Growth of covellite crystal onto azurite surface during sulfurization and its response to flotation behavior

In this work,the growth of copper sulfide crystal onto azurite surfaces during sulfurization and its response to flotation are investigated.Filed emission scanning electron microscopy-energy dispersive X-ray spectroscopy(FESEM) and X-ray diffraction(XRD) studies confirmed that the sulfurization of azurite is not limited to the mineral surface,but rather penetrates into the bulk to form covellite crystal(synCuS),creating favorable conditions for the stable adsorption of xanthate and greatly promoting the azurite flotation.Additionally,as demonstrated by X-ray photoelectron spectroscopy(XPS) and time of flight secondary ion mass spectrometry(TOF-SIMS) analyses,a redox reaction occurred during this process,and Cu(Ⅱ) onto the mineral surface was reduced to Cu(Ⅰ).Correspondingly,reduced S^(2-) was oxidized to(S_(2))^(2-),(S_n)^(-2),and even to deeper oxidation state S~0,(S_(x)O_(y))^(n-) and SO_(4)^(2-).Excess sodium sulfide strengthens copper sulfide to form onto the azurite surface,and provides enough raw material for crystal copper sulfide to grow,resulting in the formation of "flake-like" covellite with a better crystallinity.However,the floatability of azurite decreased dramatically under this condition,because the generated massive colloidal copper sulfide in flotation pulp deteriorates the flotation environment,resulting in a decreased effective adsorption of collector onto azurite surfaces.

The effects of cold stimulation and exercise on human health

Cold stimulation and exercise are two independent stimulus variables,each yielding unique impacts on human health.However,in many cases,individuals often encounter both factors simultaneously,particularly in colder regions where outdoor physical activity is prevalent.Despite numerous studies exploring the effects of cold exposure and exercise independently,only a limited number of comprehensive reviews have evaluated their combined influence on health.This review aims to bridge this gap by meticulously examining the potential benefits and detriments of both cold stimulation and exercise on human health.Specifically,the review focuses on their impacts on cardiovascular,respiratory,and immune function,as well as the favorable effects of moderate exercise on the human body.While evidence suggests that cold exposure can enhance health outcomes in certain disease contexts,it also poses risks,particularly for vulnerable populations.Furthermore,while moderate exercise is generally beneficial,engaging in physical activity in cold weather conditions can increase the risk of hypothermia,frostbite,and other cold-related injuries.Consequently,there is an urgent need to develop safe and effective guidelines for exercising in cold weather,particularly for individuals living in colder regions.This review emphasizes the necessity for further research on the combined effects of cold stimulation and exercise,with the goal of informing public health policies and guidelines for physical activity in cold weather conditions.

Role of ammonium sulfate in sulfurization flotation of azurite:Inhibiting the formation of copper sulfide colloid and its mechanism

In this study,the role of(NH_(4))_(2)SO_(4)during the sulfurization of azurite and its response to flotation were investigated.The flotation results showed that adding(NH_(4))_(2)SO_(4)prior to sulfurization decreased the formation of colloid in flotation pulp,and the floatability of the suppressed azurite caused by excess sodium sulfide was restored.After adding(NH_(4))_(2)SO_(4)prior to sulfurization,the formation of Cu(NH_(3))_(n) ^(2+)intermediate products changed the path of the sulfurization reaction,which slowed the direct impact of HSon the azurite surface.The nucleation rate was reduced,and the growth of copper sulfide crystal was improved.Covellite(syn,CuS)with larger crystal grains was formed on the azurite surface,thereby enhancing the mechanical stability of copper sulfide products onto the mineral surface.Therefore,the generated copper sulfide colloid significantly reduced,ultimately promoting the effective adsorption of xanthate on the azurite surface.

浅谈幼儿语言发展重要性及其培养策略

语言表达作为一种能力,要培养和发展就必须从幼儿时期开始,因为3~6岁是人一生中语言能力发展的关键期。在这个阶段,需重视幼儿语言能力的提升,让幼儿接受良好的语言教育,通过日常的语言训练活动和语言教学活动,有目的、有计划的训练幼儿语言表达能力。要培养好幼儿的语言表达能力,幼儿教师起着至关重要的作用。

SEC-10 is required for endocytosis in scavenger cells of Caenorhabditis elegans

The exocyst is an evolutionary conserved octameric complex involved in polarized exocytosis of proteins, neuite outgrowth and constitutive secretion. In addition to its role