具有良好可再生性的新型二氧化硅磁性氧化石墨烯纳米复合材料

Graphene oxide (GO) wrapped Fe₃O₄ nanoparticles (NPs) were prepared by coating the Fe₃O₄ NPs with a SiO₂ layer, and then modifying by amino groups, which interact with the GO nanosheets to form covalent bonding. The SiO₂ coating layer plays a key role in integrating the magnetic nanoparticles with the GO nanosheets. The effect of the amount of SiO₂ on the morphology, structure, adsorption, and regenerability of the composites was studied in detail. An appropriate SiO₂ layer can effectively induce the GO nanosheets to completely wrap the Fe₃O₄ NPs, forming a core-shell Fe₃O₄@SiO₂@GO composite where Fe₃O₄@SiO₂ NPs are firmly encapsulated by GO nanosheets. The optimized Fe₃O₄@SiO₂@GO sample exhibits a high saturated adsorption capacity of 253 mg·g?1 Pb(II) cations from wastewater, and the adsorption process is well fitted by Langmuir adsorption model. Notably, the composite displays excellent regeneration, maintaining a ~90% adsorption capacity for five cycles, while other samples decrease their adsorption capacity rapidly. This work provides a theoretical guidance to improve the regeneration of the GO-based adsorbents.     

微波预处理对复杂铜矿磨矿及浮选动力学的影响

The effect of CaCO₃, Na₂CO₃, and CaF₂ on the reduction roasting and magnetic separation of high-phosphorus iron ore containing phosphorus in the form of Fe₃PO₇ and apatite was investigated. The results revealed that Na₂CO₃ had the most significant effect on iron recovery and dephosphorization, followed by CaCO₃, the effect of CaF₂ was negligible. The mechanisms of CaCO₃, Na₂CO₃, and CaF₂ were investigated using X-ray diffraction (XRD), scanning electron microscopy and energy dispersive spectrometry (SEM–EDS). Without additives, Fe₃PO₇ was reduced to elemental phosphorus and formed an iron–phosphorus alloy with metallic iron. The addition of CaCO₃ reacted with Fe₃PO₇ to generate an enormous amount of Ca₃(PO₄)₂ and promoted the reduction of iron oxides. However, the growth of iron particles was inhibited. With the addition of Na₂CO₃, the phosphorus in Fe₃PO₇ migrated to nepheline and Na₂CO₃ improved the reduction of iron oxides and growth of iron particles. Therefore, the recovery of iron and the separation of iron and phosphorus were the best. In contrast, CaF₂ reacted with Fe₃PO₇ to form fine Ca₃(PO₄)₂ particles scattered around the iron particles, making the separation of iron and phosphorus difficult.     

不同硅饱和系数水榴石的碳酸化分解动力学

Carbonated decomposition of hydrogarnet is one of the vital reactions of the calcification–carbonation method, which is designed to dispose of low-grade bauxite and Bayer red mud and is a novel eco-friendly method. In this study, the effect of the silica saturation coefficient (x) on the carbonation of hydrogarnet was investigated from the kinetic perspective. The results indicated that the carbonation of hydrogarnets with different x values (x = 0.27, 0.36, 0.70, and 0.73) underwent two stages with significantly different rates, and the kinetic mechanisms of the two stages can be described by the kinetic functions R3 and D3. The apparent activation energies at Stages 1 and 2 were 41.96–81.64 and 14.80–34.84 kJ/mol, respectively. Moreover, the corresponding limiting steps of the two stages were interfacial chemical reaction and diffusion.     

一种超重力燃烧合成制备高性能高熵合金的新方法

A new method of high-gravity combustion synthesis (HGCS) followed by post-treatment (PT) is reported for preparing high-performance high-entropy alloys (HEAs), Cr_0.9FeNi_2.5V_0.2Al_0.5 alloy, whereby cheap thermite powder is used as the raw material. In this process, the HEA melt and the ceramic melt are rapidly formed by a strong exothermic combustion synthesis reaction and completely separated under a high-gravity field. Then, the master alloy is obtained after cooling. Subsequently, the master alloy is sequentially subjected to conventional vacuum arc melting (VAM), homogenization treatment, cold rolling, and annealing treatment to realize a tensile strength, yield strength, and elongation of 1250 MPa, 1075 MPa, and 2.9%, respectively. The present method is increasingly attractive due to its low cost of raw materials and the intermediate product obtained without high-temperature heating. Based on the calculation of phase separation kinetics in the high-temperature melt, it is expected that the final alloys with high performance can be prepared directly across master alloys with higher high-gravity coefficients.     

