圈养鲸豚类血常规和血液生化指标数值测定研究

动物的各种血液指标是判断动物健康状态和选择合格动物的重要标准。目前对鲸豚类的研究很多,但对于其正常状态下血液指标的基础数据指标测定国内外鲜有报道,也无行业标准。因此,对圈养鲸豚血液各方面基础数值进行全面、准确地测定,具有重要的理论参考价值和科研价值,同时也可为一些基础数据积累相对薄弱的单位在进行医疗处置时提供可信度较高的参考数据。

软质泡沫聚合材料硬度特性数值测定系统

硬度是一个衡量材料性能的重要物理量,是体现材料弹性、塑性、强度和韧性等力学性能的综合指标。主要从硬件及软件上讨论了针对软质泡沫聚合材料硬度的数字测试系统。该系统应用了STC12系列带A/D转换的单片机,高精度压力传感器以及可控电机,来保证测试的稳定性和高精度。实践证明,该系统满足GB/T 10807-2006/ISO 2439:1997要求,可广泛用于在国家标准要求的A法、B法、C法下对标准尺寸的海绵、泡沫等试样的硬度进行准确的测试。

不同甲烷检测仪器在新兴煤矿上隅角测定甲烷数值有偏差的原因分析

新兴煤矿11002工作面上隅角使用光干涉甲烷测定器、便携式甲烷检测报警仪及甲烷传感器测定的甲烷数值不一致,其中,便携式甲烷检测报警仪与甲烷传感器测定甲烷数据基本相同,但光干涉甲烷测定器测定数据与便携式甲烷检测报警仪和甲烷传感器测定数据相差近1.5%。通过使用不同单位的甲烷检测仪器进行测定比对、对空气中其他气体成分进行测定,并对现场气体取样进行分析,最终得出3种检测仪器测定数据有误差的原因是由于工作面上隅角氧气浓度偏低和二氧化碳浓度偏高导致光干涉甲烷测定器测定数值偏大所致,并有针对性地提出了光干涉甲烷测定器在低氧环境中检测甲烷数据的修正系数和在二氧化碳浓度偏高的环境中检测方法及相关措施,以解决类似的现场实际问题。

模糊数值测度的正则性

用模糊数空间的dp 度量刻划了局部紧T2 空间上模糊数值测试的正则性 ,证明了局部紧T2

颅内压监护的临床应用

颅内压(ICP)是神经外科临床中的一项重要指标,对疾病的诊断和判断颅脑损伤程度皆有参考价值.颅内压监护是采用传感器和监护仪测量颅内压以观察颅内动态变化的方法,Guillaume于1951年最先在实验中应用颅内压监测,1960年Lundberg首先在临床上使用[1].ICP监护之所以能准确了解ICP变化的情况,是因为它能及时准确地观察到每个瞬间颅内压的真实情况,对病情能作出正确的判断,所以亦将ICP监护称之为颅脑的"早期报警系统".

The comprehensive measure model for urban traffic congestion based on value function

According to the distribution characteristics of traffic congestion in time and space, a measure index system of urban traffic congestion is set up based on the spatial and temporal distribution. Based on the analysis of the main characteristics of traffic congestion and the generation process of traffic congestion, the measure model for urban traffic congestion is constructed by the value function. Moreover, based on the measure values of traffic congestion in urban road networks with defined different levels, a method to prevent and control traffic congestion is designed. The application results confirm that the proposed method is feasible in comprehensive measures for urban traffic congestion and they are consistent with the results of other methods. The measuring results can therefore reflect the actual situation. The comprehensive measure model is scientific and the process is simple, and it has wide application prospects and practical value.

