Integrating Remote Sensing and Proximal Sensors for the Detection of Soil Moisture and Salinity Variability in Coastal Areas

Soil moisture and salinity are two crucial coastal saline soil variables, which influence the soil quality and agricultural productivity in the reclaimed coastal region. Accurately characterizing the spatial variability of these soil parameters is critical for the rational development and utilization of tideland resources. In the present study, the spatial variability of soil moisture and salinity in the reclaimed area of Hangzhou gulf, Shangyu City, Zhejiang Province, China, was detected using the data acquired from radar image and the proximal sensor EM38. Soil moisture closely correlates radar scattering coefficient, and a simplified inversion model was built based on a backscattering coefficient extracted from multi-polarization data of ALOS/PALSAR and in situ soil moisture measured by a time domain reflectometer to detect soil moisture variations. The result indicated a higher accuracy of soil moisture inversion by the HH polarization mode than those by the HV mode. Soil salinity is reflected by soil apparent electrical conductivity (ECa). Further, ECa can be rapidly detected by EM38 equipment in situ linked with GPS for characterizing the spatial variability of soil salinity. Based on the strong spatial variability and interactions of soil moisture and salinity, a cokriging interpolation method with auxiliary variable of backscattering coefficient was adopted to map the spatial variability of ECa. When compared with a map of ECa interpolated by the ordinary kriging method, detail was revealed and the accuracy was increased by 15.3%. The results conclude that the integrating active remote sensing and proximal sensors EM38 are effective and acceptable approaches for rapidly and accurately detecting soil moisture and salinity variability in coastal areas, especially in the subtropical coastal zones of China with frequent heavy cloud cover.     

抗寒锻炼期间樟子松抗寒性与生理指标的变化

抗寒锻炼期间对11年生樟子松(Pinus sylvestris L.var.mongolica Litv.)幼树枝叶进行人工低温处理,以1年生针叶和茎的相对电导率作变化曲线,结合Logistic方程计算樟子松针叶和茎的低温半致死温度(LT50),以此评价其抗寒性;并测定了针叶和茎的干物质含量及针叶最大光化学效率(Maximum photochemical efficiency of photosystem,Fv/Fm),对干物质含量和Fv/Fm与抗寒性的相关性进行分析。结果表明:①随着抗寒锻炼的进行,樟子松针叶和茎的抗寒性逐步增强,抗寒锻炼初期的9月针叶的抗寒性强于茎的抗寒性,而抗寒性达最强的3月茎的抗寒性强于针叶的抗寒性;②这些器官的干物质含量与抗寒性为多项式相关;针叶的荧光参数Fv/Fm与抗寒性为线性相关。     

烟碱对B型和Q型烟粉虱取食行为的影响——基于EPG和液体饲囊技术体系

【目的】明确烟碱对Ｂ型和Ｑ型烟粉虱取食行为的影响,并据此建立一套研究次生物质对烟粉虱取食行为影响的利用刺吸电位（electrical penetration graph,EPG）结合液体饲囊（liquid diet sac,LDS）（EPG+LDS）指标体系。【方法】利用EPG技术测定烟粉虱对不同成分LDS的取食行为,定量研究不同浓度烟碱对烟粉虱取食行为的影响。【结果】利用植物作对照,比较5%、10%和15%蔗糖溶液对烟粉虱取食波形的影响,结果表明10%蔗糖浓度下烟粉虱EPG波形的相对振幅、频率与其在植物上的行为最为相近。在10%蔗糖溶液中加入烟碱,随着烟碱浓度的升高,烟粉虱取食波形的持续时间呈现逐渐减少的趋势,且0.001%的烟碱浓度即可显著延长烟粉虱的刺探时间并显著抑制E1波和E2波的持续时间。高浓度烟碱条件下,E2波被完全抑制。虽然B型和Q型烟粉虱在多个刺探过程的EPG指标上差异不显著,但与吸食相关的几个指标差异显著,Q型烟粉虱E2波持续时间无论在无烟碱环境下还是较低烟碱环境下都显著长于B型烟粉虱。【结论】在EPG波形指标上,C波持续总时间、E1波持续总时间及E2波持续总时间等是EPG+LDS技术体系较为重要的行为指标;对于LDS指标,10%的蔗糖溶液更适合用于不同生物型烟粉虱取食行为的EPG研究;烟碱明显抑制烟粉虱2种生物型的取食行为,Q型烟粉虱对烟碱具有更强的适应能力。     

