On 1-rate and 2-rate multicast 3-stage Clos networks

The 3-stage Clos network C（n, m, r） is considered as the most basic and popular multistage interconnection network which has been widely employed for data communications and parallel computing systems. Quite a lot of efforts has been put on the research of the 3- stage Clos network. Unfortunately, very little is known for the multirate multicast Clos network which is the most complicated case. Firstly a sufficient condition for 1-rate multicast networks to be SNB is given, from which a result for 2-rate multicast networks to be WSNB can easily be gotten. Furthermore, by using a reservation-scheme routing, more specific result for 2-rate multicast networks to be WSNB can be obtained for the case of one of them exceeding 1/2.

Modeling Interstate Banking in the United States: the Spatial 3-Stage Least Squares Approach

This study uses a spatial 3-stage least squares approach to model interstate banking of the United States in 1994 and 2014.The method simultaneously takes into account spatial dependence,outward and inward interstate banking and their interaction,and the temporal effects in interstate banking.The study shows that a healthy economic structure,an expanding market,and permissive banking legislation encourage inward interstate banking.A healthy economic structure is a basis for strong banking firms to rise and to expand in other states.Large banking institutions were dominate in outward interstate banking while smaller firm sizes tend to be associated with inward interstate banking.By 2014,large and well-capitalized banking firms from states with a healthy economic structure had expanded into states with lower income levels,and lower capital-to-labor ratios,higher labor resource use,and lower profitability in their banking industry.Evidence shows some banking geographical fragmentation remains.

南堡3-81井四开钻井液技术

南堡3-81井作为冀东油田首口超深井,钻探目的是探明南堡3号构造沙河街组、潜山的含油气情况。为了克服四开井段（4 384~5 939 m）大段硬脆性泥岩易失稳和井底异常高温的技术难题,应用了KCl抗高温钻井液体系,但在实钻过程中出现了气侵、CO2污染、钻井液高温增稠、掉块、卡钻、摩阻扭矩大等井下复杂情况,导致钻井施工困难。现场通过及时采取提高钻井液密度、加入生石灰处理、增强钻井液抗温性、强化钻井液封堵性和润滑性等技术,并加强工程措施配合,较好地解决了施工中存在的各项问题,确保了该井四开钻井施工的顺利完成。这对冀东油田超深井高温钻井液的现场应用具有较好的借鉴意义。

UPA based 3D visualization of discontinuities in great thickness EBW seam

Electron beam welding （EBW） is a fusion welding process in which a beam of high-velocity electrons is applied to two materials to be joined. It is a complex high-temperature metallurgical process, and the quality of welding may deteriorate because of defects caused by improper welding parameters, especially in the EBW of thickened aluminum alloy plate. Ultrasonic phased array（UPA） technology has been applied more widely in the field of nondestructive testing because of its ability of effectively controlling the shape and direction of the emitted ultrasonic beam. In present research, a specimen with EBW seam on thickened aluminum plate was tested with a linear array ultrasonic phased array probe, and a large number of B-scan images of the weld were acquired by electronic scanning in probe combined with the mechanical scanning of the probe along the weld direction. This large number of B-scan images were stacked to construct the volume data, with which the 3D image of the weld discontinuities were reconstructed, and the 3D visualization was realized. More details about weld discontinuities＇ spatial distribution and orientation were revealed, and this approach also made the results of non-destructive ultrasonic testing more easily to understand.

