High-quality lanthanum acetate was prepared by concentration crystallization of recycled mother liquor, and the recycled lanthanum acetate mother liquor for some times was separated for extraction reaction with P507 and then transformation into lanthanum chloride solution with hydrochloric acid.The effects of phase ratio, reaction temperature and time on the extraction efficiency were studied.The results show that the quality of lanthanum acetate is not affected by crystal precipitation from the recycled mother li-quor.Under the conditions of O/A phase ratio 4∶1,extraction temperature 35 ℃,and reaction time 6 min, the rare earth extraction efficiency from the mother liquor is optimal, which can smoothly realize the maximum resource utilization of mother liquor.

The reduction reaction of FeNb₂O₆ in microwave field was investigated by combining microwave heating with the carbon thermal reduction characteristics of FeNb2O6.The effects of temperature, particle size and carbon content on the reaction rate of microwave carbothermal reduction of FeNb₂O₆ were studied by microwave thermogravimetry, and the kinetics of the carbothermal reduction of FeNb₂O₆ in microwave field was also analyzed.The results show that FeNb₂O₆ has a good heating characteristics during microwave heating.Compared with conventional heating, FeNb₂O₆ can react at a lower temperature in microwave field under the same holding time and temperature.The weight loss rate of FeNb₂O₆ in microwave field increases with the increase of temperature, while the weight loss rate of microwave carbothermal reduction can be increased by increasing the particle size and carbon content at the same temperature.According to the kinetic analysis, the apparent activation energy of carbothermal reduction of FeNb₂O₆ in microwave field is 127.3 kJ/mol, which is lower than that of conventional heating, indicating that microwave heating can reduce the activation energy of the reaction.

A new scheme of reduction leaching with malic acid and sodium bisulfite followed by carbonate precipitation to regenerate cathode materials in spent lithium-ion batteries was proposed.The effects were investigated of stirring speed, organic acid concentration, sodium bisulfite dosage, leaching temperature and leaching time on the leaching rates of Li, Co, Ni and Mn.The results show that the optimum leaching conditions are as follows: stirring speed of 400 r/min, malic acid concentration of 2.5 mol/L,sodium bisulfite dosage of 1.25 mol/L,leaching temperature of 90 ℃ and leaching time of 120 min.Under the above conditions, the leaching rates of Li, Co, Ni and Mn reach 99.91%,98.14%,99.27% and 98.43%,respectively.The performance of the regenerated cathode material was analyzed by XRD,SEM and electrochemical test.The results show that the first cycle discharge specific capacity of the regenerated LiNi_0.5Co_0.2Mn_0.3O₂ cathode material is 175.5 mA·h/g, and its capacity retention rate is up to 71.96% after 200 cycles.The performance of the regenerated cathode material is relatively excellent.

The application of carbon materials in lithium-oxygen and lithium-carbon dioxide batteries is reviewed, including commercial carbon materials, carbon nano materials, heteroatom modified carbon materials, metal and its oxide modified carbon materials and biomass derived carbon materials.The reasons for the performance improvement of lithium-oxygen and lithium-carbon dioxide batteries with carbon materials as the air cathode are systematically discussed.It provides guidance for the future design of high-perfor-mance carbon materials applied in lithium-oxygen and lithium-carbon dioxide batteries.

The literatures of metal-based catalysts for Li-CO₂ batteries are reviewed.It is pointed out that the current noble metal-based catalysts have the characteristics of the highest catalytic activity but high price and small reserves.And transition metal-based catalysts are relatively cheap, but their catalytic activity is low.The role of different metal-based catalysts in Li-CO₂ batteries and their contribution to battery performance are summarized.It is proposed that the catalytic activity of the catalyst can be improved by structural design and multi-catalyst synergy.

In order to explore the effect of carbon content on the microstructure and properties of coarse grained cemented carbide with Co-Ni composite binder phase, the change rules of microstructure and pro-perties of WC-3 Co-3 Ni coarse grained cemented carbides with different carbon contents were studied by optical microscope, Rockwell hardness tester, coercivity tester and cobalt magnetometer.The results show that the coercive force of alloy increases with the increase of ball milling time, and reaches its maximum value when the ball milling time reaches 22 h.With the increase of carbon content, the WC grain morpho-logy is more angular, the dissolution-precipitation process makes WC grains coarser, the bending strength increases and the hardness decreases.When the milling time is prolonged, the increase of hardness caused by the decrease of carbon content is greater than that caused by the increase of carbon content.