APPROACHES TO INSPECTING COMPUTED TOMOGRAPHIC AND MAGNETIC RESONANCE STUDIES

There is a need to better understand how to optimally inspect large image datasets. The aim of the present study was to complement experimental studies of visual perception by using an online questionnaire to collect opinions of practicing veterinary radiologists about the approaches they use when inspecting clinical computed X‐ray tomography (CT) and/or magnetic resonance (MR) studies, and to test associations between radiologist's approaches and their training, experience, or caseload. Questionnaires were received from 90/454 (20%) American College of Veterinary Radiology (ACVR) Diplomates and 58/156 (37%) European College of Veterinary Diagnostic Imaging (ECVDI) Diplomates, providing 139 complete responses for CT studies and 116 for MR. Questionnaire responses differed for the following variables: specialty college, years since Board Certification, CT and MR caseload, and type of practice. ACVR Diplomates more frequently inspected multiple anatomic structures in CT and MR images before moving on to the next image, and ECVDI Diplomates more frequently inspected a specific anatomic structure through a series, then went back and checked another structure. A significant number of radiologists indicated that they initially ignore the history, adopt relatively rigid search patterns with emphasis on viewing images in a predetermined order with minimal deviation, and arrange series of images to facilitate comparisons between images, such as pre‐ and postcontrast images. Radiologists tended to adopt similar approaches for both CT and MR studies. Findings from this study could be used as foci for teaching novices how to approach large imaging studies, and provide guidance for case‐based assessment of trainees.     

ESTIMATION OF FELINE RENAL VOLUME USING COMPUTED TOMOGRAPHY AND ULTRASOUND

Renal volume estimation is an important parameter for clinical evaluation of kidneys and research applications. A time efficient, repeatable, and accurate method for volume estimation is required. The purpose of this study was to describe the accuracy of ultrasound and computed tomography (CT) for estimating feline renal volume. Standardized ultrasound and CT scans were acquired for kidneys of 12 cadaver cats, in situ. Ultrasound and CT multiplanar reconstructions were used to record renal length measurements that were then used to calculate volume using the prolate ellipsoid formula for volume estimation. In addition, CT studies were reconstructed at 1 mm, 5 mm, and 1 cm, and transferred to a workstation where the renal volume was calculated using the voxel count method (hand drawn regions of interest). The reference standard kidney volume was then determined ex vivo using water displacement with the Archimedes’ principle. Ultrasound measurement of renal length accounted for approximately 87% of the variability in renal volume for the study population. The prolate ellipsoid formula exhibited proportional bias and underestimated renal volume by a median of 18.9%. Computed tomography volume estimates using the voxel count method with hand‐traced regions of interest provided the most accurate results, with increasing accuracy for smaller voxel sizes in grossly normal kidneys (–10.1 to 0.6%). Findings from this study supported the use of CT and the voxel count method for estimating feline renal volume in future clinical and research studies.     

