基于SVG的电力图元库的设计与实现

电力系统图形信息的标准化是目前电力系统发展中的重要课题。在基本的SVG文档规范的基础上确立电力系统图形系统的构成和交换方式,建立基于SVG的电力图元库,并阐述了设备图元属性的定义方法。结合ASF(Apache Software Foundation)的开放源码项目Batik,对电力图元库模块应用面向对象的方法进行了分析和设计,基于Java开发平台实现了基于SVG的电力图元库系统。

数字化电力图档管理系统的应用

电力系统图档是电力企业管理和指导安全生产必不可少的重要资料,图档管理是企业生产管理的重要环节。为此,通过分析已在电力企业实际运行的数字化图档管理系统的结构和功能,提出相应的改良意见。

基于云雾边协同理念的“电网一张图”维护与自动更新策略研究

为了实现智能电网“源-网-荷-储”协调互动优化运行的目标,需要对发、输、变、配、用“物理一张网”进行数字建模,构建为各个业务部门提供数据服务的“电网拓扑结构关联一张图”。文章在介绍智能电网构成和云雾边技术架构的基础上,提出了基于变电站自动化系统和智能台区分别建设能量管理系统的雾节点和边节点,对“电网一张图”提供在线维护和自动更新的策略,然后讨论了这一策略涉及到的图数据库与电力图计算、电网图模型在线更新、低压配电网拓扑结构辨识等关键技术。此策略将“源-网-荷-储”各种环节以“电网一张图”的形式紧密连接,为智能电网的高效运行提供了技术基础。

油田电力系统测量与成图应用研究

油田电力系统测量、成图有其自身特点。分析了野外测绘数据采集、数据预处理、数据导入GIS系统成图、设计图纸应用性能、形成电力系统电子图的一系列工艺流程及其功能应用等。

基于面向对象的电力系统网络拓扑分析模块设计及应用

本文采用面向对象思想,在网络图形平台上将电网中电力图元设计为统一的元件模型,并用统一的数据结构进行存储,由此提出了一个利用递归搜索的电网拓扑分析模块,应用中表明这种电网拓扑分析方法具有较大的实用性和推广价值。

老年性高血压血液粘度变化与Ptfv_1的关系

高血压左心功能不全为临床尤其是老年患者的多发病。近年其血液流变学变化日益引起人们重视。本文测定不同年龄组高血压患者血液粘度和心电图Ptfv_1,值变化,探讨血液粘度改变在老年性高血压患者左心功能不全早期诊断中的意义。现报告如下: 1 材料和方法 1.1 病例选择 收集我院1991年5月至1992年3月进行血液流变学测定的高血压病例90例,符合世界卫生组织(WHO)所公布的诊断高血压的标准。其中老年组43例,男31例,女12例,年龄60～81岁,平均66.7岁;非老年组47例,男33例.女14例.年龄32～59岁,平均52.6岁。选择在我院作健康检查,排除了心、肺、脑。

Icon memory research under different time pressures and icon quantities based on event-related potential

In order to obtain related brain electrical components and neural bases of physiology assessment of icon elements in a digital human-computer interface the modified sample-delay matching task experimental paradigm is used under different time pressures 4 000 and 2 000 ms and different icon quantities three five and ten icons on icon memory based on event-related potential ERP technology.Experimental results demonstrate that P300 has significant volatility changes and the maximum amplitude around the middle line of the parietal area PZ and P200 has obvious volatility changes around the middle line of the frontal and central area FCZ during icon cognition.P300 and P200 amplitudes increase as tasks become more difficult.Thus P300 latency is positively correlated with task difficulty. ERP research on the characteristics of icon memory will be an important reference standard in guiding user neurocognitive behavior and physiology assessment on interface usability.

纯逻辑图与详细逻辑图

介绍纯逻辑图与详细逻辑图以及二者的区别与联系。

Thermodynamic analysis of Li-Ni-Co-Mn-H2O system and synthesis of LiNi0.5Co0.2Mn0.3O2 composite oxide via aqueous process

The constructed potential-pH diagrams of Li-Ni(Co,Mn)-H2O system indicate that the LiNiO2,LiCoO2 and LiMnO2 are thermodynamically stable in aqueous solution within the temperature range of 25-200°C and the activity range of 0.01-1.00.A predominant co-region of LiNiO2,LiCoO2 and LiMnO2 oxides(Li-Ni-Co-Mncomposite oxide)is found in the Li-Ni-Co-Mn-H2O potential-pH diagrams,in which the co-precipitation region expands towards lower pH with rising temperature,indicating the enhanced possibility of synthesizing Li-Ni-Co-Mn composite oxide in aqueous solution.The experimental results prove that it is feasible to prepare the LiNi0.5Co0.2Mn0.3O2 cathode materials(NCM523)by an aqueous routine.The as-prepared lithiated precursor and NCM523 both inherit the spherical morphology of the hydroxide precursor and the obtained NCM523 has a hexagonalα-NaFeO2 structure with good crystallinity.It is reasonable to conclude that the aqueous routine for preparing NCM cathode materials is a promising method with the guidance of the reliable potential-pH diagrams to some extent.

