Results 111 to 120 of about 847,250 (203)
, 1989 建立高新技术密集产业，是发展外向型经济的战略重点。本文以辽东半岛对外开放区为背景，通过对辽宁省省情，辽东半岛区情的研究，同时借鉴国际，国内发展外向型经济的经验，运用系统动力学的理论与方法，并使之与各种行之有效的规划与预测方法交叉结合，构造了辽东部岛地区科技水平及高新技术产业发展前景的系统动力学模型，从宏观上探讨了科技与经济，社会，环境系统协调发展的机制，对系统可能出现的几种方案进行了分析研究，并对此做了相应的综合评价，提出了具体的建议与措施 ...
林明
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Policy Studies Journal, Volume 54, Issue 4, November 2026.ABSTRACT Artificial intelligence (AI) has gained much interest in public administration and public policy fields in recent years. Research on and that uses AI has so far treated it as an object or context within the broader administrative and governance discourse.
Yanto Chandra, Jianxiang Tan
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, 2004 阿拉善地区是中国干旱区生态系统受损十分严重，生态环境、资源与持续发展的矛盾十分尖锐的地区。土地荒漠化是该区生态系统受损的主要表现特征和退化的基本趋势。生态问题已成为危及当地社会安定和持续发展的灾害之源，而且严重威胁到周边地区环境与发展，急需抢救与治理。该项目根据干旱区景观与生态系统分析的原则和恢复生态学的新概念，研究阿拉善地区主要生态系统在干旱胁迫和人为扰动作用下，荒漠区景观生态结构与动态，系统的受损及其演变趋势，植物—土壤—大气连续体水分传输机制，荒漠生态系统的保护 ...
朱兴运, 郝敦元
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, 2008 汶川是"五·一二"特大地震的中心地带,也是受灾最为严重的区域.本文基于震前3 a的实地调查资料,对龙门山脉主峰--九顶山西坡汶川段的植物区系进行了系统分析,以期为灾后生物多样性的监测评估提供依据.在对九顶山西坡汶川雁门沟的野外调查中共发现维管植物111科、363属、733种,其中有种子植物94科、333属、687种.科的物种丰富性很高,含10种以上的种子植物科有19个,含216属、455种植物,分别占该区维管植物总属数和总种数的59.50%和62.07%,是该区植物区系构成的主导成分 ...
涂卫国, 高信芬, 刘士华, 吴宁 +1 more
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Making Policy Evidence Traceable: A Modular Preregistration Framework for Policy Evaluation
Policy Studies Journal, Volume 54, Issue 4, November 2026.ABSTRACT Preregistration is increasingly used in policy research, but its value depends on whether preregistered commitments can be clearly linked to reported analyses. Policy studies often involve multiple outcomes, evolving administrative data, consequential design and analytic choices, and adaptive implementation, making it difficult to distinguish ...
Yiyun Xia, Tianhao Zhao, Yuhao Ba
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北庭故城遗址区种子植物区系研究/Studyof the Flora of Seed Plants in Beiting Ancient Town Site Area[J]
, 2014 通过野外调查，采集植物标本和查阅相关文献资料，对北庭故城遗址区及临近区域种子植物区系进行了分析。结果表明：北庭故城遗址区及临近区域共有种子植物122种，隶属于105属37科。科的组成中，属和种都是以单属科和单种科为主体；属的组成中，单种属和寡种属构成属的结构主体。Drude生活型中以草本植物为主，共102种，占总种数的83．60％。在水分生态类型中，以中生植物和旱生植物为主，其中中生植物共73种，占总种数的59．84％；旱生植物33种，占总种数的27．04％。种子植物区系成分在科的水平上以世界分布为主 ...
中国科学院新疆生态与地理研究所干旱区生物地理与生物资源重点实验室,新疆乌鲁木齐,830011 +11 more
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Review of Policy Research, Volume 43, Issue 6, November 2026.ABSTRACT The EU policy framework for nature restoration has undergone a significant change with the adoption of the Nature Restoration Regulation. Since 2022, the EU has developed a new comprehensive and continent‐wide legislation to restore degraded ecosystems and halt biodiversity loss, which came into force in August 2024 and is an integral part of ...
Ronit Justo‐Hanani
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, 2005 对沙鳅亚科鱼类3属14个代表种的线粒体DNA控制区序列的结构进行了分析。通过与鲤形目鱼类的控制区序列进行比较,将沙鳅亚科鱼类的控制区分为终止序列区、中央保守区和保守序列区三个区域。同时识别了沙鳅亚科中一系列保守序列,并给出了它们的一般形式。以胭脂鱼为外类群,对比条鳅亚科、花鳅亚科、以及平鳍鳅科的代表性种类,采用NJ、MP和ML法构建沙鳅亚科的分子系统树。分子系统发育分析表明,沙鳅亚科为一单系,包括3个属:沙鳅属、副沙鳅属和薄鳅属,各属均构成单系。根据分子系统学、形态学的结果及地理分布推断 ...
唐琼英,刘焕章,杨秀平,熊邦喜
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Review of Policy Research, Volume 43, Issue 6, November 2026.ABSTRACT Nature conservation conflicts increasingly extend beyond ecological objectives to disputes over decision‐making legitimacy, institutional authority, and competing understandings of landscape and expertise. This article examines the conflict over the proposed designation of Křivoklátsko as a national park in the Czech Republic between 2021 and ...
Filip Simon
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Rare Metals, Volume 45, Issue 10, October 2026.ABSTRACT The deformation behavior of NiTiNb shape memory alloys is governed by microstructural heterogeneity, specifically the interconnected topology of the β‐Nb phase. The regulatory role of the eutectic structure in load partitioning and the evolution of deformation mechanisms, particularly in high‐Nb systems, has not been clearly understood.
Qingda Zhang +11 more
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