泰安地区金纹细蛾成虫发生期及发生量预测模型研究

为适时有效防治金纹细蛾,2008—2012连续5年,在泰安肥城苹果园使用信息素诱捕法检测了金纹细蛾成虫的发生动态。金纹细蛾一年发生5代,越冬代成虫发生量较低,果园第1、2代成虫发生量均远远低于防治指标,一般选择第3代作为防治的关键时期。据检测金纹细蛾成虫的发生量动态数据,以温度、湿度、降水、日照等气象资料作为气象因子,采用简单逐步回归建立了金纹细蛾第3代发生高峰期的预测预报模型：Y=-26．07719441＋0．03172086213X1＋0．26477681472X3;采用简单逐步回归和多因子互作回归建立了金纹细蛾世代发生量的预测预报模型：YI = 76. 7670083＋1.7896678278X1＋ 3.189238346X4 ; YII =- 518. 557711 - 3.220994915X1 ＋ 0.22643837696X1X2 ＋0.14479769093X2X4 ＋0.023406769049X3X5。经检验,简单回归模型能够较为准确预测出金纹细蛾第3代发生高峰期,多因子互作回归模型和简单回归模型均能准确预测金纹细蛾的世代发生量,其中以多因子交互回归模型预测结果更可靠。     

临界温度下循环喷油量对柴油机冷起动和排放特性的影响

为探明循环喷油量对小型农用柴油机冷起动特性和排放性能的影响规律,同时寻求其临界温度下的最佳循环喷油量,该研究以一款直列双缸高压共轨柴油发动机为研究对象,利用环境模拟舱整机试验平台,通过多次预试验测得海拔2000 m下,该机不开启预热装置能够成功起动的临界温度为-5 ℃。在此工况下,采用3次喷射方式,通过改变主喷油量研究循环喷油量对该机冷起动特性和排放性能的影响。结果表明：较大或较小的循环喷油量均会导致柴油机冷起动时间增加,甚至起动失败;随着循环喷油量增大,冷起动时间先减小后增加,循环喷油量为20 mg时冷起动时间最短,且HC、CO排放峰值均最低,分别为12984和3008 mg/L;增大或减少循环喷油量均会导致HC和CO排放峰值增加。循环喷油量较大时,CO排放峰值显著增加,并且峰值出现时刻提前。改变循环喷油量对NOx排放峰值有较大影响,循环喷油量为30 mg时NOx排放峰值最小,为368 mg/L。综合考虑,海拔高度2 000 m,环境温度-5 ℃工况下该柴油机起动的最佳循环喷油量为20 mg。研究结果可为柴油机冷起动特性和排放优化提供支撑。     

人口发展与城市化水平预测——以乌兰察布市为例

科学预测人口城市化水平,对相关政策的制定、制度的改革、城市配套设施的建设以及解决就业问题都具有重要意义。本文以乌兰察布市为例,对地区总人口进行预测的基础之上,运用劳动力结构模型、劳动力地域转移模型等多种数学模型,预测了城镇人口城市化水平和非农业人口的城市化水平。最后,选取与城市化相关的七项指标,对城市化水平进行了综合预测。     

Resistance and resilience of soil biological indicators: A case study with multi-walled carbon nanotube

Soil ecosystem is experiencing stresses due to climate change, and soil inhabitants try to demonstrate their inherent resistance and resilience against those stresses. Application of nanomaterials as agricultural inputs could bring shifts in resistance and resilience patterns of soil microbes and associated enzymes, especially under short-term heat stress. With this background, the impacts of multi-walled carbon nanotube (MWCNT) on the resistance and resilience of soil biological indicators were evaluated. An incubation experiment was conducted with varied MWCNT concentrations (0, 50, 100, 250, and 500 mg kg^-1 soil) for 90 d after 24-h heat stress at 48 ±2 ℃ to assess the impacts of MWCNT on soil enzyme activities and microbial populations vis-à-vis their resistance and resilience indices under short-term exposure to heat stress. Enzyme activities were reduced after exposure to heat stress. Resistance indices of enzyme activities were enhanced by MWCNT application on day 1 after heat stress, whereas there was no recovery of enzyme activities after 90-d incubation. Like soil enzyme activities, resistance index values of soil microbial populations followed the similar trend and were improved by MWCNT application. Multi-walled carbon nanotube has the potential to improve resistance indices of soil enzyme activities and microbial populations under heat stress, although they could not recover to their original state during periodical incubation after heat stress. This study helps to understand the relative changes of biological indicators under MWCNT and their ability to withstand heat stress.     

