基于统计模拟的无显式小波幅频特性计算与分析

为确定无显式小波在两相邻尺度上的频带重叠程度,提出采用白噪声作为小波变换的输入信号,分析利用白噪声计算小波幅频特性的原理,并与统计模拟思想相结合,提出一种计算无显式小波在二进尺度的幅频特性的方法。利用此法得到Daubechies 2～10号小波在5个二进尺度上的频率窗,它们直观地反映各小波在两相邻尺度的频带重叠情况,并定量计算每个小波相邻尺度的频带重叠面积,结果表明在Daubechies小波系中,当小波号数增加时,各个尺度上的频带重叠面积单调下降,小波的信号分离效果逐渐得到改善。通过对重叠面积比的研究进一步发现,对每个Daubechies小波的两相邻尺度,其频带重叠面积在小尺度的频率窗中所占比例小,在大尺度频率窗中所占比例大,而且在大尺度的重叠面积比基本为小尺度的两倍。

无显式表达小波基的自适应选择

研究了无显式表达小波基的自适应选择问题。从不同应用角度定义了评价小波基分解效果的两种适应度函数 ;所给出的适应度函数曲面实例充分说明了对小波进行自适应选择的必要性。利用这两种适应度函数 ,提出了一种改进的遗传算法 ,对小波参数方程中的参数进行搜索 ,并利用适应度函数对搜索结果进行评价 ,实现了信号的自适应小波基分解 ,在此基础上给出了自适应小波基分解的实例 ,并与 Daubechies小波的分解结果进行对比 。

无显式表达小波基的参数方程

对无显式表达小波基的参数形式进行研究 ,得到了几种具有不同数目参数的小波基参数方程 ,同时对具有消失矩限制的小波基参数方程进行了研究。利用这些参数方程 ,给出了一个用不同参数而得到的两个小波基对同一个信号进行分解的对比实例 ,此实例说明参数的选择对于小波分解的效果起着决定性作用 ,通过对参数的适当选择可以实现对信号的最佳小波基分解。

浅谈开机无显故障诊断与排除

本文主要介绍了电脑维修的基本原则,开机无显时可能出现的原因。也介绍了处理故障的几个基本步骤,在具体检查前,应查看主板说明书及相关外围设备的说明书,向电脑使用者仔细询问在电脑出现故障前电脑的运行情况,特别是有无出现过故障和使用者是否有错误的操作?对已进行过维护再次出现故障的电脑还要了解其解决故障的方法,这样可以提供排除故障的信息,最大限度地确定解决问题的正确思路,少走弯路。这个非常的重要,这可是解决问题的关键所在。

Effect Research of Immobilized Algae-bacteria Removal Ammonia Nitrogen of Aquaculture Wastewater and Proposed Model

Applied Immobilized algae bacteria (ABI) to remove ammonia of freshwater aquaculture wastewater. Temperature (T),PH,light intensity (I),dissolved oxygen (DO) and filling rate five factors plays important role in the process of ammonia nitrogen removal ,related data between ammonia removal and five factors was received through multi-factor orthogonal test,and established relations model between the five factor and nitrogen removal. The results show that five-factors had significant effect on AR,and the best combinations for removing AR was temperature 30 ℃,pH=7.0,light intensity 6 000 lux,dissolved oxygen 5.0 mg/L and the fill rate 10%. According to the experimental data,equation model was proposed and coefficient of determination R2 =0.864 8,P<0.05. Samples T-test was done between the model predictions and the actual measured values.Test results showed that the significant difference of overall mean value sig. (2-tailed) was 0.978 (P>0.05),it Shows that had no significant difference between model predictions and the actual measured value,and model had a high degree of fitting.

Effect of Sb content on properties of Sn-Bi solders

The effect of Sb content on the properties of Sn-Bi solders was studied. The nonequilibrium melting behaviors of a series of Sn-Bi-Sb solders were examined by differential scanning calorimetry （DSC）. The spreading test was carried out to characterize the wettability of Sn-Bi-Sb solders on Cu substrate. The mechanical properties of the solders/Cu joints were evaluated. The results show that the ternary alloy solders contain eutectic structure resulting from quasi-peritetic reaction. With the increase of Sb content, the amount of the eutectic structure increases. At a heating rate of 5 ℃/min, Sn-Bi-Sb alloys exhibit a higher melting point and a wider melting range. A small amount of Sb has an impact on the wettability of Sn-Bi solders. The reaction layers form during spreading process. Sb is detected in the reaction layer while Bi is not detected. The total thickness of reaction layer between solder and Cu increases with the increase of the Sb content. The shear strength of the Sn-Bi-Sb solders increases as the Sb content increases.