Stability of finite difference numerical simulations of acoustic logging-while-drilling with different perfectly matched layer schemes

In acoustic logging-while-drilling （ALWD） finite difference in time domain （FDTD） simulations, large drill collar occupies, most of the fluid-filled borehole and divides the borehole fluid into two thin fluid columns （radius -27 mm）. Fine grids and large computational models are required to model the thin fluid region between the tool and the formation. As a result, small time step and more iterations are needed, which increases the cumulative numerical error. Furthermore, due to high impedance contrast between the drill collar and fluid in the borehole （the difference is 〉30 times）, the stability and efficiency of the perfectly matched layer （PML） scheme is critical to simulate complicated wave modes accurately. In this paper, we compared four different PML implementations in a staggered grid finite difference in time domain （FDTD） in the ALWD simulation, including field-splitting PML （SPML）, multiaxial PML（M- PML）, non-splitting PML （NPML）, and complex frequency-shifted PML （CFS-PML）. The comparison indicated that NPML and CFS-PML can absorb the guided wave reflection from the computational boundaries more efficiently than SPML and M-PML. For large simulation time, SPML, M-PML, and NPML are numerically unstable. However, the stability of M-PML can be improved further to some extent. Based on the analysis, we proposed that the CFS-PML method is used in FDTD to eliminate the numerical instability and to improve the efficiency of absorption in the PML layers for LWD modeling. The optimal values of CFS-PML parameters in the LWD simulation were investigated based on thousands of 3D simulations. For typical LWD cases, the best maximum value of the quadratic damping profile was obtained using one do. The optimal parameter space for the maximum value of the linear frequency-shifted factor （a0） and the scaling factor （β0） depended on the thickness of the PML layer. For typical formations, if the PML thickness is 10 grid points, the global error can be reduced to 〈1% using the optimal PML parameters, and the error will decrease as the PML thickness increases.

A fast explicit finite difference method for determination of wellhead injection pressure

A fast explicit finite difference method (FEFDM),derived from the differential equations of one-dimensional steady pipe flow,was presented for calculation of wellhead injection pressure.Recalculation with a traditional numerical method of the same equations corroborates well the reliability and rate of FEFDM.Moreover,a flow rate estimate method was developed for the project whose injection rate has not been clearly determined.A wellhead pressure regime determined by this method was successfully applied to the trial injection operations in Shihezi formation of Shenhua CCS Project,which is a good practice verification of FEFDM.At last,this method was used to evaluate the effect of friction and acceleration terms on the flow equation on the wellhead pressure.The result shows that for deep wellbore,the friction term can be omitted when flow rate is low and in a wide range of velocity the acceleration term can always be deleted.It is also shown that with flow rate increasing,the friction term can no longer be neglected.

俄霍布拉克煤矿工作面上隅角瓦斯浓度误差探讨

为了解决俄霍布拉克煤矿5106工作面上隅角使用光瓦斯检测仪与甲烷传感器、气相色谱法测量的瓦斯浓度结果不一致的问题,通过现场测试和现场取气样在实验室进行分析的方法,研究了低氧浓度对光瓦斯检测仪测试结果的影响。研究表明,低氧浓度环境下,光瓦斯检测仪测量结果比甲烷传感器、气相色谱法测量的瓦斯浓度高,且氧气浓度越低,测量结果误差越大,其原因为氧气浓度偏低时,氮气等气体浓度增高,导致被测气体折射率增大,使测定结果偏大。通过实验可以测得修正系数,对误差结果进行修正,并有针对性地提出了降低3种检测仪器测量误差的措施,解决了现场实际问题。

Determination of Wind Pressure Coefficients for Arc-Shaped Canopy Roof with Numerical Wind Tunnel Method

In this paper,the wind load on an arc-shaped canopy roof was studied with numerical wind tunnel method(NWTM) .Three-dimensional models were set up for the canopy roof with opened or closed skylights.The air flow around the roof under wind action from three directions was analysed respectively.Wind pressure coefficients on the canopy roof were determined by NWTM.The results of NWTM agreed well with those of wind tunnel test for the roof with opened skylights,which verified the applicability and rationality of NWTM.The effect of the closure of skylights was then investigated with NWTM.It was concluded that the closure of the skylights may increase the wind suction on the top surface of the roof greatly and should be considered in the structure design of the canopy roof.

