黑龙江垦区实施会计委派制有关问题的探讨

为了加强会计监督，保证会计信息的客观性，提高国有农场财务管理水平，从源头上预防和罅腐败，近两年黑龙江垦区普遍实行了会计委派制，实行会计委派制有积极作用，但也存在许多问题，亟需采取相应措施加以克服。     

链传动水稻穴盘精密播种机的研制

针对机械式水稻精密播种机播种质量差、机构传动复杂及伤种率高等问题,设计一种链传动/输送式水稻播种机。设计的链传动水稻播种机主要由型孔轮式排种器、波纹滚筒式覆土器及链条传动/输送机构等工作部件组成,完成了主要工作部件结构参数的设计计算。样机播种性能试验结果表明:随着生产率的提高,播种合格率下降,伤种率增大,当电机输出转速n0=0.1r/s,排种轮转速n2=0.05r/s时,播种机生产率为360盘/h,播种合格率94.3%,单粒率1.0%,重播率5.4%,空穴率0.3%,伤种率仅0.4%,播种效果最好,试验指标均达到或超过水稻精密播种机试验要求。     

Evaluation of plant seedling water stress using dynamic fluorescence index with blue LED-based fluorescence imaging

A dynamic fluorescence image index system capable of non-destructive assessment of water stress in cabbage seedlings was developed. The quenching curves of chlorophyll fluorescence characteristic to the plant's water stress status under reduced excitation energy were acquired via a multispectral imaging system. The dynamic fluorescence index (DFI), a fluorescence index derived from quantitative modeling of the quenching curves in this study, was found superior to conventional indices such as the fluorescence decrease ratio (Rfd) in evaluating water stress status in cabbage seedlings, with respect to due mainly to its significantly reduced measuring time and enhanced precision of the chlorophyll fluorescence responses. The best results of the quantitative model to predict water stress status of seedlings using the dynamic fluorescence index were r = 0.944 and SEE = 0.286 MPa using the 720 nm channel. The blue (460 nm) LED-excited fluorescence multispectral imaging system (FMSIS) coupled with DFI provides a powerful research tool for plant physiology studies as well as for improving greenhouse and agriculture management practices where quantitative assessment of water potential in leafy plants is critical.     

球勺内窝孔小麦精量排种器充种机理的研究

球勺内窝孔小麦精量排种器是以复式型孔为排种元件，应用多力联合充种原理，在结构工艺上是内侧充种垂直圆盘排种器应用于分蘖作物的新突破，从充种角度阐明其排种元素的位置和结构特点；对种子在充种过程中的受力状况进行了分析，论述了种子在重力、离心力、摩擦力和种间挤推力的联合作用下以填补空间，相向速度差、同向速度差的三种充种机理。     

影响荧光法鉴别海面溢油的各种因素研究

采用荧光光谱谱图配比法研究了在海面溢油鉴别过程中的影响因素。对溶剂、浓度、阳光辐射、海上风化、样品采集和样品贮存等影响因素进行了探讨。并提出了溶剂的纯化方法和本方法所使用的浓度范围。确定了样品贮存的最佳条件。旨在保证方法的准确性     

模拟酸雨对山核桃叶绿素荧光参数、叶绿素和生长的影响

为探明酸雨对山核桃Carya cathayensis叶绿素荧光特性的影响,设置pH 2.5,3.5,4.5和5.6（ck）共4个模拟酸雨处理,于2006年10月,2007年4月、7月、10月,利用叶绿素荧光技术测定了模拟酸雨胁迫后的山核桃的叶绿素荧光参数。结果表明：PSⅡ最大光化学效率（Fv/Fm）,PSⅡ的潜在活性（Fv/F0）,PSⅡ实际光化学量子产量（ΦPSⅡ）和叶绿素的变化都随着模拟酸雨pH值的降低而降低,pH 2.5的处理下降幅度比较大,说明模拟酸雨对这个处理的山核桃有一定的伤害,其他处理之间变化不大。各个月表现基本一致,尤其2007年10月差异明显,说明模拟酸雨处理的山核桃更容易受到低温胁迫,造成伤害。研究还表明,Fv/Fm,Fv/F0,ΦPSⅡ可作为植物受到酸雨影响的重要指标。     

