高铅Zn焙砂的浸出工艺行为研究

针对高铅Zn焙砂在浸出工艺中的行为,以Pb含量为7.20%的Zn焙砂为原料,开展了两段酸浸工艺的实验研究,将Zn焙砂中的Zn进行浸出,而Pb在渣中进行富集。实验探究了中性浸出、酸性浸出过程中温度、酸浓度、液固比、时间等不同因素对锌的浸出率和铅富集效率的影响。实验结果表明,在中性浸出过程中,Zn浸出率为90.73%,Pb在中浸渣中的富集含量为29.68%;中浸渣经酸浸处理,Zn浸出率可以达到98.60%,Pb在酸浸渣中的富集含量为36.54%。     

矿山企业矿产资源开发利用水平评价方法研究—以湖南省金矿矿山为例

河南某金矿具有嵌布关系复杂、氧化率高、泥化严重等特点,属于复杂难选泥质高氧化型金矿,选矿厂浮选指标不理想。为提高此类矿石的选矿回收率,开展了详细的实验研究,实验研究结果表明：采用单一浸出工艺和预氧化+浸出工艺均很难获得理想的浸出指标,Au浸出率仅为77.46%、80.28%;采用焙烧+浸出工艺可显著提高浸出指标,Au浸出率为93.66%,但技术经济性较差;采用浮选+浸出工艺可获得较为理想的指标,Au总回收率为94.25%,且工艺流程可操作性强。因此,浮选+浸出工艺对此类矿石具有较好的适应性,不仅可回收高度弥散分布在硫化物和脉石矿物中的超细微粒级金,而且粗粒级颗粒金也得到较好的回收。本研究为矿山企业的生产实践提供了重要借鉴。     

Relative Contribution of Blood Pressure and Renal Sympathetic Nerve Activity to Proximal Tubular Sodium Reabsorption via NHE3 Activity

We examined the effects of an acute increase in blood pressure (BP) and renal sympathetic nerve activity (rSNA) induced by bicuculline (Bic) injection in the paraventricular nucleus of hypothalamus (PVN) or the effects of a selective increase in rSNA induced by renal nerve stimulation (RNS) on the renal excretion of sodium and water and its effect on sodium-hydrogen exchanger 3 (NHE3) activity. Uninephrectomized anesthetized male Wistar rats were divided into three groups: (1) Sham; (2) Bic PVN: (3) RNS + Bic injection into the PVN. BP and rSNA were recorded, and urine was collected prior and after the interventions in all groups. RNS decreased sodium (58%) and water excretion (53%) independently of BP changes (p < 0.05). However, after Bic injection in the PVN during RNS stimulation, the BP and rSNA increased by 30% and 60% (p < 0.05), respectively, diuresis (5-fold) and natriuresis (2.3-fold) were increased (p < 0.05), and NHE3 activity was significantly reduced, independently of glomerular filtration rate changes. Thus, an acute increase in the BP overcomes RNS, leading to diuresis, natriuresis, and NHE3 activity inhibition.     

基于直流电压降法的传热管疲劳裂纹扩展速率测量

介绍了基于直流电压降法测量蒸汽发生器传热管690合金轴向疲劳裂纹扩展速率的销加载拉伸方法.该方法与其他方法相比较,可以直接采用原始管状材料,在线连续测量管状试样在不同应力强度因子下的疲劳裂纹扩展.通过对标准紧凑拉伸试样的类比分析,建立传热管试样的销加载拉伸模型,并对该模型进行电学和力学有限元模拟分析,确定直流电压降数据采集方法.验证试验采用核电蒸汽发生器用690合金传热管,分别研究了室温和高温325℃空气中载荷和温度对材料疲劳裂纹扩展速率的影响,试验结果采用Paris-Erdogan公式进行拟合,吻合度较好.扫描电镜下观察端口形貌,疲劳裂纹的扩展为穿晶形式,在穿晶断口上观察到明显的疲劳辉纹和微塑性区.     

溶解氧和温度对06Cr17Ni12Mo2Ti不锈钢在超临界水中应力腐蚀的影响

通过慢应变速率拉伸试验,在超临界水环境中研究了溶解氧和温度对06Cr17Ni12Mo2Ti不锈钢的应力腐蚀开裂倾向的影响规律.试验结果表明:在含不同溶解氧量(0/200/2000μg·kg^-1)的450℃和550℃超临界水环境中,不锈钢都呈现出不同程度的应力腐蚀开裂倾向.随着水中溶解氧含量的增加,不锈钢的应力腐蚀开裂倾向更为明显.随着温度的上升,应力腐蚀开裂倾向反而会下降.在含不同溶解氧量(0/200/2000μg·kg^-1)的650℃超临界水环境中,不锈钢只发生塑性断裂,未发现应力腐蚀开裂倾向,并且溶解氧对其影响也不是很明显.     

