泸县农业总产值预测研究

针对四川省泸县1978—2010年农业总产值的增长特征,通过平稳性检验,建立一阶差分自回归模型,对泸县2020年的农业总产值进行预测,为科学合理制定泸县农业发展策略提供参考。     

Wind Vibration Analysis on the Large -span Curtain Wall

The large-span structure requires wind vibration analysis when computing the wind load;however,the formula in current code on wind vibration coefficient can hardly be applied in large-span structure,making its computation difficult and troublesome.This paper makes wind vibration analysis on the large-span curtain wall combined with certain engineering background in the methods of both time domain and frequency domain,and then the derived results are compared.The analytical results demonstrate identical distribution and contiguous numerical value of wind vibration coefficient concluded from the two varied methods;furthermore,even if the method in time domain is higher in computational complexity,more data on the response of structure under wind can be obtained,which provides reference for the theoretical analysis and engineering design.     

短小芽孢杆菌AR03挥发性有机物的抑菌活性及其组分分析

【目的】对分离自烟草根际土壤中的一株短小芽孢杆菌(Bacillus pumilus)AR03菌株产生的挥发性有机物进行抑菌活性测定和组分分析。【方法】采用培养皿对扣熏蒸法和凹玻片孢子萌发法测定挥发性有机物对烟草黑胫病菌(Phytophthora parasitica var.nicotianae)和赤星病菌(Alternaria alternata)菌落、菌丝生长以及孢子萌发的影响,采用离体叶片接种法测定挥发性有机物对烟草黑胫病和赤星病的防治效果;采用顶空加热法收集抑菌挥发性有机物,对其进行气相色谱-质谱(GC-MS)检测,并结合保留指数(retention index,RI)和内标(internal standard,IS)1-十五烯对其组分进行定性和定量分析。【结果】短小芽孢杆菌AR03菌株分泌的挥发性有机物对供试的两种病原真菌均具有一定的抑制作用,表现为经处理后的烟草黑胫病菌菌丝生长稀疏缓慢变粗、分支增多且扭曲、断裂;赤星病菌菌丝生长畸形,其上不产生分生孢子梗,内含物大部分聚集成团导致菌丝干瘪、缢缩。对峙培养2、4、6和8 d时,挥发物对黑胫病菌和赤星病菌菌丝生长的抑制率分别为56.21%和59.23%、64.75%和59.86%、66.13%和61.10%、67.04%和70.00%;对黑胫病菌游动孢子和赤星病菌分生孢子的抑制作用表现为延迟萌发且萌发后的芽管生长缓慢;黑胫病菌产生孢子囊数明显减少,赤星病菌分生孢子各分隔处的细胞畸形肿胀成泡状。离体叶片抗病测定结果显示,挥发性有机物抑制黑胫病菌和赤星病菌病斑在叶片的扩展,对峙熏蒸40 h时,对照叶片黑胫病的发病率为92.50%,圆形坏死病斑直径是25.10 mm,经挥发物处理后叶片发病率为70.83%,病斑直径为9.45 mm,对黑胫病斑扩散的抑制率为62.35%;对峙熏蒸80 h时,对照叶片赤星病的发病率为88.33%,病斑扩散为近圆形的褐色坏死斑,平均直径为8.32 mm,经挥发物处理后赤星病的发病率为60.80%,病斑扩展较慢,平均直径为2.85 mm,挥发物对赤星病斑扩散的抑制率为65.75%。SPME GC-MS分析表明,AR03菌株胞外分泌7种组分挥发性物质,均为C15H24结构的倍半萜烯类化合物,分别是二氢姜黄烯、(E)-β-金合欢烯、γ-姜黄烯、α-姜烯、π-红没药烯、β-倍半萜水芹烯和γ-E-红没药烯;AR03培养1 d后,其中β-倍半萜水芹烯相对含量最高,为80.64%,其次为(E)-β-金合欢烯和α-姜烯,相对含量分别为7.20%和6.67%;随着AR03培养时间的延长,各组分种类相同,但相对含量差异较大,除二氢姜黄烯含量保持基本不变外,其他组分含量呈递减趋势,培养至第6天时,各组分含量下降超过50%。【结论】短小芽孢杆菌AR03菌株能够产生具有较强抑菌活性的挥发性有机物,有潜力作为开发抗真菌代谢物和新药物的重要微生物资源。     

超宽带信道频率域AR模型建立与仿真

IEEE802.15.3a推荐的超宽带信道模型的参数较多,在计算机仿真中实现起来比较繁琐.近年来频率域自回归模型由于其参数较少,计算机仿真过程较为简便而得到广泛的应用.通过对广义平稳非相关散射过程的分析,探讨了建立超宽带信道频率域自回归模型的可行性.仿真结果表明频率域自回归模型在超宽带多径信道描述上有着明显的优势.     

基于LMD和AR模型的转子系统故障诊断方法

提出了基于局部均值分解（Local mean decomposition,简称LMD）和AR模型相结合的转子系统故障诊断方法.该方法先用LMD方法将转子振动信号分解成若干个瞬时频率具有物理意义的PF（Product function,简称PF）分量之和,然后对每一个PF分量建立AR模型,提取模型参数和残差方差作为故障特征向量,并以此作为神经网络分类器的输入来识别转子的工作状态和故障类型.与EMD方法的对比研究表明,这两种方法均能有效地应用于转子系统的故障诊断.但LMD方法信号分解后数据残差比EMD方法的小.     

