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.     

Superconductivity in chromium nitrides Pr3Cr10-xN11 with strong electron correlations

Exploration of superconductivity in Cr-based compounds has attracted considerable interest because only a few Cr-based superconductors (CrAs, A₂Cr₃As₃ and ACr₃As₃ (A = K, Rb, Cs, Na)) have been discovered so far and they show an unconventional pairing mechanism. We report the discovery of bulk superconductivity at 5.25 K in chromium nitride in Pr₃Cr_10-xN₁₁ with a cubic lattice structure. A relatively large upper critical field of H_c2(0) ∼ 12.6 T is determined, which is larger than the estimated Pauli-paramagnetic pair-breaking magnetic field. The material has a large electronic specific-heat coefficient of 170 mJ K⁻² mol⁻¹—about 10 times larger than that estimated by the electronic structure calculation, which suggests that correlations between 3d electrons are very strong in Pr₃Cr_10-xN₁₁, and thus quantum fluctuations might be involved. Electronic structure calculations show that the density of states at the Fermi energy are contributed predominantly by Cr 3d electrons, implying that the superconductivity results mainly from the condensation of Cr 3d electrons. Pr₃Cr_10-xN₁₁ represents a rare example of possible unconventional superconductivity emerging in a 3D system with strong electron correlations. Nevertheless, clarification of the specific pairing symmetry needs more investigation.     

Understanding divergent domestication traits from the whole-genome sequencing of swamp- and river-buffalo populations

Domesticated buffaloes have been integral to rice-paddy agro-ecosystems for millennia, yet relatively little is known about the buffalo genomics. Here, we sequenced and assembled reference genomes for both swamp and river buffaloes and we re-sequenced 230 individuals (132 swamp buffaloes and 98 river buffaloes) sampled from across Asia and Europe. Beyond the many actionable insights that our study revealed about the domestication, basic physiology and breeding of buffalo, we made the striking discovery that the divergent domestication traits between swamp and river buffaloes can be explained with recent selections of genes on social behavior, digestion metabolism, strengths and milk production.     

黄河流域河源区土地利用变化及其影响研究综述

黄河流域河源区是国家生态屏障和“中华水塔”的重要组成部分,是生态保护优先的践行区。本文梳理了近40年来对黄河流域河源区土地利用格局和过程研究的相关文献,从土地利用现状、变化、效应及政策启示等方面进行了全面分析。研究发现：①黄河流域河源区土地利用格局相对稳定,草地面积占绝对优势。2000年是土地利用及其效应变化的重要转折点。2000年之前,草地、林地和湿地等生态用地减少,草地退化、沙化、土壤侵蚀等效应加剧。2000年之后,生态用地增加,植被指数增加,生态系统逐渐向良性方向转变,碳汇功能增强。②生态工程实施和气候变化使该区域土地利用及其效应极具复杂性。整体上土地退化面积有所减少,程度趋缓,草畜基本实现平衡。东部河湟谷地耕地面积减少,集约度提高,种植结构逐步优化;但局部恶化的态势依旧严峻,土壤侵蚀尤其高寒地带的冻融侵蚀加剧。建议应加强土地利用格局变化的影响因素、土地利用变化的生态效应以及生态保育区溢出价值与自然资产的评估研究,为黄河流域河源保护区可持续发展以供有力的科技支撑。     

国内外海洋资源研究知识图谱解析及启示

海洋经济已成为全球经济发展的重要引擎,海洋资源的开发与利用关乎海洋经济的可持续发展及海洋强国建设。运用CiteSpace文献计量方法,以CNKI和Web of Science数据库中的海洋资源文献为研究对象,通过对发文机构、发文期刊和关键词的分析,总结2000—2019年国内外海洋资源研究的总体特征。结果表明：①国外对于海洋资源研究的关注远大于国内,且国家（地区）间合作发文密切的主要是欧美海洋经济强国;国内海洋资源研究主体主要以沿海地区涉海院校为主,网络图谱结构松散,跨区域跨机构交流有待加强。②国外关注海洋资源研究的学科聚焦于生态学、环境科学、海洋学、国际关系、地理学和生物学等学科;国内主要集中在资源科学、环境科学、人文经济地理、国际关系及政治学等学科。③国外海洋资源研究视角呈多元化发展,对海洋资源综合管理、海洋资源与海洋生态系统、海洋生物资源、海洋资源可持续发展以及深远海资源探索等议题关注较多;国内海洋资源的阶段性研究具有明显的政策导向性,海洋资源与海洋经济、海洋资源可持续发展、海洋资源与生态环境、海洋资源空间治理等主题成为不同时期的研究热点。进一步提出海洋资源的开发与利用应具有大局观与全球视野、重视海洋资源基础性研究与实践、加快人海关系框架下的海洋资源开发模式转换及加强海洋资源理论研究等政策性启示。     

中小企业组织学习能力的测度分析

从中小企业组织学习能力的分析入手,用定量的方法建立了中小企业组织学习能力测度的指标集(4个评价维度,35个具体指标的测度指标体系),以求对中小企业的组织学习能力进行量化评价,指导企业在组织学习中有的放矢,有针对性的进行组织学习能力的改善,尽快发展成长为学习型组织。     

快速增长市场中的研发合作动因分析

探讨了快速增长市场中的合作研发,建立了内外双因素模型,并使用该模型对App le公司与IBM公司的两个合作研发项目进行分析。分析结果表明:内外双因素模型能解释这两个合作研发项目,技术、市场、公司内部的知识、风险承受能力等因素促成了这两个合作研发项目的形成。     

我国软件产业发展的现状分析与发展建议

在对我国软件产业发展现状进行分析的基础上,指出了我国软件产业发展存在的主要问题,并针对这些问题提出一些政策建议。     

科技管理过程中的评价体系探讨

通过科技评价体系建立的背景分析,提出应根据科技活动的特点,建立科学、合理科技评价指标,应进一步规范专家咨询制,以实现科技评价的“公平、公正和公开”,并通过多种科技评价形式相结合,以提高科技评价工作的客观性。     

研学旅行背景下我国中小学生跨文化交际能力提升的路径探究

跨文化交际能力是英语教学的根本目标,也是中小学生核心素养之一.提升我国中小学生跨文化交际能力不仅需要改革教材、教法等校内学习形式,更需要能提供真实的"跨文化交际体验"校外实践活动.研学旅行作为我国素质教育的新形式,注重中小学生各科目学习与课外实践探究的结合,使学生真正参与实践,通过"体验式学习"获得校内学习难以达到的学...