Results 41 to 50 of about 24,269 (138)
四川大学学报. 自然科学版, 1980 3.方程(1)在p≡17(mod24),q≡3(mod8)或p≡5(mod24),q≡23(mod24)或p≡5(mod24),q≡3(mod8),(p/q)=1时均无正整数解.4.当D=2p时,方程(1)除开有解p=3,x=7,y=20外,无其他的正整数解.5.方程(1)在p≡3(mod4),q≡3(mod4)时无正整数解.国外,Nagell,Ljunggren,Cohn等人有过不少工作,可参看文[4]所附文献.本文用不同于前面诸文的方法,对于D=pq的情形,得到进一步的结果 ...
柯召, 孙琦
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Zhejiang Daxue xuebao. Lixue ban, 2008 考察了非线性四阶三点边值问题的正解.通过构造适当的锥并且利用相应的积分方程证明了n个正解的存在性.主要工具是锥上的Krasnosel'skii不动点定理.
YAOQing-liu(姚庆六)
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Predictive evolutionary genomics: principles, validation, and practice
New Phytologist, EarlyView.Summary Climate change and habitat loss are driving rapid evolutionary responses in populations world‐wide, which creates an urgent need for evolutionary forecasting in conservation and agriculture. Such forecasting can be categorized into three time scales: trait‐based models that use multivariate quantitative genetic equations to project correlated ...
Daniel Ortiz‐Barrientos +5 more
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关于方程sum from j=0 to h（x+j）n=（x+h+1）n
四川大学学报. 自然科学版, 1978 我们曾证明6≤n≤33时,（1）无正整数解,以及其他若干结果。P.Erd?o对于x=1的情形,曾猜测（1）除开1+2=3外,无其他正整数解,L.Moser证明了这个猜测在h+2≤1010～6时成立。本文将证明:方程（1）在n是奇数时,除开已知的n=3,h=2,x=3和n=h=x=1外无其他正整数解,这个证明初等而简短。运用这个方法还可证明在2β|n,h（?）1,2(mod2β+3),β>0或n=2s,3·2s,s>1时,（1）均无正整数解。
柯召, 孙琦, 邹兆南
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Zhejiang Daxue xuebao. Lixue ban, 2013 采用不同链长的有机硅烷作为表面修饰剂，在正庚烷/正丁醇中利用溶剂热合成法制备得到亲油性纳米ZSM-5分子筛.通过有机硅烷与氧化物晶种表面的羟基作用，其长链化学键合到晶种表面，形成保护层，既抑制了氧化物颗粒间的团聚，又控制了纳米ZSM-5的粒径.所制备的纳米ZSM-5平均粒径为20~70 nm，且粒径随着有机硅烷碳链长度的降低而逐渐减小.添加一定量的该纳米ZSM-5到碳氢燃料模型化合物正十二烷中，在管式反应器中（550 ℃，4 MPa）考察催化裂解行为，结果表明该亲油性纳米ZSM ...
LIUJia-zhen(刘家珍) +4 more
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AI foundation models in plant biology
New Phytologist, EarlyView.Foundation models decode genomes, engineer proteins, phenotype crops, and drive AI agents across plant biology. This figure was created in BioRender (BioRender.com/xcmmkel). Summary Rapid technological progress has enabled plant biologists to accumulate unprecedented volumes of multi‐scale, multi‐modal data, yet this abundance of data has intensified ...
Haopeng Yu
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There Is Always a Bigger Fish. Determinants of Power Perceptions in Swiss Biodiversity Policy
Policy Studies Journal, EarlyView.ABSTRACT The Advocacy Coalition Framework (ACF) views power as crucial in policy processes, but the nature of coalition power, its determinants, and how to empirically measure it remain understudied. In this article, we use a mixed method approach and social network analysis to explore power relationships in the biodiversity policy subsystem in ...
Alix d'Agostino +2 more
wiley +1 more source
Zhejiang Daxue xuebao. Lixue ban, 2017 应用Dancer全局分歧理论，研究奇异边值问题正解的存在性和多解性，其中f：[0，1]×[0，∞）→[0，∞）连续.给出了关于此类问题正解存在的充分条件，该充分条件与相应线性问题的第1个特征值有关，且所涉及的值是最优的.
YANDongming(闫东明)
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