科尔沁沙地翁牛特旗气温的非对称变化分析

分析科尔沁沙地内蒙古翁牛特旗1957年以来逐月平均气温、平均最低气温、平均最高气温.结果表明:翁牛特旗近50年平均气温、日最高气温、日最低气温随时间均呈增加态势;日最低气温的增加量是日最高气温的11倍;1月最低气温的线性增加率为8.77 ℃/100 a,7月最高气温的线性增加率为3.12 ℃/100 a,其结果导致日较差减少;20世纪80年代后期年平均气温、日最高气温、日最低气温显著升高.     

The potential of flat-bed passive integrated transponder antennae for studying habitat use by stream fishes

Abstract – Describing habitat use by stream fishes is important from both basic ecological and fisheries management points of view. The most widely used methods of measuring habitat use vary in degree of effort required, level of intrusiveness and in the level of spatial and temporal resolution. In this paper, we describe a remote monitoring technique that can provide detailed and continuous data on habitat use of individual fish in the field. The technique is based on the passive integrated transponder (PIT) system, in which a newly developed flat-bed antenna is placed on the stream bottom and simply requires a PIT-tagged fish to swim over it. We present data obtained from work using this new technology on brown trout ( Salmo trutta ) in stream enclosures, in which we describe habitat use and temporal patterns of movement by individuals and relate such data to growth rate and sex of the individual fish as well as to pool depth and time of day. In addition, we describe the range of applications of the flat-bed PIT-antenna as well as the advantages and disadvantages of using the system. ^NOTE     

石河子地区犬细小病毒野毒株的PCR检测与遗传变异初步研究

为探索石河子地区的CPV野毒株是否发生遗传变异,本试验收集石河子地区自然发病犬及病死犬的粪便和组织,提取其病毒基因组,利用PCR技术对犬细小病毒VP2基因片段进行扩增,对扩增片段进行克隆和测序,并与不同地域流行株VP2基因进行比对,分析其差异。结果显示,本试验成功克隆了VP2基因,且序列分析结果显示一毒株存在14个点突变位点其和5个缺失位点,另一毒株存在7个突变位点。经基因型鉴定,野毒株的基因型均为CPV-2a型。     

土壤养分数据几种特异值处理方法的比较

利用贵州省平坝县马场镇栗木村的13项土壤养分测试数据,对比分析了3σ准则、估计邻域法、影响系数法、邻近点数据比较法4种识别与处理特异值方法的优劣。结果表明:将3σ准则与邻近点数据比较法相结合,对土壤养分测试数据进行特异值处理获得了较好的效果,对提高地质统计学研究结果的精度有积极的作用。     

葡萄A病毒外壳蛋白基因克隆及分子变异分析

为获得葡萄A病毒(Grapevine virus A,GVA)外壳蛋白(CP)基因,并为开展GVA-CP介导的抗病毒转基因研究提供基础,本研究从葡萄休眠枝条中扩增获得12个GVA分离物的CP基因序列,全长597nt,编码198个氨基酸。所得分离物间核苷酸和氨基酸序列同源性分别为83.9%~99.8%和92.4%~99.5%,与GenBank中12个GVA CP序列比较,核苷酸和氨基酸序列同源性分别为71.0%~93.1%和81.8%~98.0%。系统进化分析表明,本研究12个分离物CP序列与已报道的GVA Ⅰ组亲缘关系最近。种群变异分析表明,GVA种群具有多种变异体类型,并且多个样品存在不同变异体类型的复合侵染。但绝大多数变异体克隆聚集在GVA Ⅰ组分支,有60%的克隆序列间同源性较高,并且聚集在同一个次级分支Ⅰ Aa,表明其为该GVA种群的优势序列。克隆的GVA CP基因以及优势序列群体的分析为葡萄抗病毒转基因研究奠定了基础。     

猪肌细胞生成素基因的研究进展

综述猪肌细胞生成素(MyoG)对猪产肉量影响的作用机制和猪肌细胞生成素基因的定位及结构,并分析其PCR-RFLP遗传变异.     

CIMMYT牧草与普通玉米杂交后植物学形态变异研究

[研究目的]为发掘利用CIMMYT牧草生长繁茂和抗逆能力强等优良遗传特性,改良普通玉米材料的抗逆性和创制新型饲草材料.[方法]以CIMMYT牧草和4个普通玉米自交系为遗传交配材料,比较研究了CIMMYT牧草和4个杂交(回交)后代材料的植物学形态特征及其与普通玉米的差异.[结果]CIMMYT牧草能将其生长繁茂、分蘖力强、生物产量高的特性遗传给杂交后代材料,并有较强的世代传递能力;该牧草幼苗、植株及其生长习性、花器官、种子特征等与普通玉米差异明显,其与普通玉米的杂交后代基本保持了它的生长发育特性,但花器官和种子特征更偏向于普通玉米;回交后代除保持了一定的分蘖特性、明显的多穗和返祖现象外,其余特征特性与普通玉米基本没有区别.[结论] CIMMYT牧草生长繁茂和生物产量高的特性能遗传给杂交后代,世代传递能力较强,通过遗传改良途径,能将CIM-MYT牧草的优良特性转育到普通玉米中,培育出饲草玉米育种新材料.     

Towards flexible management of postharvest variation in fruit firmness of three apple cultivars

Stochastic modeling provides a useful tool in managing biological variation in the postharvest chain. In the current study, the fruit-to-fruit variability in the postharvest firmness of apples was modeled. Apples from three cultivars (‘Jonagold’, ‘Braeburn’, and ‘Kanzi’) were harvested at different levels of maturity, and stored at different temperatures and controlled atmosphere (CA) conditions. By using a kinetic model describing firmness breakdown as a function of time, temperature, controlled atmosphere conditions and endogenous ethylene concentration, the main stochastic variables were identified as the initial firmness and the rate constants for firmness breakdown and ethylene production. Treating these variables as random model parameters, the Monte Carlo method was used to simulate the propagation of the fruit-to-fruit variability in flesh firmness within a batch of apples during storage under different CA conditions and subsequent shelf-life exposure. The model was validated using independent data sets from apples picked in a different season. The model developed in this study can be used to predict the probability of having apples of certain firmness after long term storage for different scenarios of temperatures and CA conditions.     

Study on the Provenancc of Fraxinus Mandshurica

INTROD[JCTloNljaxli7ilsma,7'l\hllrlcaisapril11aryaccol11pan}'il1gsPCciesofthctop-gradcpopuIationofthcbroadIcafforcstinnortI1castChina.Itdistributcd\"idcl\intl1carcasofsccondary'forcst.ltispossiblctl1attl1cpro\'cnal1ccsx`-itl1diffcrcntgcl1cticstructurclla\…     

“听音辨形”——英语现场新闻听力理解的先决条件

从英语现场新闻的语音规律和语境功能的角度认识“听音辨形”的实现途径，从语音认知本质的角度尝试提高“听音辨形”的教学方法，认为英语现场新闻语音在语流中的音变规律是“听音辨形”的关键凭借，其背景声音有时候是“听音辨形”的有效辅助；由于“感知磁效”现象表明听者通过“原型音”来识别语音变体，这就意味着要从本质上提高“听音辨形”，就应拓展听者识别语音变体的能力，因而听写是从根本上提高“听音辨形”的有效方法。