细胞浆内精子注射受孕、体外授精受孕、自然受孕出生的儿童5岁时结局的国际合作研究:认知和运动能力评价

Objective. To date, very few studies have been conducted on the neurodevelopmental well-being of children conceived through intracytoplasmic sperm injection (ICSI). The limitations of these studies often include a lack of comparison with a demographically matched, naturally conceived (NC) group and the investigation of only very young children, with relatively small samples sizes. One study showed that there were no differences in IQ scores among ICSI-conceived, in vitro fertilization (IVF)-conceived, and NC children at 5 years of age. Unfortunately, psychomotor development was not assessed in that study. Because findings regarding these children’s cognitive and motor development are inconclusive, the aim of this study was to shed more light on the cognitive and motor development of 5-year-old ICSI-conceived children. Methods. A total of 511 ICSI-conceived children were compared with 424 IVF-conceived children and 488 NC controls. Children were recruited in 5 European countries, ie, Belgium, Denmark, Greece, Sweden, and the United Kingdom. Participation rates ranged from 45%to 96%in the ICSI and IVF groups and from 34%to 78%in the NC group. Cognitive and motor development was assessed with the Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R) and McCarthy Scales of Children’s Abilities (MSCA) Motor Scale, respectively. The WPPSI-R consists of 2 major scales, ie, Verbal and Performance, each including 6 subtests. The 6 Performance Scale subtests are object assembly, geometric design, block design, mazes, picture completion, and animal pegs. The 6 Verbal Scale subtests are information, comprehension, arithmetic, vocabulary, similarities, and sentences. Scores on the Performance and Verbal Scale subtests are summed to yield the performance IQ (PIQ) and verbal IQ (VIQ), respectively. Scores on both the Performance Scale and the Verbal Scale yield the full scale IQ (FSIQ). IQ scales have a mean score of 100 and a SD of 15. Each subtest has a mean score of 10 and a SD of 3. The MSCA consists of 6 scales, ie, Verbal, Perceptual-Performance, Quantitative, General Cognitive, Memory, and Motor Scale. In this study, only the Motor Scale was administered. This scale assesses the child’s coordination during performance of a variety of gross-and fine-motor tasks. Leg coordination, arm coordination, and imitative action tests provide measures of gross-motor ability. Draw-a-design and draw-a-child assess fine-motor coordination, as revealed by the levels of hand coordination and finger dexterity. The mean score for this test is 50, with a SD of 10. Results. No differences were identified among ICSI, IVF, and NC children with respect to VIQ, PIQ, or FSIQ scores of the WPPSI-R. Furthermore, there were no differences between groups regarding the discrepancy between VIQ and PIQ scores. These results were not influenced by gender, country, or maternal educational level. However, in the subgroup of first born children with mothers who gave birth at an older age (33-45 years), NC children obtained significantly better VIQ and FSIQ scores than did children conceived through assisted reproductive technologies. These differences in VIQ and FSIQ scores between ICSI/IVF and NC children were relative, because NC children scored < 1 IQ point higher than ICSI/IVF children. Therefore, these scores show no clinical relevance. For Verbal Scale subtests, variables such as age of the mother at the time of the birth, educational level of them other, and gender and nationality of the child interacted with mode of conception, resulting in clinically irrelevant differences between scores for the ICSI/IVF and NC groups on the arithmetic, vocabulary, and comprehension subtests. For Performance Scale subtests, these same demographic factors interacted with mode of conception for the block design, object assembly, and animal pegs subtests, again resulting in clinically irrelevant differences among groups. In the 3 groups (ICSI, IVF, and NC), we observed equal numbers of children scoring below 1 SD from the mean on the WPPSI-R and the MSCA. Conclusions. This study includes a substantial number of children from several European countries. Apart from a few interaction effects between mode of conception and demographic variables, no differences were found when ICSI, IVF, and NC scores on the WPPSI-R and MSCA Motor Scale were compared. Nevertheless, the aforementioned interaction effects could indicate that demographic variables such as maternal age at the time of the birth and maternal educational level play different roles in the cognitive development of IVF and ICSI children, compared with NC children. Additional research is needed to explore and verify this finding. Previous studies revealed that ICSI children, in comparison with NC children, more frequently obtained scores below 1 SD from the mean on 3 subtests of the Performance Scale (object assembly, block design, and mazes) or showed a trend of 5.2%of ICSI children, compared with 2.5%of IVF children and 0.9%of NC children, obtaining a score below 1 SD from the mean, but those findings were not confirmed in this study. Here no differences were found among the 3 groups in the numbers of children scoring below 1 SD from the mean on the VIQ, PIQ, and FSIQ tests and the Verbal and Performance Scale subtests. Motor development results were somewhat more conclusive. There were no differences between the scores of ICSI, IVF, and NC children on the MCSA Motor Scale. No interaction effects were found between mode of conception and demographic variables, indicating that these results are not influenced by gender, nationality, maternal educational level, or maternal age at the time of the birth. Furthermore, equal proportions of children in all 3 groups scored below 1 SD from the mean. The results of this study are reassuring for parents who conceived through ICSI (or IVF). The findings indicate that the motor and cognitive development of their offspring is very similar to that of NC children. However, demographic factors such as maternal educational level and maternal age at the time of the birth might play different roles in the cognitive development of ICSI and IVF children, compared with NC children.

