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控制与决策 2010年第3期25卷 425-429页

作者：曹方王伟大连理工大学电子与信息工程学院辽宁大连116023

针对电渣炉系统是一个多变量耦合、时滞、参数时变的复杂被控对象,系统难以控制的缺陷,通过大量实验和分析,确立了熔速、磁性调压与二次电压、熔炼电流的相互关系,建立起工程化的控制模型,并提出一种智能控制方法,包括多变量解耦控制策... 详细信息

针对电渣炉系统是一个多变量耦合、时滞、参数时变的复杂被控对象,系统难以控制的缺陷,通过大量实验和分析,确立了熔速、磁性调压与二次电压、熔炼电流的相互关系,建立起工程化的控制模型,并提出一种智能控制方法,包括多变量解耦控制策略、滞后时间模糊自整定和粒子群优化算法整定PID控制器参数.工业应用表明,该方法克服了电渣炉的非线性和强耦合,控制精度高,具有较强的鲁棒性和适应性.

关键词：电渣重熔解耦 PID控制器粒子群优化算法

基于Fisher算法的本体推理安卓恶意软件安全检测

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桂林电子科技大学学报 2018年第4期38卷 290-295页

作者：曹怀宝张红梅桂林电子科技大学广西高校云计算与复杂系统重点实验室广西桂林541004

针对Android平台日趋增多的恶意软件安全问题,以及缺乏有效措施解决恶意软件的危害,提出一种基于Fisher归类算法结合本体推理的Android恶意软件安全检测方法。用Fisher分类算法对运行在手机端采集的应用程序所产生的系统调用频率信息进... 详细信息

针对Android平台日趋增多的恶意软件安全问题,以及缺乏有效措施解决恶意软件的危害,提出一种基于Fisher归类算法结合本体推理的Android恶意软件安全检测方法。用Fisher分类算法对运行在手机端采集的应用程序所产生的系统调用频率信息进行处理,得出最佳线性判别函数,并据此求出最佳调用频率分界点,结合SWRL语言制定推理规则,应用本体JESS推理技术推理,实现了Android恶意软件的安全检测。实验结果表明,该方法可行、有效。

关键词：安卓安全 SWRL规则 Fisher算法 JESS推理本体

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超声波提取苦菜叶、根中总多酚的工艺研究

食品研究与开发 2016年第18期37卷 90-94页

作者：王艳萍曹发昊杨晶华运城学院生命科学系山西运城044000

以苦菜叶、根为原料,采用超声波辅助乙醇提取总多酚,福林-酚比色法在765 nm波长处测定总多酚的含量。通过单因素试验,正交试验确定最佳提取工艺。单因素试验表明:在提取温度为50℃、提取时间为1.5 h、料液比为1∶15(g/mL)、乙醇体积分数... 详细信息

以苦菜叶、根为原料,采用超声波辅助乙醇提取总多酚,福林-酚比色法在765 nm波长处测定总多酚的含量。通过单因素试验,正交试验确定最佳提取工艺。单因素试验表明:在提取温度为50℃、提取时间为1.5 h、料液比为1∶15(g/mL)、乙醇体积分数为50%时,苦菜叶、根中总多酚得率都达到最高。提取苦菜叶中总多酚的最佳条件为:提取温度为50℃、提取时间为2.0 h、料液比为1∶20(g/mL)、乙醇浓度为50%。提取苦菜根中总多酚的最佳条件为:超声波功率400 W、提取温度为40℃、提取时间为1.5 h、料液比为1∶15(g/mL)、乙醇体积分数为50%。

关键词：苦菜总多酚提取条件超声波

Upscaling conductivity and porosity in three-dimensional heterogeneous porous media

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Chinese Science Bulletin 2004年第22期49卷 2415-2423页

作者： ZHANg Yong Hydrologic Science,University of california,Davis,ca 95616,USA Desert Research Institute,2215 Raggio Parkway,Reno,NV 89512,USA Hydrologic Science University of California Davis CA 95616 USA Desert Research Institute 2215 Raggio Parkway Reno NV 89512 USA

