Results 21 to 30 of about 13,084 (117)
四川大学学报. 自然科学版, 1978 两个相互等价的型有相同的行列式,且对变元的所有整数值来说,它们所表之数相同。反之,表数相同的两个型却不一定等价。M.Bauer曾证明行列式相同,表数相同的两个真本原整系数恒正二次型必等价。曾用几何方法证明只有一对表数相同,互不等价的二元恒正型:a（x2+3y2）和a（x2+xy+y2）。后来,给出了一系列表数相同而行列式不同的三元恒正型。本文将对表数相同、行列式亦相同但互不等价的n元型（n≥3）进行探讨,并给出所得结果以一个直接的证明。
柯召, 郑德勋
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Zhongguo shiyan zhenduanxue, 2023 我国高等教育学生能力评价方法，主要采取的是专业知识能力的客观化测量，如高等学校招生统一考试、学位英语考试、课程期末终结性考试等。此类考试能够对学生专业水平特别是专业知识掌握情况进行较为准确的判断，评价往往是针对某一学科或某几个学科的，但此类能力评价维度有限，难以多维度评估学生的综合素质和能力。而班主任和班组对高等教育毕业生能力的鉴定，往往因师生比例失调，导致评价结果模板化且多流于形式。成人高等学历教育是终身教育体系和继续教育体系的重要组成部分，是我国高等教育的一种重要形式[1]。
蒙世佼 +5 more
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A risk-measure and premium pricing model(一种风险度量与保费定价模式)
Zhejiang Daxue xuebao. Lixue ban, 2004 在“修正确定等价” (modified certainty equivalent)风险度量模式的基础上，引入风险度量安全系数λ，建立了 一种适用范围吏广的组合风險的度量模式——安全修正风险度量，从而也得到一种组合风险的保费定价模式. 由此，达到了风险的度量和保费定价的有机结合，同时，也将经典的“平均值原理”从个体风险推广到了组合投资和组合风险的度量定价中.
SHENYin-fang(沈银芳)
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Rare Metals, Volume 45, Issue 7, July 2026.ABSTRACT In electrocatalysis, traditional single‐atom catalysts (SACs) face challenges in achieving coordinated control of reaction pathways due to limitations such as single local energy levels and carrier recombination. By introducing an additional defect structure, it is possible to break the electronic structure symmetry, thereby activating SACs ...
Juanjuan Huo +8 more
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Conservation Biology, Volume 40, Issue 2, April 2026.Scaling area‐based conservation, including initiatives led or comanaged by Indigenous Peoples and local communities, is a flagship goal of the Kunming‐Montreal Global Biodiversity Framework. Conservationists often aspire to scale initiatives, but this is rarely achieved in practice. Identifying and addressing factors that limit initiative adoption (i.e.
Thomas Pienkowski +39 more
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四川大学学报. 自然科学版, 2009 作者从经济均衡理论出发,考虑了区间[0,T]上基于供应链的动态网络均衡模型,导出了与空间价格均衡条件等价的变分不等式,并给出该变分不等式解的存在唯一性结果。
袁春强 +3 more
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Zhejiang Daxue xuebao. Lixue ban, 2017 通过引入参数σ和应用权函数的方法，建立了一个具有最佳常数因子的非单调且非齐次核的Hilbert型积分不等式及其等价形式，并考虑了特殊结果.
ZHONGJianhua(钟建华) +2 more
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Integrative Conservation, Volume 5, Issue 1, Page 10-15, March 2026.First confirmed breeding of the Brown Hornbill in China, documented through cooperative feeding in Shangyong Protected Area. ABSTRACT The Brown Hornbill (Anorrhinus austeni), a Near Threatened frugivore, reaches the northern edge of its distribution in southern Yunnan, China, yet breeding had not been previously documented with site‐attributed nests in
Junsong Li +8 more
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Zhejiang Daxue xuebao. Lixue ban, 2013 引入Γ-函数等特殊函数，利用权函数方法和实分析技巧，建立一个核为双曲正割函数的Hilbert型积分不等式及其等价式，证明了它们的常数因子是最佳值，并通过取特殊的参数值，得到一些有意义的结果.
LIUQiong(刘琼) +1 more
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Integrative Conservation, Volume 5, Issue 1, Page 74-85, March 2026.This study investigates distribution patterns of Galliforms in the Indian Himalayas, focusing on factors influencing their occurrence, regions of high diversity and endemism, and their overlap with protected areas. Our study highlights the need for assemblage‐level conservation strategies in high Himalaya which primarily relies on snow leopard‐focused ...
Manvi Sharma +5 more
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