风电场并网电能质量分析与评估

随着大型风电场不断接入系统以及变速风电机组的广泛应用,由其并网所引起的电网电能质量问题,越来越受到人们的关注。结合某风电场的接入实例,建立了永磁直驱式风机模型,并结合该区电网已有数据及风机厂家技术参数,对其并网引起的电压偏差、电压变动、电压闪变及谐波等电能质量问题进行了分析与评估,对今后的风电场并网电能质量评估工作具有一定的参考意义。

渤海湾X油田气云区地震资料关键处理技术研究

受郯庐断裂带活动影响,渤海湾盆地X油田气云区广泛发育。地震资料受气云影响严重,在油田主体区地震成像效果较差,无法准确描述构造和储层特征。在现有纵波资料的基础上,开展了气云区关键处理技术研究,包括Q值层析反演气云区能量吸收衰减补偿技术、潜波层析反演浅层速度建模技术等,有效解决了气云区地震能量吸收衰减严重和浅层难以实现高精度速度建模的问题,同时结合其它配套处理技术,如匹配追踪插值数据规则化技术、水层多次波压制+广义地表多次波压制技术,形成有针对性的有效处理技术流程。本工区处理结果表明,该处理流程明显提高了气云区地震资料的成像质量。

气云影响下浅水三角洲储层描述关键技术及应用

渤海海域南部渤中34地区新近系明下段发育浅水三角洲沉积,储层纵横向变化快,且局部区域受气云影响,地震资料品质低,储层描述难度大。针对研究区浅水三角洲储层发育特征,优化了地震采集参数与震源设计方案,实现了高密度、高覆盖的地震数据采集。引入气云区优势道集模拟技术,依据AVO规律,利用叠前道集中受气云影响小、成像质量高的道集模拟受气云影响大、成像比较差的道集,从而减少了气云对地震资料成像的影响范围;采用潜波层析反演技术,提高速度模型精度,有效改善了气云区内的成像质量。总结了浅水三角洲不同叠置样式砂体的沉积特征,利用等时地层切片、气云区外分流河道砂体发育参数约束气云区影响下河道展布,实现了储层的精细描述。本文方法在渤中34区域应用效果较好,气云区内部新增探明储量300万方,新增开发井10口,新增可采储量82万方。

未来服装预测

据专家预测,未来服装将出现十大变化: 一、永无皱痕:用特殊织物加工成的服装,无论放在何处,穿到身上皱痕将立即消失。 二、免于洗涤:具有良好和持久的特殊化学反应去污能力,使从事易污染工作行业的人员免洗衣服。

航鹰的奋起和沉寂

曾因《金鹿儿》、《东方女性》等作品在文坛上引起一定反响的中年女作家航鹰在八十年代初期以清新秀丽的文笔为我们塑造了一群东方女性的典雅圣洁的形象,绚烂多姿地绘制了一幅幅五彩缤纷的工笔画、写意画,为当时尚较寂默冷清的文坛添加了些许喧响和热量。在人类心理活动的海洋中,有深邃绵长的老年人心理,有激越澎湃的青年人心理,有天真幼稚的儿童心理,也有豪放粗犷的男子汉心理。航鹰的笔端置放于女子心理上。

Three-component seismic data in thin interbedded reservoir exploration

We present the first successful application of three-component seismic data to thin interbedded reservoir characterization in the Daqing placanticline of the LMD oilfield. The oilfield has reached the final high water cut stage and the principal problem is how to recognize the boundaries of sand layers that are thicker than 2 m. Conventional interpretation of single PP-wave seismic data results in multiple solutions, whereas the introduction of PS-wave enhances the reliability of interpretation. We analyze the gas reservoir characteristics by joint PP- and PS-waves, and use the amplitude and frequency decomposition attributes to delineate the gas reservoir boundaries because of the minimal effect of fl uids on S-wave. We perform joint inversion of PP- and PS-waves to obtain V P/V S, λρ, and μρ and map the lithology changes by using density, λρ, and μρ. The 3D–3C attribute λρ slices describe the sand layers distribution, while considering the well log data, and point to favorable region for tapping the remaining oil.

A Havelock Source Panel Method for Near-surface Submarines

A panel method is described for calculating potential flow around near-surface submarines. The method uses Havelock sources which automatically satisfy the linearized free-surface boundary condition. Outputs from the method include pressure field, pressure drag, wave resistance, vertical force, trim moment and wave pattern. Comparisons are made with model tests for wave resistance of Series 58 and DARPA SUBOFF hulls, as well as with wave resistance, lift force and trim moment of three length-to-diameter variants of the DSTO Joubert submarine hull. It is found that the Havelock source panel method is capable of determining with reasonable accuracy wave resistance, vertical force and trim moment for submarine hulls. Further experimental data are required in order to assess the accuracy of the method for pressure field and wave pattern prediction. The method is implemented in the computer code“HullWave”and offers potential advantages over RANS-CFD codes in terms of speed, simplicity and robustness.

