浅谈初中物理中物质的属性和特性

阐述在初中物理教学中,应淡化"物质的属性"、"物质的特性"的区别,一般强调为物质的属性或物质的固有属性即可。

基于频繁模式挖掘的风电爬坡事件统计特性建模及预测

风电爬坡事件的统计特性建模和精准预测有利于电网的安全稳定运行。文中首先通过参数分辨率自适应算法对大型历史风电数据库进行爬坡事件检测,得到风电爬坡事件的历史学习集。对该学习集进行数据挖掘,建立了单个爬坡事件的起点、终点、持续时间以及爬坡间隔的多属性联合统计特性模型,并得到爬坡事件的基本模式。通过关联规则算法建立了多个相邻爬坡事件之间的自相关性统计特性模型。在此基础上,提出了爬坡事件序列预测算法的基本概念和模型。算例结果表明,所提算法能够更为直观地描述爬坡事件的统计特性,且基于事件序列的预测算法能够较好地进行日前的爬坡预测。

我国数字经济发展的三个基本属性

数字经济正在经历高速增长、快速创新,并成为我国经济高质量发展的新动能,受到各界的普遍关注。作为一个信息和商务活动都数字化的全新社会经济系统,数字经济具有鲜明的特性、变革、路径等基本属性,有待充分认识和深入把握。其特性属性主要体现为高技术、高渗透、高融合、高增长、高安全,变革属性主要表现为质量变革、效率变革、动力变革、管理变革、治理变革,路径属性主要贯穿于平台化、智能化、生态化、人性化、共享化。

基于统计特性的DDoS攻击防御系统的设计

提出了一种基于数据包属性值的统计特性快速过滤攻击流量的新方法,它能够直接从网络结构中的物理层直接提取数据包,将其各数据段的属性值提取后,运用LB(Leaky-Bucket)方案进行评分后,导入丢弃判断模块中判断是否丢弃,从而避免了判断,为攻击性较高的数据包在TCP/IP协议栈中进行解析,节省了系统资源,有效缓解了DDoS攻击。基于该方案,设计和实现了一个DDoS攻击防御系统LB ScoreGuard,描述了其体系结构、组成、统计过程和算法,最后提出了LB Score-Guard系统中几个局限和进一步的工作。

感觉抽取诸映射间的关系结构

本文给出了思维的一个可操作定义，提出了基于属于计算的感知与认知模拟的数学理论和方法属性论，分析了感觉抽取中的属性数值检测、属性数值－特性转化、感觉特性抽取和感觉属性自身数值与特性值间的对应等映射间的关系结构，为深入研究属性论提供了一个基础。

中压配电系统供电模型研究

针对传统中压配电系统分析只关注馈线接线模式、未考虑多电压等级协同供电的不足,提出了中压配电系统综合供电模型.依据地形与负荷密度的特点,构建了能够体现变电站互联结构的供电架构.结合供电结构与中压馈线接线模式的多种类型,形成了综合供电模型.通过供电单元个数与供电能力等指标,得出了供电模型的属性与外特性.通过所构建的供电模型,可从配电网整体角度来反映变电站与中压馈线综合供电方式,对配电网供电方案的理论分析与实际构建等工作均有重要指导意义.

考虑工程实用性的综合能源系统优化配置研究

综合能源系统建设前期合理的优化配置是其良好运营的关键,优化方案的实用性和可落地性可保证方案的良好执行。考虑工程设备的性能、价格呈现离散和非线性分布的特性等因素,提出了考虑工程实用性的综合能源系统优化配置方法。首先,基于能源转换/存储设备特性,构建系统设备模型;然后,考虑工程设备属性特性,以净现值为优化目标,建立大规模混合整数线性规划求解模型;最后,基于算例对优化配置结果进行对比分析及运行和投资敏感度分析,验证了优化配置方案的合理性和工程实用性。算例验证结果表明:所研究方法保证了优化配置结果的准确性,从工程产品中匹配出最优产品组合,提高了优化结果的实用性,经济效益对总投资的敏感度较大。

