非物质文化遗产保护的社会价值分析

非物质文化遗产的保护是保持世界文化多样性的重要课题,如同生物多样性一样,它的存在是人类社会和谐发展不可或缺的因素。同时非物质文化遗产承载着民族历史发展的印痕,是民族共同血脉的体现,并且社会的进步离不开创新,非物质文化遗产也是创新的文化基础。正是基于非物质文化遗产的重大社会价值,对其的保护显得愈加重要。     

"知识失业":从"教育过度"到结构调整

连续几年的高校扩招后,我国出现了“知识失业”现象,目前的“知识失业”从本质上讲属于结构性失业。造成“知识失业”的原因是多方面的,既有教育本身的原因,又有学生和社会方面的原因。用“教育过度”来解释当前的“知识失业”问题有一定的合理性,但却忽视了这种过度是一种结构性过度。解决“知识失业”问题的主要措施是进行教育结构调整,其核心是面向市场调整教育布局,调整专业设置和课程体系。目前教育结构调整应主要考虑政府政策导向、落实学校办学自主权以及克服教育惯性影响等几个方面。     

Gene Expression and Activity of Enzymes Involved in Sugar Metabolism and Accumulation During “Huangguan” and “Yali” Pear Fruit Development

Since the carbohydrate content affects pear flavor during the process of growth, it is necessary to determine the sugar components that accumulate in the fruit. We analyzed the fruit carbohydrate content, and the gene expression and activity ofacid invertase(AI), neutral invertase(NI), sucrose synthase(SS), and sucrose phosphate synthase(SPS) during the development of "Huangguan" and "Yali" pears. The results demonstrate that during development, the fruit sugar metabolism of the "Huangguan" pear follows a typical sorbitol–starch-soluble sugars middle model, whereas the "Yali" pear fruit follows a typical sorbitol–sucrose–starch-soluble sugars middle model. In the "Huangguan" pear, we found the AI and NI gene expressions, as well as AI( P 0.05) and NI( P 0.01) enzyme activities, to be positively correlated, whereas we found the NI gene expression and NI enzyme activity of "Yali" pear to be negatively correlated( P 0.01). We observed the high levels oflate-stage AI and early-stage SS during development to roughly correspond with the gene expression found in the late and early stages, respectively, suggesting their potential regulatory roles in "Huangguan" pear fruit development. Our results indicate that the primary function of SPS during the early developmental stage is to accumulate sucrose, whereas the primary function of AI is to promote hexose accumulation during the late developmental stage ofmature "Yali" pear fruit.     

Two-dimensional ferromagnetic superlattices

Mechanically exfoliated two-dimensional ferromagnetic materials (2D FMs) possess long-range ferromagnetic order and topologically nontrivial skyrmions in few layers. However, because of the dimensionality effect, such few-layer systems usually exhibit much lower Curie temperature (T_C) compared to their bulk counterparts. It is therefore of great interest to explore effective approaches to enhance their T_C, particularly in wafer-scale for practical applications. Here, we report an interfacial proximity-induced high-T_C 2D FM Fe₃GeTe₂ (FGT) via A-type antiferromagnetic material CrSb (CS) which strongly couples to FGT. A superlattice structure of (FGT/CS)_n, where n stands for the period of FGT/CS heterostructure, has been successfully produced with sharp interfaces by molecular-beam epitaxy on 2-inch wafers. By performing elemental specific X-ray magnetic circular dichroism (XMCD) measurements, we have unequivocally discovered that T_C of 4-layer Fe₃GeTe₂ can be significantly enhanced from 140 K to 230 K because of the interfacial ferromagnetic coupling. Meanwhile, an inverse proximity effect occurs in the FGT/CS interface, driving the interfacial antiferromagnetic CrSb into a ferrimagnetic state as evidenced by double-switching behavior in hysteresis loops and the XMCD spectra. Density functional theory calculations show that the Fe-Te/Cr-Sb interface is strongly FM coupled and doping of the spin-polarized electrons by the interfacial Cr layer gives rise to the T_C enhancement of the Fe₃GeTe₂ films, in accordance with our XMCD measurements. Strikingly, by introducing rich Fe in a 4-layer FGT/CS superlattice, T_C can be further enhanced to near room temperature. Our results provide a feasible approach for enhancing the magnetic order of few-layer 2D FMs in wafer-scale and render opportunities for realizing realistic ultra-thin spintronic devices.     

谈少年跳高运动员的疲劳及消除疲劳的训练安排

结合少年跳高运动员特点,对跳高运动员产生疲劳的原因及其疲劳的特征进行分析,提出了合理安排少年跳高运动员运动训练的意见,这对于提高少年选手的整体训练效益、延缓疲劳,促进机体恢复有一定参考价值。     

Untraceable partially blind signature based on DLOG problem

This paper proposes a new untraceable Partially Blind Signature scheme which is a cross between the traditional signature scheme and the blind signature scheme. In this proposed scheme, the message M that the signer signed can be divided into two parts. The first part can be known to the signer (like that in the traditional signature scheme) while the other part cannot be known to the signer (like that in the blind signature scheme). After having signed M, the signer cannot determine if he has made the signature of M except through the part that he knows. We draw ideas from Brands' "Restricted Blind Signature" to solve the Untraceable Partially Blind Signature problem. Our scheme is a probabilistic signature scheme and the security of our Untraceable Partially Blind Signature scheme relies on the difficulty of computing discrete logarithm.