Structural perturbations of models used in mathematical biology

The paper discusses the importance of understanding structural perturbations of models used in mathematical biology, where we mainly focus on ecology and dynamical systems. We describe first briefly the classical modeling strategy and the derivation of model structures. Structural perturbations are then discussed, mainly in the framework of ODEs. We give some examples how insights obtained from this type of model could be transfered to other kinds of models. Finally we propose an alternative modeling strategy characterized by a systematic investigation of a models neighbourhood in an appropriately chosen model class.     

浙东沿海上白垩统小雄组的建立

浙东临海、三门东部的小雄盆地，发育一套中酸偏碱性的火山岩。长期以来，将其称为塘上组。详细的地质调查研究表明；这套火山岩与以天台盆地为代表的塘上组，在火山岩岩石组合、层序、古生物化石组合和同位素年龄等均不相同。火山岩是超覆于永康群馆头组、朝川组和小平田组之上，成岩时代在８５—９８Ｍａ，产晚白垩世翼龙和鸟类化石，是晚白世的喷发一沉积产物。为一独立的具有自身特色的岩石地层单位，故建立新的岩石地层单位一小雄组。     

武夷—云开构造带北段构造变形及演化

本文讨论了中国东部重要构造带,武夷——云开构造带北段的构造变形,变质作用,古压力(静压力和差异应力),古温度及它们的演化。从变形构造动力学观点入手,划分了不同构造旋回的变形变质作用,测试了变质变形的压力,温度和差异应力,进而分析了变形变质特征反地质构造环境,讨论了本区中生代以来的三期推覆构造及形成机理。     

桐柏大别山链南缘构造变形及推覆构造

本文从桐柏—大别山链南缘及其前陆地区的构造变形研究入手,划分出区内两期两种型式推覆构造,即印支—燕山早期对冲式推覆构造和喜山期背冲式推覆构造。并综合分析了它们的结构,推覆方向和规模等,讨论了它的形成演化机制和油气勘探意义。     

东濮断陷湖盆陡坡带构造演化史恢复研究

陡坡带构造演化史研究对断陷湖盆具有重要意义,平衡剖面技术在面积(体积)守恒的基础上为恢复构造演化史提供了一种科学合理的技术方法。通过对东濮凹陷兰聊陡坡带进行平衡剖面法构造演化史恢复,再现了兰聊断层的活动规律及其对东濮断陷湖盆发展演化的控制作用,明确了东濮凹陷早第三纪层序地层发育特征、坡折带类型及其对砂砾岩扇体的控制作用,指出了隐蔽油气藏发育的有利层段和分布的有利地区。     

Removal of heavy metals（Cr~（6＋），Ni~（2＋）） from polluted water using decaying leaves of plane（Plantanus orientalis）

Ｒｅｍｏｖａｌｏｆｈｅａｖｙｍｅｔａｌｓ（Ｃｒ~（６＋），Ｎｉ~（２＋））ｆｒｏｍｐｏｌｌｕｔｅｄｗａｔｅｒｕｓｉｎｇｄｅｃａｙｉｎｇｌｅａｖｅｓｏｆｐｌａｎｅ（Ｐｌａｎｔａｎｕｓｏｒｉｅｎｔａｌｉｓ）￥ＴａｎＺｈｉｑｕｎ（ＴｚｉｔｓｃｈｕｎｇＴ．Ｔａ...     

Sonographically determined anomalies and outcome in 170 chromosomally abnormal fetuses

Structural pathology and outcome were studied in 170 chromosomally abnormal fetuses. Numerical chromosomal abnormalities were established in 158 (93 per cent) cases, of which 110 (71 per cent) represented trisomies, 30 (18 per cent) Turner syndrome, and 18 (11 per cent) triploidy. Structural chromosomal abnormalities were diagnosed in 12 (7 per cent) cases. Gestational age at referral was significantly shorter for pregnancies with Turner syndrome than for the other chromosomal abnormalities. Referral before 20 weeks of gestation was mainly based on fetal structural pathology alone (92 per cent); after 20 weeks, patients were referred because of structural pathology combined with small for gestational age, oligohydramnios, or polyhydramnios. Referral as a result of suspected multiple organ pathology occurred in 73.5 per cent of pregnancies. An abnormal amniotic fluid volume was present in 59/170 (34.5 per cent) chromosomally affected pregnancies, i.e., oligohydramnios in 31 and polyhydramnios in 28 cases. Birth weight was below the tenth percentile in over half of the chromosomally abnormal fetuses, except for Turnersyndrome. Fetal outcome was poor, with a survival rate at 1 month of 30 per cent for trisomies which was mainly determined by trisomy 21 (14/18=77.5 per cent).     

Modelling farm structural change for integrated ex-ante assessment: review of methods and determinants

This paper provides a literature review of methods and determinants relevant for modelling farm structural change within an integrated modelling chain. Environmental and economic impacts at farm level and individual farm responses to agricultural and agri-environmental policies strongly depend on characteristics like farm size, specialisation, and production intensity. Consequently, up-scaling results of corresponding farm type models in ex-ante assessment exercises requires comprehensive and valid predictions of the farm types’ future relevance under different scenarios. The paper reviews methods relevant to forecasting farm numbers in classes defined by farm typologies with the objective to identify (1) a preferable modelling approach and (2) empirically relevant determinants. Despite the literature's considerable size, even recent studies are rather limited in scope and typically restricted to a subset of farm types and one or very few regions. With regard to data availability, computational complexity and statistical validation procedures, Markov chain models are identified as the only generally suitable method for a broadly scoped modelling approach across European regions and a differentiated farm typology. However, other research on determinants of farm growth, the number of farm holders, farm succession as well as new multi-agent based simulation approaches hint at relevant explanatory variables previously not considered in Markov chain analyses. Their impact seems testable in more ambitious cross-regional and cross-farm type setups.     

行为传播视角下群体压力对矿工不安全行为意向的影响*

为探究不安全行为在煤矿企业班组之间的传播机制,建立矿工的群体压力、道德推脱、道德氛围与矿工不安全行为意向之间的假设模型。以252名一线班组矿工为研究对象,基于结构方程模型分析道德推脱的中介效应和道德氛围的调节效应,对行为传播视角下的群体压力对矿工不安全行为意向的影响展开研究。研究结果表明:群体压力与矿工不安全行为意向正相关;群体压力与矿工道德推脱水平正相关;道德推脱在群体压力与不安全行为意向之间起中介作用;工具型道德氛围在群体压力与道德推脱之间起调节作用;规则型道德氛围在群体压力与矿工不安全行为意向之间起调节作用。研究结果可为煤矿企业降低矿工的不安全行为意向提供1种可借鉴的理论依据和管理方法。     

结构方程模型在城市环境管理中的应用

针对城市经济增长与环境污染负荷之间的耦合关系,选取45个样本城市,采用2004年的截面数据,开发了结构方程模型研究环境污染负荷、环境基础设施、土地利用、工业化程度和经济发展5个结构因子之间的关系。结果表明:环境污染负荷与经济发展和环境基础设施建设直接相关,而与土地利用没有明显相关,建议城市管理者应当重点调控环境基础设施、工业化发展等结构因子,以实现城市环境污染负荷的削减目标。