An empirical formula is presented to upscale the conductivity of 3-dimensional heterogeneous porous me- dia, in which the distribution of local-scale conductivity is non-gaussian with a high variance. The upscaled conductiv- ity is determined as a function of the volumetric proportion, the spatial connectivity and the statistical geometric length of high-permeable inclusions, and the arithmetic mean of con- ductivities of all hydrofacies. A systematic comparison to other traditional upscaling methods indicates that this em- pirical formula provides a better estimation of the equivalent conductivity. In the second part of this study, numerical ex- periments of solute migration reveal that porosity also needs to be upscaled to capture the transport of contaminants in a heterogeneous medium using an effective or upscaled homo- geneous medium. This is due to the tendency of contaminants to be preferrentially transported by 3-dimensional pathways composed of high-permeable materials in heterogeneous aquifer systems. The apparent difference between the actual transport velocity of contaminants and the upscaled velocity, based on the equivalent conductivity, forces upscaling of po- rosity. Further systematic analyses demonstrate that the up- scaled porosity follows a non-linear trend as the content of high-permeable sediments decreases. Resultant upscaled porosity, with values varying between 0.004 and 1.5, is be- yond the definition of the traditional porosity on the representative elementary volume (REV) scale. When the content of high-permeable materials is less than 30%, the upscaling of porosity is critical in the simulation of the contaminant transport in a heterogeneous medium using an upscaled, homogeneous counterpart.

关键词：标度方法传导率多孔性三维空间异类多孔介质多孔材料

Polar Duals of Rotors

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Acta Mathematica Sinica,English Series 1996年第1期12卷 40-42页

作者： ghandehari M. Department of Mathematics Noval Postgraduate School Monterey, ca 93943 U. S. A. Department of Mathematics Noval Postgraduate School Monterey USA

Assume K is a rotor in a regular simplex of heihgt 1 in an n-dimensional Euclidean space. Let K~* denote the polar dual of K. Then the volume V(K~*) satisfies the inequality V(K~*)≥(n+1)~nω_n, where ω_n denotes the volume of an n-dimensional unit ball. Equality holds if and only if K is a ball centered at the centroid of the simplex.

关键词： Rotor Polar dual Regulor Simplex

The effectiveness of eyespots and masquerade in protecting artificial prey across ontogenetic and seasonal shifts

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Current Zoology 2022年第4期68卷 451-458页

作者： Elizabeth g Postema Department of Entomology and Nematology University of CaliforniaDavisCA 95616USA

When constraints on antipredator coloration shift over the course of development,it can be advantageous for animals to adopt different color strategies for each life *** caterpillars in the genus Papilio exhibit unique ontogenetic color sequences:for example,early instars that masquerade as bird feces,with later instars possessing eyespots.I hypothesize that larvae abandon feces masquerade in favor of eyespots due to ontogenetic changes in signaler *** ontogenetic pattern also occurs within broader seasonal shifts in background color and predator activity.I conducted predation experiments with artificial prey to determine how potential signaling constraints(specifically size and season)shape predation risk,and consequently the expression of ontogenetic color change in Papilio ***,both predation and background greenness declined significantly from July to September,though there was little evidence that these patterns impacted the effectiveness of either color *** size and color strongly affected the attack rate of avian predators:attacks increased with prey size regardless of color,and eyespotted prey were attacked more than masquerading prey *** results may reflect a key size-mediated tradeoff between conspicuousness and intimidation in eyespotted prey,and raise questions about how interwoven aspects of behavior and signal environment might maintain the prevalence of large,eyespotted larvae in nature.

关键词： ontogenetic color change eyespots masquerade predator-prey dynamics season

Microstructure refinement,mechanical and biocorrosion properties of Mg–Zn–ca–Mn alloy improved by a new severe plastic deformation process

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Journal of Magnesium and Alloys 2022年第6期10卷 1640-1662页

作者： M.Kavyani g.R.Ebrahimi H.R.Ezatpour M.Jahazi Materials and Metallurgical Engineering Department Faculty of EngineeringFerdowsi University of MashhadMashhad ***Iran Faculty of Engineering Sabzevar University of New TechnologySabzevarIran Department of Mechanical Engineering École de Technologie SupérieureMontréalPQCanada

