近于...

Founded in 1996, it has supplied equipments and technology support to hundreds of large or medium analogic/digital TV systems. Beijing Pace has always devoted itself to promote the development and application of high-level technology and products in professional field.

公司于1996年成立，十余年来已经成功地为国内近百个大中型模拟/数字有线电视系统提供成套设备和技术支持服务，始终致力于促进高端技术和产品在专业领域中的推广和应用。

The works in the project just done can be summarized as five respects.(1) A device was designed to fabricate the asymmetrical resonant cavities by a pendant drop. A series ARCs with variable parameters provides a valuable experimental method for investigating the characteristics of ARCs.(2) The relationship between the number of active modes and the shape parameters in an ARC was investigated. The experimental lasing threshold was compared with theoretical result, the good agreement between two shown that it was the decrease of the number of active modes in an ARC that decreased lasing threshold.(3) Dye lasing gain was used to enhance the signals of stimulated Raman scattering of the weak gain Raman modes in a circular cavity made by a pendant drop, the instantaneous SRS spectra of weak gain Raman modes in ethanol was obtained by this new method.(4) The SRS signals of minority compound in a binary chemical complex was obtained by using dye lasing gain method. The detection concentration of minority compound was reduced to an order compared with normal SRS method.(5) A cylindrical circular cavity was formed by a liquid jet, which was used to reduce the pump intensity required for laser induced plasma spectroscopy. The limit of detection of trace element in aqueous sample was greatly decreased by this new method.

我们设计并成功制作了使悬垂液滴连续变形的装置，用此装置可以方便地改变非圆对称谐振腔的几何参数，为ARCs的研究提供了一种有效的实验方法；研究了ARCs中活性模式数和变形参数间的变化规律，激光阈值的数值计算结果和激光辐射的实验结果作了比较，二者吻合的曲线说明ARCs中活性模式数量的减少是受激辐射放大阈值降低的原因；在由单元化合物构成的微型圆对称谐振腔中，首次尝试用"激光增益"增强弱增益拉曼模式的受激拉曼散射信号，获得了乙醇分子中弱增益拉曼模式的瞬态SRS光谱；在由二元混合物构成的微型圆对称谐振腔中，用染料的激光增益增强了少量化合物的SRS信号，把少量化合物的SRS信号探测浓度降低了近一个数量级，在SRS应用于瞬态过程的组份分析方面做了卓有成效的探索；用石英毛细管形成的稳定液拄构成拄形谐振腔，降低了激光诱导等离子体光谱需要的激励能量，有效地降低了水相样品的痕量元素分析极限，为LIPS应用于微量元素的化学分析开拓了一条新的技术路线。

The main advantages of the methodare that(1)this method is valid for all kinds of bifurcation pointswith the codimension ≤3;(2)it does not use any informations forsecond order derivatives and does not need the bifurcation point to beknown accurately in implementation;(3)it is sufficient to implementthe method that a standard continuation procedure is only used;and(4)derivation of the method is independent on the asymptotic expan-sions of the bifurcation solutions.

这种方法的主要优点是：(1)适应于一切余维数不超过3的分支点；(2)不需要任何二阶导数的信息，也不必精确地知道分支点的位置；(3)只需使用标准延拓软件就可以实现；(4)方法不依赖于分支解的渐近展式。

So the key of decreasing the resistance of Bag Filter should solve the problem of the filter media.

袋式除尘器系统压力损失来自于两部分，近80%的阻力来自于滤料的压力损失，其余约20%来自于除尘器的结构阻力，所以解决除尘器系统阻力的关键应从滤料入手。

The results show that the surface layer of the air-exposed ZrVFe getter is covered with H20, CO2 and hydrocarbons, both Zr and V exist in the oxidized state, and vanadium oxide starts to reduce at 200℃. The activation results in the enrichment of Zr on the getter surface and the formation of the metallic carbides. H2O, CO2 and hydrocarbons sequentially desorb from the surface with the increase of temperature. H2 is the main gas which desorbs above 200℃ and O2 is not discovered. ZrO2 is reduced to near-metallic or metallic state because O in ZrO2 leaves the getter surface through diffusing into getter bulk.

结果表明：暴露于过大气的吸气剂表面覆盖着H2O、CO2及碳氢化合物等，Zr和V主要以氧化态存在；在吸气剂加热激活过程中，V的氧化物在200℃开始还原；激活过程导致表面近金属态Zr的富集以及部分金属碳化物的生成；随着温度的升高，H2O、CO2及碳氢化合物逐渐从吸气剂表面脱附，在200℃以上，主要脱附气体为H2，整个激活过程未发现O2；ZrO2还原为近金属态或金属态，主要是由于ZrO2中的O通过向吸气剂内部扩散而离开吸气剂表面所致。

The application of the modified Rytov's method to the study of the optical-wave oblique propagation is discussed in this paper. The fluctuation index of the plane wave and the spherical wave is obtained.

