3D Thermo-mechanical Coupled Simulation of Whole Rolling Process for 60kg/m Heavy Rail

3D thermo-meehanical coupled simulation of whole rolling process for 60 kg/m heavy rail was accomplished by FEM method. The finite element model, physical parameters of U75V and parameter setting of simulation were introduced in detail. The whole rolling process of 60 kg/m heavy rail was divided into 27 time cells to simulate respectively, and the model rebuilding and temperature inheritance method in intermediate pass were proceeded. Then, based on simulation results, the workpiece deformation result, metal flow, stress and strain of 60 kg/m heavy rail for typical passes were obtained. The temperature variation curves of whole rolling process for section key points of 60 kg/m heavy rail were plotted, and the temperature falling law of whole rolling process for 60 kg/m heavy rail was studied. In addition, temperature distribution of 60 kg/m heavy rail after whole rolling process was analyzed, and the results showed that temperature was highest at center of rail head and lowest at fringe of rail base. Moreover, the simulation results and measured results of rolling force for 60 kg/m heavy rail were compared, and the regularity was in good agreement.     

镰刀菌酸及其枯萎病菌培养液对棉花的毒性

[目的]了解镶刀菌酸及其枯萎病菌培养滤液对棉花感病品种及其抗性转化品系的致萎作用.[方法]用2种类型毒素制品浸泡棉花种子及幼苗,以无菌水作为CK,根据浸泡的时间不同测定种子萌发率及病情指数.[结果]25%培养滤液中镰刀菌酸的浓度为21.46μg/ml,但其处理种子萌发率却比30.00μg/ml的纯镰刀菌酸处理低,50%培养滤液镰刀菌酸的浓度为30.62μg/ml,其处理种子萌发率与50.00μg/ml的纯镰刀菌酸处理一样.病原菌培养滤液浓度不同、处理后时间不同,其病情指数均不同,随着处理后时间的延长和处理浓度的增加,病情指数也大都呈逐渐增加趋势.[结论]病原菌培养滤液对种子萌发的抑制作用要高于纯镰刀菌酸.抗性转化品系与原感病品系相比对病原菌培养滤液的抗性明显增强.     

云锡公司第二冶炼厂的几种简易取样计量设备

我厂是个处理量为500吨的湿法冶炼厂,也叫氨浸厂。处理个旧选厂重选尾矿,粒度细,—0.074m/m占70%左右。冶炼工艺流程分为二段。原矿用水采、水运到本厂经浓密机浓缩后进入干燥窑干燥得0～10%水分的矿,再经还原窑还原焙烧,还原效率达70—90%。如火法工段焙烧出来的矿在常温常压下用碳酸氢铵(NH_450—70g/l、CO_220—25g/l)溶液三段浸出。渣经四段洗涤后作为尾矿,浸出     

猪饲料用乳酸菌增菌培养基的优化研究

[目的]通过对培养基成分及pH值的研究,得到最佳乳酸菌螬菌培养基.[方法]采用pH值梯度培养确定培养基的最适pH值;采用PB试验确定培养基主要影响因子;采用响应面试验对乳酸菌培养基进行优化,得出影响因子间的相互关系,并得到最佳培养基.[结果]适于乳酸菌培养的最适起始pH值为6.8;牛肉膏、葡萄糖和NaAc为乳酸菌增殖的主要影响因子,牛肉膏是最重要的影响因子;优化后的最佳培养基:牛肉膏23.70g/L、葡萄糖47.53g/L、NaAc4.87 g/L、蛋白胨10.0 g/L、酵母膏10.0 g/L、柠檬酸二胺2.0 g/L、MnSO40.2g/L、吐温80 0.5 g/L.[结论]优化后的乳酸菌增菌培养基使活菌密度显著提高,达到制备乳酸菌菌剂需求.     

活性炭固载三氯化钕非均相催化合成乙酸环己酯

以活性炭固载三氯化钕为非均相催化剂,对环己醇与乙酸酐之间的酰化反应进行了研究,考察了催化剂用量、醇酐摩尔比、反应时间对乙酸环己酯收率的影响。结果表明,活性炭固载三氯化钕有着较好的催化活性,当乙酸酐的加入量为0.1 m o l,醇酐摩尔比为1.1∶1时,催化剂质量为0.25g,反应30m in后,乙酸环己酯收率可达到92.2%,且催化剂重复使用5次仍保持较高活性,所得产品无色透明,具有很高的纯度。产品经折光率和红外光谱进行了表征。     

