基于Google maps API的地图Mashup

Mashup作为最具有战略性意义的十大信息技术之一,正在Internet上逐渐兴起。本文对基于Google maps API的地图Mashup进行介绍,分析研究这种新技术的应用方法,最后给出了具体的地图Mashup实例。     

Hot deformation behavior of uniform fine-grained GH4720Li alloy based on its processing map

The hot deformation behavior of uniform fine-grained GH4720Li alloy was studied in the temperature range from 1040 to 1130℃ and the strain-rate range from 0.005 to 0.5 s?1 using hot compression testing. Processing maps were constructed on the basis of compression data and a dynamic materials model. Considerable flow softening associated with superplasticity was observed at strain rates of 0.01 s?1 or lower. According to the processing map and observations of the microstructure, the uniform fine-grained microstructure remains intact at 1100℃ or lower because of easily activated dynamic recrystallization (DRX), whereas obvious grain growth is observed at 1130℃. Metallurgical instabilities in the form of non-uniform microstructures under higher and lower Zener–Hollomon parameters are induced by local plastic flow and primary γ′ local faster dissolution, respectively. The optimum processing conditions at all of the investigated strains are proposed as 1090–1130℃ with 0.08–0.5 s?1 and 0.005–0.008 s?1 and 1040–1085℃ with 0.005–0.06 s?1.     

Feature extraction of gear-localized defect using adaptive lifting scheme and local gradient map

In this paper,the adaptive lifting scheme (ALS) and local gradient maps (LGM) are proposed to isolate the transient feature components from the gearbox vibration signals. Based on entropy minimization rule,the ALS is employed to change properties of an initial wavelet and design adaptive wavelet. Then LGM is applied to characterize the transient feature components in detail signal of decomposition results using ALS. In the present studies, the orthogonal Daubechies 4 (Db 4) wavelet is used as the initial wavelet. The proposed method is applied to both simulated signals and vibration signals acquired from a gearbox for periodic impulses detection. The two conventional methods (cepstrum analysis and Hilbert envelope analysis) and the orthogonal Db4 wavelet are also used to analyze the same signals for comparison. The results demonstrate that the proposed method is more effective in extracting transient components from noisy signals.     

诺基亚推全球网页版地图服务

诺基亚最新推出全球网页版诺基亚地图服务,用户只需登录http：／／maps．nokia．com．cn即可进入诺基亚全球,地图支持卫星地图和地形地图的一键切换网页版地图。与其他地图不同的是,诺基亚全球网页版地图的用户可以随时随地实现手机和电脑双向同步操作,即用户在PC端存储的路线可以自动同步到手机端,这样用户可以将出行前在电脑上查询的兴趣点和出行路线放入收藏夹,     

Constitutive behavior and processing maps of low-expansion GH909 superalloy

The hot deformation behavior of GH909 superalloy was studied systematically using isothermal hot compression tests in a temperature range of 960 to 1040℃ and at strain rates from 0.02 to 10 s-1 with a height reduction as large as 70%. The relations considering flow stress, temperature, and strain rate were evaluated via power-law, hyperbolic sine, and exponential constitutive equations under different strain conditions. An exponential equation was found to be the most appropriate for process modeling. The processing maps for the superalloy were constructed for strains of 0.2, 0.4, 0.6, and 0.8 on the basis of the dynamic material model, and a total processing map that includes all the investigated strains was proposed. Metallurgical instabilities in the instability domain mainly located at higher strain rates manifested as adiabatic shear bands and cracking. The stability domain occurred at 960-1040℃ and at strain rates less than 0.2 s-1; these conditions are recommended for optimum hot working of GH909 superalloy.     

Hot deformation characteristics of as-cast high-Cr ultra-super-critical rotor steel with columnar grains

Isothermal hot compression tests of as-cast high-Cr ultra-super-critical (USC) rotor steel with columnar grains perpendicular to the compression direction were carried out in the temperature range from 950 to 1250°C at strain rates ranging from 0.001 to 1 s-1. The softening mechanism was dynamic recovery (DRV) at 950°C and the strain rate of 1 s-1, whereas it was dynamic recrystallization (DRX) under the other conditions. A modified constitutive equation based on the Arrhenius model with strain compensation reasonably predicted the flow stress under various deformation conditions, and the activation energy was calculated to be 643.92 kJ·mol-1. The critical stresses of dynamic recrystallization under different conditions were determined from the work-hardening rate (θ)–flow stress (σ) and -?θ/?σ–σ curves. The optimum processing parameters via analysis of the processing map and the softening mechanism were determined to be a deformation temperature range from 1100 to 1200°C and a strain-rate range from 0.001 to 0.08 s-1, with a power dissipation efficiency η greater than 31%.     