松嫩平原不同土壤基质条件下羊草种群年龄结构的研究

通过对不同土壤基质条件下羊草Leymus chinensis种群年龄结构进行研究,结果表明:5月中旬在松嫩平原羊草种群营养生长期,分蘖株均由1龄、2龄、3龄3个龄级组成,呈增长型年龄结构,其中均以1龄和2龄级分蘖株占绝对优势,为89.4%～99.7%,3龄株仅占0.3%～10.6%;根茎均由2龄、3龄、4龄3个龄级组成,根茎长度及其质量均以2龄级最高,3龄次之,4龄最小;根茎物质的储量均随着龄级的升高而降低,羊草种群对低龄植株、根茎的大比例投资是羊草种群扩大其空间的一种十分有效的生态对策.     

松嫩平原羊草草地水淹干扰恢复过程的群落动态

根据随机取样的测定数据，经过幂函数和多元回归分析及相关检验，揭示了草地水淹干扰对羊草 寸草苔、羊草 杂类草群范数量性状的变化规律。水淹干扰对草地植被的物种组成及其比例有明显的影响。水淹后基本恢复到正常草地的种类数量和生产量配置大约需要6—7年。随着生境水分减少和土壤变干，羊草种群的数量和生物量均以幂函数形式增加，而寸草苔和杂类草的数量和生物量则呈先增后降的变化过程。     

羊草种群各类地下芽的发生、输出与地上植株的形成、维持动态

羊草地下芽库中各类型芽及所形成子株和母株的季节动态变化研究结果表明,当年返青母株是由上一年母株形成的80%的分蘖芽与分蘖芽子株,15%的根茎顶芽与根茎顶芽子株,以及5%根茎节芽和根茎节芽子株组成的,分蘖芽与分蘖芽子株是返青母株的主体。随着返青母株的生长,根茎顶芽是在5月20日早于分蘖芽和根茎节芽1个月发生,并首先呈水平生长方式远离母株,占据生态位;在6月20日水平根茎顶芽开始向地面弯曲,输出子株的同时,分蘖芽和根茎节芽开始形成,并输出子株。羊草母株以产生低比例根茎芽和高比例分蘖芽的扩展和丛生联合生长方式,以年内和年间的芽、子株、母株之间的不断循环,年复一年地维持着种群的无性繁殖机制。高降水年份可显著地增加地下芽库各类型芽数量,从而使地上子株和母株密度增加。     

RAPD技术对地方鸡种群体遗传结构的分析

利用ＲＡＰＤ技术对４个地方鸡种和１个引进鸡种的群体遗传结构进行分析，通过筛选的５个随机引物ＯＰＨ－０２、ＯＰＨ－０５、ＯＰＨ－１３、ＯＰＨ－１６、ＯＰＧ－０７对５个鸡种的池ＤＮＡ进行多态性研究，结果表明：５个引物共产生条带６１个，扩增产物片段的长度一般从１５０ｂｐ－４ｋｂ。     

An insight into population structure and gene flow within pure‐bred cats

Investigation of genetic structure on the basis of pedigree information requires indicators adapted to the specific context of the populations studied. On the basis of pedigree‐based estimates of diversity, we analysed genetic diversity, mating practices and gene flow among eight cat populations raised in France, five of them being single breeds and three consisting of breed groups with varieties that may interbreed. When computed on the basis of coancestry rate, effective population sizes ranged from 127 to 1406, while the contribution of founders from other breeds ranged from 0.7 to 16.4%. In the five breeds, F_IS ranged between 0.96 and 1.83%, with this result being related to mating practices such as close inbreeding (on average 5% of individuals being inbred within two generations). Within the three groups of varieties studied, F_IT ranged from 1.59 to 3%, while values were estimated between 0.04 and 0.91%, which was linked to various amounts of gene exchanges between subpopulations at the parental level. The results indicate that cat breeds constitute populations submitted to low selection intensity, contrasting with relatively high individual inbreeding level caused by close inbreeding practices.     

稻田青蛙种群动态及其作用评价

文中根据稻田青蛙种群密度消长调查和蛙胃解剖内容物的分析,评价了稻田青蛙对主要水稻害虫的控制效果。