不同磷水平下雷竹幼苗叶绿素荧光特性

 为了解不同磷水平下雷竹Phyllostachys violascens幼苗叶片叶绿素荧光特性的变化,试验以无性繁殖的雷竹幼苗作为试验材料,采用砂培试验方法,研究了不同磷水平（0,0.5,5.0,50.0,500.0 mg·L^－1）对雷竹幼苗叶绿素荧光参数和光通量密度?鄄光合电子传递速率（P_AR-E_TR）响应曲线的影响。结果表明,随着磷质量浓度的升高,幼苗叶片潜在光化学活性（F_o /F_m）呈逐渐降低趋势,最大光化学效率（F_v /F_m）在0~50.0 mg·L^－1磷质量浓度范围内逐渐下降。磷质量浓度为5.0 mg·L^－1时,初始荧光（F_o）,最大荧光（F_m）,适时最小荧光（F_t）和可变荧光（F_v）均达到最大值,电子传递速率（E_TR）和光系统Ⅱ（PSⅡ）实际光化学效率（Y）较大,光化学猝灭系数（q_P）和非光化学猝灭系数（q_N和N_PQ）相对较低,说明在5.0 mg·L^-1磷质量浓度下,雷竹幼苗叶片的光合能力较强,接近适宜雷竹幼苗生长的磷质量浓度。磷质量浓度过高（50.0和500.0 mg·L^-1）均导致雷竹幼苗叶片E_TR下降,热耗散增加,光化学效率和光量子产额降低。图1表3参20     

H9亚型禽流感病毒间接免疫荧光检测方法的建立与比较

将禽流感病毒(AIV)接种犬肾上皮细胞(MDCK),24h后以鸡抗禽流感抗体和兔抗鸡荧光抗体进行间接免疫荧光试验(IFA),结果于细胞核、细胞质内观察到特异性的荧光。利用96孔细胞板培养MDCK细胞,以间接免疫荧光作为判定指标对禽流感病毒进行毒力测定,并与禽流感病毒通用荧光反转录-聚合酶链反应(荧光RT-PCR)检测方法进行比较。结果表明间接IFA、荧光RT-PCR对同一样品检测的最高稀释度分别为10-5.25TCID50和10-6,Ct<30,两种方法对禽流感病毒的检测敏感性均很高。但由于荧光RT-PCR仅对抽提的RNA进行检测,而间接IFA是对禽流感活病毒进行检测,因此在临床样品检测和动物产品检疫中间接IFA更具准确性和实用性。     

Visualization of turbulent flame fronts with planar laser-induced fluorescence

This report concerns the quantitative time-resolved visualization of reaction zones in laminar, transitional, and turbulent nonpremixed flames. Two-dimensional OH molecular concentrations were measured with planar laser-induced fluorescence excited by a sheet of light (formed from a single tunable ultraviolet laser pulse) and detected with a two-dimensional, image-intensified photodiode array camera. From the resulting data details of instantaneous flame front structures (including positions, shapes, and widths) were obtained.     

5种悬钩子属植物的光合荧光特性

研究了高粱泡Rubus lambertianus,寒莓R. buergeri,山莓R. corchorifolius,茅莓R. parvifolius和蓬蘽R． hirsutus等5种悬钩子属植物叶片的光合色素含量、气体交换参数-光响应曲线和叶绿素荧光参数-光响应曲线。结果表明,在5种植物中,山莓的拟合最大净光合速率、光饱和点和光补偿点光强最小,且光饱和点小于500 μmol·m^－2·s^－1,而其余4种均高于800 μmol·m^－2·s^－1;蓬蘽和山莓的叶绿素 a/b和叶绿素/类胡萝卜均显著低于和高于其他3种;光强超过光饱和点时,净光合速率、气孔导度、胞间二氧化碳浓度、水分利用效率、光系统Ⅱ有效光化学量子产量、光化学猝灭和表观电子传递速率随光强增加而引起的变化以山莓为最大,蓬蘽、茅莓和高粱泡次之,寒莓最小;非光化学猝灭的变化却以寒莓为最大,山莓为最小;光饱和点以下的水分利用效率以山莓最大,蓬蘽和高粱泡最小。光系统Ⅱ最大光化学量子产量和量子需要额也以山莓最大,蓬蘽和高粱泡为最小。说明山莓耐阴但不耐光,容易发生光抑制;其余4种较耐光又耐阴,并忍耐光抑制,而又以寒莓最强,其次分别为高粱泡、茅莓和蓬蘽。图2表3参13     

