精准测风方法及相关测风装置

当空气在井巷中流动时,垂直于流动方向上的各分层流速不等,靠近井巷周壁的流速较小,井巷中心的流速最大。为了测定巷道风速,通常采用风表法,风表测风方法分为定点测风法和线路测风法。人为因素对风表法测风的影响较大,测风精度不高。测风时要求手持风表不能抖动,风表必须与风流垂直;定点法测风一般取9个测点,遇到大断面时需要取12个测点,每个测点测1min风速,取平均风速计算风量,工作量大,人为误差大;线路法测风是在1min内匀速走完规定路线,缺乏技术和经验的测风员很难胜任。精准测风利用毕托管、斜管压差计、精密数字气压计配合测量风量,测量设备均在静止状态下完成数值测量,经计算得出风速、风量,相比风表测风而言,受到人为因素影响小,测风精度高。

煤矿井巷测风方法的改进

分析传统井巷测风方法的不足,并通过风量测定的理论计算和对现场风量进行实际验证,提出了井巷中心点定点测风法和井巷平均风速点定点测风法,较好地解决了当前测定风速慢、可靠性差的问题。

基于CFD的定点风速测定法的分析

为了准确测量巷道风速,针对井巷平均风速定点测风法,通过CFD计算流体力学的相关知识,对梯形、半圆拱形和方形3种巷道内部的风速分布进行了数值模拟分析,验证了平均风速定点测风法的可行性。

无人机测风技术研究

随着航空、大气探测以及微电子技术的发展和应用,无人机测风技术日益成为无人机应用的一项重点研究内容。介绍了目前常用的无人机测风方法,如水平空速归零法、解析测风方法、航位推算法以及皮托-静压管测风法等,阐述了各种高空风风速测量原理以及各自优缺点,指出皮托-静压管测风法更适合复杂环境下实时探测,具有良好的应用前景,同时分析了皮托-静压管测风法的关键技术,以达到提高无人机风场测量精度的目的。

加强地方小煤矿测风工作

把方小煤矿测风工作 ,是目前矿井通风工作中的一个薄弱环节。由于测风方法不合理 ,管理制度不健全 ,严重影响着矿井的通风管理以及安全生产 ,必须迅速改善。

Ratio K: a New Way of Metering and Evaluating the Risk and Return of Stock Investment

Although widely used, both the Markowitz model and VAR (Value at Risk) model have some limitations in evaluating the risk and return of stock investment. By the analysis of the conceptions of risk and return, together with the three hypotheses of technological analysis, a novelty model of metering and evaluating the risk and return of stock investment is established. The major indicator of this model , risk-return ratio K, combines the characteristic indicators of risk and return. Regardless of the form of the risk-return probability density functions, this indicator K can always reflect the risk-return performances of the invested stocks clearly and accurately. How to use the model to make optimum investment and how to make portfolio combined with clustering analysis is also explained.

CONTROL OF GAS EMISSION AT COAL FACE IN CHINA

All the underground coal mines in China are gassy mines. The gas emission at coal face increasingly grows with the increase of working depth and coal output, for example, the gas emission at a full mechanized coal face of mine No. 2 at Yongquan with a daily output of 2. 000t/d is up to 66-72m2/min. Special gas emission phenomena such as gas blowout, gas and coal outburst etc. have occurred at some faces, which threatens the safe production of face. obstructs the growth of productivity and limits the full play of mechanized equipment.In this paper, gas at face is divided, according to its origin, into three constituents, namely , coming from the coal wall, mined coal and goaf;and a formula for calculation is given. Also , the characteristics of the variation of gas emission at coal face, and the influence of mining sequence of a group of seams and supplied air quantity on the gas emission are discussed. Furthermore . based on the regularity of gas emission at coal face from the above three sources, and on the experiences of years, three principles on controlling gas emission at coal face are presented, that are managing the gas on classification basis, harnessing each source separately and comprehensive prevention and control. Finally, technical measures for prevention and treatment of the accumulation of gas in the upper corner of face, at the working place of coal-winning machine and in the bottom trough of conveyor are introduced.