窄板坯结晶器内连铸工艺参数对钢液流场的影响

Computational simulations and high-temperature measurements of velocities near the surface of a mold were carried out by using the rod deflection method to study the effects of various operating parameters on the flow field in slab continuous casting (CC) molds with narrow widths for the production of automobile exposed panels. Reasonable agreement between the calculated results and measured subsurface velocities of liquid steel was obtained under different operating parameters of the CC process. The simulation results reveal that the flow field in the horizontal plane located 50 mm from the meniscus can be used as the characteristic flow field to optimize the flow field of molten steel in the mold. Increases in casting speed can increase the subsurface velocity of molten steel and shift the position of the vortex core downward in the downward circulation zone. The flow field of liquid steel in a 1040 mm-wide slab CC mold can be improved by an Ar gas flow rate of 7 L·min?1 and casting speed of 1.7 m·min?1. Under the present experimental conditions, the double-roll flow pattern is generally stable at a submerged entry nozzle immersion depth of 170 mm.     

电渣重熔脱硫技术研究进展

Electroslag remelting (ESR) gives a combination of liquid metal refining and solidification structure control. One of the typical aspects of liquid metal refining during ESR for the advanced steel and alloy production is desulfurization. It involves two patterns, i.e., slag–metal reaction and gas–slag reaction (gasifying desulfurization). In this paper, the advances in desulfurization practices of ESR are reviewed. The effects of processing parameters, including the initial sulfur level of consumable electrode, remelting atmosphere, deoxidation schemes of ESR, slag composition, melting rate, and electrical parameters on the desulfurization in ESR are assessed. The interrelation between desulfurization and sulfide inclusion evolution during ESR is discussed, and advancements in the production of sulfur-bearing steel at a high-sulfur level during ESR are described. The remaining challenges for future work are also proposed.     

利用皮秒激光烧蚀制备非球形铝纳米颗粒

We report the picosecond laser ablation of aluminum targets immersed in a polar organic liquid (chloroform, CHCl₃) with ~2 ps laser pulses at an input energy of ~350 μJ. The synthesized aluminum nanoparticles exhibited a surface plasmon resonance peak at ~340 nm. Scanning electron microscopy images of Al nanoparticles demonstrated the spherical morphology with an average size of (27 ± 3.6) nm. The formation of smaller spherical Al nanoparticles and the diminished growth could be from the formation of electric double layers on the Al nanoparticles. In addition to spherical aluminum nanoparticles, triangular/pentagonal/hexagonal nanoparticles were also observed in the colloidal solution. Field emission scanning electron microscopy images of ablated Al targets demonstrated laser induced periodic surface structures (LIPSSs), which were the high spatial frequency LIPSSs (HSF-LIPSSs) since their grating period was ~280 nm. Additionally, coarse structures with a period of ~700 nm were observed.     

Mineral transition and formation mechanism of calcium aluminate compounds in CaO?Al2O3?Na2O system during high-temperature sintering

The mineral transition and formation mechanism of calcium aluminate compounds in CaO?Al₂O₃?Na₂O system during the high-temperature sintering process were systematically investigated using DSC?TG, XRD, SEM?EDS, FTIR, and Raman spectra, and the crystal structure of Na₄Ca₃(AlO₂)₁₀ was also simulated by Material Studio software. The results indicated that the minerals formed during the sintering process included Na₄Ca₃(AlO₂)₁₀, CaO·Al₂O₃, and 12CaO·7Al₂O₃, and the content of Na₄Ca₃(AlO₂)₁₀ could reach 92wt% when sintered at 1200°C for 30 min. The main formation stage of Na₄Ca₃(AlO₂)₁₀ occurred at temperatures from 970 to 1100°C, and the content could reach 82wt% when the reaction temperature increased to 1100°C. The crystal system of Na₄Ca₃(AlO₂)₁₀ was tetragonal, and the cells preferred to grow along crystal planes (110) and (210). The formation of Na₄Ca₃(AlO₂)₁₀ was an exothermic reaction that followed a secondary reaction model, and its activation energy was 223.97 kJ/mol.     

