几种包膜缓控释肥料养分释放特征的研究

采用水浸泡法对国内外4种包膜控释肥料的养分释放特性进行了系统的研究.结果表明,4种缓控释肥料的初期溶出率均小于12%,微分溶出率在0.4%～1.5%之间,这符合国际上公认的缓/控释肥的评价标准,初期溶出率小于15%、微分溶出率在0.25%～2.5%之间.采用水浸泡法测定包膜控释肥料养分释放特征,简便快速,检测时间短.重复次数少.养分浓度变化直接反映出包膜控释肥料的释放速率特性,还可以定量的测定其供肥性能,控释肥料有控制养分释放、延长供应时间的作用;其中腐殖酸和炭基有利于提高肥料颗粒的水稳定性,减缓养分的释放速率.     

保水剂与肥料互作及保水缓/控释肥料研究展望

保水剂在农业上的作用日益重要,肥料与保水剂一体化使用是水肥调控的重要技术,是肥料研究的国际前沿。保水剂是吸水量超过自身重量数百倍以上的亲水性高聚物。保水剂一般分为天然的,合成的及半合成的。保水剂与肥料可以通过物理混合、包膜或化学合成三种方式结合为一体化的保水缓/控释肥料。保水剂具有吸水吸肥功能,保水剂可吸附大量中性分子,对阳离子养分也有较强吸附作用,对阴离子养分吸附弱。肥料种类与盐浓度影响保水剂的吸附作用与膨胀能力。保水缓/控释肥料在土壤中对肥料养分有延迟释放作用。保水缓/控释肥料可改善土壤持蓄水分和水肥交互作用,促进植物对养分的吸收和作物增产。保水缓/控释肥料发展方向是包膜和化成保水缓/控释肥料。保水缓/控释肥料湿润及养分控释机理研究也需要加强。     

控释肥料的研究现状与进展

对控释肥料进行分类,控释肥料可分为物理型、化学型以及物理化学型。并分别对各种类型的控释肥料给以简单的概述。同时还阐述了影响控释肥料养分释放的因素、控释肥料养分释放特性的评价和预测方法,最后指出控释肥料存在问题及解决对策。     

控释氮肥养分释放特征快速评价方法的研究

本文研究了不同室内模拟试验条件下控释氮肥的养分释放特征。结果表明,60℃水浸泡培养法所反映控释氮肥的养分释放特征与标准参比方法(25℃水浸泡法)一致,其中养分累积释放曲线都呈一元二次抛物线型;不同释放阶段的平均释放速率成极显著的直线相关关系,相关系数达0.98。60℃水浸泡培养法步骤简单,所需时间短,可作为快速评价包膜控释氮肥养分释放特征的方法。     

控释复肥在盆栽玉米上的肥效研究

本文对采用流化床包膜技术制作的控释复肥进行了玉米盆栽试验,并与普通复肥进行了肥效对比。从玉米的长势变化来看,控释复肥处理的叶绿素值、叶面积、叶数和生长势均比普通复肥有明显优势。植株的平均干重在各施肥处理上均大于普通复肥,而且在施用量减少一半以上的情况下,仍能获得高于普通复肥的生物产量。     

包膜控释尿素对大棚辣椒的增产及土壤肥力效应的研究

对施用包膜控释尿素的大棚辣椒进行了田间试验,并对辣椒的品质进行了测试分析。结果表明:控释尿素与普通尿素相比有显著的增产效果,D90产量最高为34.83thm-2,比对照增产10.51thm-2,增产率为43.2%;比尿素增产6.59thm-2,增产率为23.3%;D60与普通尿素产量差异不显著;比对照增产5.68thm-2,增产率为23.4%;控释尿素具有增加单株果数、单果重的效果和增强辣椒生长的作用;辣椒施用控释尿素的硝酸盐含量最低,普通尿素最高;Vc和可溶性糖含量均以控释尿素为最高,普通尿素最低。综合品质指标依次为:控释尿素>普通尿素。说明控释尿素具有提高蔬菜品质的突出效应,特别在提高蔬菜的安全品质方面贡献最大。控释尿素的施用可增强土壤多酚氧化酶活性、磷酸酶、脲酶活性,特别能协调氮、磷、钾养分供应的平衡性,土壤酶活性的高低可以反映土壤养分转化的强弱。综合各项,在辣椒生产中以选用D90包膜控释尿素为最好,并适当配合D60和普通尿素。     

缓/控释肥对小麦增产与提高氮肥利用率的效果研究

以不施氮肥、尿素基施和尿素基追比5∶5等3个处理做对照,对3种包膜缓/控释肥处理冬小麦产量、产量相关因子、不同时期植株含氮量及肥料利用率进行了分析比较。结果表明,缓/控释肥处理的以上几个指标均接近于尿素基追比5∶5处理。与尿素基施相比,包膜缓/控释肥增产10.03%~11.17%,有效穗数和穗粒数增加,返青-拔节期植株含氮量明显提高,氮肥利用率提高了6.18%~11.57%。3种缓/控释肥相比较,产量、产量因子、植株含氮量及肥料利用率没有显著性差异。     

缓/控释肥对小麦增产与提高氮肥利用率的效果研究

以不施氮肥、尿素基施和尿素基追比5:5等3个处理做对照,对3种包膜缓/控释肥处理冬小麦产量、产量相关因子、不同时期植株含氮量及肥料利用率进行了分析比较。结果表明,缓/控肥处理的以上几个指标均接近于尿素基追比5:5处理。与尿素基施相比,包膜缓/控释肥增产10.03%～11.17%,有效穗数和穗粒数增加,返青-拔节期植株含氮量明显提高,氮肥利用率提高了6.18%～11.57%。3种缓/控释肥相比较,产量、产量因子、植株含氮量及肥料利用率没有显著性差异。     

控释肥料的大蒜肥效研究

对控释肥料(CRFs)的大蒜肥效进行了田间试验,结果表明控释肥料与普通肥料(OFs)相比,在肥料施用量低和中等时具有提高肥效、增加产量的作用,大蒜的生物量分别增加80.5%和51.1%,蒜苔和蒜头产量分别增加180%、100%、和69.2%、29.3%,而高用量时产量反而降低;在比普通肥料(300kg/hm2)减少一半用量的情况下,控释肥料(150kg/hm2)处理的大蒜生物量、蒜苔和蒜头产量分别增加15.6%、61.5%和11.6%.经过大蒜的整个生长季,控释肥料处理的根际土壤有效养分仍能维持较高的水平,控释肥料能显著提高大蒜体内的氮磷钾含量及肥料的养分利用率.     

中国控释肥料的现状与发展前景

分析我国肥料目前的生产与施用情况,针对肥料(特别是氮肥)利用率低的状况,提出我国发展控释肥料的必要性,介绍了控释肥料定义、优良特性以及它的应用前景,使更多的人能够认识控释肥料,从经济、生态、社会等多方面正确地评价控释肥料,旨在为控释肥料能在我国推广应用提供理论依据。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。