Modeling the hot working behavior of near-α tita nium alloy IMI 834

The hot working behavior of near-a titanium alloy IMI 834 with a duplex starting microstructure was studied using the technique of processing map.The processing map was interpreted in terms of the microstrucmral processes occurring during deformation,based on the values of dimensionless parameter η which represents the energy dissipation through microstructural processes.An instability criterion（ξ<0） was also applied to demarcate the flow instability regions in the processing map.Both the parameters（η and ξ） were computed using the experimental data generated by carrying out hot compression tests over a range of temperatures（850-1060℃） and strain rates(3×10^-4-1/s).The deterministic domains observed under the investigated temperature and strain rate conditions were attributed to continuous dynamic recrystallization or globularisation of a lamellae,dynamic recrystallization and growth of β grains through microstructural observations.An unified strain compensated constitutive equation was established to describe the hot working behavior of the material in the selected temperature-strain rate range.The established constitutive equation was validated using standard statistical parameters such as correlation coefficient and average absolute relative error.     

Differential Coherent Algorithm Based on Fast Navigation-Bit Correction for Airborne GNSS-R Software Receivers

Signals from the Global Navigation Satellite System (GNSS) scatter over the sea surface resulting in relatively low Signal-to-Noise Ratios (SNR). A differential coherent algorithm is given here to improve the SNR and reduce the performance degradation due to the Squaring-Loss and the navigation-bit effect. The algorithm uses fast navigation-bit correction for Delay-Doppler Maps (DDM) in airborne Global Navigation Satellite Signal Reflectometry (GNSS-R) software receivers. The system model is introduced with an analysis of the statistical properties with simulations to support the theoretical analysis. Field experiments with real airborne receivers then demonstrate the effectiveness of this algorithm. Comparisons with test results show that this algorithm offers a significant SNR gain over conventional algorithms.     

P-调和映射的稳定性

分别探讨以欧氏空间的子流形为起始流形和目标流形的p-调和映射的稳定性,推广了忻元龙、P.F.Leung和Ohnita的相应结果.     

关于地图计数方法的一点注记

在地图计数理论中,适当地选择计数的方法不仅能使汁数过程得到简化,而且还能使计数结果尽可能地优化.利用参数化的计数方法使得近2-正则有根平面地图依根点次、非根点数和根面次的一组计数结果得到了充分的简化.     

三维数字地图在设备管理系统中的应用

通过对设备管理中数字地图的研究,将三维数字地图技术应用于设备管理.利用设备管理数据库中的记录,将单个的实体模型组合成设备场景地图;利用OpenGL处理场景的绘制及场景与用户交互的方法,提升管理系统的人机界面,增强数据表现力,实现了设备的可视化管理.     

单连通负曲率流形上指数调和映照的常边值问题

应用重要等式∫FaD(|du|2 2)g(x,n)oR=∫F1aD(|du|2 2)h(u.X,u.n)6R ∫D(divSf(M)(X)uR ∫D《Sf(u),▽X》uR,讨论完备单连通具有负截曲率黎曼流形上指数调和映照的常边值问题,得到相应的刘维尔型定理.     

土地利用基础图件的矢量化方法

从土地利用图件的特征出发,提出了一套具有实用价值的矢量化流程,并对线状目标半自动提取和边界一致性轮廓优化等关键技术进行探讨,提出了基于方向估计的变向骨架跟踪算法,快速有效地实现了线状目标的半自动提取;同时提出了一种基于三色点的边界一致性轮廓优化策略,有效地解决了图斑共用边界的同一化问题.实验结果表明,算法完全满足土地利用基础图件的实用要求,具有一定的理论意义和实用价值.     

T122耐热钢热变形加工图及热成形性

在Gleeble 3500热模拟试验机上进行热压缩实验. 采用动态材料模型理论、双曲线本构方程及Liapunov稳定性判据,建立了T122耐热钢热变形加工图. 利用所建立的加工图,分析了不同温度和应变速率下T122钢的热成形性及其与显微组织的关系. 结果表明:T122钢在1085℃以上、应变速率小于0.37s-1压缩变形时,功率耗散效率达到峰值0.2,此时发生了完全动态再结晶;对于工业热加工,建议在变形温度为1085～1150℃和应变速率大于0.13s-1的范围内选择加工参数.     