Physicochemical and environmental properties of arsenic sulfide sludge from copper and lead-zinc smelter

Physicochemical properties of arsenic sulfide sludge(ASS) from copper smelter(ASS-I) and lead-zinc smelter(ASS-II) were examined by XRD, Raman spectroscopy, SEM-EDS, TG-DTA, XPS and chemical phase analysis method. The toxicity characteristic leaching procedure(TCLP), Chinese standard leaching tests(CSLT), three-stage sequential extraction procedure(BCR) and batch leaching experiments(BLE) were used to investigate the environmental stability. The ASSs from different smelters had obviously different physicochemical and environmental properties. The phase composition and micrograph analysis indicate that ASS-I mainly consists of super refined flocculent particles including amorphous arsenic sulfide adhered with amorphous sulfur and that ASS-II mainly consists of amorphous arsenic sulfide. The valence state of arsenic in both sludges is trivalent, but the valence composition of sulfur is quite different. The ASSs have thermal instability properties. The results of TCLP and CSLT indicate that the concentrations of As and Pd in the leaching solution exceed the standard limits. More than 5% and 90% of arsenic are in the form of acid soluble and oxidizable fractions, respectively, which explains the high arsenic leaching toxicity and environmental activity of ASS. This research provides comprehensive information for the disposal of ASS from copper and lead-zinc smelter.

Isolation and identification of bacteria associated with the surfaces of several algal species

We conducted this study to assess the diversity of bacteria associated with the surfaces of algae based on 16S rDNA sequence analyses.Twelve strains of bacteria were obtained from the surfaces of the following four species of algae:Gracilaria textorii,Ulva pertusa,Laminaria japonica,and Polysiphonia urceolata.The isolated strains of bacteria can be divided into two groups:Halomonas and Vibrio,in physiology,biochemical characteristics and 16S rDNA sequence analyses.The phylogenetic tree constructed based on 16S rDNA sequences of the isolates shows four obvious clusters,Halomonas venusta,Vibrio tasmaniensis,Vibrio lentus,and Vibrio splendidus.Isolates from the surface of P.urceolata are more abundant and diverse,of which strains P9 and P28 have a 16S rDNA sequence very similar(97.5%-99.8%) to that of V.splendidus.On the contrary,the isolates from the surfaces of G.textorii,U.pertusa and L.japonica are quite simple and distribute on different branches of the phylogenetic tree.In overall,the results of this study indicate that the genetic relationships among the isolates are quite close and display a certain level of host species specificity,and alga-associated bacteria species are algal species specific.

Damping characteristics analysis of squeeze film damper with metal rubber

A squeeze film damper (SFD) with metal rubber (MR) ring installed on the end and the radial direction of rotor are implemented in this paper. Based on the hypothesis of π film, the description of the new SFD/MR flux and nonlinear oil film damping force is derived according to the Reynolds Eq. and Darcy’s law. It proves that the SFD/MR has better damping characteristics than the traditional SFD after comparatively analyzing characteristics of oil film between the traditional short SFD and the SFD/MR.

Plastic characterization of metals by combining nanoindentation test and finite element simulation

Materials with the same elastic modulus E and representative stress and strain （σr,εr） present similar indentation-loading curves, whatever the value of strain hardening exponent n. Based on this definition, a good approach was proposed to extract the plastic properties or constitutive equations of metals from nanoindentation test combining finite element simulation. Firstly, without consideration of strain hardening, the representative stress was determined by varying assumed representative stress over a wide range until a good agreement was reached between the computed and experimental loading curves. Similarly, the corresponding representative strain was determined with different hypothetical values of strain hardening exponent in the range of 0-0.6. Through modulating assumed strain hardening exponent values to make the computed unloading curve coincide with that of the experiment, the real strain hardening exponent was acquired. Once the strain hardening exponent was determined, the initial yield stress ay of metals could be obtained by the power law constitution. The validity of the proposed methodology was verified by three real metals： AISI 304 steel, Fe andA1 alloy.

