《数据结构》教学方法浅谈

“数据结构”课程是计算机程序设计的重要理论技术基础，因此，对其教学方法进行多方面的研究是目前应加以重视的重要课题。本文针对“数据结构”教学中发现的学生缺乏学习兴趣、理论基础薄弱、解决实际问题能力差的情况进行了分析，同时讨论了为了让学生扎实掌握理论知识，应该注重归纳、小结和实验教学，从而加深学生对理论知识的理解。     

Graphene/SrTiO3 hetero interface studied by X-ray photoelectron spectroscopy

The present paper focuses on study of graphene and strontium titanate(SrTiO_3 or STO) interface. An ambient pressure chemical vapour deposition(AP-CVD) setup is used to grow graphene on STO(110)substrates in the presence of methane, argon and hydrogen gases at 1000 °C for 4 h. Raman spectroscopy measurements confirm the presence of graphene on STO substrates due to the existence of typical D and G peaks referring to graphene. These characteristic peaks are missing in the spectrum for bare substrates.X-ray photoelectron spectroscopy(XPS) is carried out for elemental analysis of samples, and study their bonding with STO substrates. We employed the valence band spectrum to calculate the valence band offset(VBO) and conduction band offset(CBO) at the G-STO interface. Also, we present an energy band diagram for Bi-layer and ABC(arranging pattern of carbon layers) stacked graphene layers.     

A 160-kilobit molecular electronic memory patterned at 10(11) bits per square centimetre

The primary metric for gauging progress in the various semiconductor integrated circuit technologies is the spacing, or pitch, between the most closely spaced wires within a dynamic random access memory (DRAM) circuit. Modern DRAM circuits have 140 nm pitch wires and a memory cell size of 0.0408 mum(2). Improving integrated circuit technology will require that these dimensions decrease over time. However, at present a large fraction of the patterning and materials requirements that we expect to need for the construction of new integrated circuit technologies in 2013 have 'no known solution'. Promising ingredients for advances in integrated circuit technology are nanowires, molecular electronics and defect-tolerant architectures, as demonstrated by reports of single devices and small circuits. Methods of extending these approaches to large-scale, high-density circuitry are largely undeveloped. Here we describe a 160,000-bit molecular electronic memory circuit, fabricated at a density of 10(11) bits cm(-2) (pitch 33 nm; memory cell size 0.0011 microm2), that is, roughly analogous to the dimensions of a DRAM circuit projected to be available by 2020. A monolayer of bistable, [2]rotaxane molecules served as the data storage elements. Although the circuit has large numbers of defects, those defects could be readily identified through electronic testing and isolated using software coding. The working bits were then configured to form a fully functional random access memory circuit for storing and retrieving information.     

A copy number variation morbidity map of developmental delay

To understand the genetic heterogeneity underlying developmental delay, we compared copy number variants (CNVs) in 15,767 children with intellectual disability and various congenital defects (cases) to CNVs in 8,329 unaffected adult controls. We estimate that ～14.2% of disease in these children is caused by CNVs >400 kb. We observed a greater enrichment of CNVs in individuals with craniofacial anomalies and cardiovascular defects compared to those with epilepsy or autism. We identified 59 pathogenic CNVs, including 14 new or previously weakly supported candidates, refined the critical interval for several genomic disorders, such as the 17q21.31 microdeletion syndrome, and identified 940 candidate dosage-sensitive genes. We also developed methods to opportunistically discover small, disruptive CNVs within the large and growing diagnostic array datasets. This evolving CNV morbidity map, combined with exome and genome sequencing, will be critical for deciphering the genetic basis of developmental delay, intellectual disability and autism spectrum disorders.     

Transplantations interspécifiques de gonades embryonnaires de Phasianidés

Summary When indifferent gonads from red-legged partridges, Japanese quail or pintado embryos were transplanted into the coelomic cavity of early chick embryos, they differentiated into ovaries and testes, regardless of the sex of the host. Testicular transplants brought about the retrogression of both Müllerian ducts in female hosts, and ovarian transplants the feminization of the left testis in male hosts. This demonstrates hormonal activity of the embryonic gonads in the 3 species under study. Since the embryonic sex hormones show inter-specific activity, they may be of identical chemical nature.

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Avec la collaboration technique deA. Zeis.     

新疆拳击队的现状分析

拳击运动是新疆各体育项目中的重中之重,近几年来在新疆拳击队中涌现出了许多优秀运动员,在国际,国内各级比赛中取得了可喜的成绩.文章中笔者作为一名新疆拳击队队员,根据其长期的训练与比赛经验,结合已学过的理论知识对新疆拳击队的现状进行了较全面的调查与分析,并针对上述情况提出了提高我区拳击运动训练水平的建议.     

Silicon nanowires as efficient thermoelectric materials

Thermoelectric materials interconvert thermal gradients and electric fields for power generation or for refrigeration. Thermoelectrics currently find only niche applications because of their limited efficiency, which is measured by the dimensionless parameter ZT-a function of the Seebeck coefficient or thermoelectric power, and of the electrical and thermal conductivities. Maximizing ZT is challenging because optimizing one physical parameter often adversely affects another. Several groups have achieved significant improvements in ZT through multi-component nanostructured thermoelectrics, such as Bi(2)Te(3)/Sb(2)Te(3) thin-film superlattices, or embedded PbSeTe quantum dot superlattices. Here we report efficient thermoelectric performance from the single-component system of silicon nanowires for cross-sectional areas of 10 nm x 20 nm and 20 nm x 20 nm. By varying the nanowire size and impurity doping levels, ZT values representing an approximately 100-fold improvement over bulk Si are achieved over a broad temperature range, including ZT approximately 1 at 200 K. Independent measurements of the Seebeck coefficient, the electrical conductivity and the thermal conductivity, combined with theory, indicate that the improved efficiency originates from phonon effects. These results are expected to apply to other classes of semiconductor nanomaterials.