In this study,the microstructural evolution,mechanical properties and biocorrosion performance of a Mg–Zn–ca–Mn alloy were investigated under different conditions of heat treatment,extrusion,one pass and two passes of half equal channel angular pressing(HEcaP)*** results showed significant grain refinement of the homogenized alloy after two passes of HEcaP process from 345μm to 2μ*** emission scanning electron microscopy(FESEM)revealed the presence of finer Mg_(6)Zn_(3)ca_(2)phase as well asα-Mn phase after HEcaP *** results also showed that mechanical characteristics such as yield strength,ultimate tensile strength and elongation of the HEcaPed samples improved by~208%,~144%and~100%compared to the homogenized one,*** texture analysis indicated that most of the grains at the surface were reoriented parallel to the(0001)basal plane after HEcaP *** corrosion tests and immersion results indicated that the sample with two passes of HEACP had the highest biocorrosion resistance confirming that the basal planes had the lowest corrosion rate compared to the non-basal *** mechanical behavior and bio-corrosion evaluation demonstrated that the HEcaPed Mg–Zn–ca–Mn alloy has great potential for biomedical applications and a mechanism was proposed to explain the interrelations between the thermomechanical processing and bio-corrosion behavior.

关键词： Mg–Zn–ca–Mn alloy HEcaP process Microstructure Mechanical properties Bio-corrosion performance

Perspectives on atmospheric mercury and its fate in aquatic ecosystems

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Journal of Environmental Sciences 2000年第S1期12卷 85-91页

作者： D.B. Porcella (1034 Lindsey Court, Lafayette ca 94549 USA E mail: dporcell@***)

Mercury (Hg) is a neurotoxin to humans and wildlife that has a quantitatively important gas phase that makes its atmospheric cycle an important part of exposure pathways to these organisms. The important atmospheric forms are elemental Hg (Hg(0)), inorganic gas phase Hg (HgH gs ), and inorganic particulate Hg(HgIIp). Each form has different behavior depending on its chemical and physical properties. generally, scientists have found with trace metal clean sampling and analytical techniques, that background Hg levels are 1—2 ng/m\+3 in air, 0.1—2 ng/L in surface waters, 5—25 ng/L in rainwater, and less than 0.1 μg/g in sediments remote from natural Hg minerals and wastewater sources. Values in excess of these concentrations generally indicate local anthropogenic influences or contaminated samples. Broad scale estimates of Hg inputs to the atmosphere suggest that annual anthropogenic fluxes to the atmosphere as Hg(0) are about 40 percent of the total global cycle, oceanic evasion is about 40 percent, and (by difference) the remaining input to the global cycle (20 percent) is evasion from terrestrial sources, largely via soils and vegetation. This paper summarizes recent data that will constrain estimates from these sources. For example, terrestrial sources could approach 40 percent and annual anthropogenic inputs be correspondingly less. Furthermore, a historic perspective is needed because Hg has cycled atmospherically over geologic time. In addition to the uncertainty in source quantification, methylation must be a focus of risk analysis, because this process is responsible for risks to human and ecosystem health for almost all modern day Hg exposures.

关键词： Perspectives on atmospheric mercury and its fate in aquatic ecosystems

AN INSTABILITY THEORY OF AIR-SEA INTERACTION FOR COASTAL UPWELLINg

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Advances in Atmospheric Sciences 1988年第3期5卷 277-285页

作者： P.C. Chu Department of Oceanography Naval Postgraduate School, Monterey, ca 93943, U.S.A. 1. Department of Oceanography Naval Postgraduate School 93943 Monterey CA USA

A surface wind (seabreeze), thermally generated by differential sea surface temperature, is introduced to gill-Clarke’s model (1974) through wind stress for investigating the effects of seabreeze on coastal upwel-ling. A coupled air-sea system is treated as an eigenvalue problem. The solutions show that the thermally forced local winds break down the coastal Kelvin wave into three parts: small-scale (Lgrowing and stationary modes, mesoscale (100 kmcaying and fast-moving modes, and ’large’-scale (L>200 km) coastal Kelvin modes. The consistency of the length scale between the most growing mode predicted by this model and the observed cold/warm alternation pattern of surface water near the Peruvian Coast (around 15 °S) implies that seabreeze may play some role in coastal upwelling.

关键词： mode AN INSTABILITY THEORY OF AIR-SEA INTERACTION FOR COASTAL UPWELLINg length SEA