孔源性视网膜脱离或糖尿病牵拉性视网膜脱离患者玻璃体液中NO通路代谢产物增加

Background:Nitric oxide(NO)plays a significant role in physiological and pathological processes in the retina.In the Larginine-NO pathway,NO synthase(NOS)converts L-arginine to NO and L-citrulline.Increased NO production,mediated by inducible NOS has been implicated in the pathogenesis of various vitreoretinal diseases.In the present study it is hypothesized that in rhegmatogenous retinal detachment(RRD),the production of NO pathway metabolites might be upregulated.Methods:Using high-pressure liquid chromatography citrulline,arginine and nitrite were measured in vitreous fluid of 93 eyes with RRD,nine eyes with a traction retinal detachment due to proliferative diabetic retinopathy(PDR),and in 49 control samples of vitreous fluid from eyes without retinal detachment.Results:The mean vitreous concentrations of citrulline and arginine were significantly increased in eyes with RRD(9.6± 4.3 and 97.3± 29.2;respectively)or in eyes with a traction retinal detachment(25.8± 10.3 and 130.7± 23.7;respectively)as compared to control eyes(7.1± 3.2 and 75.9± 18.1;respectively).The mean level of nitrite was also higher in vitreous fluid of patients with RRD(2.24± 1.4)or patients with a traction retinal detachment(2.21± 0.72)than in the controls(2.01± 0.72),although not significantly so.Conclusions:We found increased levels of NO pathway metabolites in the vitreous fluid of eyes with retinal detachment,which may reflect a possible role of NO in the pathogenesis of this disease.

Microstructural evolution during hot and cold deformation of Ti-36Nb-2Ta-3Zr-0.35O alloy

The Ti-36Nb-2Ta-3Zr-0.350 （mass fraction, %） （TNTZO） alloy was produced by cold isostatic pressing and sintering from elemental powders, followed by hot and cold deformation. The effects of deformation process on microstructures and mechanical properties were investigated using the SEM, TEM, OM and the universal material testing machine. Results show that the alloy can be easily hot forged and cold swaged due to the fine-grained microstructure. Only after cold swaging by 85%, the alloy shows the typical ＂marble-like＂ structure. And thecold deformation is accompanied by stress-induced a＂ phase transformations. Moreover, both the strength and the ductility of the alloy are significantly improved by hot and cold working.

Preparation of lead-free free-cutting graphite brasses by graphitization of cementite

Graphite brasses were prepared by graphitizing annealing of cast brasses containing cementite particles,which were in-situ formed during the fasting process.The eutectic cast iron as carbon source was added into common brasses by casting.SEM and EDS were used to analyze the microstructure of graphite brasses,and the relationship between the microstructure and machinability was investigated.The results show that graphite particles are formed by the decomposition of cementite particles in cast brasses.The graphite particles are uniformly dispersed in the brass matrix with the average size of 5.0 μm and the volume fraction of ~1.1%.The machinability in the graphite brass is dramatically increased relative to the common brass,because of the lubricating properties of graphite particles and its role in chip breaking.The workpiece surface of the graphite brasses chips is smooth and burr-free,and the chips of graphite brasses are short（C-shape） and discontinuous,which is much better than that of the long spiral chips of common brasses.

