气流冲击造型线计算机监控系统

介绍了一套气流冲击造型线计算机监控系统的画面组成及功能，以用其实现对生产线运行进行监视、故障报警和生产管理。

BMD气流冲击造型线型砂质量的控制

本文在保证型砂性能的前提下，从经济方面考虑，论证了以回用覆膜砂代替新砂的可能性，从而使新砂加入量由3-5%降为0.25%，年可节约新砂4000t，同时对型砂出现质量问题所涉及的重要指标的控制予以阐述。

BMD气流冲击造型线的使用

东风朝阳柴油机公司铸造一厂，从德国进口ＢＭＤ气流冲击造型线，经广大工程技术人员的努力，目前已经可以熟练地运行设备并处理运行中出现的故障。该厂６１系列和４１系列两大系列柴油机缸体和缸盖的生产主要由这条线承担。现介绍该线的组成、工艺流程及特点。

铸钢件气流冲击造型自动线工艺

介绍了生产铸钢件的气流冲击造型自动线的工艺分析主布置。该造型线使用粘土湿型砂及耐火制品的浇注系统，砂型不喷涂料，所产铸钢件达到了产品质量要求。造型线采用了开放式布置，满足了间歇供应钢水和铸件冷却时间长的要求。

储粮通风气流运动研究

本文报道了粮堆气流运动的研究方法和结果,研究结果表明,获得的气流分布图,不仅能反映粮堆内部杂质情况,气流运动情况,气流穿过粮堆任一点所需的时间,还能反映粮堆内部管道上各空气分配器的风量分配情况。因此,它为比较不同通风系统性能的优劣,选择推荐较好的通风系统提供了可靠的依据。通过该研究方法和结果,可确定粮仓通风的途径比率,从而为储粮通风的风网布局,提供了理论和实践依据。

力争上游 有效稀释——雷火双神山病房气流组织刍议

为改善病房内通风效果,降低医护人员感染的风险,对雷神山、火神山医院病房的通风系统进行分析,并提出改进意见。提出将层式通风应用于隔离病房通风系统中,通过CFD模拟并结合实验对其通风效果进行验证。结果表明,层式通风使医护人员处于呼吸区上游,可有效降低医护人员呼吸区污染物浓度,提高病房呼吸区换气效率,从而降低医护人员感染的风险。

用于气流粉碎机的超音速喷管设计研究

针对气流粉碎机上超音速喷管的使用特点 ,根据超音速风洞喷管设计的一般原理以及三元特征线理论和附面层修正的理论 ,提出了一种实用的三元轴对称超音速喷管的设计方法。本方法以喷管的过中心轴的半截面为研究对象 ,对收缩段、扩张段分别进行设计。根据设计制成样品 ,经实验验证出口马赫数达到设计要求 ,可用于气流粉碎。

S5-135U型可编程序控制器在BMD铸造生产线中的应用

BMD造型线是东风朝阳柴油机公司从公司从德国引进的自动化气流冲击造型线，该线结构紧凑，布置合理，生产效率高，全线采用S5－135U型可编程序控制器集中控制，性能稳定，工作可靠。

CAS面的某些几何特征对风阻系数的影响分析

汽车风阻系数是影响油耗的一个重要技术参数,本文基于某欧系轻型商用客车模型,对压差阻力贡献量较大的部位分析对风阻系数的影响,包括车头前端形状、发动机罩盖板与挡风玻璃之间的夹角和汽车尾部的上下形状等。分析结果表明车头前端形状对风阻系数贡献不大,发动机罩盖板与挡风玻璃之间的夹角和汽车尾部的上下形状对风阻系数由较大的影响。

我国铸造机械的现状与发展

1.铸造机械的现状 铸造机械是基础机械的基础,机械工业如拖拉机、机床、汽车等行业所使用的铸件占自重的40％～80％之多,我国铸件年产量约1000万吨左右。预测到2000年产量可达1339万吨,并对铸件质量提出相应的高要求。 近年由上级下达并开展了《铸造设备与工艺采用微电子技术发展研究和预测》。

