转基因水稻纯系对褐飞虱的抗性研究

利用基因枪法将含潮霉素抗性基因、ＧＵＳ报告基因和雪花莲凝集基因的２个质粒ｐＷＲＧ１５１５和ｐＲＳＳＧＡ１共同转化粳稻品种鄂宜１０５的成熟胚诱导的愈伤组织,从轰击的１５２块愈伤组织中共再生出２６株独立转基因植株,ＰＣＲ／Ｓｏｕｔｈｅｒｎ印迹法分析发现,７３％的转基因植株含有所有３个外源基因,遗传分析证实外泊基因在转基因植株后代中以孟德尔方式遗传,从其Ｒ１代亲本为孟德尔３：１方式遗传的Ｒ２代中,鉴定出     

罐形磁芯法测量软磁薄膜复数磁导率的研究

介绍了罐形磁芯法测量软磁薄膜材料磁导率的磁路结构原理,根据磁路磁通分布,给出了计算的等效磁路;推导了复数磁导率的计算表达式;利用罐形磁芯法在阻抗分析仪上测量了几种软磁薄膜样品的复数磁导率,并与冲击法的实验结果做了比较,获得了较为一致的结果。     

对数正态分布参数的最大似然估计

对数正态分布是工程、医学、生物学中常见的分布之一。讨论分组数据情况下,对数正态分布参数的最大似然估计,给出分布函数似然方程组解的唯一性的一种证明方法。     

逆流和并流操作时旋转床气相压降的对比

对逆流和并流旋转床的气相压降进行了实验研究。结果表明:在并流和逆流操作条件下,旋转床的湿床压降小于干床压降;且随液量增大而略有减小,随气量增大而增大;当转速增大时,并流操作的压降减小,逆流操作的压降增大;拟合结果与实验结果吻合很好。     

CFSM模型的有限自动机语义

研究CFSM模型的自动机语义,提出了一种从CFSM到自动机转换的算法。该算法的核心思想是构造一个包含控制自动机、输入自动机、输出自动机的有限状态自动机系统,利用自动机的同步性模拟CFSM的异步行为。本文的工作为进一步利用自动机理论和工具对CFSM模型进行分析和验证奠定了基础。     

自体造血干细胞移植后的胸腺近期输出功能

目的:了解血液病患者接受自体造血干细胞移植(auto-HSCT)后外周血中的T细胞受体重排删除环(TRECs)水平,从而了解其胸腺近期输出功能和T细胞免疫重建情况。方法:采用实时定量PCR法检测9例血液病患者经auto-HSCT治疗后外周血单个核细胞(PBMNCs)中的TRECs水平;22例正常人外周血样本作为对照。结果:PBMNCs中的TRECs水平有着较大的个体差异,年龄与PBMNCs中的TRECs水平呈负相关;auto-HSCT组的每1 000个PBMNCs中的TRECs平均拷贝数(2.533±4.194)明显低于正常组(4.367±3.626)(P<0.05),但部分病例的TRECs水平已基本达到正常水平。结论:在一定时间内,auto-HSCT后的胸腺近期输出功能仍较低,不同个体T细胞免疫重建时间存在差异。     

黄大铁路黄河特大桥顶推施工分析与监控技术

针对黄大铁路黄河特大桥连续钢桁梁多点同步顶推施工,利用倒拆法建模计算顶推施工全过程,找出主桁杆件在支点处的最大应力值以及导梁悬臂端变形规律和最大变形值,确定出全过程施工中的最不利工况为M2工况;设置变形监测点,监控导梁前段竖向位移变形,实测值基本与理论值吻合,施工线形可控;在M2工况中,将主桁和导梁自重荷载乘以1.35的放大系数,计算主梁在导梁悬臂140m,悬臂160m和导梁上墩20m后的主桁杆件的应力值,并在主桁上设置24个监测点监测杆件应力值,对比发现实测值均略小于理论值,施工过程中材料强度储备是安全可靠的。作为国内最大跨度的平行弦桁架桥顶推成功,对其他同类大跨度桥梁顶推施工具有较高的参考价值。     

Forecast robustness in macroeconometric models

This paper investigates potential invariance of mean forecast errors to structural breaks in the data generating process. From the general forecasting literature, such robustness is expected to be a rare occurrence. With the aid of a stylized macro model we are able to identify some economically relevant cases of robustness and to interpret them economically. We give an interpretation in terms of co‐breaking. The analytical results resound well with the forecasting record of a medium‐scale econometric model of the Norwegian economy.     

Beating the VAR: Improving Swedish GDP Forecasts Using Error and Intercept Corrections

This paper examines the forecast accuracy of an unrestricted vector autoregressive (VAR) model for GDP, relative to a comparable vector error correction model (VECM) that recognizes that the data are characterized by co‐integration. In addition, an alternative forecast method, intercept correction, is considered for further comparison. Recursive out‐of‐sample forecasts are generated for both models and forecast techniques. The generated forecasts for each model are objectively evaluated by a selection of evaluation measures and equal accuracy tests. The result shows that the VECM consistently outperforms the VAR models. Further, intercept correction enhances the forecast accuracy when applied to the VECM, whereas there is no such indication when applied to the VAR model. For certain forecast horizons there is a significant difference in forecast ability between the intercept corrected VECM compared to the VAR model. Copyright © 2015 John Wiley & Sons, Ltd.     

Emergence of life——how and where? -An update based on recent ideas

Panspermic origins notwithstanding, life, assuming that it started on Earth, may have taken root as soon as it became geologically permissible. There are multiple possibilities for early biogenesis from complex inorganic/organic geochemistry at diverse geological niches. Recent theoretical calculations have revived the possibility of Earth having a rather reduced early atmosphere, and had refueled arguments for a surface origin of life. Laboratory modeling of possible prebiotic RNA polymerization has seen interesting experimental advances, although a plausible replicator-like molecule has not yet been produced. The hydrothermal origin school of thought has also seen an interesting postulation for life's early emergence and evolution—within contiguous, porous hydrothermal iron-sulfide (FeS) compartments, leading to a non-free living last universal common ancestor (LUCA). A confined LUCA evolving later into free-living archaebacteria and eubacteria could potentially reconcile some problems of molecular divergence between these two kingdoms. There are, however, many unresolved problems, and experimental evidence for such a scheme is lacking. Here, recent updates and refinements to the mainstay hypotheses for the emergence of life on Earth are reviewed and discussed.