四川成都经济区土壤腐殖质重金属元素含量特征研究

通过对四川成都经济区16件土壤样品腐殖质组成及其各组分中重金属元素含量的分析表明,胡敏素是土壤腐殖质的主要组成部分,富里酸和胡敏酸次之.土壤腐殖质中重金属元素含量占土壤伞量20%～44%,是土壤重金属污染元素主要存在方式.重金属元素在腐殖质不同组分中的含量具有很大的差异,Cr主要赋存在胡敏素中,Cd、As、Cu、Zn等元素主要赋存在富罩酸中.各重金属元素在腐殖酸中含量较高,富里酸中的含量均大于胡敏酸,其机理是富里酸对重金属元素的络合是腐殖酸与重金属相互作用的主要方式.     

不同土地利用方式对贵州岩溶土壤微量重金属元素含量的影响

利用地统计学的方法,对贵州水城岩溶盆地复合土地利用方式下土壤微量重金属元素含量的时空变异进行了研究。结果表明:贵州水城盆地岩溶土壤微量重金属元素含量的变化与不同的土地利用方式时空上的变异有很好的一致性。盆地中工业区往往成为土壤微量重金属元素迁移富集的高值中心,而受人类活动影响较小的自然林区则基本保持了原始状况成为低值中心。因此合理进行土地利用对保护土壤和岩溶地下水免受污染具有重要的意义。     

洛川苹果园地土壤重金属污染调查与评价

通过对洛川苹果园地土壤样品的采集、监测,依据无公害果同产地土壤环境质量标准和绿色食品产地土壤环境质量标准,重点分析评价了对土壤环境及人体危害较大的Cd、As、Cr、Ph等重金属元素的污染现状.评价结果表明:以无公害果园产地土壤环境质量为评价标准,洛川苹果园地土壤重金属污染程度有As＞Cr＞Cd＞Ph的特征,土壤重金属综合污染指数为0.51,土壤Cd、As、Cr、Pb单项污染指数平均值均小于0.7,土壤环境中的重金属元素含量现状水平符合无公害苹果生产的要求;以绿色食品产地土壤环境质量为评价标准,洛川苹果园地土壤重金属污染程度有As＞Pb＞Cr＞Cd的特征,土壤重金属综合污染指数为0.64,土壤Cd、Cr、Pb单项污染指数平均值均小于0.7,土壤As单项污染指数平均值大于0.7,但小于1.土壤环境中的重金属含量现状水平符合绿色食品苹果生产的要求.但土壤As单项污染指数平均值为0.74,已超过绿色食品产地土壤污染警戒线.洛川苹果园地土壤重金属As污染程度较高,主要是由于人为长期不合理使用含As农药、化肥所致.因而,洛川苹果生产中应将土壤环境中的As作为严控的土壤污染物.     

铁路交通对铁路旁土壤重金属污染的影响——以陇海铁路郑州-圃田段为例

以陇海铁路郑州-圃田段为例,在野外调查、采样和实验室分析的基础上,探讨了铁路交通对周围土壤N i、Pb、Cr、Zn、Cu和Cd六种重金属含量与分布的影响。结果表明,铁路南侧农田土壤六种重金属元素都出现不同程度的富集,最大含量均分布在距铁路路基30m的范围内,随着距离的增加,各重金属元素含量表现出不同的下降趋势。土壤各重金属污染程度的次序为:Zn>Pb>Cd>Cu>Cr>N i。土壤Pb和Zn污染最为严重,近路基处为重度污染,随着距路基距离的增加,由中度污染逐渐变为轻度污染。土壤N i和Cr虽不构成污染,但仍具有明显的铁路影响特征。在距路基10 m范围内为土壤重金属重度污染带,10~100 m范围内为中度污染带,100~500 m范围内为轻度污染带。     

新时期沈阳农业大学科技工作的思考

采用盆栽试验方法 ,研究了粉煤灰施入砂姜黑土的改良效果及Cd、Cr、Pb、Hg和As等重金属元素在小麦各部位的积累与分布。结果表明 :粉煤灰施入砂姜黑土可以降低土壤容重、比重及土壤粘粒含量 ,增加孔隙和土壤渗透系数。被吸收的重金属元素主要分布在根系中 ,其次是叶片 ,在茎杆、叶鞘及籽粒中的分布极少。根系对Cd和As具有富集作用 ;籽粒中Cd、Cr、Pb、As随用灰量的增加而增加 ,Hg则减少 ,但在 3 6× 10 4kg/hm2 的用灰量范围内 ,5种重金属元素在籽粒及土壤中的含量均在安全标准之内     