Experimental and Numerical Analysis of Rock Block Stability Using a Remotely Positioned Laser Doppler Vibrometer

This paper examines a new method of evaluating the stability of a rock slope using a remotely positioned LDV （laser Doppler vibrometer）. We conducted an experiment using physical models and performed a numerical analysis to evaluate the new method. The physical model included： （l） concrete blocks on an artificial soil slope with two block sizes and three slopes; （2） concrete blocks bonded to the concrete base with different contact area. The LDV measurements agreed with conventional seismometer measurements. The dominant frequency of the blocks varied with the stability and dominant frequency and the amplitude varied with the block size. The numerical model was used to examine a concrete block adhered to a concrete base with different contact areas. The dominant frequency of the blocks determined using the numerical model agreed with those obtained from the physical experiments. We analyzed different sized blocks to examine the scaling effects. The dominant frequency of the blocks was inversely related to the block size. These results demonstrated the effectiveness of LDV for evaluating the stability of rock slopes and cleared the block size scaling effects.

Determination of protection range of mining upper protective layers and its numerical simulation

Aiming at the limitation of the traditional method for determination of protection region, combined with the actual situation of a mine, a new method for determination of protection region was put forward （including the protection of working face layout and development direction）, that is, gas flow observation analysis on the spot and gas content contrast method. The protection region was determined by gas flow observation analysis, gas content contrast, and computer numerical simulation combined with engineering practice. In the process of gas content test, the fixed sampling method ＂big hole drill reaming, small orifice drill rod connected with core tube＂ was employed. The results show that the determined protection region is in accordance with the actual site situation. The fixed sampling method ensures the accuracy of gas measurement of gas content.

The experiment study on slippage effect of the coal-bed methane transfusion

When the gas flow in the compact porous medium at low speed,it has slippage effect which is caused by the gas molecular collision whit the solidskeleton.Using the gas transfusion slippage effect at researching the coal bed transfusion rule,established the transfusion mathematical model of the coal bed which had considered the slippage effect. Observing the influence of the different toencircle presses,the different hole press and the different actual stress to the coal bed by using the three-axles permeameter.Thus sum- marized the transfusion rule of the coal bed.The experiment indicates that the bigger of the surrounding pressure,the more obvious of the slippage effect.At the same condition of axial pressure and the surrounding pressure,with the increase of the hole pressure,the coal permeability became bigger and then smaller.The coal body effective tress and the permeability curve nearly also has the same change tendency.Thus we can draws the conclusion that the transfusion of the gas in the coal bed generally has the slippage effect.

A Quantitative Structure Property Relationship for Prediction of Flash Point of Alkanes Using Molecular Connectivity Indices

Many structure-property/activity studies use graph theoretical indices, which are based on the topological properties of a molecule viewed as a graph. Since topological indices can be derived directly from the molecular structure without any experimental effort, they provide a simple and straightforward method for property prediction. In this work the flash point of alkanes was modeled by a set of molecular connectivity indices （Х）, modified molecular connectivity indices （ ^mХ^v ） and valance molecular connectivity indices （ ^mХ^v ）, with ^mХ^v calculated using the hydrogen perturbation. A stepwise Multiple Linear Regression （MLR） method was used to select the best indices. The predicted flash points are in good agreement with the experimental data, with the average absolute deviation 4.3 K.

平炉钢中〔%Al_s〕~2〔%∑O〕~3值的测定

本文测定了平炉冶炼过程,铝的表观脱氧常数—S=[%Al_s]~2[%ΣO]~3,其值为:S=(5.2107±1.1861)×10^(-12),N=12。钢中未被排尽的脱氧产物,是导致[%∑O]较a_([o]平)大一个数量级的原因。[%O]受控于(%FeO),并使 Al—O 处于非平衡状态。

Numerical predictions and stability analysis of cavitating draft tube vortices at high head in a model Francis turbine