将修正的Rytov方法推广应用于研究斜程传输问题，推导了平面波和球面波斜程传输时的闪烁指数，并根据ITU-R湍流大气结构模型，对平面波和球面波在不同传播高度、近地面风速、近地面大气结构常数、零内尺度以及非零内尺度下的闪烁指数进行了理论据导，做出了具体的数值分析。

Scape suberect, usually shorter than leaves, loosely bearing 6-12cm or more flowers; bracts 5mm long; pedicel including ovary 4cm long; flower light yellow-green, faintly fragrant like Osmanthus fragrans ; dorsal sepal nearly oblong, 4.5-6cmlong, 1.2-1.8cm wide, yellow-green ,base tinged purple-brown on back, lateral sepals oblique-oblong, slightly narrow, petals narrower than sepals, 5-12mm wide, light yellow-green, spotted purple-red at base; lip slightly short-clawed, 3-lobed, side lobes erect, striped purple-red, mid-lobe somewhat reflexed, waved at margin, disk pubescent above, with 2paralles lamellae, long-hairy.

花葶近直立，常短于叶，疏生6~12朵或更多朵；花苞片长约5mm ；花梗连子房长约4cm ；花浅黄绿色，稍有桂花香气；中萼片近矩圆形，长4.5~6cm ，宽1.2~1.8cm ，黄绿色，背面基部有紫褐色晕，侧萼片斜矩圆形，稍窄；花瓣比萼片窄，宽5~12mm ，浅黄绿色，基部有紫红色的小斑点；唇瓣略有短爪，3裂，侧裂片直立，具紫红色条纹，中裂片略反折，边缘波状，唇盘上表面被短柔毛，2条褶片平行，生长毛；合蕊柱须长，3~4.2cm 。

The lowest Fst value shows that less genetic variations exist among population of F.gracilipes whic is close to panmictic There is almost no genetic differentiation between populations of F.statice . Genetic similarity is 55.3%~ 65.2% between species of F.tataricum and its related species, which is close to the average level among species in seed plants.

这些种的近交繁育系数 F 值-0.54～-0.80，为随机交配的居群，杂合体过多；营养繁殖为主的金荞麦的FST值最高，相对较多的遗传多样性存在于居群间，长柄野荞麦相对较少的遗传多样性存在于居群间，更接近于自由交配。

The analysis shows that with given grid size higher accurate difference scheme can give higher resolutions with wider range of scales, or with given accuracy large grid size can be used for the higher accurate difference scheme. The second part is the numerical simulation of two-dimensional axisymmetric jet. The simulation results show the structure in the near field and the initial transition. In the near field, Kelvin-Helmholtz instability leads to the formation of vortex ring, and nonlinear growth leads to the merging of vortex ring. This is the main instability form. Under the assumption of axisymmetry and two-dimensional computing conditions, the results are applicable only in the near field.

第二部分采用高精度的差分格式对二维轴对称射流进行了数值模拟，模拟结果显示了射流流场结构和涡结构的发展过程，在射流流场近区，K-H失稳导致涡环的产生以及非线性效应的增长导致涡环的对并是射流失稳的主要形式；分析指出在轴对称假设下的射流数值模拟只适用于射流近区的分析。

The results of the simulation analysis and experiments indicate that the loss of ultraviolet scattering transmission in atmosphere is high because of the particle scattering and absorbing in solar-blind zone; that is, the received power can descend 20 dB with the distance increasing 10 times. Therefore, the ultraviolet scattering is fit for short range communication. In short range, the pulse extension due to scattering is at microsecond order and its influence for low and moderate bit rate communication systems is weak. Since the light output power of a single ultraviolet LED is low, a multi-LED array can be used to increase the transmit power and extend the communication range.

仿真分析与实验结果显示：日盲区紫外光在大气中散射传输时由于大气粒子的强烈散射与吸收，传输损耗较大，距离每增加10倍，接收功率下降20dB，因此日盲区紫外光大气散射通信适用于近距离通信场合；近距离传输时散射造成的光脉冲多径展宽为微秒量级，对中低速通信系统影响较小；单个紫外LED发光功率较低，可通过多个LED阵列来提高发射功率，增大通信距离。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。