漏磁腐蚀检测器新型探头机构的设计

为了解决漏磁腐蚀检测器在管道内检测过程中因探头机构姿态不稳、偏磨及支撑弹簧易折断、易震颤带来的一系列问题,对检测器所用探头机构进行研究,设计制造了一种全新的探头机构.该机构增加了辅助支撑弹簧和柔性连接铰链,很好地解决了传统探头机构存在的不足.该机构的检测探头将以往探头加耐磨层结构变为整体灌装探头壳形式,改善了检测探头的提离值,提高了检测信号的可靠性.与传统探头机构相比,该机构的使用能够有效提高检测数据的可靠性和稳定性.     

低温对小麦麸皮拉伸力学特性参数的影响

为了揭示温度对小麦麸皮破碎性能的影响规律,选取?80～30℃作为试验温度,利用动态热机械分析仪(DMA)对小麦麸皮试样进行拉伸破坏试验,研究温度对小麦麸皮杨氏模量、极限应力、极限应变等力学特性参数的影响。结果表明:随着试验温度的下降,小麦麸皮逐渐由弹塑性材料转变为脆性材料,玻璃化转变温度为?80℃。杨氏模量随着温度的下降而显著增大,?80℃时的杨氏模量增大了93.14%。极限应力对温度的变化似乎不太敏感,在整个温度变化范围内的增幅较小,约为14.58%。极限应变随着温度的下降而减小,在整个温度变化范围内,极限应变降低了66.68%。液氮消耗量随着温度的下降而呈线性升高,?80℃时的液氮消耗量是?40℃的1.74倍,是?10℃的2.94倍。同时发现,在?10℃附近杨氏模量、极限应力、极限应变、液氮消耗量均出现了一个局部极小值现象。综合考虑小麦麸皮力学特性与冷媒消耗量之间的关系,低温粉碎小麦麸皮的适宜温度可取?40～0℃。基于试验结果,分别给出了杨氏模量、极限应力、极限应变、液氮消耗量关于温差的函数关系式。研究结果初步揭示了低温脆化对小麦麸皮力学特性参数的影响规律,可为小麦麸皮超微粉碎温度的选择提供参考。     

辣椒新品种“鄂椒香帅”的选育

"鄂椒香帅"是以BL8为母本,CA1324-4为父本育成的鲜食长线椒辣椒杂交一代品种。该品种植株生长势较强,株高55 cm,开展度52 cm,叶片绿色,卵圆形,少茸毛,单叶互生,分枝性较强且分枝处有紫色斑块,始花节位8~9节,花冠白色,花萼平展;坐果力较强,果实长28~32 cm,果实横径1.3 cm,果肉厚0.2 cm,果实长羊角形,椒条顺直,果面较光滑,三心室,单果质量约26 g,果色绿色,肉质脆,味辣,适合鲜食。抗疮痂病、中抗黄瓜花叶病毒病(CMV),挂果性好,产量高;适合长江流域地区春夏季露地和高山栽培。     

Net primary productivity (NPP) dynamics and associated urbanization driving forces in metropolitan areas: a case study in Beijing City,China

Context

Eco-environmental effects of urbanization are a focus in landscape ecology.

Objective

The influences of population, economic and spatial development during the urbanization process in Beijing City, China on net primary productivity (NPP) were analyzed. The responding mechanism of NPP in different urbanization stages was also examined to develop advice about eco-environmental sustainability of urban development.

Methods

Using the Carnegie Ames Stanford Approach model, we estimated NPP. Using linear regression and polynomial regression analysis, we analyzed NPP responses to stages of urbanization.

Results

High NPP areas were located in northeast Yanqing, northwest Miyun, northern Huairou and Pinggu. The distribution of NPP generally occurred in the following order from high NPP to low NPP: outer suburbs, inner suburbs, encircled city center, and inner city. Because of the heat island effect in winter, the estimated NPP in the encircled city center and inner city was higher in 2009 than in 2001. There was a negative correlation between NPP and both economic and spatial urbanization, but an increase in population did not necessarily lead to an immediate decrease in NPP. An analysis of NPP dynamics in five kinds of urban development zones showed that urbanization resulted in a lasting and observable loss of NPP over time and space, although there was some promotion of NPP in highly urbanized zones.