COMPARISON BETWEEN SHOULDER COMPUTED TOMOGRAPHY AND CLINICAL FINDINGS IN 89 DOGS PRESENTED FOR THORACIC LIMB LAMENESS

Computed tomography (CT) is an established technique for detecting shoulder lesions in dogs, however the clinical significance of shoulder CT lesions often remains uncertain. The purposes of this retrospective study were to describe the prevalence of CT lesions in both shoulder joints for 89 dogs presenting with thoracic limb lameness and to compare CT lesions with clinical characteristics. For all included dogs, results of a full orthopedic examination, other diagnostic tests, and signalment data were available in medical records. Multilevel, multivariable logistic regression was used to test clinical significance of the most prevalent CT lesions and determine factors associated with their presence. Computed tomographic lesions were detected in one or both shoulder joints for 51/89 dogs (57.3%). Mineralization of one or more surrounding peri‐articular soft‐tissue structures was identified in 31.5% of dogs, with supraspinatus muscle/tendon mineralization being the most frequently identified (24.7%). The prevalence of humeral head osteochondrosis was 9 and 21.3% of dogs had shoulder osteoarthritis. Border collies (odds ratio [OR] 9.3; 95% CI 1.39–62.1, P = 0.02) and dogs with shoulder pain (OR 4.3; 95% CI 1.08–17.1, P = 0.04) had increased risk of osteochondrosis lesions. Border collies (OR 8.4; 95% CI 1.27–55.6; P = 0.03) and older animals (OR 1.04; 95% CI 1.02–1.1, P < 0.001) had increased risk of osteoarthritis lesions. Female entire dogs had an increased risk of supraspinatus mineralization lesions (OR 6.8; 95% CI 1.55–29.5, P = 0.01). Findings indicated that shoulder CT lesions are common in dogs with thoracic limb lameness, and that some CT lesions are not associated with shoulder pain.     

Computed tomography features of bronchial and non-bronchial collateral arterial circulation development in a dog diagnosed with multiple chronic pulmonary thrombi

A 5 year-old female Lhasa Apso was diagnosed with a large right pulmonary artery thrombus, multiple smaller pulmonary thrombi, and pulmonary hypertension. In addition, thoracic computed tomography angiography revealed numerous periesophageal arterial vessels, tortuous and dilated bronchial arteries, and an enlarged tortuous left phrenic artery, consistent with systemic bronchial and non-bronchial collateral arterial circulation development. These features of chronic pulmonary arterial thrombi have not been described in dogs but are recognized in people. One year after the diagnosis, the dog was still alive and there were no clinical signs reported.     

基于混沌遗传算法的PHEV能量管理策略优化

提出了一种新的混沌遗传算法,改进了混沌映射和遗传算法的结合方式,使种群在进化的过程中能够混沌搜索解空间,从而增强遗传算法的遍历性.该算法有效地克服了遗传算法局部收敛的缺陷.在软件ADVISOR2002中,以一辆采用模糊能量管理策略的插电式混合动力电动汽车(Plug-in Hybrid Electrical Vehicle,PHEV)为研究对象,应用该混沌遗传算法对其隶属函数和控制规则进行了优化.仿真结果表明,该算法可以实现对模糊控制器的全局优化.与原模糊控制策略相比,优化后的燃油经济性提高了5.15%,CO排放减少了6.39%.     

A dual-boost three-phase DC link active power filter based on coupled impedance

A three-phase DC link active power filter (APF)based on coupled impedance and its control strategy are proposed in order to eliminate the input current harmonics of the three-phase diode rectifier. The presented APF is composed of impedance network and two asymmetric dual Boost converters. Average current control is adopted to control the DC link APF. The switch signals of the two asymmetric Boost converters are obtained respectively by leading and trailing edge modulation methods. Compared with the normal DC link active power filter,this topology reduces an active switch and a capacitance. So it can reduce costs,and there is no voltage imbalance in the DC link. Simulation results verify the correctness of the proposed topology and the corresponding control method.     

220V交流电压自动开关装置的开发与应用

农村用户利用稳压器实现用电保护的成本高,且使用方式不是活.针对这种状况,利用单片机技术和比较器原理,通过课题研究,研制出了一套结构简单、成本低廉、性能稳定和应用灵活并根据电压变化自动开关从而保护用电安全的设备装置.