Atom ordering in cuboctahedral Ni-Al nanoalloys

Energy calculations have been carried out on high-symmetry cuboctahedral Ni-Al nanoalloy clusters, of varying composition, with the interatomic interactions modelled by the Gupta many-body potential. Relaxations of cuboctahedral fragments cut from the bulk lattice of Ni₃Al, with 13-561 atoms, were undertaken, as were relaxations of high symmetry clusters with 55 and 147 atoms. The lowest energy isomers were found to be dominated by three factors: the tendency toward mixing due to the favourable energy of mixing, Δ_mixE; the size difference between nickel and aluminium; and the higher cohesive and surface energy of nickel compared to aluminium. The latter two factors favour Al-segregation to the surface. The most stable Ni:Al composition approaches 3:1 for larger clusters.     

白木香种子脱水耐性的发育变化及贮藏特性

研究白木香种子发育进程中种子性状、萌发能力和脱水耐性的变化,以及不同光温条件对种子萌发的影响和种子的贮藏特性。结果表明：白木香种子在花后78d获得最大干重,进入生理成熟期,此时萌发率接近最大值;胚在花后57～85d,脱水耐性逐渐增强,并在花后85d获得最大脱水耐性。种子萌发的适宜温度范围为25℃-35℃,光照对种子萌发有一定的抑制作用。新鲜自木香种子（含水量27．45％）在4℃低温条件下贮藏1个月后萌发率仅为30％左右,而含水量7．38％的干燥种子在4℃低温条件下贮藏120d,萌发率仍有53．33％,因此,4℃低温和适度脱水有利于种子短期贮藏。白木香种子能忍耐一定程度的脱水,但干燥至含水量7．50％以下时种子会发生损伤,因此推测白木香种子是一种中间性种子。     

Facilitative and competitive interactions between plant species (an example from Nodushan rangelands, Iran)

The interactions between species in six sites located in arid and semi arid rangelands of Nodushan were assessed studying association, covariation, segregation and dispersion patterns of plants. The results indicated that facilitation and competition between species were mainly affected by the life form of the species, environmental conditions and the species involved. The dominant chamaephytic shrub species (in particular Artemisia sieberi) ameliorate microenvironmental conditions and facilitate the establishment and survival of hemicryptophytic species (in particular the caespitose grass Stipa barbata). Establishment of different shrub species seems to depend mainly on soil type. Once established, they mostly are in competition with each other for limited resources on the basis of their similar life forms.     

急性冠脉事件发病特点及院前急救对策

目的分析我院急诊科对急性冠脉事件包括急性心肌梗死（AMI）和不稳定型心绞痛（UAP）的院前急救情况,就其存在的问题提出对策。方法回顾性分析1989～2010年救治的急性冠脉事件患者166例临床资料,其中AMI患者72例,UAP患者94例。结果急性冠脉事件发生率占急性心脏事件的48．8％,其院前急救率为31．3％（52／166）,院前抢救成功率为82．69％（44／52）。结论（1）急性冠脉事件的院前急救率仍低,主要与患者及其家属不了解急性冠脉综合征的发病先兆和表现等相关知识以及呼救意识有关,因此加强相关知识的群众性普及教育迫在眉睫。（2）缩短出诊半径、加强医务人员对急诊处理特别是院前处理急性冠脉事件知识的培训、完善院前急救设备,是提高急性冠脉事件院前抢救成功率的保障。     

影响侧脑室脑膜瘤手术疗效的多因素分析

目的：探讨影响侧脑室脑膜瘤手术疗效的因素,从而更好的促进侧脑室脑膜瘤的手术治疗。方法：回顾性分析侧脑室脑膜瘤显微手术30例的临床病理特征与顸后情况,其中KPS〉70分表示为预后良好,KP懿70分表示为预后不良。对各性别、年龄、部位、肿瘤大小、病理分型及术后有无并发症因素与预后进行χ^2检验与用Logistic回归分析其影响因素。结果：单因素分析表明肿瘤部位、病理分型及术后有无并发症对侧脑室脑膜瘤的预后有明显影响,P〈0．05,差异有统计学意义。经Logistic回归分析,最终进入模型的影响因素有2个,它们分别是肿瘤部位和术后有无并发症,其P值均小于0．05。结论：在显微手术下,侧脑室脑膜瘤大部分可以全切并取得了较好的远期疗效。肿瘤部位和术后有无并发症是影响预后的一个重要因素,及时处理并发症能显著地改善预后。     

Characteristics of asymptomatic patients with SARS-CoV-2 infection in Jinan,China

Coronavirus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) is continuously and rapidly circulating at present. Asymptomatic patients have been proven to be contagious and thus pose a significant infection control challenge. Here we describe the characteristics of asymptomatic patients with SARS-CoV-2 infection in Jinan, Shandong province, China. A total of 47 patients with confirmed COVID-19 were recruited. Among them, 11 patients were categorized as asymptomatic cases. We found that the asymptomatic patients in Jinan were relatively young and were mainly clustered cases. The laboratory indicators and lung lesion on chest CT were mild. No special factors were found accounting for the presence or absence of symptoms. The presence of asymptomatic patients increased the difficulty of screening. It is necessary to strengthen the identification of such patients in the future.     

针对留学生的教学特点提高全英文教学质量

针对留学生英语基础好,思维活跃,爱记笔记但有少数学生学习积极性不高、旷课和迟到等特点,在教学过程中通过选拔英语基础好、教学能力强、教学经验丰富的教师,采用灵活多样的教学方法和加强学生教学过程的管理等途径有效的提高全英文教学质量。     

Development of 81 new polymorphic EST-derived microsatellite markers for the olive flounder,Paralichthys olivaceus

Expressed sequence tags (ESTs) can be used to identify microsatellite markers. We developed 81 polymorphic microsatellite markers from 4,940 ESTs of the olive flounder, Paralichthys olivaceus. Out of 100 EST-derived microsatellites for which PCR primers were designed, 81 loci were polymorphic in 30 individuals from a single natural population with 2–28 (mean 10.6) alleles per locus. The observed and expected heterozygosities of these loci were 0.033–1.000 and 0.033–0.965, respectively. Segregation analysis within a mapping family revealed non-amplifying null alleles at five loci. These new EST-derived microsatellite markers should be useful for population genetic analyses, pedigree tracing and constructing a linkage map for olive flounder.     

Multi-scale lines and edges in V1 and beyond: Brightness,object categorization and recognition,and consciousness

In this paper we present an improved model for line and edge detection in cortical area V1. This model is based on responses of simple and complex cells, and it is multi-scale with no free parameters. We illustrate the use of the multi-scale line/edge representation in different processes: visual reconstruction or brightness perception, automatic scale selection and object segregation. A two-level object categorization scenario is tested in which pre-categorization is based on coarse scales only and final categorization on coarse plus fine scales. We also present a multi-scale object and face recognition model. Processing schemes are discussed in the framework of a complete cortical architecture. The fact that brightness perception and object recognition may be based on the same symbolic image representation is an indication that the entire (visual) cortex is involved in consciousness.     

浸矿细菌-钩端螺旋菌属菌株研究进展

钩端螺旋菌属菌株在微生物浸矿工业中具有重要作用。介绍了钩端螺旋菌属菌株的种类、特性,分离、培养方法,以及近些年来有关该属菌株在分子生物学及浸矿机理方面的研究进展。