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.     

青海省三种常见棘豆主要营养成分研究

采用标准方法对青海省的甘肃棘豆,黄豆棘豆和宽苞棘豆风干样的主要营养成分进行了测定,结果为：甘肃棘豆,粗蛋白１２．６％,粗脂肪１．８％,粗纤维１６．７％,无氮浸出物５３．２％,粗灰分９．４％,钙０．８５％,磷０．２２％,黄花棘豆：粗蛋白１５．２％,粗脂肪１．３％,粗纤维１９％,无氮浸出物４８．３％,粗灰分９．７％,钙０．８０％,磷０．１４％,宽苞棘豆：粗蛋白１３．４％,粗脂肪１．６％,粗纤维１８．７     

甜荞部分营养成份分析及评价

经测定甜荞蛋白质含量为１０．３４％，必需氨基酸含量为４０８．１ｍｇ／ｇ ｐｒｏｔｅｉｎ。其限制性氨基酸仅为苏氨酸一种，甜荞氨基酸主分为９２分；甜荞矿物质元素含量丰富，锰含量为１０．１４，锌为２１．２，铁为２１．３倍，铬为２．５，钼为２．０４，锗为３．８，铜４．１，钙为１７２；其总黄酮含量为２０ｍｇ／１００ｇ。甜荞有很高的营养价值。并对中老年具有多种作用保健作用，是一种急待开发利用的天然营养保健食品     

苦荞部分营养成分分析及评价

经测定苦荞蛋白质含量为１０．１８％，必需氨基酸含量为４１３．７％ｍｇ／ｇｐｒｏｔｅｉｎ。其限制性氨基酸仅为苏氨酸一种，苦荞蛋白质的氨基酸评分为８８．５分。苦荞矿物质元素含量丰富，其中铁为３２．８，锰为１２．５，锌为２１．４，铬为２．５４，钼为１．６６，锗为４．２，铜为４．３，钙为１２７（单位均为ｐｐｍ）．总黄酮含量为１１０ｍｇ／１００ｇ。苦荞具有很高的营养价值，并对中老年人具有多种预防保健功能，是一种急待开发利用的天然营养保健食品资源。     

超声降粘实验研究

通过实验,研究了超声对原油的降粘效果,比较了不同含水率时超声对原油降粘作用的大小,发现原油含水率为32％时,降粘率仅为22．4％。含水率为50％时,降粘率可以达到83％,但此进形成的乳状液不稳定,在原油中掺入表面活性剂,再经超声处理后,形成的乳状液比较稳定,其粘度也较小。     

烯效唑和多效唑对万寿菊生育及生理活性的调控

在万寿菊幼苗上盆后，根灌不同浓度的烯效唑及多效唑，明显提高其过氧化物酶活性，提高叶绿素含量，增强光合速率，降低呼吸消耗，降低内源吲哚乙酸含量，进而显著缩短节间，抑制其株高，减少叶面积，增加叶厚，增加花朵数，从而使其花艳叶绿，提高观赏价值．在低浓度下，烯效唑的活性明显大于多效唑     

从菜子油中提取磷脂的研究

进行了从菜子油中提取磷脂方法的研究。试验证明,菜子油水化脱磷的加水量为0.85％～1％,水化温度为70℃～80℃,水化时间60min,搅拌速度80r/min,第一次萃取加丙酮为10∶1,萃取时间为30min,制取磷脂得率较高。试验还证明,以直接用含50％水分的粗磷脂加丙酮萃取效果较好,去油磷脂得率较高。     

黑龙江地区小麦麸皮化学组成分析

以我国黑龙江地区的小麦麸皮为原料,对其化学组成成分进行了定量分析,实验测得小麦麸皮中灰分质量分数5．41％、木质素质量分数6．01％、淀粉质量分数25．90％、脂肪质量分数3．45％、戊聚糖质量分数19．42％、综纤维素质量分数46．05％、纤维素的质量分数2．35％及总糖质量分数89．62％,实验结果表明,黑龙江地区的小麦麸皮中综纤维素含量较高,其中以半纤维素为主;戊聚糖含量较高,木质素含量低,易于提取戊聚糖,适应于作为制备功能性食品低聚糖的原料。     

唐古特虎耳草叶绿体和线粒体超微结构的研究

通过对生长在青藏高原东北部高海拔地区的唐古特虎耳草（Ｓａｘｉｆｒａｇａｔａｎｇｕｔｉｃａ）叶绿体和线粒体超微结构的分析表明：叶绿体长度缩短,厚度增加,局部有损伤,基粒垛叠程度小,类囊体有肿胀现象。线粒体的形态由棒状变为球状,被膜不整齐,局部有损伤,嵴的数目少而且有肿胀现象。这些特征的出现,是与青藏高原强辐射,低气压,高寒的生态环境密切相关。     

Measurements of leucocyte membrane elasticity based on the optical tweezers

A 1-μm in diameter polystyrene bead coated with lectin is trapped by optical tweezers whics is formed by a focused laser beam (740nm).A leucocyte adhered to the bottom of sample cell is chosen to close to the trapped bead.When their stable combination is confirmed,the leucocyte is displaced by moving the sample stage.A“tether”is then formed between the trapped bead and the membrane.The force acting on the tether is measured by a detector equipped on the optical tweezers system.The deformation of the membrane is diverse in different contact conditions.When the contact area is small,the tether is very thin and the force on it is 7.4pN(10^-12N),while the tether is much thicker under a larger contact area and its corresponding force is about 14pN.It is presumed that the latter is related to the deformation of cytoskeleton.     

康德至善论与康德伦理学

康德的至善概念实际上有四种含义，即“最高的善”——德性、“完满的善”——德性与幸福的统一、人类“共同的善”——“伦理共同体”、“最高的本源的善”——上帝。四种至善及其逻辑关系不仅形成了康德的至善论思想，而且构成了康德伦理思想的主要内容，反映了康德伦理学的逻辑发展。