稠油开采微生物的生理生化特征及其对原油特性的影响

从原油及含油污水中分离并培育出一株能有效地降解稠油中重质组分的菌株3-28,其生理生化特征和分子鉴定结果表明,该菌株属于微杆菌属(Microbacterium)。用该菌株对渤海和新疆等油田的稠油进行了微生物降解实验,分析了细菌降解对原油粘度等物理特征的改变及其对饱和烃、芳烃以及胶质、沥青质各组分在原油中相对含量和内部组成的影响。结果表明,该菌株降解作用使原油性质发生了明显变化:渤海绥中36-1油田的原油粘度降低24.9%,凝固点降低5.2℃;克拉玛依油田的原油粘度降低32.4%,凝固点降低7.7℃;绥中36-1油田的原油中饱和组分和芳烃组分含量增加8.0%,克拉玛依油田的原油增加21.4%;沥青质含量分别降低了37.5%和58.7%。原油组成也发生了一定的变化,原油饱和烃轻、重组分比值增加,改善了原油的理化特征。

仓上金矿氧化矿絮凝沉降试验研究

仓上金矿氧化矿含泥量大难沉降，为配合高效浓密机选择好絮凝剂，进行了絮凝沉降试验的研究，试验结果表明，３＃絮凝剂能有效地加速该矿石的沉降速度。

八矿选煤厂浮选尾煤梯次减量技术的创新和应用

针对环保和选煤厂产能提升给浮选尾煤处理系统带来的压力,八矿选煤厂通过采用浮选尾煤梯次减量技术,实现了对浮选尾煤的三段浓缩、三段回收梯次减量化处理。生产实践表明,该技术不仅有效缓解了浮选尾煤处理系统压力,提高了选煤生产系统的稳定性,并且节约了生产成本,取得了良好的经济效益和社会效益。

农药制剂中皮肤接触致敏组分BIT的检测和控制

在实验的基础上,提出了一种农药制剂中BIT(1,2-苯并异噻唑啉-3-酮)的检测方法和BIT纯品定值的方法。该方法中,BIT纯品的定值,采用"气相色谱法+水分"相组合的杂质倒扣法及用差示扫描量热(DSC)法测定纯度,使标准品定值结果更接近真值。结果表明:该法的检测下限(LOQ):39.38ng/μL,线性相关系数r=0.99995,回收率:99.96%～102.7%,检测精度RSD:0.032%～2.043%。

Preliminary Assessment of the COVID-19 Outbreak Using 3-Staged Model e-ISHR

The outbreak of coronavirus disease 2019(COVID-19)in Wuhan has aroused widespread concern and attention from all over the world.Many articles have predicted the development of the epidemic.Most of them only use very basic SEIR model without considering the real situation.In this paper,we build a model called e-ISHR model based on SEIR model.Then we add hospital system and time delay system into the original model to simulate the spread of COVID-19 better.Besides,in order to take the government's control and people's awareness into consideration,we change our e-ISHR model into a 3-staged model which effectively shows the impact of these factors on the spread of the disease.By using this e-ISHR model,we fit and predict the number of confirmed cases in Wuhan and China except Hubei.We also change some of parameters in our model.The results indicate the importance of isolation and increasing the number of beds in hospital.

四元共聚物降失水剂抗盐性能的室内评价

从四元共聚物抗盐降失水剂的角度,以常规密度盐水水泥浆为主要研究对象,系统研究了不同加量盐的水泥浆在不同温度下的密度、稠化时间、流变失水等性能变化。结果表明:XJL-3降失水剂能够在饱和盐水中仍能控制住浆体的失水,盐的加入没有改变浆体的流态,但降低了浆体的塑性粘度和动切力,在80℃进行水泥浆安全施工稠化时间设计时,要密切注意该温度节点存在的缓凝现象有可能对现场固井存在的影响,高于93℃,要保证现场的安全施工,需要加入一定量的中高温缓凝剂。

色连二矿选煤厂低质煤洗选实践

为实现色连二矿选煤厂低质煤的有效分选,引入了弛张筛深度筛分技术,并构建了3 mm深度筛分+分级分选+煤泥水三段浓缩的一体化工艺体系;针对洗选低质煤过程中的问题,基于对低质煤煤质和产品结构深入分析,提出了针对性的洗选方案。生产实践表明:与洗选低质煤的相邻选煤厂相比,色连二矿选煤厂的商品煤产率低14.03%,但发热量高2.15 MJ/kg;由于具有发热量和价格优势,吨煤收益更好。