Thermoelectric properties and thermal stability of metal-doped cuprous sulfide thermoelectrics

Mn doping and S-evaporation are strategies used to improve the thermoelectric properties and thermal stability of cuprous sulfide thermoelectric materials. Cu_1.8S and Mn-alloyed Cu_1.8S powders were prepared via ball milling, and different samples were obtained via current-assisted sintering at different times. It was found that Mn and S-evaporation optimized the carrier concentration and thus improved the figure of merit (ZT) of the samples. The introduction of pore defects induced by S-evaporation also improved the ZT. The maximum ZT of the optimized sample reached 0.89 at 500 °C. Mn in the samples reacted with oxygen to form an oxide film on the surface of the block, which inhibited the kinetic process of Cu_1.8S decomposition and improved the thermal stability of the samples. However, the reaction between Mn and oxygen led to a continuous loss of metal cations in the material, resulting in changes in the thermoelectric properties.     

含重质油污泥非均相氧化降解特性及其强化机制

含油污泥广泛产生于石油开采、炼制与使用过程中。对含油污泥进行资源化与无害化低碳处理一直是行业的难题。以传统水洗处理后的含重质油污泥残渣为例,本文系统研究了采用过一硫酸盐-高铁酸盐-FeS（PFI）氧化体系对其进行氧化降解的规律及过程强化机制。结果表明PFI氧化体系能够对含重质油组分（胶质、沥青质等）的油泥残渣进行降解,将大分子物质转化为小分子有机物。然而,由于油泥固相颗粒多孔孔道吸附等原因,会有一部分的重质组分残留于孔道内,难以降解去除。此外,油泥经PFI氧化后,所得固体表面会覆盖一层二次产物氧化铁薄层,阻碍氧化剂分子进一步与石油分子的接触,从而降低氧化效果甚至终止氧化过程。采用表面酸性调控方法可以大幅度溶解氧化铁薄层,增加氧化剂与有机物的接触机会,从而强化残留重质油有机物降解率。     

活性碳纤维负载型脱硫剂在矿井气体环境条件下的应用

H₂S作为煤炭开采过程中经常会出现的气体,对煤矿的生产安全造成不利影响,必须进行脱除工作。然而煤矿中还可能存在其他组分的气体,这些气体可能会一定程度上影响H₂S的脱除。本文选取活性碳纤维分别负载氢氧化钠及氧化铜,并选取两种材料的最佳负载量。之后,模拟煤矿实际条件,探讨复合脱硫剂在实际矿井气氛条件下的脱硫性能。结果表明,煤体在受热情况下会产生的多组分混合性气体,这些气体会对脱硫剂性能产生极大的影响,当煤体温度升高,其产生的CO、CO₂等气体呈指数增大,并且会产生少量的CH₄、C₂H₆、C₂H₄、C₂H₂等气体,随着这些气体生成量增大,脱硫剂脱硫性能开始下降。且在矿井气体氛条件下SO₂气体的产生受到了抑制,特别在煤气组分含量大的情况下,SO₂气体甚至晚于H₂S气体出现。此外通过测量脱硫剂失活后的表面pH,发现即便在一些气体氛围下脱硫剂的脱硫时间更短,其脱硫后产物的表面pH极为相近,说明煤体产生的酸性气体CO以及CO₂等可能也被吸附到脱硫剂的表面上生成酸性物质。     

N-Positive ion activated rapid addition and mitochondrial targeting ratiometric fluorescent probes for in vivo cell H2S imaging

Heterocyclic compound quinoline and its derivatives exist in natural compounds and have a broad spectrum of biological activity.They play an important role in the design of new structural entities for medical applications.Similarly,indoles and their derivatives are found widely in nature.Amino acids,alkaloids and auxin are all derivatives of indoles,as are dyes,and their condensation with aldehydes makes it easy to construct reaction sites for nucleophilic addition agents.In this work,we combine these two groups organically to construct a rapid response site(within 30 s)for H₂S,and at the same time,a ratiometric fluorescence response is presented throughout the process of H₂S detection.As such,the lower detection limit can reach 55.7 nmol/L for H₂S.In addition,cell imaging shows that this probe can be used for the mitochondrial targeted detection of endogenous and exogenous H₂S.Finally,this probe application was verified by imaging H₂S in nude mice.     