A Tangential Wind Profile for Simulating Strong Tropical Cyclones with MM5

A new tangential wind profile for simulating strong tropical cyclones is put forward and planted into the NCAR- AFWA tropical cyclone bogussing scheme in MM5. The scheme for the new profile can make full use of the information from routine typhoon reports, including not only the maximum wind, but also the additional information of the wind speeds of 25.7 and 15.4 ms-1 and their corresponding radii, which are usually provided for strong cyclones. Thus, the new profile can be used to describe the outer structure of cyclones more accurately than by using the earlier scheme of MM5 in which on- ly the maximum wind speed is considered. Numerical experimental forecasts of two strong tropical cyclones are performed to examine the new profile. Results show that by using the new profile the prediction of both cyclones’ intensity can be obvi- ously improved, but the effects on the track prediction of the two cyclones are different. It seems that the new profile might be more suitable for strong cyclones with shifted tracks. However, the conclusion is drawn from only two typhoon cases, so more cases are needed to evaluate the new profile.

Study of Rotor Spun Basofil/Cotton Blended Yarn Quality Characteristics during Optimisation of Processing Parameters

Yarn quality characteristics are affected by processing parameters. A 36 tex rotor spun yarn of 50/50 Basofil/ cotton （B/C） blended yarn was spun, and the spinning process optimised for rotor speed, opening roller speed and twist factor. Selected yarn characteristics were studied during the optimization process. During the optimizations process yarn elongation and hairiness reduced with increase in rotor speed. Tenacity increased with increase of rotor speed. The increase in TF caused tenacity and CV of count to increase up to a peak and then started to decrease with further increase of TF.While TF caused an increase in yarn hairiness, elongation decreased to a minimum level and then started to increase with further increase of TF. CV of count and hairiness increased with increase in opening roller speed, but tenacity and elongation decreased with increase in opening roller speed. The optimization process yielded the optimum levels for rotor speed, opening roller speed and twist factor （TF） as 45,000 rpm, 6,500 rpm and 450 respectively. As per uster Standards the optimum yam showed good results for CV of count, CV of tenacity and thin places/km.

A case study of cold-seasonthundersnow in Beijing

The characteristics of local thundersnow at ne spatiotemporal scale on 9 and 10 November 2009 in Beijing were analyzed,using wind pro ler,microwave radiometer,automatic weather station,Doppler weather radar,and satellite data.Furthermore,the causes of winter convection are discussed.The results showed that it was reflux weather.The cause of the thunder and lightning was the elevated convection above the lower cold and dry air,and the trigger for convection was the short wave trough and convergencein the middle level.This thundersnow event developed from monsoon-like long-lasting water vapor transport at 850 hPa from the South China Sea along with strong instability of,and convergence in,the conveyor layer.

Using Path Analysis to Identify the Influence of Climatic Factors on Spring Peak Flow Dominated by Snowmelt in an Alpine Watershed

Spring snowmelt peak flow （SSPF） can cause serious damage. Precipitation as rainfall directly contributes to the SSPF and influences the characteristics of the SSPF, while temperature indirectly impacts the SSPF by shaping snowmelt rate and determining the soil frozen state which partitions snowmelt water into surface runoff and soil infiltration water in spring. It is necessary to identify the important and significant paths of climatic factors influencing the SSPF and provide estimates of the magnitude and significance of hypothesized causal connections between climatic factors and the SSPF. This study used path analysis with a selection of five factors - the antecedent precipitation index （API）, spring precipitation （SP）, winter precipitation as snowfall （WS）, 〈0℃ temperature accumulation in winter （[ATNI）, and average 〉0℃temperature accumulation in spring （AT） - to analyze their influences on the SSPF in the Kaidu River in Xinjiang, China. The results show that {ATN}, AT and WS have a significant correlation with the SSPF, while API and SP do not show a significant correlation. AT and WS directly influence the SSPF, while as the influence of[ATN] on SSPF is indirect through WS and AT. The indirect influence of [ATN[ on SSPF through WS accounts for 69% of the total influence of [ATN] on SSPF. Compared to the multiple linear regression method, path analysis provides additional valuable information, including influencing paths from independent variables to the dependent variable as well as direct and indirect impacts of external variables on the internal variable. This information can help improve the description of snow melt and spring runoff in hydrologic models as well as the planning and management of water resources.