大豆异黄酮对去卵巢大鼠小脑ERα、NGF、IL-2、AR mRNA表达的影响

建立去卵巢SD大鼠模型,运用原位组织杂交方法,通过补充不同剂量大豆异黄酮观察其对ERα、NGF、IL-2、AR mRNA在小脑中的表达和分布影响,探讨大豆异黄酮对小脑的作用机制和意义及其剂量关系。结果显示:ERα、NGF、IL-2、AR mRNA杂交信号主要分布于小脑皮质的蒲肯野氏细胞层和小脑室顶核、间位核和齿状核中,小脑皮质的分子层和颗粒层也有少量弱杂交信号表达;杂交信号主要定位于胞核,也存在于胞浆、胞膜和突起中,4种杂交信号变化的总趋势为去卵巢大鼠小脑皮质及小脑核中ERα、NGF、IL-2、AR mRNA的表达强度和阳性数目显著降低;而补充不同剂量大豆异黄酮后,4种物质的阳性杂交信号强度和数目均有不同程度回升,其中高剂量组基本恢复到假手术组水平,低剂量组仅有少许回升或无变化,中剂量组介于两者之间。从以上结果得出:大豆异黄酮可在基因水平上促进ERα、NGF、IL-2、AR在小脑中的表达,且存在剂量依赖性;这4种物质表达变化的相似性提示四者在大豆异黄酮对小脑的作用中是相互调节和影响的。     

基于AR增强现实技术的数字图书馆服务创新研究

简要介绍了AR增强现实技术,分析了数字图书馆应用AR增强现实技术的必要性,指出AR增强现实技术在数字图书馆的应用形式、工作流程以及图像识别机制,探究了基于AR增强现实技术的数字图书馆创新服务模式。     

AR、ER基因在鸡、鹌鹑及其杂交种睾丸组织中的表达及其对睾丸生长发育的影响

为探讨鸡（♂）与鹌鹑（♀）属间杂交种睾丸生长发育不良的分子机理,采集新罗曼蛋用型公鸡、朝鲜公鹌鹑、鸡与鹌鹑杂交的雄性杂交种不同发育时期的睾丸组织样共计96份并测定其体质量与睾丸质量。采用实时荧光定量PCR对公鸡、公鹌鹑及其杂交种不同生长发育期睾丸组织中AR、ER基因的mRNA表达进行了检测。结果显示：（1）鸡和鹌鹑的睾丸均能随着日龄、体质量的增长而正常生长发育,但鸡与鹌鹑杂交的杂交种的睾丸却生长缓慢而发育不良;（2）鸡和鹌鹑不同生长发育期睾丸组织中AR、ER基因mRNA的表达具有相似性,AR基因均有一个极显著的峰值,ER基因均呈波动性变化;鸡与鹌鹑的杂交种均为极端性表达,AR基因呈直线下降,ER相反则一直升高;与鸡和鹌鹑相比,杂交种AR、ER基因mRNA的极端性表达均应为异常表达。（3）鸡、鹌鹑及其杂交种的共同点是AR表达为最高峰时,ER则趋于最低点,反之,ER表达为最高峰时,AR则趋于最低点,表明ER基因对AR基因具有上调作用或者AR基因对ER基因具有下调作用,从而推测AR与ER即相对立而又协同作用的表达模式是鸡和鹌鹑睾丸组织正常生长发育的分子调控模式,探明了鸡与鹌鹑的杂交种睾丸组织发育不良的分子影响因素是其睾丸组织中的AR、ER基因mRNA异常表达。     

Feeding of Hartley Guinea Pigs for Experiment and Establishment of Allergic Rhinitis Model of Nasal Drops

The assay was aimed to explore the feeding and the best method to establish allergic rhinitis (AR) model in Hartley guinea pigs.Using the single factor experiment, the assay studied the effects of animal species, feeding way, ovalbumin (OVA) sensitization dose, time for AR model, and observed allergic reaction symptoms and nasal mucosal pathological section of Hartley guinea pig.The results showed that Hartley guinea pig was the best experimental animal for the AR experiment of nasal drops;Feed was ordinary mice feed + lettuce leaves or leaf lettuce;OVA as the sensitizer, concentration of basic sensitization was 0.1 to 0.3 mg/mL OVA, the next day intraperitoneal injection 1 time, for 7 times;Concentration of stimulated sensitization was 2% OVA, 10 to 30 μL each nostril, 1 time a day, after 6 to 9 d, compared with the blank group, the Hartley guinea pig model group had significant allergic symptoms and nasal mucosa lesions.This modeling method was simple and economic, good reproducibility, and could be used as the best method for AR model establishment of nasal drops.     

The input load and its influence factors of wind turbine based on variational wind speed

The auto regressive (AR) method is applied to build the model of wind speed in wind field,and with the model, the wind time-history is obtained. The Glauert method is used to calculate time-varying input load,such as the time histories of thrust and torque of the wind turbine under the condition of variational wind speed. Based on statistical analysis,the design loading spectrum and rain flow histogram of the loads are obtained. The effects of wheel blade parameters on the input load under the condition of variational wind speed are analyzed,and the average loads of thrust and torque are obviously affected by the pitch angle. When the pitch angle increases,the loads of thrust and torque both decrease,meanwhile the amplitude of thrust first increases then decreases,while the amplitude of torque decreases monotonously. The thrust is obviously affected by twist and attack angles of blade while the torque is less affected by the twist and attack angles of the blade. The results lay foundations for reliability design,load control of the wind turbine as well as the parameter optimum of the wheel blade aerofoil under the real wind condition.