WC/Co ultrafine grain cemented carbide is the ideal material for preparing high-performance me-tal cutting tools, but Co is a valuable resource.In order to find the bonding phase to replace Co and prepare WC-based ultrafine grain cemented carbide with excellent performance, using TiAl-xCo-Mo-Ni as the composite bonding phase, WC-based ultrafine grain cemented carbide was prepared by spark plasma sintering(SPS).The effects of SPS temperature and composition of the composite binder phase on the performance and microstructure of the cemented carbide were systematically analyzed.The results show that the ave-rage size of WC grains increases with the increase of sintering temperature, and the density and comprehensive mechanical properties are optimized at 1 400 ℃.When the composition is WC-10%(TiAl-Co-Mo-Ni),the cemented carbide has the highest density and the best comprehensive mechanical properties, and its density, average WC grain size, Vickers hardness and fracture toughness are respectively 98.3%,285 nm, 21.04 GPa and 16.95 MPa·m^1/2.

Composite TiC-ZrC steel bonded cemented carbide was manufactured by powder metallurgy techniques using TiC and ZrC as hard phases and other components such as Mo, Ni and C,and the effect of different TiC/ZrC mass ratio on the microstructure and properties of TiC-based steel-bonded cemented carbide was studied.The microstructure of the cemented carbide sample was analyzed by scanning electron microscope, and the hardness, bending strength and other mechanical properties of the samples were tested by Vickers hardness tester and universal electronic testing machine.The results show that when the TiC/ZrC mass ratio is 4/1,more shell phase of(Ti, Mo, Zr)C appears on TiC particles.As the mass ratio of TiC/ZrC decreases, the number of(Ti, Mo, Zr)C shell phase decreases.When the TiC/ZrC mass ratio is 4/1,the TiC particles in the cemented carbide are fine and uniformly distributed, and the mechanical pro-perties are the best with hardness and bending strength of 847.2 HV10 and 444.48 MPa, respectively.As the mass ratio of TiC/ZrC decreases, the ZrC grains in the cemented carbide gather together, resulting in the decrease of mechanical properties.

Using WC with particle size of 0.9 μm and 2.4 μm and Co as raw materials, the bimodal-grained WC-6%Co cemented carbides were fabricated by conventional roller ball milling and following vacuum sintering.The phase change and microstructure morphology of alloys were observed by XRD and SEM,and the effect of ball milling on the comprehensive mechanical properties of the alloy was studied by comparing the density, hardness, coercive force, bending strength and fracture toughness.The results show that with the increase of milling time and ball-to-powder ratio, WC grains gradually grow up, the percentage of(0001) basal plane of the alloy significantly increases, and the ratio of (1010) prism plane decreases.Compared with the ball milling time, increasing the ball-to-powder ratio can break and activate the fine WC particles.The comprehensive properties of the alloy prepared by pre-milling for 24 h with ball-to-powder ratio of 4∶1 and mixed ball milling for 24 h with ball-to-powder ratio of 2∶1 are the best, its density, hardness and coercive force are excellent, the bending strength is up to 3 250 MPa, and the fracture toughness reaches 11.5 MPa·m^1/2.

电信诈骗是指犯罪分子通过电话、网络和短信方式,编造虚假信息,设置骗局,对受害人实施远程、非接触式诈骗,诱使受害人给犯罪分子打款或转账的犯罪行为。一、网络购物诈骗(一)"网络钓鱼"诈骗"网络钓鱼"利用欺骗性的电子邮件和伪造的互联网站进行诈骗活动,为事主发送虚假链接或网页,事主在虚假网页上输入自己的银行帐号及密码后,交易往往显示不成功,让事主多次往里汇钱,甚至通过虚假网页捕获事主输入的帐号及密码信息,将事主的钱款秘密划走。