Relationship between Crohn’s disease, infection with Mycobacterium avium subspecies paratuberculosis and SLC11A1 gene polymorphisms in Sardinian patients

AIM： To study the association between Crohn＇s disease （CD）, Mycobacterium avium subspecies paratubercuolsis （MAP）, and genetic factors by examining the role of natural resistance-associated macrophage protein 1 （NRAMP1） gene polymorphisms （now SLCllA1） in Sardinian patients with CD and controls. METHODS： Thirty-seven CD patients and 34 controls with no inflammatory bowel disease （IBD） were recruited at the University of Sassari after giving written consent. Six SCL11A1 polymorphisms previously reported to be the most significantly associated with IBD were searched. M, pafatubefculosis was identified by IS900 PCR and sequencing. Logistic regression was used to calculate odds ratios （OR） for the associations among CD, presence of MAP, and 6 loci described above.＇ RESULTS： For the first time, a strong association was observed between polymorphisms at NRAMP1 locus 823C/T and CD. While CD was strongly associated with both NRAMP1 and MAP, NRAMP1 polymorphisms and MAP themselves were not correlated. CONCLUSION： Combined with previous work on the NOD2/CARD15 gene, it is clear that the interplay of genetic, infectious, and immunologic factors in the etiology of CD is complex.

Physicochemical and environmental characteristics of alkali leaching residue of wolframite and process for valuable metals recovery

Physicochemical and mineralogical characteristics of an alkali leaching residue of wolframite were studied by XRD,SEM−EDS,chemical phase analysis,mineral liberation analyzer(MLA),and TG−DSC methods.Batch leaching tests,toxicity characteristic leaching procedure(TCLP)tests and Chinese standard leaching tests(CSLT)were conducted to determine the environmental mobility of toxic elements.The results show that,due to the high contents of W,Fe,Mn,Sn,and Nb,the residue is with high resource value,but the content of a toxic element,As,is also high.The existing minerals of the investigated elements mainly occur as monomer particles,but it is difficult to extract these valuable metals by conventional acid leaching due to their mineral properties.The release of As increases over time in acidic environment.The leaching concentration of all investigated harmful elements through TCLP is within the limiting value,while the leaching concentration of As through CSLT exceeds the limiting value by more than 4 times,so the residue is classified as hazardous solid waste based on the Chinese standard.A process for valuable metals recovery from this residue was proposed.Preliminary experimental results indicated that the main valuable metals could be extracted effectively.

Relationship between Physical and Chemical Soil Attributes and Plant Species Diversity in Tropical Mountain Ecosystems from Brazil

Although the high diversity of plant species in the rupestrian fields has been primarily attributed to the existence of a set of distinct habitats, few studies support this assertion. The present study aimed to further investigate the relationship between physical and chemical attributes of soils with the diversity of plant species in this unique ecosystem. The rupestrian field is a unique vegetation formation that covers some of the southeastern Brazilian mountains in the transition of the Atlantic rain forest and the Cerrado(savanna). Different habitats occur according to soil characteristics(e.g., presence of rocks, sand, fertility, hydrology, etc.). These attributes ultimately influence the vegetation that is highly adapted to the harsh edaphic and climatic mountain conditions. Five distinct habitats were studied by us: rocky outcrops, peat bogs, sandy bogs, quartz gravel fields, and "cerrado"(savanna). A floristic survey indicated that four families are found at greater frequency: Poaceae, Asteraceae, Cyperaceae, and Leguminosae. The greatest diversity of plant species was found in the rocky outcrops habitat, followed by cerrado, peat bog, quartz gravel grassland, and sandy bogs, respectively. The main difference in the floristic composition among these habitats was related to the dominant species. Trachypogon spicatus(Poaceae) was the most dominant species in the rocky outcrops, Axonopus siccus(Poaceae) in the peat bogs, Lagenocarpus rigidus(Cyperaceae) in the sandy bogs, Schizachyrium tenerum(Poaceae) in the cerrado, while Vellozia sp. 8(Velloziaceae) dominated the vegetation in the quartz gravel grassland. This study demonstrated that physical and chemical soil properties strongly related the diversity of plant species occurring in the different habitats of rupestrian fields.

