credits is significantly below the biophysical mitigation potential from deforestation. A literature review identified an annual RED emission reduction potential between 1.6 and 4.3 Gt CO₂e. Feasible RED supply estimates applying the OSIRIS model were 1.74 Gt CO₂e annually between 2011 and 2020, with a cumulative supply of 17.4 Gt CO₂e under an ‘own-efforts’ scenario. Estimates from the Forest Carbon Index were very low at $5/t CO₂e with 8 million tonne CO₂e annually, rising to 1.8 Gt CO₂e at $20/t CO₂e. Cumulative abatement between 2011 and 2020 was 9 billion Gt CO₂e ($20/t CO₂e). These volumes were lower, sometimes dramatically, at prices of $5/t CO₂e suggesting a non-linear supply of credits in relation to price at a low payment level. For policy makers, the results suggest that inclusion of RED in a climate framework increases abatement potential, although significant constraints are imposed by political and technical issues.     

专业认证背景下的“计算机地图制图”课程教学改革

专业认证是教育部提升高校专业竞争力,满足社会需求的重要举措.专业认证对专业设置、课程改革提出了全新的理念和要求,已成为高校改革的原动力.基于专业认证背景,文中讨论“计算机地图制图”课程教学存在的问题,基于专业认证的现实需要,提出课程改革的方案,论述培养学生实践能力和创新能力方法.使“计算机地图制图”在工程文化教育中发挥重要作用.     

Legal Geographies of Catastrophe: Forests,Fires, and Property in Colonial Algeria

Forest fires in Algeria in the 1850s and 1860s suggest a link between environmentally induced catastrophes and the geographies of property and territory in the colony. In eastern Algeria, these fires helped fuel a discussion over the security and reliability of European settlers’ property rights and of the colonial state's ability to guarantee them. Following a brief analysis of forestry policy in France and Algeria, this paper analyzes some of the correspondence and official reports that emerged in the wake of major conflagrations. By the early 1860s, settlers and private forestry companies were calling the colonial state's credibility into question and demanding far‐reaching changes to the property law and land‐use regimes in place in the colony. Eventually, colonial authorities moved to help cement settlers’ property claims, eliminating enclaves and imposing new rules on “native” Algerians’ rights to use the forest. This essay concludes by suggesting that the process of making property private, in Algeria and elsewhere, is informed by perceptions of risk and by the modes of awareness inspired by environmentally induced catastrophic events.