萝卜蚜新蚜虫疠霉的分离鉴定及其致病性测定

[目的]分离鉴定萝卜蚜的病原真菌,并测定其对萝卜蚜的致病性.[方法]采用形态学方法进行病原真菌种类鉴定,利用孢子浴方法对萝卜蚜进行致病性测定.[结果]初生分生孢子,卵形,双囊壁,单核,(24.7±1.4)μm×(10.7±0.9)μm, L/D=2.3±0.2.次生分生孢子形似初生分生孢子,大小为:(18.6±2.1)μm×(13.3±1.3)μm,L/D=1.4±0.2.菌丝段菌丝状,直径为(10.6±0.8)μm.分生孢子梗掌状分枝,直径(10.0±0.9)μm 假囊状体不分枝,基部粗大,直径(19.2±1.7)μm,向端部渐尖,直径(8.0±0.9))μm.假根单菌丝状,基部直径(21.0±3.0)μm,底端具有规则的盘状固着器.休眠孢子未见.该菌对萝卜蚜的致死中量为18.21 cfu/mm2.[结论]感染萝卜蚜的昆虫病原真菌被鉴定为新蚜虫疠霉, 该菌对萝卜蚜表现出较强的致病性.     

产絮凝剂双菌复合发酵体系的研究以及在水处理中的应用

从土壤和活性污泥中筛选到三株絮凝剂产生菌,将其进行双菌混合培养的正交试验,构建出了比单一菌所产絮凝剂絮凝活性更高的复合菌群LH,通过16SrRNA序列分析,初步判定二菌分别为Micrococcus sp.和Paenibacill usvelaei菌.对其性质的初步研究发现,复合菌LH所产絮凝剂MBF-LH为胞外代谢产物,其热稳定性好.LH产絮凝剂的最适碳源、最适培养温度、最适pH值和通气量分别为蔗糖、30℃、pH8和120r/min恒温振荡培养.培养基中添加KCl、CaSO₄、K₂HPO₄能明显提高发酵液絮凝率.絮凝剂MBF-LH处理废水时具有用量少、絮凝率高的特点.     

Particle size dependent sinterability and magnetic properties of recycled HDDR Nd-Fe-B powders consolidated with spark plasma sintering

The dependence of the magnetic properties on the particle size of recycled HDDR Nd-Fe-B powders was investigated,with the aim to assess the reprocessing potential of the end-of-life scrap magnets via spark plasma sintering(SPS).The as received recycled HDDR powder has coercivity(H_(ci))=830 kA/m and particles in the range from 30 to 700 μm(average 220 μm).After burr milling,the average particle size is reduced to 120 μm and subsequently the H_(ci) of fine(milled) powder was 595 kA/m.Spark plasma sintering was exploited to consolidate the nanograined HDDR powders and limit the abnormal grain coarsening.The optimal SPS-ing of coarse HDDR powder at 750℃for 1 min produces fully dense magnets with H_(ci)=950±100 kA/m which further increases to 1200 kA/m via thermal treatment at 750℃for 15 min.The burr milled fine HDDR powder under similar SPS conditions and after thermal treatment results in H_(ci)=940 kA/m.The fine powder is further sieved down from 630 to less than 50 μm mesh size,to evaluate the possible reduction in H_(ci) in relation to the particle size.The gain in oxygen content doubles for 50 μm sized particles as compared with coarser fractions(200 μm).The XRD analysis for fractionated powder indicates an increase in Nd_2O_3 phase peaks in the finer(100 μm)fractions.Similarly,the H_(ci) reduces from 820 kA/m in the coarse particles(200 μm) to 460 kA/m in the fine sized particles(100μm).SPS was done on each HDDR powder fraction under the optimal conditions to measure the variation in H_(ci) and density.The H_(ci) of SPS-ed coarse fraction(200 μm) is higher than 930 kA/m and it falls abruptly to just 70 kA/m for the fine sized particles(100 μm).The thermal treatment further improves the H_(ci) to1000 kA/m only up to 100 μm sized fractions with90% sintered density.The full densification(99%) is observed only in the coarse fractions.The loss of coercivity and lack of sinterability in the fine sized particles(100 μm) are attributed to a very high oxygen content.This implies that during recycling,if good magnetic properties are to be maintained or even increase the HDDR powder particles can be sized down only up to≥100 μm.     

THE USE OF CHELATING RESIN FOR THE PRE-CONCENTRATION OF TRACE RARE EARTH ELEMENTS IN BIOLOGICAL SAMPLES AND THEIR DETERMINATION

Macroporous amino-carboxvlic chelating resin of acrylic acid series may concentrate trace rare earth inthe presence of 0.1 mol/l α-hydroxy-isobutyric acid at pH 4.5.With 0.10 mol/l HCl as eluant rare earthmay be eluted quantitatively and separated from Ca,Mg,Fe and Cu.This method is used to determine traceamount of rare earth in human hair,stone (in kidney and bladder),peanut,grape,strawberry,cucumber,pigliver and other biological samples.     