运用人机联作解释站研究周7井西岩性圈闭

本文使用了GEOQUST解释站的多种先进解释手段，用井曲线编辑、迭图、多框显示等手段确定了周矶断裂带T0波组的地质层位，追踪了用7井西岩性圈闭的外形及构造背景。用瞬时频率、瞬时振幅、频谱、二维模型和断面滑移剖面等资料预测：圈闭内渗透性砂岩发育，圈闭落实可靠，建议可作为下一步钻探的目标。

Analysis and interpretation on the concrete quality of shaft lining by elastic wave technique

The quality problem of the concrete body and backwall grouting of shaft lining must be taken into consideration during the engineering construction of the shaft. Detection and evaluation are needed to determine the parameters such as the location and depth of drilling. The record of elastic wave can be gained through laying the surveying lines of the ring and ver- tical direction in the shaft lining by the elastic wave method. And specifically, through analyzing the different parameters of seismic attribute such as the velocity of high frequency reflection wave, amplitude and frequency, the abnormal range on the wall or under the wall can be forecasted. The concrete quality of shallow layer in the shaft lining can be evaluated through the velocity of surfer wave. Using the evaluating technique of comprehensive frequency and the phase feature of waveform, the basic features such as inner construction, wall back filling and failure depth of shaft lining can be interpreted from qualitatively to half quantitatively, and the interpreting section can be drawn. The results show that the detection effect for the shaft quality is significant by elastic wave technique, and the delineation of abnormal areas is accurate. Its guidance function is better for pro- duction.

Preparation of bimetallic nano-composite by dissimilar friction stir welding of copper to aluminum alloy

Butt friction stir welding between pure copper and AA5754 alloy was carried out.Reinforcing SiC nanoparticles were utilized in friction stir welded(FSW)joints to decline the harmful effects of intermetallic compounds.Tensile tests,micro-hardness experiments,scanning electron microscopy and X-ray diffraction analysis were applied to studying the properties of welded joints.The joints with a travel speed of 50 mm/min and a rotation speed of 1000 r/min showed the best results.The presence of nano-sized SiC particles reduced the grain size of aluminum and copper in the stir zone(SZ)from 38.3 and 12.4μm to 12.9 and 5.1μm,respectively.The tensile strength of the joint in the presence of reinforcing SiC nano-particles was~240 MPa,which is~90%of that for the aluminum base.Furthermore,the highest microhardness of the weld zone was significantly increased from HV 160 to HV 320 upon the addition of SiC nano-particles.The results also showed that raising the heat generation in FSW joints increased the amount of Al_(4)Cu_(9) and Al_(2)Cu intermetallic compounds.

GIS数据质量的控制

从GIS系统的三个基本内容,即具有地理位置的空间实体、描述实体的属性、实体之间的拓扑关系,分别描述了地理信息系统中空间数据的质量特性,属性数据的质量特性,空间实体间关系和实体与属性之间关系的质量特性,以及GIS数据质量控制(过程控制和结果控制)的内容,阐述了两个环节实施GIS系统质量控制。

Thermal and piezoelectric properties of Bi_(3.15)Nd_(0.85)Ti_3O_(12) thin film prepared by metal organic decomposition

Bi3.15Nd0.85Ti3O12 （BNT） powder and thin film were prepared by metal organic decomposition （MOD） method. The heat flow curve of BNT powder was measured with a modulated temperature differential scanning calorimeter, and thermal physical parameters such as thermal conductivity coefficient and thermal diffusion coefficient were obtained from the heat flow curve. The phase identification, ferroelectric, and piezoelectric properties of BNT thin film annealed at 700℃ were investigated with X-ray diffractometer, ferroelectric analyzer, and scanning probe microscope. The results show that the thin films consisting of a single phase of bismuth-layered perovskite are polycrystalline, without a preferred orientation. Remnant polarization 2Pr is 63.2 μC/cm2 under 530 kV/cm applied field, and the effective piezoelectric coefficient d33 is 30 pm/V.