Surface physicochemical properties of semi-anthracitic coal from Painan-Sumatra during air oxidation

Painan coals of West Sumatra were selected as semi-anthracitic coal sample for studying the physicochemical properties such as measurement, evaluation and description of the changes of surface characteristic of coal sample and their oxidation in the atmospheric air at a temperature ranging from 105 to 400 ℃ for 30 min. Several methods are adopted to analyze and discuss several phenomena of the oxidized Painan coal surface during oxidation process for the change in the physicochemical properties as determined by Atomic Force Microscope （AFM）, contact angle, Fourier Transform Infrared Spectroscopy （FTIR）, Thermogravimetric and Differential Thermal Analysis （TG-DTA） analyses as well as other supporting analytical equipment. AFM analyses revealed some changes in adhesion force and surface morphology with more adhesion force available between 0.6 and 8.6 nN on polished coal surfaces due to the increased oxidation temperature. The study revealed that the extent of hydrophobicity of coal surface decreased with the increased of oxidation temperature expressed as contact angles at about 80° and 20°. Another phenomenon occurred during the experiment was hydrophilicity index of coal surface increase at approximately 1.3 and 2.9. Oxidation of coal that occurred with increased temperature also indicated an increase in oxygen content from 3.8% to 22.9 wt%. Increased oxygen functional group also noted that oxidation of coal took place during the treatment. We also found that oxidation treatment also affected the combustion properties of coal： decreasing ignition temperature between 452.9 and 317.6, lowering the reactivity of coal at maximum combustion rate temperature, and reflecting their char characteristics as burnt out, ranging from 652.3 to 648.5 ℃.

Effects of Ag contents in Sn-xAg lead-free solders on microstructure,corrosion behavior and interfacial reaction with Cu substrate

The effects of Ag on the microstructure and corrosion behavior of pre-soldering Sn-xAg lead-free solders,and on the formation of intermetallic layer of the solders with Cu substrate were investigated.The Ag contents(x)were 0,3.0,3.5,4.0,and5.0 wt.%.The Ag content played a role in the morphology of Ag3 Sn phase in the solders.The microstructure analysis showed that theβ-Sn phase was surrounded by eutectic networks in the 3.0 Ag and 3.5 Ag solders and large plate-like Ag3 Sn formed in the 4.0 Ag and5.0 Ag solders.Nonetheless,the Ag content slightly impacted the corrosion behavior of the as-cast solders as characterized using potentiodynamic polarization test.After soldering,only a single layer of a Cu6 Sn5 intermetallic compound formed at the Sn-xAg/Cu interface.By comparison,the Cu6 Sn5 intermetallic layer of the Ag-doped solders was thinner than that of the 0Ag solder.The fine Ag3 Sn particles in the eutectic networks precipitating in the 3.0 Ag and 3.5 Ag solders effectively hindered the growth of Cu6 Sn5 grains compared to large plate-like Ag3 Sn in the 4.0 and 5.0Ag solders.

Generalized solutions to the Benjamin-Ono equations in sense of Colombeau

This paper discusses the existence and uniqueness of the generalized solution in the sense of Colombeau to the Benjamin-Ono (B-O) equation and the relationship between the new generalized solution and the classical solution.

Is Precipitation the Dominant Controlling Factor of High Inorganic Nitrogen Content in the Changjiang River and Its Mouth?

The main reasons for the high content of inorganic N and its increase by several times in the Changjiang River and its mouth during the last 40 years were analysed in this work. The inorganic N in precipitation in the Changjiang River catchment mainly comes from gaseous loss of fertilizer N, N resulting from the increases of population and livestock, and from high temperature combustions of fossil fuels. N from precipitation is the first N source in the Changjiang River water and the only direct cause of high content of inorganic N in the Changjiang River and its mouth. The lost N in gaseous form and from agriculture non point sources fertilizer comprised about 60% of annual consumption of fertilizer N in the Changjiang River catchment and were key factors controlling the high content of inorganic N in the Changjiang River mouth. The fate of the N in precipitation and other N sources in the Changjiang River catchment are also discussed in this paper.

Effect of Mo addition on microstructure, ordering, and room-temperature mechanical properties of Fe-50Al

The effects of Mo addition on microstructures,phase relationships,order–disorder phase-transition temperatures and room-temperature mechanical properties of Fe50Al50-nMon alloys(n=1,3,5,7,and 9,mole fraction,%)were investigated after solidification and heat treatment.Structural characterization of the samples was performed via X-ray diffraction(XRD),scanning electron microscopy(SEM)and differential scanning calorimetry.Room-temperature mechanical properties were investigated by conducting compression and microhardness tests.Mo3Al particles precipitated in all alloys because of the limited solid solubility of Mo in the Fe-Al-based phases.The as-cast Fe50Al50-nMon alloys exhibited brittle behavior with high yield strength and limited fracture strain at room temperature.Compared with the as-cast alloys,all the heat-treated alloys except for the Fe50Al41Mo9 alloy exhibited enhanced mechanical properties at room temperature.The heat-treated Fe50Al43Mo7 alloy exhibited the highest fracture strain and compressive strength of 25.4%and 2.3 GPa,respectively.