Analysis of Serum Advanced Glycation Endproducts Reveals Methylglyoxal-Derived Advanced Glycation MG-H1 Free Adduct Is a Risk Marker in Non-Diabetic and Diabetic Chronic Kidney Disease

Accumulation of advanced glycation endproducts (AGEs) is linked to decline in renal function, particularly in patients with diabetes. Major forms of AGEs in serum are protein-bound AGEs and AGE free adducts. In this study, we assessed levels of AGEs in subjects with and without diabetes, with normal renal function and stages 2 to 4 chronic kidney disease (CKD), to identify which AGE has the greatest progressive change with decline in renal function and change in diabetes. We performed a cross-sectional study of patients with stages 2–4 CKD, with and without diabetes, and healthy controls (n = 135). Nine protein-bound and free adduct AGEs were quantified in serum. Most protein-bound AGEs increased moderately through stages 2–4 CKD whereas AGE free adducts increased markedly. Methylglyoxal-derived hydroimidazolone MG-H1 free adduct was the AGE most responsive to CKD status, increasing 8-fold and 30-fold in stage 4 CKD in patients without and with diabetes, respectively. MG-H1 Glomerular filtration flux was increased 5-fold in diabetes, likely reflecting increased methylglyoxal glycation status. We conclude that serum MG-H1 free adduct concentration was strongly related to stage of CKD and increased in diabetes status. Serum MG-H1 free adduct is a candidate AGE risk marker of non-diabetic and diabetic CKD.     

水洗法去除蓖麻饼粕中蓖麻碱工艺优化

采用响应面法优化蓖麻饼粕中蓖麻碱的去除工艺,以蓖麻碱去除率为考察指标,在单因素基础上,选取料液比、处理温度及处理时间三个因素进行中心组合实验,通过响应面分析法对处理温度、处理时间及料液比进行优化,得到蓖麻碱去除工艺的最佳料液比为1:7,最佳处理温度80℃,最佳处理时间6h,此时蓖麻碱的去除率为84.12%。      

蓝宝石衬底CMP中氧化硅磨粒粒度分布对抛光液体系性能影响研究

目的 化学机械抛光(CMP)包含化学腐蚀和机械磨削两方面,抛光液pH、磨粒粒径和浓度等因素均会不同程度地影响其化学腐蚀和机械磨削能力,从而影响抛光效果。方法 采用30~150 nm连续粒径磨粒抛光液、120 nm均一粒径磨粒抛光液、50 nm和120 nm配制而成的混合粒径磨粒抛光液,分别对蓝宝石衬底晶圆进行循环CMP实验,研究CMP过程中抛光液体系的变化。结果 连续粒径磨粒抛光液中磨粒大规模团聚,满足高材料去除率的抛光时间仅有4 h,抛光后的晶圆表面粗糙度为0.665 nm;均一粒径磨粒抛光液中磨粒稳定,无团聚现象,抛光9 h内材料去除率较连续粒径磨粒抛光液高94.7%,能至少维持高材料去除率18 h,抛光后的晶圆表面粗糙度为0.204 nm;混合粒径磨粒抛光液初始状态下磨粒稳定性较高,抛光9 h内材料去除率较连续粒径磨粒抛光液高114.8%,之后磨粒出现小规模团聚现象,后9 h材料去除率仅为均一粒径磨粒抛光液的59.6%,18 h内材料去除率仅为均一粒径磨粒抛光液的87.7%,但抛光后的晶圆表面粗糙度为0.151 nm。结论 一定时间内追求较高的材料去除率和较好的晶圆表面粗糙度选用混合粒径磨粒抛光液,但需要长时间CMP使用均一粒径磨粒抛光液更适合,因此,在工业生产中需要根据生产要求配合使用混合粒径磨粒抛光液和均一粒径磨粒抛光液。     

稀土Y对铜线材抗氧化行为的影响机理研究

目的 针对纯铜线材的抗氧化性能不足问题,通过稀土微合金化制备了含微量Y元素的铜线材,研究稀土Y含量对铜线材抗氧化性能的影响。方法 采用扫描电子显微镜(SEM)、EDS能谱仪和X射线衍射仪等表征手段,分析了氧化膜脱落后基体表面形貌以及稀土Y元素在氧化过程中的存在形式与氧化膜的生长过程,揭示了添加稀土元素Y提高纯铜抗氧化性能的作用机理。结果 稀土Y的引入提高了纯铜线材的抗氧化性能,在600 ℃、10 h条件下,Cu-0.03Y线材相对于Cu线材氧化增重率由0.55%降低至0.2%,降幅达63%。稀土元素Y的添加使铜线材的(100)晶面占比减少,(111)晶面占比增多,基体表面易被活化的(100)原子面占比降低,铜线材的抗氧化性能提高。在Cu-0.1Y线材中稀土元素浓度较高时发生偏聚,稀土元素与氧的亲和力大于铜与氧的亲和力,偏聚处形成不连续的稀土氧化物,使氧离子与铜离子的接触反应面积增大,相比Cu-0.03Y线材抗氧化性能降低。结论 氧化过程中稀土离子的扩散速率慢、半径大,对铜离子的向外扩散起到阻碍作用,降低了铜离子的扩散速度,提高了铜线材的抗氧化性能。     

超声振动对W形金属密封环滚压成形不均匀变形的影响

为了提高W形金属密封环的成形质量,本文对W形金属密封环的超声振动滚压成形过程进行了研究。基于ABAQUS/Explicit有限元仿真软件,搭建了W形金属密封环超声振动辅助滚压成形三维有限元模型,研究了超声频率对环件不均匀变形的影响。结果表明：随着超声频率的增加,环件的应力不均匀度呈现先增后减的规律;环件的应变不均匀度呈现先略微减小,然后激增,再减小的规律;壁厚不均匀度呈现先减小,后增大,再减小的趋势。其中在超声频率为30kHz与40kHz时环件变形不均匀程度显著增大,这是由于环件产生了起皱现象造成的;通过对截面的应力、应变和壁厚不均匀分析,证明了波峰与波谷位置是成形过程中的关键部位。