心源性猝死一级预防植入心律转复除颤器前非持续室性心动过速与植入后恰当治疗的关系

目的探讨植入型心律转复除颤器(implantable cardioverter defibrillator,ICD)用于心源性猝死一级预防时,植入前发生非持续性室性心动过速(non-sustained ventricular tachycardia,NSVT)与植入后ICD恰当治疗的关系。方法本研究为单中心回顾性队列研究,连续纳入2006年1月至2017年12月在北京协和医院住院植入ICD用于一级预防的心脏病患者,患者在住院期间ICD植入前均完善Holter检查。根据Holter检查是否出现NSVT,将患者分为NSVT组及无NSVT组。门诊或电话随访至2018年8月,随访事件包括全因死亡、植入后ICD放电治疗及抗心动过速起搏(antitachycardia pacing,ATP)治疗情况。结果纳入60例符合入选和排除标准的患者,随访时间37 (14～61)个月,KaplanMeier生存曲线及Log-Rank检验提示,NSVT组与无NSVT组相比,全因死亡率无统计学差异(P=0. 108),NSVT组恰当治疗的风险高于无NSVT组(P=0. 033),NSVT和左心室射血分数与ICD恰当治疗独立相关(NSVT:HR=5. 099,95%CI:1. 399～18. 588,P=0. 014;左心室射血分数:HR=1. 077,95%CI:1. 013～1. 145,P=0. 018)。结论 ICD一级预防患者植入前出现NSVT提示接受ICD恰当治疗的风险增加。     

LMG200型可调高滚筒式露天采煤机

介绍了可调高滚筒式露天采煤机的结构特点及在露天煤矿应用所产生的效益和其广 阔的发展前景。     

离心萃取装置中硝酸羟胺还原反萃钚的研究

用十六级分离式混合—离心澄清萃取装置,在20-24℃,30-34℃,45-50℃等不同温度下进行了3B槽硝酸羟胺还原反萃钚的实验。结果表明,钚的收率均可达99.9%以上。在20-24℃时,有机相出口级附近几级的钚浓度较高,实验条件一旦波动,有可能造成钚的流失,且钚在萃取设备中有明显的积累。温度升高,14级反萃(停留时间约18min)时,钚的收率基本得到保证。     

井巷掘进控制斜形炮孔钻孔精度的试验研究

井巷掘进爆破工程中，工作面按设计要求，布置各种斜形炮孔，利用量角器和垂直尺控制钎杆与工作面夹角，使炮孔钻孔精度与设计炮孔角度基本上符合，在生产中取得了良好的爆破效果．     

A comparison of backpropagation and general regression neural networks in quantative trace metal analysis using anodic stripping voltammetry and cybernetic instrumentation

A comparison is made between backpropagation and general regression neural networks for the prediction of parts per billion lead concentration when used to process data obtained from digested curry powder by the electrochemical analysis method of differential pulse, anodic stripping at a thin film mercury electrode (TFME). Two data sets are used, one requiring the net to classify an unknown analytical data vector into one of a number of previously learnt concentrations, and one requiring the net to predict the probable concentration of an unknown sample by interpolation of the already learnt concentrations. For both of these data sets the general regression neural network is shown to train faster and to provide results superior to those obtained by backpropagation.     

用发展的Sachs法研究模拟轧辊中的残余应力

对不同辊型，尺寸，材料与加工处理方法的模拟冷轧辊进行了内剥层试验研究，求出了原辊和打中心孔或扩孔后辊内残余应力分布曲线，提出了虚拟打孔法和虚拟剥层法，解决了实心辊中心和空心辊内表层的残余应力的精确测量问题，丰富了Ｓａｃｈｓ内剥层法的内容，机械法打中心孔，热处理前打中心孔，空心辊表淬前改变温度场的方法可降低残余应力值，后者降低残余应力的效果尤为显著。     

含氨废水处理方法的探讨

对催化剂厂含氨废水的处理，提出了多种方法，着重分析了A/O生物法、膜分离法和汽提法，比较后确定采用汽提法处理该废水，建成投产达到预期效果。     

单塔汽提水罐开裂原因分析及解决对策

单塔汽提装置原料水罐产生腐蚀裂纹的原因分析判断为低温HCN-H2S-H2O环境下的硫化物应力腐蚀开裂,根据腐蚀成因制定了合理的焊接补焊工艺;涂料防护施工的重点在于表面处理,喷砂后用面粘效果理想且节约施工时间,可延长涂层寿命。     

Process for cobalt separation and recovery in the presence of nickel from sulphate solutions by Cyanex 272

The present paper deals with the extraction of cobalt from a solution containing cobalt and nickel in a sulphate medium similar to the leach liquor obtained by the dilute sulphuric acid pressure leaching of the Pacific Ocean nodules matte followed by copper extraction. The commercial extractant Cyanex 272 (bis (2, 4, 4-trimethylpentyl) phosphinic acid) is used for this purpose. The leach liquor used for the present study contains Co =1.78 g/L and Ni=16.78 g/L. Before cobalt extraction, impurities, such as copper and iron, are removed from the leach liquor by the precipitation method. Increasing the concentration of Cyanex 272 increased the extraction percentage of cobalt due to the increase of equilibrium pH. Cobalt extraction efficiency of >99.9 % is achieved with 0.20 M Cyanex 272 in two counter-current stages at an aqueous: organic (A:O) phase ratio of 1.5∶1. Complete stripping of cobalt from the loaded organic containing 2.73 g/L Co was carried out at pH 1.4 by a synthetic cobalt spent electrolyte in two stages at an A:O ratio of 1∶2. The enrichment of cobalt during extraction and stripping operations was about 3.5 times. A complete process flowsheet for the separation and recovery of cobalt is presented.     

提高发酵过程乙醇分离效率的新型反应器

设计了一种新型的带侧臂循环的气升式反应器,该反应器可以有效地把真空闪蒸发酵和汽提发酵2项技术结合起来。实验结果表明,与单独的汽提和闪蒸过程相比,利用此反应器进行同步汽提闪蒸操作,大大提高了乙醇的移出效率,从而进一步提高了发酵强度。