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.     

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.     

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.     

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.     

内蒙古葱属植物的分类

本文确认了内葱属植物有32种,除葱、蒜、韭莱和洋葱4个栽培种外,共有野生种28个,本文首次记录了蜜囊葱在内蒙古的分布,比《内蒙古植物志》第8卷中葱属植物增加了阿拉善葱、鄂尔多斯葱、球序葱、毓泉葱和蜜囊葱5种,在内蒙古没有新疆韭、北韭的分布。     

近红外漫反射光谱法在川续断属植物鉴别中的应用

用近红外漫反射光谱法对川续断和部分川续断属其它植物进行鉴别,为川续断的品种鉴别和质量评价提供一种新的可能的方法和手段.分别对6种川续断属植物的近红外漫反射原始图谱和经过多元散射校正(MSC)和二阶导数(SD)处理后的图谱建立PLSDA模型.快速、准确地鉴别川续断和部分川续断属其它植物,同时不同产地的同种样品也得到了准确的区分.本方法快速.准确,不破坏样品,能用于鉴别川续断和川续断属其它植物.     

木犀属的分支系统学分析

基于22个广义的形态学性状,对木犀属进行了分支系统学分析,利用PAUP*计算机程序分别构建了最大简约树(MP)和距离树(NJ、UPGMA),所得树的拓扑结构基本一致.基本上支持P.S.Green的经典分类,圆锥花序组聚为一类,管花木犀组、离瓣木犀组和木犀组聚为一类.木犀组又可以分为2个分支:蒙自桂花、毛木犀、齿叶木犀、岛屿木犀、柊树、坛花木犀、毛柄木犀、狭叶木犀、宁波木犀聚为一个分支;野桂花、桂花、网脉木犀、短丝木犀、显脉木犀、细脉木犀、石山桂、高氏锐叶木犀、红柄木犀和锐叶木犀聚为另外一个分支.除了红柄木犀和无脉木犀外,其结果与经典分类完全相同.不过,管花木犀组、离瓣木犀组和木犀组之间的亲缘关系,在本研究中无法确定,需要分子手段进一步研究.     

神农架苹果属(Malus Mill.)野生资源调查报告

在实地考察采集基础上记载了7种（变种）神农架地区野生苹果属（Malus Mill．）植物,即山荆子、湖北海棠、垂丝海棠、陇东海棠及其变种光叶陇东海棠、滇池海棠及其变种川鄂海棠,报道了大面积野生湖北海棠群落和陇东海棠群落,并对神农架地区野生苹果属植物保护与利用提出相应的对策．     

中国近海蝉虾科Scyllaridae的研究（甲壳纲：十足目）

首次对中国近海的蝉虾科Ｓｃｙｌａｒｉｄａｅ种类作了系统的研究,现已知有１２种,对各种的文献记录及主要形态特征和地理分布作了记述,并对科的分属和属的分种作了检索．     

武陵山区湖南新记录植物（I）

报道了产自武陵山区的湖南植物分布新记录属1个:葶苈属Draba Linn..新记录种10个：柳叶黄肉楠Actinodaphne lecomtei、轮叶八宝Hylotelephium verticillatum、细叶景天Sedum elatinoides、三小叶翠雀花Delphinium trifoliolatum、毛黄堇Corydalis tomentella、纤细黄堇Corydalis gracillima、川鄂黄堇Corydalis wilsonii、葶苈Draba nemorosa、锐棱阴山荠Yinshania acutangula、双花堇菜Viola biflora.新记录亚种1个：湖北紫菫Corydalis acuminata subsp.Hupehensis.新记录变型1个：水棉花Anemone hupehensis f.alba.补充描述了1种,即石门小檗Berberis oblanceifolia的果实特征.归并了2种：保靖淫羊藿Epimedium baojingense、花叶尾花细辛Asarum caudigerum var. cardiophyllum.     

武陵山区湖南新纪录植物（Ⅴ）

报道湖南植物分布新纪录属1个,即鞭打绣球属Hemiphragma Less.;新纪录种13个,即光叶党参（Codonopsis cardiophylla Diels ex Kom.）、多毛沙参（Adenophora rupincola Hemsl.）、车前紫草（Sinojohnstonia plantaginea Hu）、湖北附地菜（Trigonotis mollis Hemsl.）、广西地海椒（Physaliastrum chamaesarachoides (Makino) Makino）、青杞（Solanum septemlobum Bunge）、美穗草（Veronicastrum brunonianum (Benth.) D. Y. Hong）、岩白翠（Mazus omeiensis H. L. Li）、鞭打绣球（Hemiphragma heterophyllum Wall.）、藓生马先蒿（Pedicularis muscicola Maxim.）、野芝麻马蓝（Pteracanthus lamius (C. B. Clarke ex W. W. Smith) C. Y. Wu et C. C. Hu）、日本黄猄草（Championella japonica (Thunb.) Bremek.）、紫苞野靛棵（Mananthes latiflora (Hemsl.) C. Y. Wu et C. C. Hu）、莸（Caryopteris divaricata Maxim.）,隶属6科,13属.     

贵州省云台山亚气生蓝藻植物初报

本文为贵州省舞阳河国家级风景区四大景区之一的云台山的亚气生蓝藻类的首次报道。据初步调查鉴定，共收录正气生蓝藻１８６种（含变种）。其中包括３个新种和４个新变种。     

中国地杨梅属植物的分类和地理分布

本文对中国地杨梅属植物进行了研究,记载了3个亚属,4个组,2个系,16种和1亚种,3变种,其中有5个新种和1新变种。同时还简述了本属植物的地理分布。     

绒螯蟹的分类与中华绒螯蟹种质资源研究进展

绒螯蟹主要有新绒螯蟹属(Neoeriocheir)和绒螯蟹属(Eriocheir)两个有效属,新绒螯蟹属仅有狭颚绒螯蟹(N.leptognatha)一个有效种,绒螯蟹属有直额绒螯蟹(E.recta)和日本绒螯蟹(E.japonica)两个有效种,日本绒螯蟹有日本绒螯蟹指名亚种,日本绒螯蟹中华亚种和日本绒螯蟹合浦亚种3个不同的地理亚种.分布在我国大陆的是日本绒螯蟹中华亚种和日本绒螯蟹合浦亚种.中华绒螯蟹在我国大陆被按水系分成南方组与北方组,组内水系间为同种不同地理种群.利用RAPD等分子生物学技术,可以鉴别出中华绒螯蟹的中华亚种和合浦亚种,各种群间的鉴别还有待于进一步研究.