阻滞增长模型支持下对益虫和害虫数量关系及农药影响的分析

研究了在自然状态和喷洒农药情况下益虫和害虫数量的发展趋势.基于logistic模型并加以改进建模,通过分析微分方程平衡点的稳定性,分别得出了自然状态下益虫和害虫的数量发展规律.在此基础上,进而建立了农药影响的模型并进行了计算机仿真,仿真结果证明了新模型的合理性和适用性,解决了Lotka—Volterra模型存在的问题.另外,该仿真程序本身可以作为应用程序用于实际的农田管理.     

Numerical integration of the shallow water equations over a sloping shelf

A finite-difference method is described for the numerical integration of the one-dimensional shallow water equations over a sloping shelf that allows for a continuously moving shoreline. An application of the technique is made to the propagation of non-breaking waves towards the shoreline. The results of the computation are compared with an evaluation based upon an exact analytical treatment of the non-linear equations. Excellent agreement is found for both tsunami and tidal scale oscillations.     

莱州湾海水入侵区李家宋村农业生态经济系统的结构、功能与技术对策

以位于莱州湾海水入侵区的李家宋村为例，研究了其农业生态经济系统的结构、功能，并提出防治海水入侵危害的相应技术措施。     

基于WIA-PA标准的农田信息传感网设计与实现

WIA-PA是一种新兴的工业无线传感器网络协议,提出一种基于WIA-PA协议的农田温湿度信息传感网络的设计与实现方法。基于分层状态机原理构建WIA-PA的各层协议,并采用QP (Quantum Platform)量子编程平台作为任务调度的枢纽。温湿度传感器节点通过星状网和网状网组合形式组建成自组织的无线网络,并将信息汇聚至网关节点。此外,设计了传感器协议的低功耗模式和网关与服务器之间信息交互的协议,并对设计的WIA-PA传感网络的功耗以及丢包率等进行了实测,验证了所设计传感网的良好性能。     

柱后加碱-高效阴离子交换色谱-脉冲安培检测法测定农田土中草铵膦、氨甲基膦酸和草甘膦残留

应用柱后加碱-高效阴离子交换色谱-脉冲安培检测法同时测定了农田土中草铵膦、氨甲基膦酸和草甘膦的残留。土壤样品用2 mmol/L氢氧化钠振荡提取，混匀后依次用0.22 μm滤膜、IC-C₁₈和IC-Na柱处理。滤液中的3种目标物和共存离子经IonPacAS11-HC离子色谱柱分离，柱后加碱-脉冲安培检测器检测。结果表明，草铵膦和草甘膦质量浓度在20.0~1000 μg/L、氨甲基膦酸质量浓度在5.0~400 μg/L范围内线性关系良好，相关系数均大于0.999。草铵膦、氨甲基膦酸和草甘膦的检出限分别为0.08、0.02和0.04 mg/kg，回收率为80.2%~106%，相对标准偏差为0.7%~5.0%（n=6）。该方法抗干扰性强、灵敏度和准确度高，操作简便快捷，适用于农田土中草铵膦，氨甲基膦酸和草甘膦残留量的检测。     

An Improved Encoder-Decoder Network Based on Strip Pool Method Applied to Segmentation of Farmland Vacancy Field

In the research of green vegetation coverage in the field of remote sensing image segmentation, crop planting area is often obtained by semantic segmentation of images taken from high altitude. This method can be used to obtain the rate of cultivated land in a region (such as a country), but it does not reflect the real situation of a particular farmland. Therefore, this paper takes low-altitude images of farmland to build a dataset. After comparing several mainstream semantic segmentation algorithms, a new method that is more suitable for farmland vacancy segmentation is proposed. Additionally, the Strip Pooling module (SPM) and the Mixed Pooling module (MPM), with strip pooling as their core, are designed and fused into the semantic segmentation network structure to better extract the vacancy features. Considering the high cost of manual data annotation, this paper uses an improved ResNet network as the backbone of signal transmission, and meanwhile uses data augmentation to improve the performance and robustness of the model. As a result, the accuracy of the proposed method in the test set is 95.6%, mIoU is 77.6%, and the error rate is 7%. Compared to the existing model, the mIoU value is improved by nearly 4%, reaching the level of practical application.     

区间数排序法在土壤重金属生态风险分析中的应用

将土壤重金属含量以区间形式表示,并引入区间数排序法,建立了一种基于区间数排序法的土壤重金属生态风险分析模型,并对土壤重金属进行生态风险分析.结果表明,7种重金属的区间排序向量排序为PbCdAsZnCuCrNi,重金属Pb、Cd、As和Zn的生态风险较大.此分析结果符合当地的实际情况,同时与地积累指数法的结果相符,说明区间数排序法在土壤重金属生态风险分析的应用是合理的,其分析结果具有可靠性,也为土壤重金属的风险管理提供理论依据.     

Phthalate sum determination in farmland soils using high‐performance liquid chromatography with tandem mass spectrometry

A selective and low organic‐solvent‐consuming method of sample preparation combined with high‐performance liquid chromatography and tandem mass spectrometry is introduced for phthalate sum analysis in farmland soil. Sample treatment involves a one‐step hydrolysis of phthalates using methanol and alkaline and tetrabutylammonium bromide for 20 min at 80℃. Then, the resulting phthalic acid in the acidified hydrolysate is extracted using an octanol‐based supramolecular solvent without purification. Under optimized conditions, the correlation coefficients were 0.992–0.999 and standard errors (S_y/x) were 0.018–0.138 for calibration curves within the range of 50–2000 ng/mL. No obvious matrix effect occurred between the pure supramolecular solvent and soil extract. The recovery rates ranged from 91 to 107% with the relative standard deviation ranging from 0.5–7.3%. Intra‐ and interday repeatability, expressed as relative standard deviation, was less than 8.0 and 11.0%, respectively. The detected limit was 2.49 nmol/g, and the quantification limit was 3.64 nmol/g. Fifteen soil samples were analysed, and the background corrected phthalate sum ranged from 1.44 to 120 nmol/g.     

基于熵和灰色关联的耕地系统研究

运用文献资料法、改进的熵值法以及灰色关联分析法确定了影响系统总熵变的各因素及其权重,建立了熵流模型．研究结果表明：实现耕地系统集约利用的关键在于较好地控制系统内熵的增长速度,因地制宜地从外界环境中获取负熵流．认为基于耗散结构的熵流模型是研究耕地系统的有效方法之一,通过熵值法和灰色关联法确定不同地区各指标的权重,可以为耕地系统集约节约提供有效方法．