Sylvatest-Duo装置的探针触式与计示压强对木材超声波测量精度的影响

为了提高应用Sylvatest-Duo超声波测量装置进行木材质量和缺陷检测的精度,研究了该装置的探针与木材接触方式（探针触式）及其计示压强对木材中超声波传播速度和信号能量衰减幅度的影响,确定了测量过程中宜采用的最佳探针触式和最佳计示压强。以美国红松Pinus resinosa的小规格试样材（25.4 mm × 25.4 mm × 407.0 mm）为研究对象,采用单因素重复试验,经SPSS统计分析中多元检验的研究结果表明:不同的探针触式对超声波测量结果影响显著（P值为0.000）,探针-木材的“持续性接触”比“非持续性接触”测量偏差小,检测效果稳定;在探针“持续性接触”方式下,超声波的传播速度和信号能量衰减幅度随着计示压强增大而增加,在计示压强为275.8 kPa（40 psi）时,两者趋于稳定。因此,建议在应用Slyvatest-Duo进行木材超声波测量过程中,宜保持探针与木材持续性接触,同时采用275.8 kPa的计示压强,可达到最优检测精度。     

球勺内窝孔小麦精量排种器投种机理的研究

简要介绍球勺内窝孔小麦精量排种器结构和工作原理,对护种区种子的受力和运动进行了分析,通过种子的运动特征,着重研究排种轮转速、投种口的位置和尺寸对排种均匀性的影响,并优化各参数。     

香蕉假茎自动对靶精准施肥装置的设计与试验

目的 针对华南地区蕉园施肥模式不能满足农艺要求、施肥效率低以及施肥机械自动化程度低等问题,设计一种香蕉假茎自动对靶精准施肥装置。方法 根据蕉园实际沟施过程和农艺要求,确定装置的控制原理和关键部件的安装位置,并基于此建立施肥时间滞后模型;对外槽轮排肥器结构进行创新设计,建立排肥机构单圈排肥量和周期排肥量的数学模型,并通过EDEM仿真对肥料运动特性进行验证。采用响应曲面优化方法对排肥机构的工作参数进行优化,满足香蕉在不同生长时期的需肥要求,并以施肥量变异系数、施肥长度变异系数和假茎中心偏移距离为评价指标,进行最优参数组合下的田间试验,进一步验证精准施肥装置的工作性能。结果 确定排肥机构最优工作参数为：排肥轴转速85 r/min,槽轮内芯初始有效工作长度6 mm。田间试验结果表明,施肥量变异系数和施肥长度变异系数均小于4%,假茎中心偏移距离平均值最高为7.4 cm,满足农艺要求。结论 该施肥装置工作性能可满足香蕉施肥要求,本研究可为蕉园精准施肥装置的设计提供参考。     

Simulating field-scale variability and precision management with a 3D hydrologic cropping systems model

Effective variable-rate nitrogen (N) management requires an understanding of temporal variability and field-scale spatial interactions (e.g. lateral redistribution of nutrients). Modeling studies, in conjunction with field data, can improve process understanding of agricultural management. CropSyst-Microbasin (CS-MB) is a fully distributed, 3-dimensional hydrologic cropping systems model that simulates small (10 s of hectares) heterogeneous agricultural watersheds with complex terrain. This study used a highly instrumented 10.9 ha watershed in the Inland Pacific Northwest, USA, to: (1) assess the accuracy of CS-MB simulations of field-scale variability in water transport and crop yield in comparison to observed field data, and (2) quantify differences in simulated yield and farm profitability between variable-rate and uniform fertilizer applications in low, average and high precipitation treatments. During water years 2012 and 2013 (a “water year” refers to October 1st through the following September 30th, where a given water year is named for the calendar year on September 30th), the model simulated surface runoff with a Nash–Sutcliffe efficiency (NSE) of 0.7, periodic soil water content (comparison to seasonal soil core measurements) with a root mean square error (RMSE) ≤0.05 m³ m^?3, and continuous soil water content (comparison to in situ soil sensors) at 15 of 20 microsites with NSE ≥0.4. The model predicted 2013 field variability in winter wheat yield with RMSE of 1100 kg ha^?1. Simulated uniform N management resulted in 0–35 kg ha^?1 greater field average yield in comparison to variable-rate management. The savings in fertilizer costs under variable-rate N management resulted in $23–$32 ha^?1 greater field average returns to risk. This study demonstrated the capacity of CS-MB to further understanding of simulated and observed field-scale spatial variability and simulated crop response to low, medium and high annual precipitation.     