Reduced Popdc3 expression correlates with high risk and poor survival in patients with gastric cancer

AIM： To investigate the expression of Popeye domain containing 3 （Popdc3） and its correlation with clinicopathological features and prognosis of gastric cancer.METHODS： The method of immunohistochemistry was used to investigate the expression of Popdc3 in 306 cases of human gastric cancer and 84 noncancerous gastric tissues. Simultaneously, the relationship between Popdc3 expression and the survival of the patients was retrospectively analyzed.RESULTS： Popdc3 was detected in 72 （85.71%） of 84 human nontumor mucosa. High expression of Popdc3protein was detected in 78 （25.49%） of 306 human gastric cancer cases, and low expression was detected in 228 （74.51%）. Low expression of Popdc3 correlated with depth of invasion （P 〈 0.0001）, regional lymph nodes （P 〈 0.0001） and distant metastasis （P =0.02）, and tumor, nodes, metastasis （TNM） stages （P 〈 0.0001）. On multivariate analysis, only the patient＇s gender, regional lymph node metastasis, distant metastasis, TNM stages, and the expression of Popdc3 were independent prognostic factors in patients with gastric cancer. The Kaplan-Meier plot showed that low Popdc3 expression had a much more significant effect on the survival of those patients with early-stage tumors X^2 = 104.741, P 〈 0.0001）, with a 〉 51.9% reduction in the three-year survival compared with high Popdc3 expression. In late stages, the difference was also significant X^2 = 5.930, P = 0.015）, with a 32.6% reduction in the three-year survival.CONCLUSION： Reduced expression of Popdc3 may play a significant role in the carcinogenesis and progression of gastric cancer. Popdc3 may be an independent prognostic factor.

NUMERICAL SIMULATION OF TYPHOON WAVE UNDER THE INFLUENCE OF WINNIE (NO. 9711)

In this paper, the wind field provided by a meso-scale atmospheric model is employed. When main physical processes, including wave-current interactions, are considered, the latest version of the third generation wave model SWAN is applied to simulate the typhoon wave generated by Typhoon Winnie. The model results are compared with the TOPEX/POSEIDON and ERS-2 satellite altimeter data and analyzed in details. Then the distribution of wave fields are analyzed, with the results showing that applying SWAN to simulate large-scale domain can also fairly reproduce the observed features of waves and realistically reflect the distribution of typhoon waves.

EAG and behavioral responses of Helicoverpa armigera males to volatiles from poplar leaves and their combinations with sex pheromone

Electroantennogram (EAG) evaluation of selected compounds from wilted leaves of black poplar, Populus nigra, showed that phenyl acetaldehyde, methyl salicylate, (E)-2-hexenal elicited strong responses from male antennae of Helicoverpa armigera. When mixed with sex pheromone (Ph), some volatiles, e.g. phenyl acetaldehyde, benzyl alcohol, phenylethanol, methylsalicylate, linalool, benzaldehyde, (Z)-3-hexenol, (Z)-3-hexenylacetate, (Z)-6-nonenol, cineole, (E)-2-hexenal, and geraniol elicited stronger responses from male antennae than Ph alone. Wind tunnel bioassay demonstrated that various volatiles could either enhance or inhibit the effect of synthetic sex pheromone. (E)-2-hexenal, (Z)-3-hexenol and linalool in combination with Ph could not induce any male to land on source at all, whereas phenyl acetaldehyde, benzaldehyde, (Z)-6-nonenol and salicylaldehyde combined with Ph enhanced male response rates by 58.63%, 50.33%, 51.85% and 127.78%, respectively, compared to Ph alone. These results suggested that some volatiles shouldmodify sex pheromone caused behavior and that some of them could possibly be used as a tool for disrupting mating or for enhancing the effect of synthetic sex pheromone in the field.

Influence of a Deflector or a Wall on Savonius Rotor Efficiency

The Savonius rotor is a vertical axis-wind machine composed of two half cylindrical blades presenting a central gap. It is a slow velocity machine compared with horizontal wind machines. Its efficiency is about twenty per cent. In this work experimental tests are presented using two kind of deflectors placed in front of the resistive blade. Such disposition allows to hide the resistant blade and to guide the flow toward the motrice blade. Two deflectors have been used： a short one and a long one. The results obtained in wind tunnel have shown that the long deflector is the more efficient, essentially for high values of the tip speed ratio. One has been interested, using a numerical approach, in the study of the influence of a wall on the aerodynamical field near the rotor.

