SINAMICS SM150在热轧主传动中的应用

交-交变频器传动系统是电压源型矢量控制技术产品,具有高功率因数,拥有灵活强大的通讯功能,结构简单紧凑,可靠性高,适合于低转速、大容量的场合。本文结合日照钢铁1580mm热连轧工程,介绍了交-交变频传动系统的组成、控制功能,着重介绍了矢量控制、速度控制和电流控制的主要控制功能。     

采用气相色谱—质谱法测定纺织品中的11种REACH高关注度有机物

以正己烷为提取溶剂,超声提取纺织品中的11种高关注度有机物,建立气相色谱—质谱联用检测方法。对色谱柱类型进行选择,并对提取条件进行优化。该方法简便快捷、灵敏度高,确定了11种高关注度有机物的检出限。该方法在本文研究范围内呈线性关系,相关系数均大于0.996。以纺织品为基质,加入三个不同浓度的11种高关注度有机物的标准溶液做回收率试验,测得回收率为80.53%～105.88%,相对标准偏差小于10%。实验室间的比对结果表明:该方法实验室间的偏差小,DBP和DEHP的相对标准偏差仅分别为8.0%和4.7%。     

断路器暂态模型及参数对VFTO影响的仿真分析

气体绝缘变电站(Gas Insulated Substation,GIS)设备模型的选取是快速暂态过电压(Very Fast Transient Overvoltage,VFTO)仿真计算的关键,断路器作为GIS主要的电气设备,其模型及参数的选取必然会影响VFTO的仿真结果.为此文中利用EMTP-ATP软件对1 100 kV变电站进行建模,建立了考虑断路器结构的暂态仿真模型,分析断路器结构参数对VFTO的影响.结果表明,合闸电阻对VFFO的幅值具有明显的抑制作用;随着断路器并联电容的增大系统中VFTO幅值呈减小趋势,主要频率和频率幅值减小;断路器对地电容变化对不同节点处VFTO的影响程度不同;空载母线变化对母线端部和断路器处的VFT0影响最大.     

风电场超短期风功率预测问题研究

以河北省某实际风电场为例,选取风电机组历史功率数据、风速以及数值天气预报的风速和风向作为输入因子,采用人工神经网络法对风电场超短期功率预测问题进行研究.研究结果显示,输入因子的差异性对风功率预测结果影响较大.另外,风电机组历史数据对功率预测结果的影响随时间增加而减小,进行3h以上风电场功率预测时预测结果精度在很大程度上依赖数值天气预报数据精度.     

深层巨厚砾岩稠油油藏划分开发层系的隔夹层研究

方法根据砂体岩性变化及电性特征,利用测井资料、压裂分析结果,计算出不同岩性隔夹层的杨氏模量、泊松比、破裂压力等,从而选择隔夹层。目的为深层巨厚砾岩稠油油藏开发层系的划分与组合,提高油层纵向动用程度和采收率提供依据。结果该方法应用于冷４３块开发方案,有效地选择了非泥质隔夹层,将Ｅ２ｓ２３油层划分为两套层系开发,利用天然能量开采,单井初期日产油１０～１５ｔ;转注水后,非泥质隔夹层起到划分开发层系的隔层作用。结论对于巨厚砾岩稠油油藏,在泥岩隔层不发育情况下,将非泥岩隔夹层有效组合隔离段,可以实现划分层系开发。     

极近距离煤层瓦斯抽放参数考察

李子垭煤矿已确定为有煤和瓦斯突出危险矿井，有两个可采煤层，其层间距平均１．１ｍ。矿井瓦斯涌出量达到４１．９ｍ￣３／ｍｉｎ，回采面达到８．０３～１０．８３ｍ￣３／ｍｉｎ，仅用通风的办法不能解决瓦斯问题，为了矿井安全生产的需要，建立矿井瓦斯抽放系统势在必行。通过试抽考察研究，证明在李子垭矿极近距离煤层条件下，采用综合抽放方法可以获得较好的抽放效果，并为合埋设计矿井瓦斯抽放系统提供了必要的设计参数。     

Fatigue behaviour of SiCp-reinforced aluminium composites in the very high cycle regime using ultrasonic fatigue

The fatigue behaviour of a 2009/SiC/15p‐T4 DRA composite has been examined in the very high cycle fatigue (VHCF) regime where 10⁷≤N_f≤ 10⁹ cycles. Ultrasonic fatigue was used to achieve the very high cycle counts. Careful processing yielded a composite with a very homogeneous particle distribution with minimal clustering. Fatigue crack initiation was observed almost exclusively at AlCuFe inclusions with no crack initiation observed at SiC particle clusters. Fatigue lives at a given stress level exhibited minimal scatter and subsurface crack initiation was observed in all cases. This behaviour is consistent with the presence of a low number density of critical inclusions that are responsible for crack initiation very early in fatigue life.     

超大型硫磺制酸装置的设计

论述我国近年来在设计600 kt/a以上超大型硫磺制酸装置方面的技术进展,详细介绍一些典型装置的工艺布局、设备结构与材料选择.指出我国的硫酸工业技术水平有了较大的进步,已具备设计和制造超大型硫磺制酸装置的能力,与世界先进水平的差距正在拉近,但是在低温位热能的利用、钒催化剂的研发、新装备和新材料的研制等方面还需要进一步努力.     

Protease and DNase Activities of a Very Stable High-Molecular-Mass Multiprotein Complex from Sea Cucumber Eupentacta fraudatrix

Only some human organs, including the liver, are capable of very weak self-regeneration. Some marine echinoderms are very useful for studying the self-regeneration processes of organs and tissues. For example, sea cucumbers Eupentacta fraudatrix (holothurians) demonstrate complete restoration of all organs and the body within several weeks after their division into two parts. Therefore, these cucumbers are a prospective model for studying the general mechanisms of self-regeneration. However, there is no data available yet concerning biomolecules of holothurians, which can stimulate the processes of organ and whole-body regeneration. Investigation of these restoration mechanisms is very important for modern medicine and biology because it can help to understand which hormones, nucleic acids, proteins, enzymes, or complexes play an essential role in self-regeneration. It is possible that stable, polyfunctional, high-molecular-weight protein complexes play an essential role in these processes. It has recently been shown that sea cucumbers Eupentacta fraudatrix contain a very stable multiprotein complex of about 2000 kDa. The first analysis of possible enzymatic activities of a stable protein complex was carried out in this work, revealing that the complex possesses several protease and DNase activities. The complex metalloprotease is activated by several metal ions (Zn²⁺ > Mn²⁺ > Mg²⁺). The relative contribution of metalloproteases (~63.4%), serine-like protease (~30.5%), and thiol protease (~6.1%) to the total protease activity of the complex was estimated. Metal-independent proteases of the complex hydrolyze proteins at trypsin-specific sites (after Lys and Arg). The complex contains both metal-dependent and metal-independent DNases. Mg²⁺, Mn²⁺, and Co²⁺ ions were found to strongly increase the DNase activity of the complex.