带有蓄土装置的胡麻精量穴播联合作业机的设计与试验

针对西北地区胡麻播种机旋耕取土装置取土不均匀导致膜上覆土不均匀的问题,设计一款带有蓄土装置的胡麻精量穴播联合作业机。该机具由旋耕装置、地膜覆土装置、滴灌带铺设装置、地膜铺设装置和播种装置组成。根据农艺种植要求对机具的关键装置进行理论分析和功率计算,确定满足覆土工作时运土带线速度、双向螺旋输送器转速、双排取种勺式穴播器的半径及整机配套拖拉机功率。采用EDEM软件对地膜覆土装置覆土过程进行仿真,验证蓄土装置的可行性。田间试验结果表明：机具前进速度为0.6m/s时,其空穴率为1.2%、穴粒数合格率89.3%、播种深度合格率86.5%、膜孔错位率5.1%、膜边覆土厚度合格率95.7%、邻接行距合格率92.4%。田间播种性能试验相关指标均达到覆膜穴播机作业质量要求,田间试验覆土结果与仿真结果基本一致。     

Soil mapping for precision agriculture using support vector machines combined with inverse distance weighting

Precision Agriculture - Kriging has been shown to be the best interpolator to interpolate maps in precision agriculture. However, Kriging requires a high number of sampling points to generate...     

吸盘式精密播种装置气力吸种部件流场仿真分析

以吸盘式精密播种装置为研究对象,应用CFD技术数值模拟吸种盘不同吸孔直径、气源真空度和气吸室形状下气力吸种部件内气流的压力场,并进行试验验证。仿真结果表明:较大的吸孔直径可提高吸种能力,但气吸室内压力呈不均匀分布趋势,影响吸种性能;较大的气源真空度有利于提高吸种能力,且不影响气吸室流场的均匀分布;气吸室形状对吸种能力和吸种均匀性均不造成影响。试验分析与仿真分析结果一致。对于自制吸盘式精密播种装置,播种水稻种子时吸种盘上吸孔孔径2.0 mm左右、真空度为6.7~15.0 kPa时具有较好的吸种效果。     

A conceptual framework for judging the precision agriculture hypothesis with regard to site-specific nitrogen application

In this study we derive a test that aims to show that the economic optimum nitrogen applications in site-specific management zones are different. In addition, a confidence interval is derived for the difference between optima, and here we show that separate confidence intervals for either optimum are not as good as the former for judging the precision agriculture hypothesis. Both the test and the confidence interval for the difference are based on modeling the returns above N fertilizer cost by quadratic functions of the nitrogen rate. The data are from an N-rate trial at a heterogeneous field in Thalhausen, Germany. This trial could barely support the economic benefit of precision agriculture. A statistical proof that high- and low-yielding zones should be discriminated against just failed to meet the standard 5% level. We also discuss what design of nitrogen fertilizer levels should be used for the test and the confidence intervals.     

新一代超高清亚毫米级管道内检测技术的研发与应用

针对油气管道中普遍存在的环焊缝缺陷、类裂纹缺陷以及针孔小缺陷检测能力和识别率较低的难题,通过理论分析、建模仿真、设备研制、现场应用等环节,自主研发了新一代超高清管道漏磁内检测器.该检测器实现了探头通道间距0.6 mm、轴向采样间距1mm,满足海量数据存储和采集要求,信号数据采集量增加15倍,并将漏磁检测、变形检测及定位...     

基于图像识别的无人机精准喷雾控制系统的研究

【目的】针对传统的植保无人机喷雾作业时化肥农药浪费大,利用率低,造成环境污染的问题,研制一种基于图像识别的无人机精准喷雾控制系统。【方法】利用中值滤波算法对田间航拍图像进行去噪,采用分层K_means硬聚类算法实现对农田航拍图像的分割,提取非作物区域的颜色、纹理特征空间的22个特征参数,设计支持向量机分类器进行分类识别。根据优选的17个特征参数,利用以径向基函数作为核函数的支持向量机对非作物区域图像进行识别,并根据识别结果控制喷头,实现精准喷雾。【结果】测试样本的识别率可达为76.56%,在无干扰风场情况下,当P_阀为10%时,减施率可达32.7%。【结论】本系统为农业航空精准喷雾控制技术的应用提供了参考方向和决策支持。