深圳市主要公园及道路绿地土壤重金属含量状况比较研究

对深圳城市主要公园和道路绿地土壤Cu、Zn、Pb、Cd含量状况进行取样调查分析。研究结果表明,绿地土壤重金属含量与土地利用类型有关,表现为道路绿地土壤Cu、Zn、Pb平均含量高于公园绿地土壤,而Cd平均含量则相反。采用不同土壤重金属污染评价方法对深圳城市绿地土壤进行的环境质量评价均表明深圳城市绿地土壤Cd污染现象显著。在考察的四种重金属元素中,Zn含量与土壤有机质、pH有关,其中pH对Zn含量的影响相对较大;土壤Cu与Pb、Zn呈直线相关,表现出相互依存的关系。     

船舶辐射噪声的多重分形特性分析

介绍了多重分形维数分布的概念和快速算法,并着重研究了船舶辐射噪声的多重分形分布特征。经研究发现,其多重分形分布特征不仅仅与辐射噪声的传播有关,而且与测量时的工况有着密切的关系。这一结论对应用多重分形分布进行船舶噪声的检测与识别具有重要的意义。     

吐鲁番盆地葡萄园土壤重金属铅含量高光谱估算

土壤重金属铅污染作为现代工矿业发展的产物,已逐渐入侵到农业生产和农产品中。高光谱技术由于具有宏观、快速、高效的特点已成为土壤重金属监测的重要手段。以新疆吐鲁番盆地葡萄园土壤Pb元素为研究对象,分析土壤原始光谱在内的15种光谱变换下的土壤光谱反射率数据与土壤Pb含量的关系,构建土壤Pb含量偏最小二乘回归（PLSR）模型和地理加权重回归（GWR）模型,对比分析并探讨运用土壤高光谱估算葡萄园土壤Pb含量的可行性。结果表明：土壤原始光谱反射率通过光谱变换能有效增强葡萄园土壤Pb元素的光谱特征及模型估算精度,其中,平方根二阶微分（SRSD）变换的PLSR模型和GWR模型估算能力最优。采用GWR模型比PLSR模型更好的解释葡萄园土壤重金属Pb含量高光谱估算。从模型稳定性和精确性来看,在平方根二阶微分变换中GWR模型R²从PLSR模型的0.262提高至0.866, 平方根误差减少了1.009。采用GWR模型可有效提高估算葡萄园土壤Pb含量的精度,为中国葡萄园基地土壤重金属污染以及土壤环境安全研究提供有益借鉴。     

不同风沙土壤颗粒的分形特征

应用土壤颗粒的重量与粒径分布原理来描述了古尔班通古特沙漠地风沙土壤颗粒的分形特征.通过对10种样品颗粒的机械组成进行分析,分别计算出了它们的分形维数(D=2.3237～2.9347),并分析了其与流动风沙土、半同定风沙土和固定风沙土之间的关系.分析结果表明,风沙土壤结构具有明显的分形特征,其粒径分布分形维数为2～3.土粒表面分形维数与2～0.2mm间的土粒含量存在显著的负相关;而与0.02～0.002mm和＜0.002mm的颗粒含量存在显著的正相关,表现为随着土壤质地从流动风沙土、半固定风沙土到固定风沙土的变化,其土粒表面的平均分形维数呈依次增高.土粒表面分形维数与三种典型风沙土壤有机质含量为极显著正相关,而与其硬度为显著负相关.     

沈阳南部沿城乡梯度土壤铅时空分布研究

对沈阳南部沿城乡梯度土壤铅含量的分布特征进行了研究.结果表明,全量Pb沿城乡梯度显著降低,但不同土层之间无显著差异.有效态Ph含量沿城乡梯度具有显著降低,并且在城市土壤中呈现较明显的季节性变化.另外,土壤有效态Pb含量在夏季郊区样品和秋季城市样品的层次之间也有显著变化.相关性分析表明,土壤理化性质如土壤质地、pH和CEC对全量及有效态Pb含量产生了一定影响,而人为等因素是影响土壤全量及有效态重金属的主要因素.     