Adapting cities to sea level rise： A perspective from Chinese deltas

In recent years, intensifying waterlogging, salt water intrusion, wetland loss, and ecosystem degradation in Chinese delta cities and adjacent regions have generated the pressing need to create an urban form that is suited to both current and future climates incorporating sea level rise. However, adaptation planning uptake is slow. This is particularly unfortunate because patterns of urban form interact with mean sea level rise （MSLR） in ways that reduce or intensify its impact. There are currently two main barriers that are significant in arresting the implementation of adaptation planning with reference to the MSLR projections composed of geomorphologic MSLR projections and eustatic MSLR projections from global climate warming, and making a comprehensive risk assessment of MSLR projections. The present review shows recent progresses in mapping MSLR projections and their risk assessment approaches on Chinese delta cities, and then a perspective of adapting these cities to MSLR projections as following six aspects. 1） The geomorphologic MSLR projections are contributed by the natural tectonic subsidence projections and the MSLR projections by anthropogenic geomorphologic change. The former needs to be updated in a global framework. The latter is accumulated by land subsidence from underground water depletion, water level fall caused by the erosion of riverbeds from a sediment supply decline attributed to the construction of watershed dams, artificial sand excavation, water level raise by engineering projects including land reclamation, deep waterway regulation, and fresh water reservoirs. 2） Controlling MSLR projections by anthropogenic geomorphologic changes. 3） The IPCC AR5 RCPs MSLRs scenarios are expected to be projected to the local eustatic MSLR projections on the Chinese deltas. 4） The MSLR projections need to be matched to a local elevation datum. 5） Modeling approaches of regional river-sea numerical with semi- analytical hydrodynamics, estuarine channel network, system dynamics and adaptation points are perspective. 6） Adaptation planning to MSLR projections requires a comprehensive risk assessment of the risk of flood, fresh water supply shortage, coastal erosion, wetland loss, siltation of ports and waterway in Chinese delta cities and adjacent regions.

Determination method of load balance ranges for train operation safety under strong wind

The aerodynamic performances of a passenger car and a box car with different heights of windbreak walls under strong wind were studied using the numerical simulations, and the changes of aerodynamic side force, lift force and overturning moment with different wind speeds and wall heights were calculated. According to the principle of static moment balance of vehicles, the overturning coefficients of trains with different wind speeds and wall heights were obtained. Based on the influence of wind speed and wall height on the aerodynamic performance and the overturning stability of trains, a method of determination of the load balance ranges for the train operation safety was proposed, which made the overturning coefficient have nearly closed interval. A min(|A1|+|A2|), s.t. |A1|→|A2|(A1 refers to the downwind overturning coefficient and A2 refers to the upwind overturning coefficient)was found. This minimum value helps to lower the wall height as much as possible, and meanwhile, guarantees the operation safety of various types of trains under strong wind. This method has been used for the construction and improvement of the windbreak walls along the Lanzhou–Xinjiang railway(from Lanzhou to Urumqi, China).

Determination of Weak Points Based on Risk Theory and Application to Transmission Network Planning

In the traditional power transmission network planning,deterministic analysis methods are widely used.In such methods,all contingencies are deemed to have the same occurrence probability,which is not reasonable.In this paper,risk assessment is introduced to the process of transmission network planning considering the probabilistic characteristics of contingencies.Risk indices are given to determine the weak points of the transmission network based on local information,such as bus risk,line overload risk,contingency severity.The indices are calculated by the optimal cost control method based on risk theory,which can help planners to quickly determine weak points in the planning and find solution to them.For simplification,only line overload violation is considered.Finally,the proposed method is validated by an IEEE-RTS test system and a real power system in China from two aspects.In the first case,the original system is evaluated by the proposed method to find the weak points,and then four planning schemes are established,among which the best scheme is selected.In the second case,four initial planning schemes are established by combining the experiences of planners,and after the evaluation by using the proposed method,the best planning scheme is improved based on the information of weak points in the initial schemes,and the risk of improved scheme is reduced from 42 531.86 MW·h per year to 4 431.26 MW·h per year.