新日铁公司八幡厂一号连铸机设备改造

为调整八幡厂的连铸生产 ,在其一号连铸机上生产不锈钢、高碳钢及 3% Cr- SML 钢等特殊钢 ,将其中的一流改为板坯 /方坯连铸共用机构。该连铸机为弧型连铸机 ,六点矫直 ,弧型半径为 10 .5m。连铸板坯尺寸为 2 5 0 mm× 6 5 0～ 16 5 0 m m、2 90× 190 0mm,最大连铸速度为 1.4m/ m in;连铸方坯尺寸为 2 2 0 mm× 2 2 0 mm、 2 90 m m× 2 90 m m,最大连铸速度为1.9m/ m in。中间包容量为 30 t。(1)钢包回转台具有可适用 35 0 t钢包和 16 0 t钢包的特点。(2 )为适应板坯一流连铸或方坯三流连铸 ,有上插入引锭杆装置和下插入引锭杆装置。(3)…     

China's Major Non-ferrous Metals Imports & Exports

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Zinc Production by Province in 2014

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80% of Chinese Firms Purchasing Overseas Mines Ended up in the Red

<正>Minmetals Resources acquired the world’s largest copper mine under construction for USD5.85 billion.One after another,listed companies Jien Nickle,China Molybdenum and Chihong Zinc and Germanium raised money to get involved in overseas mining projects…SOEs and private enterprises are engaged in a frenzy of overseas mine purchasing.A reporter with Economic     

Copper Processing Profit Dropped Sharply,Copper Consumption Will Face Impact in the Second Half of the Year

正Judging from China’s copper consumption field,the biggest consumption unit is electric power,which accounts for 47%of total consumption;it is followed by light industry sector,including household electrical appliance,machinery,durable goods and hardware etc,which accounts for 22%of total consumption;followed by transportation field,     

Central Geological Prospecting Fund Newly Added 16.47 Million Tonnes of Bauxite in 2013

正In 2013,the Central Geological Prospecting Fund(CGPF)Project newly discovered 15 ore fields,including 3 large above ore fields,and 5medium sized ore fields.The reporter learned from the recently published"Annual Report of Central Geological Prospecting Fund Project(2013)"that,from 2006 to 2013 the CGPF     

Manufacturers of Copper Tube for Central Air Conditioner Use Face Mounting Pressure in the Final Quarter of the Year

正This year,the investment growth rate of real estate industry continued to slow down,sold area of commercial housing also dropped significantly,which brought huge pressure to the domestic air conditioning manufactures.In the first half of the year,by relying on high growth in national financial expenditure,along with investment in public infrastructure     

Xinjiang Ranks No.1 in Production of Primary Aluminum in China

正Kang Yi,Honorary Chairman of China Nonferrous Metals Industry Association,said recently at the Forum on Development of the Non-ferrous Metals Industry in Central and Western China held in Zhengzhou that,as more and more electrolytic aluminum factories in Xinjiang came into operation,the electrolytic aluminum output of Xinjiang had reached2,275,000 tons in the first 7 months this year,     

Shenhuo Coal Industry and Electricity Power Completed800,000 t/a Aluminum Project in Xinjiang

正"Xinjiang project has been completed according to schedule,but total completion and total start of production are two different concepts,after completion it still needs a gradual process of reaching production target."On the morning of November 3,Shenhuo Coal Industry and Electricity Power told investors the above statement on the investor interaction platform.     

Guangdong Metal Transaction Center has Become the Second Largest Precious Metal Transaction Platform Nationwide

正The reporter learned from Guangdong Province Precious Metal Transaction Center that in 2013the Center maintained healthy development momentum,and had become the second largest precious metal transaction platform in China in terms of market size;currently Guangdong is quickening steps of financial innovation for the Center,aiming to build a transaction center with international core competitiveness.     

Seven Rare Earth Projects Involving Close to 3 Billion Yuan Investment Landed In the HighTech Zone

正On May 22,Baotou Rare Earth Industry Cooperation Consultation MeetingProject Agreement-signing Ceremony was held in Ningbo,nearly 40 enterprises from Ningbo,Guangdong,Hunan,and Shanxi participated in project consultation.After multi-lateral communication,agreements were signed for a total of 7 rare earth projects successfully.