多钒酸铵熔化过程中钒损失的分析

对多钒酸铵(APV)的物料性质、熔化过程、熔化特点及温度控制等进行了分析,对熔化过程中的钒损失形态及操作工艺进行了讨论,并根据研究结果,采取了有效措施,使APV熔化过程中的钒回收率提高到了97.25%.     

氯化铵沉钒工业试验研究

就NH4Cl沉钒进行了工业试验研究,并与（NH4）2SO4沉钒进行了对比试验,对NH4Cl沉钒过程中的一些现象作了分析;同时,跟踪考察了NH4Cl沉钒得到的多钒酸铵（APV）在溶化过程中的基本现象,:肜NH4Cl代替（NH4）2SO4沉钒技术上可行,经济上合理。     

铵盐沉钒过程产物形貌控制技术研究

采用酸性铵盐沉钒工艺沉淀多钒酸铵,研究了钒液浓度、沉淀pH值、铵盐加入量、沉淀时间、沉淀温度对沉淀产物多钒酸铵(APV)形貌的影响。结果表明:在沉钒pH=2.2,加铵系数K=2.3,70℃以上反应30 min即可获得球形的APV产品,且沉钒率99%。稳定试验结果验证了沉钒条件的可靠性,通过APV产品形貌的控制,可获得高品质APV产品,且保持较高的钒收率。     

流态化制取三氧化二钒研究

对采用流态化技术,还原多钒酸铵(APV)制取三氧化二钒工艺及相关参数进行了研究,得到了合格的三氧化二钒产品.试验表明: APV在还原温度700～750 ℃、保温时间10～15 min的条件下可以得到TV≥63%的三氧化二钒产品,比回转窑方法所需时间短、温度低;更容易实现对温度和时间的控制,得到较高品位的三氧化二钒产品(TV>67%);流态化生产的三氧化二钒产品C含量低,更有利于钒铁冶炼对C含量的控制;同时,流态化生产三氧化二钒效率高、还原剂消耗少、设备固定、相对安全性更高.     

提高酸性铵盐沉钒效果的研究

以江西某地含钒石煤经焙烧-水浸-离子交换所得的富钒液为对象, 研究了加酸加铵方式、添加晶种以及产品洗涤方式对酸性铵盐沉钒制备多聚钒酸铵(APV)的影响. 结果表明: 冷态下采用2次加酸1次加铵、加铵pH值为5左右的方式沉钒有助于提高沉钒效果, V_2O_5纯度可达99%以上; 低浓度含钒溶液沉钒时, 按其生成APV质量的1/200加入晶种破坏溶液过饱和度, 可将沉钒时间缩短25%; 得到的沉淀物经液固比为40∶ 1的自来水洗涤, 能将APV中Na~+, K~+含量降至0.24%, 且钒损失率仅为0.2%.     

提高酸性铵盐沉钒质量的探讨

针对酸性铵盐沉钒生产过程,优化了工艺参数和控制手段,为生产高品位的V2O3提供优质的原料。主要讨论了含钒浸出液浓度、铵盐加入量、沉钒温度、反应时间、pH值、搅拌条件及板框压滤过程中洗涤条件等因素对酸性铵盐沉钒法制备的多聚钒酸铵(APV)质量的影响。结果表明:含钒浸出液钒浓度为25～35 g/L,采用两次加酸工艺,沉淀终点温度95℃,沉淀反应时间约35 min,APV滤饼洗涤时间20 min,洗涤水温度在75℃左右,压榨吹风时间80 min,风压≥0.5 MPa,滤饼厚度≤25 mm等工艺条件下,可降低沉淀产物多聚钒酸铵的杂质含量,从而提高产品质量。     

钙对钒渣提钒的影响

分析了攀钢钒渣的物理、化学性质，研究了钒渣焙烧、浸出过程的工艺参数对钒回收率的影响规律，优化工艺条件用于钒氧化物生产。     

高密度多钒酸铵制备技术研究

介绍一种高密度多钒酸铵的制备方法,研究TV浓度、pH、搅拌速度、加药与酸温度、加铵系数以及晶种对多钒酸铵的堆密度和沉钒率的影响。研究结果表明:以含钒20～30 g/L的溶液在60～85℃加入大于1/50倍于全钒质量的晶种和1.5～2.5倍于全钒质量的硫酸铵后,用硫酸调节pH到2.1～2.4,沸水浴95℃依次在350 r/min和200 r/min转速下分别沉淀40 min和20 min,可获得98.5%以上的沉钒率,烘干后的APV堆密度大于0.95 g/cm3,APV焙烧后的粉钒中含V2O5大于98.5%,Na2O小于0.10%。     

微波干燥APV技术研究

对微波干燥不同水分含量的APV（多钒酸铵）工艺条件及相关参数进行了研究,得到了满足干燥后水分含量的APV物料。试验表明：微波干燥APV工艺在技术上是完全可行的,对于不同含水量的APV,经过微波干燥,其水分含量均可降至3%以下,满足钒生产工艺对APV水分含量的要求;在微波加热干燥过程中,无粉尘产生,对环境无影响且钒的回收率高,属绿色环保技术;微波干燥设备的操作性好,微波功率、温度、时间等参数易于控制。     