Analysis on Application of Wavelet Neural Network in Wind Electricity Power Prediction

Wind electricity power has fluctuation, and accurate and reasonable wind electricity power prediction is very important for solving wind electricity network and combination. This paper takes an analysis of a lot of actual data of a certain wind electricity field. Through wavelet neural network and time series method rolling, it can predict the overall power of wind electricity field. The result shows that for the original data of sampling time length and large sampling frequency, the model constructed by this paper has very good prediction effect. Because of the fan installation position, wind electricity fan flow effect and other random factor influence, wind electricity field overall power and single unit power distribution have difference. Through comparing with the time series parameters, it puts forward that single wind electricity unit power has smooth effect for overall power of wind electricity field. Finally, it summarizes the prediction effect and puts forward some reasonable suzestions for wind electricity network troblems.

Risk Evaluation of Workers Exposure to Magnetic Fields in Indoor Distribution Substations

Due to possible health effects of electric and magnetic fields, a directive on minimum health and safety requirements regarding the exposure of workers to electromagnetic fields has been disposed by European Parliament and Council regarding the exposure of workers to electromagnetic fields. This legislation will be nationally implemented in 2012.The aim of this work was to develop a electromagnetic field exposure measurement method and further a magnetic field hazard evaluation method for exposure of workers in indoor medium to low voltage （MV/LV） distribution substations. Magnetic field exposure was also reflected with BS 8800 general risk classification procedure to accomplish specifications to execute magnetic field measurements and carry our risk assessment procedure for working tasks. The risk assessment procedure is based on magnetic field exposure measurements and dosimetric FEM calculations founded on EU Directive 2004/40/EC. According to field measurements action values were exceeded in several working tasks but limit values were not exceeded.

A Combination Method for Wind Power Prediction Based on Cooperative Game Theory

Accurate prediction of wind power is significant for power system dispatching as well as safe and stable operation. By means of BP neural network, radial basis function neural network and support vector machine, a new combined method of wind power prediction based on cooperative game theory is proposed. In the method, every single forecasting model is regarded as a member of the cooperative games, and the sum of square error of combination forecasting is taken as the result of cooperation. The result is divided among the members according to Shapley values, and then weights of combination forecasting can be obtained. Application results in an actual wind farm show that the proposed method can effectively improve prediction precision.

Measurement errors and correction of the UAT-2 ultrasonic anemometer

Two kinds of measurement errors have been observed in the recently developed UAT-2 ultrasonic anemometer.One is the flow distortion produced by a"blocking effect",and the other is the angle of attack caused by the vertical misalignment of the instrument.Here,we study these errors and discuss the possible correction methods.Via a wind tunnel experiment and numerical simulation,a 3D calibration matrix was developed to correct the"blocking effect".In the field test,the angle of attack was detected by an inclinometer settled on the reference plane of the anemometer,and the instrumental misalignment or tilt was corrected by a coordinate transformation.The combined use of an inclinometer and the proposed correction method may help find a new approach for vertical velocity correction.

Retrieval of middle and upper atmospheric wind based on non-full circular fringe recorded by Fabry-Perot Inteferometer

Fabry-Perot Interferometer(FPI) has been used widely for wind measurements of the middle and upper atmosphere.To date, most of FPIs have been based on full-closed circular fringe, which needs 15–25 min to obtain a group of wind velocity(zonal and meridional). However, it is hard to improve the temporal resolution because full-closed circular fringe in several directions cannot be easily imaged onto the same Charge-Coupled Device(CCD) with enough airglow intensity. In this paper, a data processing method is proposed for non-full circular fringe of FPI, which can support CCD with enough area of observations in several directions simultaneously. The method is focused on the center determination of non-full fringe. It includes radial cross-section, peak coordinate determination, and center calculation. Based on the calculated center, the fringe is annular summed. Then its radius is determined subsequently using Gaussian fitting. Finally, the wind is retrieved from the fringe radius. For validation, fringes from two ground-based FPIs were used, which are deployed in Kelan(38.71°N, 111.58°E) and Xinglong(40.40°N, 117.59°E) in China. The results retrieved from non-full fringes of FPIs were compared with that from full-closed circular fringe. The averaged wind deviation between them demonstrates reasonable difference with 5.38 ms^-(1) for 892.0 nm airglow emission, 5.81 ms^-(1) for 630.0 nm emission, and 3.03 ms^-(1) for 557.7 nm emission. Besides, wind results of Xinglong FPI are compared roughly with measurements of meteor radar which is deployed in Ming Tombs of Beijing(40.3°N,116.2°E). Good agreement demonstrates that this method is robust enough for FPI wind retrieval of mesosphere and thermosphere.