Energy Potential of Canton of Tuzla （Bosnia and Herzegovina） and Possibilities of Its Rational Economic-Industrial Exploitation

Canton of Tuzla takes cca 2,650 km2 area of north-east Bosnia and Herzegovina. Economic structure of this geographic region, traditionally, dominates the energetic. In the last few years, this part Bosnia and Herzegovina produces near 4 million tons of coal, which is over 40% of coal producing in Bosnia and Herzegovina. Over 80% produced coal is burning away in local thermal power plants, where is producing cea 3,000 GWh electro energy. Today, Canton of Tuzla is starting the restructuration process of energetic sector towards improving its efficiency. Therefore, we expect the similar problems, as in other transition regions （e.g., closing some coal pits, ecology, reduction of labour, etc.）. Also, we should take all well known fact that investing in energy capacities last over five years, and in this propriety time, here will not be any adequate thermal power plants as a relevant substitute. According to European Energy Charter, south-east Europe is forced to give up from technological outdated and economic inefficiency productive capacities, so the situation is becoming more complicated. For its welfare, it is essential to speed up all investment and reconstruction by using all available resources, as domestic, as foreign. Hence, this paper presents technical-technological and economic analysis of the energy problems in Canton of Tuzla, and of course, it＇s possible solving in near future.

A-E equation of potential field transformations in the wavenumber domain and its application

A shift sampling theory established by author （1997a） is a generalization of Fourier transform computation theory. Based on this theory, I develop an Algorithm-Error （A-E） equation of potential field transformations in the wavenumber domain, which not only gives a more flexible algorithm of potential field transformations, but also reveals the law of error of potential field transformations in the wavenumber domain. The DFT0η η（0.5, 0.5） reduction-to-pole （RTP） technique derived from the A-E equation significantly improves the resolution and accuracy of RTP anomalies at low magnetic latitudes, including the magnetic equator. The law （origin, form mechanism, and essential properties） of the edge oscillation revealed by the A-E equation points out theoretically a way of improving the effect of existing padding methods in high-pass transformations in the wavenumber domain.

Is Wave Power a Promising Renewable in the UK Energy Market?——UK Wave Energy Market Analysis

This paper introduces the potential of wave energy and the market potential of wave power in the United Kingdom.It presents the current wave power market in the UK by analyzing in detail the market size, key competitors,market price,financial supports and current technologies.On this basis,the paper gives a prediction on the wave power development in the UK,including market trend,technology trend,as well as opportunities and risks in the development.Finally the paper concludes that the UK wave energy market is growing healthily and prosperously,and submits some recommendations to new entrants.

Improvement Methods for Genetic Evaluation of Hanwoo Cows

A total of 1,101 heads were used to improve the selection of superior cows in Gangwon regional Hanwoo. Characteristics of each cow were analyzed using ultrasound evaluation and trace of reproductive potential. A comparison of live carcass traits classified by parity was analyzed in all characteristics. The results of the comparison showed all characteristic increased rapidly after the 2nd parity, and decreased after the 4th parity （P 〈 0.01）. The result of comparison classified by the group showed a tendency, whereas Back Fat Thickness Ultrasound （BFTU） and P8 Fat Thickness Ultrasound （P8-FTU） were significant （P 〈 0.01） thinnest in Pedigree group and using a lot of reproduction in advanced group. Also, we made comparisons of the cow＇s calves on the carcass traits among the group. High quality calves of the pedigree group showed 30.77%. These are the highest carcass traits in meat quality grade above 1＋ and yield grade above A. Frequency of fertilization failure per rump fat thickness showed a significantly （P 〈 0.0｜） higher difference. The average frequency of fertilization failure demonstrated 1.11 times of experimental Hanwoo cows. In the analysis, frequency of fertilization failure appeared 0.9 times at rump fat thickness below 5 mm. However, it is higher than average above 5 mm. The result of the study will be used to improve cows, select optimum semen, as well as contribute to the improvement of farms income.

Harmfulness of Leaf Miners （Agromyzidae） on Winter Wheat Plantations in Poland

The aim of the study was to determine the harmfulness of leaf miners and their species composition on winter wheat for the improvement of methods to control them. In order to determine the dates of the treatments, it was necessary to catch adult flies. The researchers used yellow 25 x 40 cm sticky traps placed on three control plots to catch the adults. Monitoring of cereal leaf miners flights in winter wheat was carried out in Babor6wko （greater Poland voivodeship）. Yellow traps were placed above the tops of wheat during vegetation period. The number of damaged wheat stems was recorded. Fluctuations in weather conditions during the research affected the dynamics of leaf miner flies considerably. The maximum flights of leaf miner flies on winter wheat crops in years of the studies took place in May. The dynamics of leaf miners flights were different in growing season 2008 and 2009. The most common species were： Chromatomyia nigra （Ztt.）, Chromatomyia fuscula （Ztt.） and Poemyza superciliosa （Ztt.）. It was also discovered that the species composition of Agromyzidae damaging the winter wheat, changes in particular years. The results differ from the results of the previous research, which the dominant species were Phytomyza nigra （Mg.） and Agromyza ambiqua （FII.）.