Order and Disorder in Product Innovation Models

This article argues that the conceptual development of product innovation models goes hand in hand with paradigmatic changes in the field of organization science. Remarkable similarities in the change of organizational perspectives and product innovation models are noticeable. To illustrate how changes in the organizational paradigm are being translated into changes in new product development (NPD) practices, five NPD models are presented: the sequential, compression, flexible, integrative and improvisational models. The evolution of product innovation management shows a move from planned and mechanistic, towards emergent and organic models. Such a process of re‐orientation poses several challenges that are presented in the form of six propositions: from universal to contingent models, from invariant to flexible practices, from avoiding risks to taking advantage of opportunities, from planning to learning, from exclusive teams to inclusive networks, from structure to structured chaos.     

Theoretical and experimental models in physiological and psychological research of pattern perception and recognition in humans

Classical models in a human-machine system for physiological and psychological research are reviewed. Actual experimental data in this realm of science for psychophysiology are given. Main logical conclusions that can be used to develop software suitable for physiological and psychological research are made. Sergei V. Ivanov. Born in 1972. Graduated from St. Petersburg State University of Electrical Engineering in 1997. Graduated from the extension courses for teachers held in St. Petersburg State University of Electrical Engineering in 2000. At present, he teaches at St. Petersburg State University of Electrical Engineering. Ivanov applied for his candidate’s degree (05.11.16, Information and Measuring Control Systems, Medicobiological and Ecological Research). He is a candidate master in chess and checkers and his area of expertise is the development of algorithms and software tools for medicobiological research and processing medicobiological data (mostly of psychophysiologic nature) from the point of the game theory and statistical decisions, copyright issues for algorithms and software. He is the author of 25 scientific works (several papers in peer reviewed journals and theses in proceedings of Russian and international conferences) and the owner of two software registration certificates and author of one innovation proposal. In 1998–2000, his scientific research was supported at the Motorola grants contest held in St. Petersburg State University of Electrical Engineering. Awarded the bonus prize and the third degree diploma from St. Petersburg and Lenenergo authorities at the “tElectricity in St. Petersburg: 110 Years of History” R&D works contest in 2002. Ivanov was awarded a letter of commendation from the St. Petersburg Chess Federation for the moral and scientific popularization of chess in St. Petersburg in 2004. He was also awarded his third degree diploma as the winner of the R&D works contest for young scientists of St. Petersburg State University of Electrical Engineering in 2005.     

Detecting Irregularities in Images and in Video

We address the problem of detecting irregularities in visual data, e.g., detecting suspicious behaviors in video sequences, or identifying salient patterns in images. The term “irregular” depends on the context in which the “regular” or “valid” are defined. Yet, it is not realistic to expect explicit definition of all possible valid configurations for a given context. We pose the problem of determining the validity of visual data as a process of constructing a puzzle: We try to compose a new observed image region or a new video segment (“the query”) using chunks of data (“pieces of puzzle”) extracted from previous visual examples (“the database”). Regions in the observed data which can be composed using large contiguous chunks of data from the database are considered very likely, whereas regions in the observed data which cannot be composed from the database (or can be composed, but only using small fragmented pieces) are regarded as unlikely/suspicious. The problem is posed as an inference process in a probabilistic graphical model. We show applications of this approach to identifying saliency in images and video, for detecting suspicious behaviors and for automatic visual inspection for quality assurance. Patent Pending     

Lines and Points in Three Views and the Trifocal Tensor

This paper discusses the basic role of the trifocal tensor in scene reconstruction from three views. This 3× 3× 3 tensor plays a role in the analysis of scenes from three views analogous to the role played by the fundamental matrix in the two-view case. In particular, the trifocal tensor may be computed by a linear algorithm from a set of 13 line correspondences in three views. It is further shown in this paper, that the trifocal tensor is essentially identical to a set of coefficients introduced by Shashua to effect point transfer in the three view case. This observation means that the 13-line algorithm may be extended to allow for the computation of the trifocal tensor given any mixture of sufficiently many line and point correspondences. From the trifocal tensor the camera matrices of the images may be computed, and the scene may be reconstructed. For unrelated uncalibrated cameras, this reconstruction will be unique up to projectivity. Thus, projective reconstruction of a set of lines and points may be carried out linearly from three views.     