Draft tube vortex is one of the main causes of hydraulic instability in hydraulic reaction turbines,in particular Francis turbines.A method of cavitation calculations was proposed to predict the pressure fluctuations induced by draft tube vortices in a model Francis turbine,by solving RANS equations with RNG k-turbulence model and ZGB cavitation model,with modified turbulence viscosity.Three cases with different flow rates at high head were studied.In the study case of part load,two modes of revolutions with the same rotating direction,revolution around the axis of the draft tube cone,and revolution around the core of the vortex rope,can be recognized.The elliptical shaped vortex rope causes anisotropic characteristics of pressure fluctuations around the centerline of the draft tube cone.By analyzing the phase angles of the pressure fluctuations,the role of the vortex rope as an exciter in the oscillating case can be recognized.An analysis of Batchelor instability,i.e.instability in q-vortex like flow structure,has been carried out on the draft tube vortices in these three cases.It can be concluded that the trajectory for study case with part load lies in the region of absolute instability(AI),and it lies in the region of convective instability(CI)for study case with design flow rate.Trajectory for study case with over load lies in the AI region at the inlet of the draft tube,and enters CI region near the end of the elbow.

Extraction of line-of-sight ionospheric observables from GPS data using precise point positioning

Here we propose a method for extracting line-of-sight ionospheric observables from GPS data using precise point positioning(PPP).The PPP-derived ionospheric observables(PIOs) have identical form with their counterparts obtained from leveling the geometry-free GPS carrier-phase to code(leveling ionospheric observables,LIOs),and are affected by the satellite and receiver inter-frequency biases(IFBs).Based on the co-location experiments,the effects of extracting error arising from the observational noise and multipath on the PIOs and the LIOs are comparatively assessed,and the considerably reduced effects ranging from 70% to 75% on the PIOs with respect to the LIOs can be verified in our case.In addition,based on 26 consecutive days' GPS observations from two international GNSS service(IGS) sites(COCO,DAEJ) during disturbed ionosphere period,the extracted PIOs and LIOs are respectively used as the input of single-layer ionospheric model to retrieve daily satellite IFBs station-by-station.The minor extracting errors underlying the PIOs in contrast to the LIOs can also be proven by reducing day-to-day scatter and improving between-receiver consistency in the retrieved satellite IFBs values.

A branching particle system approximation for nonlinear stochastic filtering

The optimal filter 7r = {π,t ∈ [0, T]} of a stochastic signal is approximated by a sequence {Try} of measure-valued processes defined by branching particle systems in a random environment （given by the observation process）. The location and weight of each particle are governed by stochastic differential equations driven by the observation process, which is common for all particles, as well as by an individual Brownian motion, which applies to this specific particle only. The branching mechanism of each particle depends on the observation process and the path of this particle itself during its short lifetime δ = n-2α, where n is the number of initial particles and ~ is a fixed parameter to be optimized. As n → ∞, we prove the convergence of π to πt uniformly for t ∈ [0, T]. Compared with the available results in the literature, the main contribution of this article is that the approximation is free of any stochastic integral which makes the numerical implementation readily available.

Empirical Model for the Quantitative Prediction of Losses of Radial Fans based on CFD Calculations

In a classical layout process of a fan the quantity of losses is estimated as a sum and expressed in the overall efficiency rote However the characteristic of the pressure rise, the losses and the efficiency rate beside the design point is not known. Against this background a numerical model was developed to calculate quantitative values of occurring losses at radial fan impellers at an early stage in the design process. It allows to estimate the pressure rise and efficiency rate of a given fan geometry at and beside the design point. The physics of losses are described in literature, but obtaining quantitative values is still a challenge. As common in hydraulic theory the losses are calculated with analytic formulas supported by coefficients and efficiency rates, which have to be determined empirically. This paper shows the method how to determine the coefficients for a given radial fan. Therefore a representative radial fan with backward curved blades was designed in reference to classical design guidelines. Performance measuring was done conform to ISO 5801. The flow was calculated at 8 different operation points using CFD methods. The RANS equations are solved by using the SST-k-omega turbulence model. The flow do- main consists of one blade section including inlet channel and outflow chamber. Spatial discretization is done by a block-structured mesh of approx. 1.8 million cells. Performance data show a very good agreement between measurement and calculation.