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, 1997 本研究通过对被试求解换位棋过程的记录与分析，重点研究了问题表征在换位棋求解过程中的作用。实验结果表明：（1）正确表征问题规则是解题的必要前提.对问题规则信息的误解和遗漏，是影响解题正确率的重要因素。其中对非隐含问题规则的错误表征也占全部错误表征的很大比率。（2）“关键结构”的发现是解决换位棋的必要条件，对问题规则的错误表征影响“关键结构”的发现.（3 ...
王东晖, 傅小兰
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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
doaj
Resource Substitution: Local Governments' Issue Attention and Policy Reinvention
Policy Studies Journal, EarlyView.ABSTRACT Research on policy reinvention, where a government modifies rather than replicates policy innovations introduced by other governments, has progressed significantly, but how it is influenced by the government's issue attention has not been thoroughly examined.
Yingxin Zhang, Yixue Yao, Kaifeng Yang
wiley +1 more source
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
doaj +1 more source
Regional News, Regional Bias? Evidence From Media Discourses and Welfare Decisions in Germany
Policy Studies Journal, EarlyView.ABSTRACT How do media representations of immigrants shape their treatment by street‐level bureaucrats? Despite a uniform federal legal framework, decision‐making varies substantially across local welfare offices. Though prior research links national news reporting and policy implementation, little is known about how regional variation in news reporting
Stefanie Rueß
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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Equine Veterinary Journal, Volume 58, Issue 6, Page 1627-1635, November 2026.Abstract Background The middle conchal sinus (MCS) (ethmoidal sinus) remains one of the least understood equine paranasal compartments. Despite recognition of its involvement in sinonasal disease, disorders of the MCS often remain underdiagnosed in the absence of computed tomographic (CT) imaging due to limited anatomical understanding and challenges ...
J.‐B. Pavard +3 more
wiley +1 more source
World Food Policy, Volume 12, Issue 2, November 2026.ABSTRACT Prevailing levels of hunger, malnutrition, and food insecurity—driven by conflict, global economic crises, and ecological destruction—are threatening fulfillment of the right to adequate food. The integration of human rights in food systems policies can address these challenges; however, progress in the adoption of human rights–based ...
Ellen Johnson +4 more
wiley +1 more source