沉钒工艺现状和研究进展

钒作为战略金属在众多领域中扮演着关键角色，而且随着钒氧化还原液流电池商业化应用的增多，各领域对钒的需求量将会进一步增加。焙烧-浸出-除杂-沉钒是从含钒资源中提取钒的最成熟技术之一。其中，从溶液中沉淀出钒是提钒的重要步骤，与钒的回收率和产品质量密切相关。本文首先综述了目前存在的较为成熟的传统沉钒工艺，主要包括水解沉钒、铵盐沉钒、铁盐沉钒和钙盐沉钒，并对其沉钒机理、适用场景和优缺点进行初步分析。其中，酸性铵盐沉钒虽然因其生产周期较短、铵耗量小、五氧化二钒产品纯度高等优点被大规模用于工业生产中，但该方法在生产过程中不可避免地会产生大量难处理的氨氮废水，制约了钒生产企业的进一步发展。因此，提出了一些减少铵盐消耗的新型沉钒方法，主要包括微波强化沉钒、以低价氧化钒的形式沉钒、氨基化合物沉钒等，以期为实现少铵甚至无铵沉钒提供研究思路和方向。     

提高攀钢五氧化二钒车间多钒酸铵回收率

针对攀钢五氧化二钒车间沉淀工段生产中存在的问题，研究了多钒酸铵的溶解性，找出了钒损失大的根本原因。对生产工艺进行改造，采用ＰＥ烧结微孔管式过滤机处理含多钒酸铵固体的沉钒废水，提高了钒收率，减少了环境污染。     

In vitro evaluation of the intravasal Doppler guide wire: determination of hemodynamic effects of stenoses in a flow model

PURPOSE: In a pulsatile hydraulic model, haemodynamic changes caused by stenoses were assessed using an intravascular Doppler guide wire. MATERIAL AND METHODS: In defined stenoses (25, 50, 75 and 87.5% diameter ratio), and with and without collateral flow, a 0.018 inch (0.46 mm) 12 MHz Doppler guide wire was assessed. Flow velocity measurements were taken 20 mm proximal, in, and 20 mm distal to the stenoses. Average peak velocity (APV) and ratios of pre-/poststenotic velocities and pre-/intrastenotic velocities of APV were compared with the grade of stenosis. The degree of the stenosis calculated by the ratio of the cross-sectional area, using the pre- and intrastenotic APV, was correlated with the actual stenosis. RESULTS: The intrastenotic APV increased significantly (APV proximal to the stenosis 15.15 +/- 4.5 cm/s, intrastenotic APV 134.8 +/- 130.9, p < 0.01, Wilcoxon-Mann-Whitney test). The difference between APV pre- and poststenotic was not significant (p > 0.5). Concerning the grade of stenosis the ratio APV pre-/intrastenotic and the consecutively calculated cross-sectional area stenoses was the best predictor (correlation with the known cross-sectional area stenosis r = 0.94 Pearson). CONCLUSION: Using the Doppler guide wire, APV measurements pre- and intrastenotic enable a reliable quantification of the grade of stenosis. The stenosis calculated via the cross-sectional area correlates significantly with the actual stenosis.     

Infections and reinfections with avian pneumovirus subtype A and B on Belgian turkey farms and relation to respiratory problems

A longitudinal study was performed on six turkey farms in order to determine whether infections with avian pneumovirus (APV) occur and if they are related to outbreaks of respiratory problems in Belgium. Blood was taken at 1-3 week intervals of 20 identified animals during the fattening period. On five farms, the turkeys seroconverted against APV shortly after the appearance of respiratory problems. On two farms, where the animals had not been vaccinated against APV, attempts were made to isolate APV during the outbreaks. Two isolates were obtained: one of subtype A, the other of subtype B. These results indicate that the respiratory problems on five farms were related to an infection with APV. A second increase in APV antibody titres detected on four farms at the end of the fattening period, indicates that reinfections frequently occur. This is, to our knowledge, the first report on the isolation of an APV subtype A on the continent.     

六聚钒酸铵的等温绝热过程

利用ＤＳＣ差示扫描量热仪分析了六聚钒酸铵在氮气，氧气下的反应过程，利用ＤＳＣ动力学软件计算了六聚钒酸铵的反应动力学参数；讨论了等温，绝热过程中，反应百分数，反应时间，温度之间的相互关系。     

Selective impairment of long-term but not short-term conditional fear by the N-methyl-D-aspartate antagonist APV.

Previous research has indicated that the competitive N-methyl-D-aspartate (NMDA) antagonist APV ({dl}-2-amino-5-phosphonovalerate) prevents the Pavlovian conditioning of fear to contextual stimuli when tested 24 hrs, but not immediately, after training. The present study investigated this differential time-dependent effect of APV on fear conditioning. Rats were given either APV or saline and presented with 3 footshocks in a distinctive chamber. Promptly after the shock, rats that had received APV exhibited a species-typical fear response: freezing. However, the freezing lasted for only a short period of time (