The sulfide electrode in bacterial studies

The applicability of a glass/Ag, Ag₂S (silver sulfide coated silver) electrode, which is capable of selectively detecting the H₂S fraction of total reduced inorganic sulfur (S_tot) concentration in biological systems is demonstrated. This electrode was used to monitor photosynthetic sulfide oxidation by Chlorobium phaeobacteroides. The electrode was resistant to Pfennig's medium and bacterial attack and after five months of use showed a potential drift within ±2 mV corresponding to ±13% maximum. The results obtained in a batch type experiment of growth of Chlorobium at different pH values suggest that Chlorobium cells preferentially take up the HS⁻ ion rather than H₂S.     

新疆沙泉子铜镍硫化物矿原生地球化学异常分带特性研究

基性—超基性硫化物矿床是岩浆熔离作用的产物,其围岩蚀变通常不如热液矿床发育,以往研究普遍认为该类矿床元素分带特征不明显。在热液型矿床原生地球化学异常结构研究基础上,文章以新疆沙泉子基性—超基性岩铜镍硫化物矿为研究对象,对其原生地球化学异常分带特征进行了分析。研究结果表明,与热液型矿床相似,该矿床成矿元素Ni、Cu及伴生元素Co、Ag、As等形成的正异常不仅表现出十分明显的元素浓度分带现象,而且同时具有较为显著的元素分带特征,建立了沙泉子铜镍硫化物矿床元素分带序列:(As,Mo,Cl)—(Se,Ag,Bi)—(Te,Au,Co,S,Cu,Ni)。     

某复杂铜铅锌多金属硫化矿选矿试验研究

根据某铜铅锌矿矿石中铜、铅、锌等硫化矿物嵌布关系复杂、嵌布粒度极不均匀的特点,采用"铜铅混合浮选—混合精矿再磨—铜铅分离—混合浮选尾矿选锌"的工艺流程及合理的药剂制度,闭路试验获得良好的铜、铅、锌选矿技术指标,同时,矿石中的伴生银也得到了较好回收,铜、铅、锌及银的回收率分别达到65.98%、88.83%、85.31%、84.98%。     

含金铜硫矿石优先浮选与混合浮选对比试验

在对某含金铜硫矿石性质研究的基础上,采用优先浮选工艺与混合浮选工艺进行实验室小型闭路试验对比,探索两种工艺的最优流程与药剂制度,并对精矿、尾矿进行分析。结果显示优先浮选工艺在细度-74μm 90%时取得的指标最优,铜精矿品位为21.25%、回收率为91.62%、金品位为12.28 g/t、金回收率为70.26%;混合浮选工艺在磨矿细度为-74μm 80%时指标最优,与优先浮选工艺对比显示精矿铜品位下降2.10个百分点,回收率下降8.58个百分点,金品位下降2.47g/t,金回收率下降13.90个百分点。精矿指标显示优先浮选工艺明显优于混合浮选工艺,且优先浮选艺流程简单,操作过程稳定可靠,指标较好,药剂制度简单,易于控制,适用于生产。对类似的含金铜硫矿物浮选具有重要参考价值。     

白铅矿的硫化电位控制浮选机理研究

以乙基黄药为捕收剂,硫化钠为硫化剂,通过单矿物浮选试验系统地研究了白铅矿浮选时硫化钠用量、硫化时间、搅拌条件、加药方式以及矿浆p H对硫化过程中矿物的浮游性、矿浆电位、硫离子电极电位的影响。采用多元回归方法建立了浮选回收率与硫化电位的数学模型,数学模型很好地反映了两者之间的关系。使用相关系数法分析了各因素对硫化电位的影响趋势及两者间的相关性。利用Matlab数学软件拟合出硫化电位与主要影响因子间的数学模型方程,再结合回收率与电位的数学模型,可以实现对硫化过程及时、合理的调控。     

内蒙古某铜铅锌多金属矿选矿试验研究

以内蒙古某铜铅锌复杂多金属硫化矿为研究对象,在对该矿石工艺矿物学研究的基础上,进行了大量的探索试验研究。最终采用先磁选除铁—铜铅混合浮选—铜铅分离—铜铅尾矿选锌的工艺流程,以及应用新型高效铜铅捕收剂QF-11、抑制剂CMC等,获得了含铁49.42%、回收率为56.93%的磁精矿,含铜21.12%、回收率75.49%的铜精矿,含铅48.29%、回收率79.23%的铅精矿,含锌46.73%、回收率86.30%的锌精矿,银综合回收率76.60%,实现了对该矿石综合利用的目的。