Interannual decrease in condition factor of the western sand lance Ammodytes japonicus in Japan in the last decade: Evidence for food‐limited decline of the catch

Annual catch of the western sand lance Ammodytes japonicus in the eastern Seto Inland Sea, Japan, has shown a decreasing trend since the 1990s. To examine whether food shortage was the main cause for the catch decrease, we investigated the condition factor of the age‐0 fish at the beginning of the estivation period (late July) in Harima‐Nada, eastern Seto Inland Sea, for 10 years from 2008 to 2017. The mean abundance of copepods as food for the age‐0 fish during the fish growth period (from February to June) around the estivation area was also determined. The condition factor showed a significant decrease, and values for 2011 and later years were mostly lower than the known minimum threshold (4.2) for maturation. In the recent 4 years from 2013 to 2016, the mean copepod abundance was much lower than values for the other years. The condition factor showed a significant positive correlation with the copepod abundance. These results indicate that decline of western sand lance catch after 1990 was caused mainly by food shortage.     

试论茶叶的清洁生产

论述了清洁生产与茶叶清洁生产的概念;分析了茶叶的污染来源及茶叶生产对环境的污染与破坏;提出了实现茶叶清洁生产的主要措施与途径：加强管理,建立茶叶清洁生产知识和技术培训体系;优化茶园生态环境;科学合理施用肥料;茶园病虫害实行综合治理,积极采用生物防治措施,减少使用化学农药;减少茶叶加工中的污染;与无公害茶叶生产相结合。     

云南紫稻细胞质无花粉型三系及杂种F1的AFLP指纹图谱的构建与分析

利用AFLP分子标记对云南紫稻细胞质无花粉水稻三系及杂种F1进行了指纹图谱的构建与比较分析。从14对引物中筛选出8对具有明显多态性的引物。天香018（天香A×珞恢018)材料组（不育系、保持系、恢复系及杂种F1）共扩增出179条带,其中有52条多态性谱带,占总带数的29.05％,平均每对引物可以扩增出6.50条多态性谱带;天香806(天香A×珞恢806)材料组(不育系、保持系、恢复系及杂种F1）共扩增出177条带,其中有50条差异带,占总带数的28.25％,平均每对引物可以扩增出6.25条多态性谱带。特别明显的是在引物对E ATG/M CAC的扩增中,在AFLP指纹图谱中出现两条特征带（a带和b带）,为保持系所特有,能够明显区别于不育系、恢复系和F1。在另外一些引物对中也观察到不育系与保持系之间的差异带。     

基于RGB模型的脱绒棉种颜色特征与发芽状况的关系

为了得到脱绒棉种质量与其表面颜色特征之间的关系,采用数码相机拍照,利用图像处理技术提取脱绒棉种表面颜色特征,并严格按照GB/T3543.4－1995进行发芽试验,通过线性拟合和逐步回归分析,建立了脱绒棉种质量的颜色特征估算模型,并对其精度进行了评价和验证。结果表明：基于R/(R+G+B)、G/(R+G+B)、(R-G-B)/(R+G)和R/G 4个颜色特征参数,逐步回归模型决定系数R2分别为0.6949和0.7148,且均通过了P=0.01极显著性检验水平。该研究为基于RGB颜色模型对脱绒棉种实施快速、有效的分选提供了理论依据。     

包膜尿素氮素的溶出特性研究

 【目的】研究包膜尿素（LP 30）氮素的溶出特性。【方法】采用土壤、纯水两种培养方式,在4种温度（10、15、20、25 ℃）条件下对不同培养时期氮素溶出率进行测定,利用具体的方法——The number of days transformed to standard temperature（DTS）,对自然温度条件下氮素的溶出率进行预测。【结果】培养试验表明,土壤和纯水两种培养方式对包膜尿素氮素溶出率的影响很小,不同温度对氮素溶出率的影响显著。分析表明,一级反应动力学模型可很好地描述包膜尿素氮素的溶出过程。氮素溶出速率随温度升高而加快,在10～25℃内,每升高5℃,速率常数约提高1倍左右。包膜尿素埋藏土壤后实测的氮素溶出率值与采用DTS法预测的氮素溶出率值之间无明显差异。【结论】包膜尿素（LP 30）氮素溶出率大小主要取决于温度的变化,DTS法能较准确地预测包膜尿素施入土壤后,自然温度条件下,任意天数的氮素溶出率。     

