催化还原法合成谷氨酰胺

本文研究了以粉末Raney镍作催化剂，在常压下进行L－谷氨酸r－酰肼的催化还原，试验了谷氨酰胺的合成．该催化剂在反应液当碱性条件下显示出高活性，在pH＝11，50℃下反应8h谷氨酰胺的收率为81％，副产物焦谷氨酸收率为17％．在使用氢化硼钠还原时，生成物为脯氨酸，作为谷氨酰胺的合成法是不适宜的．     

PNEUMATICALLY CONTROLLED MULTI-STAGE FLUIDIZED BED AND ITS APPLICATION IN SOLVENT RECOVERY FROM A PLANT WASTE GAS

The downcomer is the key component of a multi-stage fluidized bed.A pneumatically controlleddowncomer has been devised,consisting of a fully fluidized dipleg followed by a conical spout for upwarddischarge in dense phase.Such a design has been found to insure against bridging of solids in descent andagainst spouting of solids from a lower layer caused by gas by-passing.In experimental investigations,flow characteristics are measured including the pressure drops of thedifferent fluidized beds and of the downcomers for various gas and solids flow rates as well as the solidsresidence time distribution,operating either with a multiplicity of gas sources for the various downcomersor with only two gas sources.In a particular design,a multi-stage ftuidized bed with dual gas supply,inwhich one half is incorporated centrally in the other,has been tested on pilot scale for recovering solventfrom low concentration ethylene dichloride streams of a plant waste gas.Main test results obtained wereas follows:adsorption rate>97%concentration of waste gas<25 mg/m~3active carbon loss<0.1%This kind of conical downcomer in which the solids arc either transported from a high- to a low-pressure region,or from a low- to a high-pressure region,is also used to control the solids discharge ofcyclone diplcgs or the feeding and discharging in other solids circulation systems.     

气控式多层流化床及其在净化排放气中的应用

溢流管是多层流化床的关键构件。本文设计的由下料料腿和锥斗组成的气控式锥形溢流管,由于物料在料腿中处于流态化状态,在锥斗中以气固顺流浓相向上输送,因此,这种溢流管可以防止物料在料腿中的架桥和喷料。 试验中测定了多气源和双气源两种气控式多层床的流动特性,包括各床层和溢流管压降以及固体停留时间分布。在回收低浓度二氯乙烷的中间工厂试验中,采用了具有同心圆的双气源多层流化床,获得以下主要结果: 吸附率>97%,排放气浓度<25mg/m~3,活性炭损失<0.1%。 这种能使固体物料由高压区输至低压区,或从低压区输至高压区的气控锥形溢流管结构,亦可用于旋风器料腿的返尘以及在循环系统中固体物料的连续加、排装置。     

煤田选择γ-γ测井仪

本文介绍煤田低能γ射线散射测井的一种方法。定名为选择γ-γ测井。该装置使用~(241)Am放射源,对等效原子序数Z_e_q灵敏,并可估价煤中灰含量。