纺纱系统对针织物表面抗起球的影响

本论文主要研究了由气流纺纱线(OE)和环锭纺纱线(RS)制成的针织物的抗起球性。采用马丁代尔磨损及起球方法来评价试样的起球性。分析了各种纺纱系统对于针织物抗起球性的影。利用T试验法比较了两种纱线制成的针织物的平均起球速率。

Numerical modeling airflow in soil with impact of groundwater

In order to simulate the airflow in anhydrous case and the water-air flow in groundwater case, a numerical model of airflow in soil was developed. For the nonlinearity of the governing partial differential equation, the corresponding discretization and linearization methods were given. Due to the mass transfer between air-phase and water-phase, phase states of the model elements were constantly changing. Thus, parameters of the model were divided into primary ones and secondary ones, and the primary variables changing with phase states and the secondary variables can be obtained by their functional relationship with the primary variables. Additionally, the special definite condition of this numerical model was illustrated. Two examples were given to simulate the airflow in soil whether there was groundwater or not, and the effectiveness of the numerical model is verified by comparing the results of simulation with that of exoeriment.

蚕状强回波与其强对流天气的预报初探

一、简述 蚕状强回波是造成我地区春季局地强对流天气的重要回波之一。它通过常只有30—60公里长,5—15公里宽,强度≥50db。它生命史短,从产生到消失,一般在两小时以内。它出现的次数不多,平均每年春季约1—2次,但它的出现,几乎都伴有冰雹和破坏力很强的大风。

Relationship between cross-equatorial flows over the Bay of Bengal and Australia in boreal summer:Role of tropical diabatic heating

The interannual variability of cross-equatorial flows(CEFs)over the Asian–Australian monsoon(AAM)region during boreal summer was analyzed by applying the empirical orthogonal function(EOF)method to the meridional wind at 925 h Pa.The first mode(EOF1)exhibits an in-phase relationship among different CEF channels over the AAM region,which has received much attention owing to its tight linkage with ENSO.By contrast,the second mode(EOF2)possesses an out-of-phase relationship between the Bay of Bengal(BOB)CEF(90°E)and Australian CEF,among which the New Guinea CEF near 150°E shows the most significant opposite correlation with the BOB CEF.Observational and numerical model results suggest that the equatorially asymmetric heat source(sink)over the western(eastern)Maritime Continent,closely associated with the in-situ sea surface temperature anomaly,can induce cross-equatorial northerly(southerly)flow into the heating hemisphere,which dominates the out-of-phase relationship between the BOB and New Guinea CEFs.Furthermore,an equatorially symmetric heating over the central Pacific may indirectly change the CEFs by modulating the zonal atmospheric circulation near the Maritime Continent.

Fluids discrimination by ray-path elastic impedance inversion: A successful case from Sulige tight gas field

Existing seismic prediction methods struggle to effectively discriminate between fluids in tight gas reservoirs,such as those in the Sulige gas field in the Ordos Basin,where porosity and permeability are extremely low and the relationship between gas and water is complicated.In this paper,we have proposed a comprehensive seismic fluid identification method that combines ray-path elastic impedance(REI)inversion with fluid substitution for tight reservoirs.This approach is grounded in geophysical theory,forward modeling,and real data applications.We used geophysics experiments in tight gas reservoirs to determine that Brie's model is better suited to calculate the elastic parameters of mixed fluids than the conventional Wood’s model.This yielded a more reasonable and accurate fluid substitution model for tight gas reservoirs.We developed a forward model and carried out inversion of REI.which reduced the non-uniqueness problem that has plagued elastic impedance inversion in the angle domain.Our well logging forward model in the ray-path domain with different fluid saturations based on a fluid substitution model proved that REI identifies fluids more accurately when the ray parameters are large.The distribution of gas saturation can be distinguished from the crossplot of REI(p=0.10)and porosity.The inverted ray-path elastic impedance profile was further used to predict the porosity and gas saturation profile.Our new method achieved good results in the application of 2D seismic data in the western Sulige gas field.

Roll Vortices in the Boundary Layer Caused by a Concave Wind Profile: A Theoretical Study

The present study solves a two-layer atmospheric wave equation model with a lower atmosphere concave wind profile and cold-air outbreak over sea, while simultaneously proving that such a wind shear may cause neutral boundary layer roll vortices in the presence of disturbing sources upstream. Without thermal effects, the wind shear-induced waves have band structures at the top of the boundary layer that are similar to cloud street patterns observed over sea. This study proves that dynamic and thermal effects can act independently to initiate the roll vortices in the lower atmosphere. At the same time, a quantitative comparison shows that dynamic effects play a large role in the formation of roll vortices in the initial stage of cold-air outbreak and will be surpassed by thermal effects soon after surface heating commences.