Passive Matrix Organic Electroluminescent Display for 3G Cellular Phone

The major features of the display technologies for 3G cellular phone are reviewed. The comparison between their potential candidates for 3G cellular phone is given, and a detailed discussion is made on passive matrix organic electroluminescent display technology. A novel method to improve display contrast ratio is presented. Finally several 3G phone set prototypes with OLED display panels are given as well as the market forecast.

Effect of cyclic drying and wetting on engineering properties of heavy metal contaminated soils solidified/stabilized with fly ash

Solidification/stabilization （S/S） is one of the most effective methods of dealing with heavy metal contaminated soils. The effects of cyclic wetting and drying on solidified/stabilized contaminated soils were investigated. A series of test program, unconfined compressive strength （UCS） test, TCLP leaching test and scanning electron microscopy （SEM） test, were performed on lead and zinc contaminated soils solidified/stabilized by fly ash. Test results show that UCS and the leaching characteristics of heavy metal ions of S/S contaminated soils are significantly improved with the increase of fly ash content. UCS of S/S soils firstly increases with the increase of the times of drying and wetting cycles, after reaching the peak, it decreases with it. When the pollutant content is lower （1 000 mg/kg）, the TCLP concentration first slightly decreases under cyclic drying and wetting, then increases, but the change is minor. The TCLP concentration is higher under a high pollutant content of 5 000 mg/kg, and increases with the increase of the times of drying and wetting cycles. The results of scanning electron microscopy （SEM） test are consistent with UCS tests and TCLP leaching tests, which reveals the micro-mechanism of the variations of engineering properties of stabilized contaminated soils after drying and wetting cycles.

Study of the Adherence Mechanism Between the Metal and Inorganic Coating with Mill Addition of Li_2Ni_8O_(10) Nano Powder

The adherence strength between the metal and the inorganic coating can be greatly increased by mill addition of Li2Ni8O10. The interface structure between metal and the inorganic coating with excellent adherence has been studied by investigating the chemical composition and the microstrncture as well as elements valence bond on the interface with the help of scanning electron microscope （SEM）, electron microprobe, and Auger elctron spectroscope （AES）. The results show that there is a non-stoichiometrieal transitional layer on the interface between metal and the inorganic coating with excellent adherence, the adherence between metal and the non-stoichiometrical transitional layer is achieved by the metallic bond and the adherence between the non- stoichiometrical transitional layer and the inorganic coating is produced by ionic and covalent bond. The non-stoichiometrical transitional layer results in the strong adherence.

THE RELATION BETWEEN THE CHAIN PILLAR WIDTH AND THE SURROUNDING ROCK DEFORMATION OF ROADWAY

Based on the analysis and research into ground pressure behavior law and surrounding rock deformation of a large number of roadways affected by mining activity,this paper proposed a relation between the surrounding rock deformation during mining ,the surrounding rock deformation rate during stable stage of mining and the chain pillar width. Moreover,it established the relation between the total amount of surrounding rock deformation during service period of roadway and the chain pillar width,which provides a principal basis for choosing the chain pillar width.

ARROW-WTCP:A fast transport protocol based on explicit congestion notification over wired/wireless networks

An explicit congestion notification (ECN)-based distributed transport protocol,ARROW-WTCP (AcceleRate tRansmission towards Optimal Window size TCP for Wireless network),was proposed.The ARROW-WTCP enables feasible deployment of ARROW-TCP from wired to wireless networks by providing a joint design of source and router algorithms.The protocol obtains the actual capacity of the wireless channel by calculating the queue variation in base station (BS) and adjusts the congestion window by using the feedback from its bottleneck link.The simulation results show that the ARROW-WTCP achieves strong stability,max-min fairness in dynamic networks,fast convergence to efficiency without introducing much excess traffic,and almost full link utilization in the steady state.It outperforms the XCP-B (eXplicit Control Protocol Blind),the wireless version of XCP,in terms of stability,fairness,convergence and utilization in wireless networks.