安邦河湿地底栖动物群落结构与水质生物评价

分析了安邦河湿地底栖动物的物种组成与群落结构,同时利用Shannon-Wiener指数（ H′）、生物学污染指数（ BPI）和Chandler生物指数（ CBI）对安邦河湿地水体污染状况进行了评价。共采集底栖动物431个,鉴定出底栖动物37种,隶属于5纲7目,其中昆虫纲种类最多,为27种,腹足纲4种,瓣鳃纲3种,寡毛纲2种,蛭纲1种。底栖动物优势种为卵萝卜螺（ Radix ovate）和白旋螺（ Gyraulus albus）。底栖动物的栖息密度较低,为（390±422）个· m-2。典型对应分析（ CCA）表明,水深是影响安邦河湿地底栖动物物种分布的主要环境因子。安邦河湿地水质呈轻度污染状态。     

A ground-based hyperspectral imaging system for characterizing vegetation spectral features

A cropping system is usually characterized by continuous spatio-temporal vegetation variability. Vegetation variability can be detected by changes in several vegetation parameters defined according to purpose. Estimation of these vegetation parameters has been made possible by calculating various vegetation indices (VIs), usually by ratioing, differencing, ratioing differences and sums, or by forming linear combinations of spectral band data. Spectrometers or sensors have been used to acquire visible and infrared spectral properties of vegetation. This paper presents a ground-based hyperspectral imaging system for characterizing vegetation spectral features. The hyperspectral sensor used was a ground-based line sensor, ImSpector (V10-12-102), with a nominal spectral resolution of 1.5–2 nm and a wavelength range of 360–1010 nm. A graphical user interface (GUI) was developed in a MATLAB environment to aid in processing and analysis of acquired multidimensional spectral image data. Issues that arise when applying the imaging system to a particular field include acquiring hyperspectral images, selecting appropriate vegetation features or VIs, and quantifying the selected vegetation features or indices with the GUI developed. Vegetation features extracted by the proposed imaging system contribute not only to monitoring vegetation variability in crop systems, but also provide a potential source of relevant variables that can be used to estimate various vegetation parameters. A study that was set up to investigate the alternate bearing phenomenon of citrus trees illustrates the basic elements of the proposed approach.     

土地利用现状调查资料在耕地地力评价中的应用

以1∶10 000土地利用现状图为空间数据框架基础,结合农业部门现有的土壤普查和样点调查分析资料进行耕地地力评价,相比目前我国测土配方施肥工作方案中以1∶50 000为基础进行的耕地地力评价结果,本研究方法的评价结果耕地分布的空间定位更正确、更切合现状,评价单元的划分更合理、耕地地力等级划分更加精细,能大幅度提高耕地地力评价的精度。本研究方法在耕地地力评价上的应用,有利于为建立测土配方施肥信息管理系统提供详细的基础信息和科学管理耕地,更好地满足精准农业和农业生产中施肥管理对耕地信息的需要。     

轿车冲击高路阶的安全性动态仿真研究

应用计算机模拟仿真的方法,对轿车冲击高路阶的安全性进行研究,可以改善实车试验的成本高、周期长、重复性差以及检测数据量有限等缺点。根据实车试验的条件和要求,建立轿车-高路阶系统的有限元模型,进行动态仿真,并与试验数据对比。对比表明仿真结果与试验吻合良好,能量变化也符合实际的情况,在此基础上可以进一步研究车辆在冲击载荷作用下的非线性动态响应,为深入研究车辆的可靠性、安全性提供依据。