Reflectances in the Ganges and Brahmaputra rivers and in the adjacent coastal sea

The distribution patterns of reflectance were analysed from Landsat TM band 3, along the course of the Ganges and Brahmaputra rivers and their adjacent coastal sea. It was observed that during the high discharge period, reflectance values in the Ganges river are higher than that in the Brahmaputra. But in the low discharge period, it is vice versa. Reflectances varied significantly throughout the river courses but increased distinctly at their confluence zones. In the coastal sea, reflectance values decreased markedly with a narrow zone, which corresponded to the zone of spectral contrast as seen from band 3 image. Influence of river discharge in reflectance values is not distinct in the coastal sea.     

Processing and interaction in robotics

Sensor science is a modern discipline which addresses issues, problems and solutions involving various facets of the phenomenon of perception of phenomena. Perception is oriented toward natural phenomena, both external and internal to man, moreover, perception is oriented toward artifacts devised by man. In both cases any sensor device is itself an artifact that man has conceived and designed in order to substitute and to emulate his own sensory organs. The purpose of the paper is to present a perspective of sensor science oriented toward the emulation of man as a subject able to perform, firstly, interactive activities between himself, from one side, and the external world together with himself and other men, from the other side, and, secondly, intellectual functions driven by the sensorial aspects of interaction and directed to the actuatorial aspects of interaction. The paper, therefore, addresses the analysis of sensor science in relation with the most advanced artificial system, developed in the history of science by man in addressing the emulation of man, namely the robot. The global view, oriented to understand the relationship existing between the three hierarchically arranged disciplines of information science, robotics and informatics, from one side, and sensor science, from another side, is a very interesting arena for discussing in a novel approach the modern and dynamic outlook of sensor science.     

Concurrency and parallelism in MC and MD simulations in physics

Certain problems lend themselves admirably to SIMD architecture computers. A number of such problems in physics will be discussed and their implementation on the ICL DAP analyzed. Monte Carlo (MC) problems such as the 3-D Ising model and quantum chromodynamics (QCD) calculations need care and attention with respect to maintaining detailed balance on a SIMD architecture, whereas molecular dynamics (MD) problems do not pose such problems. The efficient use of a DAP requires the development of parallel algorithms designed to make use of the particular architecture and size of the machine, though further software developments must be made which remove the user one stage farther from the particular details of the computer. Experience on the DAP, especially those with only 2 Mbytes of store such as the Edinburgh DAPs, has led to thought about the detailed precisions necessary for the various calculations being done—many computers operate at an accuracy which is in excess of requirement whereas the bit-serial DAP can have its program finely tuned in accuracy.The present DAPs are far from the modern state of the art in fabrication, and future engines of similar design could be made with present technology with a rating well over a Gflop, providing very cost-effective computing.     

Comparing dropouts and persistence in e-learning courses

Several studies have been conducted related to dropouts from on-campus and distance education courses. However, no clear definition of dropout from academic courses was provided. Consequently, this study proposes a clear and precise definition of dropout from academic courses in the context of e-learning courses. Additionally, it is documented in literature that students attending e-learning courses dropout at substantially higher rates than their counterparts in on-campus courses. Little attention has been given to the key factors associated with such substantial difference. This study explores two main constructs: (1) academic locus of control; and, (2) students’ satisfaction with e-learning. Results show that students’ satisfaction with e-learning is a key indicator in students’ decision to dropout from e-learning courses. Moreover, dropout students (non-completers) reported to have significantly lower satisfaction with e-learning than students who successfully completed (completers or persistent students) the same e-learning courses. Additionally, results of this study show that the academic locus of control appears to have no impact on students’ decision to drop from e-learning courses.     

Rigour and intuition in professional life

Rigour is not a characteristic of quantitative as distinct from qualitative research; both may be carried out with greater or less rigour. Intuition has a role in scientific work and, in turn, intuitive understanding needs to be open to systematic testing. Rigour and intuition interact in the research process, they are not in opposition. Similarly in applied work a finding cannot be taken from a textbook and applied to a situation without passing through the person of the researcher/practitioner. There it is modified by the researcher/practitioner's sense of the meaning of that finding and understanding of the context within which it is to be applied. Illustrations of these points include examples from evaluation research in hospitals where the Electronic Patient Record (EPR) was being implemented.