基于PDA/GPS/GIS的田间信息采集方法与精度分析

为了获取田间采样点的位置信息,分别配备了由2台AgGPS132接收机、1台Trimble PDA组成的DGPS采样系统及由手持GPS76、HP iPAQx2100组成的手持GPS导航采样系统。在一块冬小麦田,操作这2套系统进行采样点的位置信息采集,并进行数据转换,计算分析相邻两点之间的定位测量误差。实验表明,2套系统均能够快速、方便地实现田间信息的定位采集。从定位测量的精度看,DGPS采样系统的稳定性好、定位误差小,达到了亚米级,但成本较高。手持GPS导航采样系统定位稳定性较差、误差较大,可是成本低,因此该系统对于精度要求不高的采样比较实用。     

GPS水下地形测量原理与实践初探

随着GPS技术的迅速发展，水下地形测量技术基本上定型于“GPS+计算机（含数据处理软件）+数字测深仪”的测量模式，简单阐述了这种测量模式在水下侧量中的应用以及测深仪的工作原理，讨论了测量设备的选择、仪器参数设置、数据检验和测量过程中应注意的事项。通过1个工程实测，提出了采用这种测量模式的一些经验和体会。     

探讨智能手机在林业调查工作中的应用

从6个方面介绍了智能手机在林业调查工作中的应用实例和优势,并阐述了其良好的发展前景.     

浅谈PDA掌上电脑与GPS在林业二类调查中使用的几种形式的实现途径

介绍了PDA掌上电脑与GPS使用在林业二类调查中的应用。     

PDA与3S技术在年度造林核查中综合应用

基于PDA的森林资源数据采集是数字林业建设的重要内容,在年度造林核查中,利用PDA运行高效数据采集软件,结合3S技术,实现林业数据野外采集和更新的无纸化,提高工作效率和精度,增加造林核查的公开性,为林业数据野外采集探索新的方法和出路。     

车载行进式农田土壤压实度实时测量系统

基于应变片测力原理研制了一种新型嵌入式土壤压实度传感器和车载行进式农田土壤压实度实时测量系统。该系统将微型压力传感器嵌入到锥体前部,直接测量行进过程中锥头受到的土壤阻力,简化了测量结构,提高了系统的复合度。以超低功耗MSP430单片机作为内核的数据采集器实现了多路模拟信号的测量,2个串口分别用于与上位机的通讯和GPS信号的接收,采用PDA作为数据处理、存储以及显示终端。传感器实验室标定结果表明,嵌入式土壤压实度传感器输出电压与标准载荷具有良好的线性关系。田间试验结果表明,车载行进式农田土壤压实度实时测量系统工作稳定,土壤压实度测量结果与GPS信息融合效果良好,系统能够快速获取农田土壤压实度及其空间变异信息。     

Synthesis and efficacy of divalent metal complexes with ligand derived from 2,2-dihydroxyindane and aromatic diaminopyridines against fungi

The synthesis of macrocyclic ligands and their metal complexes is a fast developing area of research in bioinorganic and inorganic chemistry as witnessed by biologically important systems. A new series of divalent copper, nickel, iron and cobalt complexes has been prepared templately with 2,2-dihydroxyindane-1,3-dione and isomeric diaminopyridines and efficacy of these complexes is studied against Alternaria alternata and Fusarium oxysporum. The complexes have been characterized by the aid of elemental analyses, molar conductance, electronic spectra, ESR, magnetic measurements and IR spectral data has been collected. The complexes are proposed to be distorted octahedral. The value of molar conductance (11-13 Ω⁻¹ cm² mol⁻¹) indicates them to be non-electrolytes. The fungicidal properties of these complexes has been compared with the standard indofil M-45 and bavistin. Some of the complexes have been found to be anti-fungal in nature.     

Long-term follow-up after transvenous single coil embolization of patent ductus arteriosus in dogs

Background: Long‐term follow‐up studies after interventional therapy of patent ductus arteriosus (PDA) in dogs are rare. Hypothesis: Transvenous PDA embolization with a single detachable coil is a highly effective method in patients with an angiographically determined PDA ≤ 4.0 mm. Animals: Twenty‐eight dogs with an angiographic PDA ≤ 4.0 mm were included. Methods: Prospective follow‐up study after PDA coil embolization. Results: The median follow‐up time was 792 days (range, 2–3, 248 days). The rate of complete closure demonstrated by Doppler color flow was 54% at day 3 after intervention and the final cumulative rate was 71%. The rate of complete closure was significantly different between small and moderately sized PDA over the study period (P < .0001) and finally was 100 and 50%, respectively. In 16 dogs with complete closure, no recanalization was found. Disappearance of the continuous heart murmur was found in 89% after 3 days, and this increased to a final cumulative rate of 96%. Indexed left ventricular internal diameter in diastole (LVDd‐I) decreased significantly (P < .0001). In the group with moderately sized PDA, a significant difference (P= .0256) was seen in LVDd‐I between patients with and without residual shunt after exclusion of patients with persistent severe mitral valve regurgitation. Conclusion and Clinical Importance: Long‐term follow‐up after single coil embolization showed complete closure in all small PDA but a residual shunt with mild hemodynamic consequences was present in half of the moderately sized PDA.     

基于PDA的农产品市场数据采集系统

以PDA为硬件平台,采用C/S架构,对GSM、蓝牙、GPRS、合并复制等技术进行了集成应用,设计、开发了基于PDA的农产品市场数据采集系统,该系统有利于提高工作效率、实现信息发布的及时性,具有一定的实用价值。