脆性X染色体综合征临床与脑电图的研究

目的研究青春期前脆性Ｘ染色体综合征临床和ＥＥＧ表现特点。方法对３０例该综合征患儿的临床表现、脑电图及其与脆性Ｘ细胞表达率的关系进行研究。结果智力低下、语言障碍及行为异常十分常见，但特殊面容和巨睾出现率低。４６．７％的患儿有癫痫发作，且发作有无与脆性Ｘ表达率相关。ＥＥＧ有癫痫放电者９／２１，但仅１例局限于双颞区。结论特殊面容及巨睾不应作为青春期前脆性Ｘ染色体综合征患儿筛选和诊断的依据。癫痫的发生可能与脆性Ｘ位点有关。

Development and Implementation of GSM-Based Distribution Automation System with Graphic User Interface in Nigeria Electric Power Distribution Network

Lack of up-to-date information on efficient operation and maintenance of EPDS （electric power distribution systems）, Nigeria is addressed by designing and implementing an indigenous real-time monitoring and diagnosis system. The system encompasses the development of software driven hardware positioned at the remotely located sub-stations at the low voltage level to keep track of the network in real-time. The detection of faults exploits threshold passing algorithm through continuous monitoring of the network power quality. Communication between the RTU （remote terminal unit） and the DCC （distribution control center） which is based on GSM is initiated by disturbance. The DCC performs fault evaluation processing using the received data and predetermined faults signatures to determine the nature of disturbance and presents the result in graphic user interface environment. A fault reporting time of 2 s was achieved. The developed system exhibits a high degree of accuracy and manifests no spurious reports during testing. The resultant system limits the effects of interruption and increases power availability by reducing the down time. The system strengthens engineering and management capabilities required to enhance reliability by providing information about the network health status.

E-pH diagram of ZnS-H_2O system during high pressure leaching of zinc sulfide

The values of GΘ,EΘ or pH from 110 to 160℃ were calculated and the relevant potential expressions were obtained.E-pH diagrams of ZnS-H2O system at oxygen partial pressure of 0.8 MPa,ionic activity of 1.0 and different temperatures were drawn through thermodynamical calculation.With the temperature increasing,the stable regions of S and Zn(Ⅱ) in the E-pH diagrams become gradually larger,but the amplification decreases over 150℃.The impacts of leaching parameters,such as temperature,liquid to solid ratio,initial acidic concentration,leaching time,oxygen partial pressure and stirring speed on the leaching rate of Zn(Ⅱ) and conversion rate of S in the single factor of high pressure leaching experiment of ZnS in autoclave,were studied.The leaching residue was examined by X-ray fluorescence(XRF) chemical composition identification and X-ray diffraction(XRD) phase identification,and the content of the leaching solution was tested by inductively coupled plasma-atomic emission spectrometry(ICP).The experimental results indicate that the leaching rate of zinc increases from 60.05% to 97.85% and the conversion rate of sulfur increases from 38.90% to 80.92% with the temperature increasing from 110℃ to 150℃,5:1 of liquid-to-solid ratio,150 g/L of initial acidic concentration,120 min of leaching time,0.8 MPa of oxygen partial pressure,and 480 r/min of stirring speed,which tend to be stable over 150℃.The experimental results correspond with theoretical calculation.

Detection and Separation of Event-related Potentials from Multi-Artifacts Contaminated EEG by Means of Independent Component Analysis

Event-related potentials (ERP) is an important type of brain dynamics in human cognition research. However, ERP is often submerged by the spontaneous brain activity EEG, for its relatively tiny scale. Further more, the brain activities collected from scalp electrodes are often inevitably contaminated by several kinds of artifacts, such as blinks, eye movements, muscle noise and power line interference. A new approach to correct these disturbances is presented using independent component analysis (ICA). This technique can effectively detect and extract ERP components from the measured electrodes recordings even if they are heavily contaminated. The results compare favorably to those obtained by parametric modeling. Besides, auto-adaptive projection of decomposed results to ERP components was also given. Through experiments, ICA proves to be highly capable of ERP extraction and S/N ratio improving.

Area-Efficient Low Power CMOS Image Sensor Readout Circuit with Fixed Pattern Noise Cancellation

A low cost of die area and power consumption CMOS image sensor readout circuit with fixed pattern noise(FPN) cancellation is proposed.By using only one coupling capacitor and switch in the double FPN cancelling correlative double sampling(CDS),pixel FPN is cancelled and column FPN is stored and eliminated by the sampleand-hold operation of digitally programmable gain amplifier(DPGA).The bandwidth balance technology based on operational amplifier(op-amp) sharing is also introduced to decrease the power dissi...