Wave Attenuation Properties of Double Trapezoidal Submerged Breakwaters on Flat-Bed

This paper investigates the wave attenuation properties of the double trapezoidal submerged breakwaters on the flat-bed by conducting physical experiments subjected to linear and cnoidal incident waves.The method of Goda's two points is used to separate the heights of incident,reflected and transmitted waves based on the experimental data.The possible factors affecting the wave attenuation properties of the double trapezoidal submerged breakwaters(i.e.,the relative submerged water depth,relative breakwater spacing,wave steepness and relative wave height) are investigated with respect to the reflection and transmission coefficients.The results show that there is a range,within which the breakwater spacing has little impact on the reflection coefficient,and the transmission coefficient tends to be a constant.The influence of the wave steepness is reduced while the breakwater spacing is too large or too small.Within the range of the relative wave height tested in this study,the reflection and transmission coefficients increase and decrease with the relative wave height,respectively.The double trapezoidal submerged breakwaters model indicates a good attenuation effect for larger wave steepness,big relative wave height and within the range of the relative breakwater spacing between 12.5 and 14 according to linear and cnoidal waves.The changes of wave energy spectra between the double submerged breakwaters on the flat-bed are investigated by the fast Fourier transform(FFT) method,showing that wave energy dissipation can be reached more effectively when the relative breakwater spacing is 12.5.

用折线法分析一种自动屏极调幅——Ⅱ

图表及应用的参数从上面列举的公式,我们将结果示於图1,图2（θ,θg）,图3（θg,r）,图4（θg,Ug）,图5（θ,Ug）,图6（Ug,Ua）,图7（Ug,Ea）和图8(Ug,Eg—Eg0)。图中用折线法摹拟RCA—880的特性。880与12A相似,采用的参数如下[註9]:

意象杨家埠

屋里有一只风筝,在门帘开阖的微风中轻轻摆动。那是一只青灰色的软翅蝴蝶风筝,摇摇曳曳挂在里间门框的上面。门帘里间便是爷爷奶奶的通铺大炕了。那是打开无数童年回忆的窗口……

Volume growth for gradient shrinking solitons of Ricci-harmonic flow

In this paper,we derive an estimate on the potential functions of complete noncompact gradient shrinking solitons of Ricci-harmonic flow,and show that complete noncompact gradient shrinking Ricci-harmonic solitons have Euclidean volume growth at most.

Large second-harmonic vortex beam generation with quasi-nonlinear spin–orbit interaction

A harmonic vortex beam is a typical vector beam with a helical wavefront at harmonic frequencies(e.g.,second and third harmonics). It provides an additional degree of freedom beyond spin-and orbitalangular momentum, which may greatly increase the capacity for communicating and encoding information. However, conventional harmonic vortex beam generators suffer from complex designs and a low nonlinear conversion efficiency. Here, we propose and experimentally demonstrate the generation of a large second-harmonic(SH) vortex beam with quasi-nonlinear spin–orbit interaction(SOI). Highquality SH vortex beams with large topological charges up to 28 are realized experimentally. This indicated that the quasi-angular-momentum of a plasmonic spiral phase plate at the excitation wavelength(topological charge, q) could be imprinted on the harmonic signals from the attached WS2 monolayer. The generated harmonic vortex beam has a topological charge of l_(n)= 2 nq(n is the harmonic order). The results may open new avenues for generating harmonic optical vortices for optical communications and enables novel multi-functional hybrid metasurface devices to manipulate harmonic beams.

Predicting Potential Geographic Distribution of Tibetan Incarvillea younghusbandii Using the Maxent Model

Incarvillea younghusbandii is a well-known Tibetan medicinal plant with considerable development and research value distributed widely throughout the Tibetan plateau.It is important to study spatial distribution patterns of the plant in order to develop effective protection measures.Based on field survey work and environmental data, the potential geographic distribution of Incarvillea younghusbandii was delineated using a Maximum Entropy (Maxent)model with 28environmental variables that screened for climate,topography,human activity and biological factors.Our results showed that the main geographic range of Incarvillea younghusbandii included the valley between the Yarlung Zangbo river and the Duoxiong Zangbo river,the valley in the middle section of the Himalaya Mountains,and the area between the north side of the east section of the Himalayas and the south bank of the middle reach of the Yarlung Zangbo river.Distribution may spread to parts of the eastern Himalayas.The Jackknife test indicated that soil types,ratio of precipitation to air temperature,extreme atmospheric pressure differences and annual precipitation were the most important predictive factors for the model,while other variables made relatively small contributions.