含细夹层的分矿充填层中流动特性的可视化

Ore particles, especially fine interlayers, commonly segregate in heap stacking, leading to undesirable flow paths and changeable flow velocity fields of packed beds. Computed tomography (CT), COMSOL Multiphysics, and MATLAB were utilized to quantify pore structures and visualize flow behavior inside packed beds with segregated fine interlayers. The formation of fine interlayers was accompanied with the segregation of particles in packed beds. Fine particles reached the upper position of the packed beds during stacking. CT revealed that the average porosity of fine interlayers (24.21%) was significantly lower than that of the heap packed by coarse ores (37.42%), which directly affected the formation of flow paths. Specifically, the potential flow paths in the internal regions of fine interlayers were undeveloped. Fluid flowed and bypassed the fine interlayers and along the sides of the packed beds. Flow velocity also indicated that the flow paths easily gathered in the pore throat where flow velocity (1.8 × 10?5 m/s) suddenly increased. Fluid stagnant regions with a flow velocity lower than 0.2 × 10?5 m/s appeared in flow paths with a large diameter.     

湖北省五峰后河国家级自然保护区蛾类昆虫调查初报

报道了后河国家级自然保护区蛾类昆虫的初步调查结果．已鉴定出17科152种．其中天蛾科3种．木蠹蛾科1种,刺蛾科2种,毒蛾科7种．斑蛾科1种．虎蛾科3种．舟蛾科3种．鹿蛾科2种．钩蛾科6种,枯叶蛾科3种．灯蛾科18种．蚕蛾科1种,波纹蛾科2种,夜蛾科40种,尺蛾科41种,螟蛾科18种,燕蛾科1种．56种为湖北省新记录种．根据调查结果．对该自然保护区内蛾类昆虫的区系结构进行了分析,该地区蛾类昆虫以东洋种为主．     

北京麋鹿苑脊椎动物调查报告

麋鹿苑脊椎动物173种,隶属63科,29目.其中鱼类5目,9科,20种;两栖、爬行类3目,5科,8种;鸟类15目,4l科,133种;兽类6目,8科,12种.麋鹿苑脊椎动物的分布类型中,古北型41种,东洋型22种,东北型(东北地区及附近地区)22种,全北型15种,季风型9种,东北-华北型7种,华北型(主要分布于华北区)2种,东北型(东部为主)1种,中亚型(中亚温带干旱区)1种,喜马拉雅-横断山区型1种,南中国型2种,不易归类的,其中不少分布较广泛的29种.麋鹿苑鱼类以江河平原鱼类为主,其次还有东洋区印度平原鱼类,缺少北温带北部的北方平原鱼类.麋鹿苑脊椎动物的适应类型中,依赖湿地的41种,部分依赖湿地的有8种,不依赖湿地的有103种.麋鹿苑及其附近地区分布有国家Ⅰ级保护动物1种,国家Ⅱ级保护的16种,北京市一级保护的14种,北京市二级保护的51种.     

河北小五台山景观昆虫研究I.蝶类(一)

记述河北省小五台山景观昆虫鳞翅目蝶类8科75属117种,隶属于凤蝶科(3种),绢蝶科(3种),粉蝶科(13种),眼蝶科(20种),蛱蝶科(45种),灰蝶科(24种),弄蝶科(8种),喙蝶科(1种),其中14种为河北省新纪录.     

四川乐山市“三江”地区鸟类资源初步调查

2006年9月-2008年7月对四川乐山市“三江”地区鸟类资源进行了初步调查,共记录野生鸟类126种,分属16目35科．其中：优势种鸟类10种,常见种鸟类30种,稀有种鸟类B6种;留鸟58种,冬候鸟29种,夏候鸟21种,旅鸟18种;繁殖鸟79种,属东洋界43种,古北界11种,广布种25种;列入国家二级重点保护的鸟类4种,四川省重点保护的鸟类11种．讨论认为该地区鸟类具有重要的生态保护、科研与利用价值．同时,对该地区当前鸟类保护工作面临的主要问题进行了初步分析,并提出了相应的保护对策．     

网湖湿地自然保护区鸟类初步研究

2003年-2004年对湖北阳新网湖湿地自然保护区鸟类资源进行了调查,共记录到鸟类173种,隶属于15目38科．对鸟类的区系组成、居留型及重点保护鸟类进行研究,发现当地有繁殖鸟类104种（夏候鸟42种、留鸟62种）,非繁殖鸟类69种（冬候鸟51种、旅鸟18种）;古北种88种,东洋种62种,广布种23种;国家重点保护野生动物31种（其中,国家Ⅰ级保护动物3种,国家Ⅱ级的有28种）,有湖北省重点保护鸟类47种,被列入《濒危野生动植物种国际贸易公约》的鸟类有30种,被列入《中国濒危动物红皮书》的鸟类有12种．对鸟类的保护提出了存在的问题和建议．     