Conclusion

There are three stages in the response of NPP to urbanization: damage stage, antagonistic stage, and coordination stage. The stage threshold depends on local eco-environmental management and urban planning interventions.

     

仔猪咬尾症的原因及其防治方法

仔猪咬尾症是仔猪常见的异食癖,常由于营养机能紊乱及饲养管理不当导致的该应激反应发生。常见于仔猪12~14周龄,在每年1-3月份及8-12月份发病率较高,母仔猪较公仔猪发病率高。其特征症状是咬尾仔猪的行动敏捷,被咬仔猪一阵尖叫挣扎,猪尾断节,鲜血淋漓。轻者猪尾被咬掉半截,重者全部被咬掉。被咬仔猪,因失血而发生贫血,生长发育受阻,个别仔猪因失血过多而死亡。如果没有及时处理并采取治疗措施,会导致伤口发生感染,引发局部发炎和组织脓肿、坏死,使肉质下降、减产。文章通过分析仔猪咬尾症的症状、发病原因,并根据病因提出应对的防治措施。阐释仔猪咬尾症在养殖生产过程中的危害及在现代化养殖中如何科学合理地避免因咬尾造成的经济损失。     

基于蓝牙技术的车载免提系统研究

通过对蓝牙技术的简单介绍,分析蓝牙技术在车载免提系统中的应用,同时给出系统的硬件设计与软件结构。介绍了系统的主要器件的选择、工作原理和主要功能。     

Application of partial least squares regression in detecting the important landscape indicators determining urban land surface temperature variation

Context

Revealing the interaction between landscape pattern and urban land surface temperature (LST) can provide insight into mitigating thermal environmental risks. However, there is no consensus about the key landscape indicators influencing LST.

Objectives

This study sought to identify the key landscape indicators influencing LST considering a large number of landscape pattern variables and multiple scales.

Methods

This study applied ordinary least squares regression and partial least squares regression to explore a combination of landscape metrics and identify the key indicators influencing LST. A total of 49 Landsat images of the main city of Shenzhen, China were examined at 13 spatial scales.

Results

The landscape composition indicators derived from biophysical proportion, a new metric developed in this study, more effectively determined LST variation than those derived from land cover proportion. Area-related landscape configuration indicators independently characterized LST variation, but did not give much more new information beyond that given by land cover proportion. Shape-related landscape configuration indicators were effective in combination with land cover proportion, but their importance was uncertain when temporal and spatial scales varied.

Conclusions

The influence of landscape configuration on LST exists but should not be overestimated. Comparison of numerous variables at multiple spatiotemporal scales can help identify the influence of multiple landscape characteristics on LST variation.

     

辣椒CONSTANS-like转录因子家族的生物信息学分析

CONSTANS(CO)基因介于生物节律钟与下游开花基因之间,是光周期途径中的关键基因。以‘Zunla-1’辣椒基因组数据为试验材料,利用生物信息学工具对辣椒CO-like转录因子基因家族进行研究,以期为进一步揭示CO-like转录因子基因家族在辣椒开花中的作用提供参考。结果表明:‘Zunla-1’辣椒基因组中共有9个CO-like基因,CO-like的蛋白大小相似,理论等电点均小于7;多序列和进化树分析将辣椒CO-like基因家族划分为3个组;利用转录组数据对9个CO-like基因家族成员的基因表达情况进行了分析,发现上述基因在叶片均有表达。     

猪圆环病毒病的流行病学、临床症状和防治

随着集约化、规模化的生猪养殖业的高效快速发展,养殖中出现的疾病也越来越多。猪圆环病毒病是由猪圆环病毒引发的传染病,该病毒是一种无囊膜的DNA病毒,是已知最小的动物病毒之一。不同年龄段的猪感染会表现出不同的临床症状,主要包括仔猪多系统衰竭综合征、猪皮炎肾病综合征等,给养猪业造成了巨大的经济损失。文章主要就猪圆环病毒病的流性病学、临床症状和防治等方面做出总结综述,为猪场对于猪圆环病的日常诊断及防控提供理论指导,也为后续的研究提供了参考。     

Sustainable landscape pattern: a landscape approach to serving spatial planning

Landscape Ecology - Spatial planning system needs the support of approaches toward achieving sustainability, with sustainable landscape pattern (SLP) for one potential spatial approach. However,...