烧结铁矿中FeO含量对其在富氢高炉中还原行为的影响

Japan started the national project “COURSE 50” for CO₂ reduction in the 2000s. This project aimed to establish novel technologies to reduce CO₂ emissions with partially utilization of hydrogen in blast furnace-based ironmaking by 30% by around 2030 and use it for practical applications by 2050. The idea is that instead of coke, hydrogen is used as the reducing agent, leading to lower fossil fuel consumption in the process. It has been reported that the reduction behavior of hematite, magnetite, calcium ferrite, and slag in the sinter is different, and it is also considerably influenced by the sinter morphology. This study aimed to investigate the reduction behavior of sinters in hydrogen enriched blast furnace with different mineral morphologies in CO–CO₂–H₂ mixed gas. As an experimental sample, two sinter samples with significantly different hematite and magnetite ratios were prepared to compare their reduction behaviors. The reduction of wustite to iron was carried out at 1000, 900, and 800°C in a CO–CO₂–H₂ atmosphere for the mineral morphology-controlled sinter, and the following findings were obtained. The reduction rate of smaller amount of FeO led to faster increase of the reduction rate curve at the initial stage of reduction. Macro-observations of reduced samples showed that the reaction proceeded from the outer periphery of the sample toward the inside, and a reaction interface was observed where reduced iron and wustite coexisted. Micro-observations revealed three layers, namely, wustite single phase in the center zone of the sample, iron single phase in the outer periphery zone of the sample, and iron oxide-derived wustite FeO and iron, or calcium ferrite-derived wustite 'FeO' and iron in the reaction interface zone. A two-interface unreacted core model was successfully applied for the kinetic analysis of the reduction reaction, and obtained temperature dependent expressions of the chemical reaction coefficients from each mineral phases.     

Mg和La对Ca–Ti 处理钢中夹杂物演变和组织的影响

The evolution of inclusions and the formation of acicular ferrite (AF) in Ca–Ti treated steel was systematically investigated after Mg and La addition. The inclusions in the molten steel were Ca–Al–O, Ca–Al–Mg–O, and La–Mg–Ca–Al–O after Ca, Mg, and La addition, respectively. The type of oxide inclusion in the final quenched samples was the same as that in the molten steel. However, unlike those in molten steel, the inclusions were Ca–Al–Ti–O + MnS, Ca–Mg–Al–Ti–O + MnS, and La–Ca–Mg–Al–Ti–O + MnS in Mg-free, Mg-containing, and La-containing samples, respectively. The inclusions distributed dispersedly in the La-containing sample. In addition, the average size of the inclusions in the La-containing sample was the smallest, while the number density of inclusions was the highest. The size of effective inclusions (nucleus of AF formation) was mainly in the range of 1–3 μm. In addition, the content of ferrite side plates (FSP) decreased, while the percentage of AF increased by 16.2% due to the increase in the number of effective inclusions in the La-containing sample in this study.     

摩擦焊接碳钢（EN24）和镍基高温合金（IN718）的显微组织和力学性能

Continuous-drive rotary friction welding was performed to join cylindrical specimens of carbon steel (EN24) and nickel-based superalloy (IN718), and the microstructures of three distinct weld zones—the weld interface (WI)/thermo-mechanically affected zone (TMAZ), the heat-affected zone (HAZ), and the base metal—were examined. The joint was observed to be free of defects but featured uneven flash formation. Electron backscatter diffraction (EBSD) analysis showed substantial changes in high-angle grain boundaries, low-angle grain boundaries, and twin boundaries in the TMAZ and HAZ. Moreover, significant refinement in grain size (2–5 μm) was observed at the WI/TMAZ with reference to the base metal. The possible causes of these are discussed. The microhardness profile across the welded joint shows variation in hardness. The changes in hardness are ascribed to grain refinement, phase transformation, and the dissolution of strengthening precipitates. The tensile test results reveal that a joint efficiency of 100% can be achieved using this method.     

采用超声组装与滚压工艺制备铝–碳纳米管复合材料

This study introduced a novel fabrication of aluminum–carbon nanotube (CNT) composites by employing bulk acoustic waves and accumulative roll bonding (ARB). In this method, CNT particles were aligned using ultrasonic standing wave in an aqueous media, and the arrayed particles were precipitated on the aluminum plate substrate. Then, the plates rolled on each other through the ARB process with four passes. Optical and scanning electron micrographs demonstrated the effective aligning of CNTs on the aluminum substrate with a negligible deviation of arrayed CNTs through the ARB process. The X-ray diffraction pattern of the developed composites showed no peaks for carbon and aluminum carbide. In addition, tensile tests showed that the longitudinal strength of the specimens processed with aligned CNTs was significantly greater than that of the specimens with common randomly dispersed particles. The proposed technique is beneficial for the fabrication of Al–CNT composites with directional mechanical strength.     

活化天然矿石选择性还原二氧化碳为无定形碳

Natural magnetite formed by the isomorphism substitutions of transition metals, including Fe, Ti, Co, etc., was activated by mechanical grinding followed by H₂ reduction. The temperature-programmed reduction of hydrogen (H₂-TPR) and temperature-programmed surface reaction of carbon dioxide (CO₂-TPSR) were carried out to investigate the processes of oxygen loss and CO₂ reduction. The samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray spectroscopy (EDS). The results showed that the stability of spinel phases and oxygen-deficient degree significantly increased after natural magnetite was mechanically milled and reduced in H₂ atmosphere. Meanwhile, the activity and selectivity of CO₂ reduction into carbon were enhanced. The deposited carbon on the activated natural magnetite was confirmed as amorphous. The amount of carbon after CO₂ reduction at 300°C for 90 min over the activated natural magnetite was 2.87wt% higher than that over the natural magnetite.