江西庐山自然保护区药用植物资源

据江西庐山自然保护区药用植物调查显示,该保护区共有1 859种药用植物,其中药用藻类4种,药用真菌22种,药用地衣10种,药用苔藓21种,药用蕨类131种,药用种子植物1611,常用中药328种,药用珍稀濒危植物137种,药用观赏植物180余种,药用特有种植物116种,农兽药植物169种。此外,还发现24种江西地区记录新分布,模式标本24种,以庐山、牯岭命名的植物有25种,并介绍了药用植物资源合理利用的概况。     

漓江河岸植物功能性状的分类研究

对漓江河岸植物的功能性状(生活型、生态类群、叶片质地、花序类型、果实类型、种子传播方式)进行统计分析。结果表明,漓江河岸共有乔木37种,灌木63种,亚灌木6种,藤本15种,草本182种;中生植物201种,湿生植物55种,半湿生植物38种,两栖植物9种;草质叶122种,纸质叶121种,革质叶片53种,肉质叶4种,膜质叶3种;总状花序62种,圆锥花序56种,聚伞花序54种,头状花序37种,伞房花序、轮伞花序和肉穗花序均仅6种,团伞花序、复伞房花序及复二岐聚伞花序均仅1种;蒴果66种,瘦果53种,核果41种,颖果28种,胞果、角果、翅果、分果、柑果和梨果分别仅为8种、7种、5种、3种、2种和1种;动物传播有111种,风媒传播83种,水媒传播58种,自体传播51种。     

贵州野生兰科植物地理分布研究

贵州有野生兰科植物76属268种,其中紫茎兰属Risleya、馥兰属Phyreatia等2属及紫茎兰Risleya atropurpurea、套叶馥兰Phyreatia evrardii、长距虾脊兰Calanthe masuca、裂距虾脊兰C.trifida、短序隔距兰Cleisostoma brevipes、长叶兰Cymbidiumerythraecum、马齿毛兰Eria szetschuanica、二叶兜被兰Neottianthe cucullata、丛生羊耳蒜Lipatis caespitosa、二褶羊耳蒜L.cathcartii、粗花茎鸢尾兰Oberonia integerrima、小叶鸢尾兰O.japonica等12种为贵州新记录。在省内自然分布不均,多数种类分布于自然保护区,其中兴义坡岗保护区102种居前,茂兰保护区87种,雷公山86种,梵净山71种。以生长母岩和土壤pH值划分,喜钙种类有157种,酸性土种类有76种,对土壤要求不甚严格种类有35种。按行政区划分黔西南州166种为第一位;黔南州136种居第二;黔东南州以88种排列第三;后面依次为铜仁地区76种,贵阳市67种,遵义市66种,安顺市56种,毕节地区45种,六盘水市37种。     

贵州南部喀斯特地区非褶菌名录I

本文报道了贵州南部喀斯特地区非褶菌物8科20属44种，其中鸡油菌科Canharellaceae 11种、齿菌科Hydnaceae3种、齿耳菌科Steccherinaceae3种、耳匙菌科Auriscaopiaceae1种、皱孔菌科Meruliaceae3种、杯珊瑚菌科Clavicoronaceae1种、丛枝珊菌科Ramariaceae7种、锁瑚菌科Clavulinaceae3种、珊瑚菌科Clavariaceae4种、革菌科Thelephoraceae3种、伏革菌科Corticiaceae1种、韧革菌科Stereaceae4种、牛舌菌科Fistuliaceae1种，有12囊为贵州省新纪录。     

贵州唇形科、苦苣苔科药用植物资源的调查研究

通过野外调查、标本采集、分类学研究及资料考证,基本搞清了贵州唇形科、苦苣苔科药用植物资源的种类与地理分布。结果发现贵州现有唇形科药用植物120种24变种,苦苣苔科药用植物42种4变种,其中1种为药用植物新种,2种为贵州地理分布新记录属和种,1种为贵州地理分布新记录种,7种4变种为贵州特有药用植物,31种3变种为贵州药用新资源。