Estimation of the electromechanical characteristics of power systems based on a revised stochastic subspace method and the stabilization diagram

Estimating low-frequency oscillation modes and the corresponding mode shapes based on ambient data from WAMS measurements has a promising prospect in power system analysis and control.Based on the stochastic subspace method,this paper proposes a revised stochastic subspace method by introducing reference channels,which can estimate the modes and the mode shapes simultaneously with great computational efficiency.Meanwhile,the accuracy of the estimated results is not degraded.To discriminate the real modes from the spurious ones,the stabilization diagram is introduced.A novel algorithm is designed to deal with the stabilization diagram which can detect the real modes automatically.Tests conducted on the IEEE-118 system indicate that the proposed method has good performance in terms of both computational efficiency and accuracy,and has the potential of being used on-line.

Multiple Image Method for the Two Conductor Spheres in a Uniform Electrostatic Field

A method using multiple mirror images of point charges is put forward to analyze the polarization of two identical conductor spheres in a uniform electrostatic field.By use of the method,the electric field distribution and the interaction force between two spheres can be calculated accurately even for very small gap between two spheres.Our results show that the magnitude of the product of the gap between two spheres and the local electric field in the center of the gap is approximately in the same order and the interaction between two spheres increases very fast as the two spheres are close to each other.We also show that the interaction force between two conductor spheres is almost same with that between two dielectric spheres with high permittivity.

Self-powered electrochromic devices with tunable infrared intensity

Triboelectric nanogenerator （TENG） is an efficient way to convert ambient mechanical energy into electricity to power up portable electronics. In this work, a flexible inflared electrochromical device （IR-ECD） with stable performances was assembled with a TENG for building self-powered infrared detector with tunable intensity. As driven by TENG, the electrochromic device could be operated in the mid-lR region due to the reversible electrochromic reactions. An average infrared reflectance contrast of 46% was achieved in 8-14 μm regions and as well a clear thermal image change can be observed. This work indicates that the TENG-driven infrared electrochromical device has potential for use in self-powered camouflage and tbermal control.

EEG dynamics reflects the partial and holistic effects in mental imagery generation

Mental imagery generation is essential in the retrieval and storage of knowledge.Previous studies have indicated that the holistic properties of mental imagery generation can be evaluated more easily than the partial properties.However,the relationship between partial and holistic mental imagery generations has not been clearly demonstrated.To address this issue,we designed a task to investigate the changes in the spectrum of the electroencephalogram (EEG) during partial or holistic imagery generation.EEG signals were obtained from 18 healthy subjects,and a statistical measure of spectral dynamics between two EEG signals in per frequency band was performed.Additionally,a bicoherence spectrum analysis was used to detect the phase coupling within these two imagery conditions.Our results indicated that EEG of the partial imagery appeared earlier and stronger than that of the holistic imagery in the theta (5–8 Hz) range in a time window around 220 to 300 ms after cue onset,and a slight decrease in the alpha (8–12 Hz) band was observed at around 270 ms.The scalp topography of these changes in the theta and alpha bands distributed overall significantly in the frontal and central-temporal areas.The significant phase coupling within two conditions was remarkable at high frequency.From these results,we infer that there are complex relations between partial and holistic imageries.The generation of partial mental imagery is not a subprocess of holistic imagery,but it is relevant to holistic imagery and requires correct modification from the holistic information.

Clinical research on acupuncture combined with TDP for stump stomach atony after subtotal gastrectomy

Objective To verify the therapeutic methods and clinical efficacy on stump stomach atony after subtotal gastrectomy （SSASG） treated with acupuncture and TDP. Methods Fifty-three cases were divided into an observation group （23 cases） and a control group （30 cases） according to the random number table. In the observation group, acupuncture was applied in combination with TDP. The main acupoints were Zúsānlǐ （足三里 ST 36）, Píshū （脾俞 BL 20）, Wèishū （胃俞 BL 21） and Zhōngwǎn （中脘 CV 12）. The treatment was given once per day. 10 treatments made one session. Two sessions of treatment were required. In the control group, Motilium was prescribed for oral administration, 10 mg each time, three times per day, continuously for 20 days. The changes in the relevant parameters in electrogastrogram （EGG） were observed before and after treatment. The efficacy was assessed. Results The principle frequency and the waveform reaction area of EGG were improved apparently after treatment in both groups （all P0.01）, and those in the observation group were superior to those in the control group （all P0.01）. The ratio of the power after/before meal was more than 1 in the observation group after treatment and that in the control group was less than 1. The effective rate was 100.0% （23/23） in the observation group, which was superior to that of 80.0% （24/30） in the control group, presenting statistically significant difference （P0.01）. Conclusion Acupuncture in combination with TDP can effectively treat SSASG. This therapy apparently improves the gastric motility, tremendously promotes the gastrointestinal peristalsis and recovers the gastrointestinal function after operation. The efficacy of it is superior to that achieved by the oral administration of Motilium.