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Effects of calcium compounds on the carbothermic reduction of vanadium titanomagnetite concentrate

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International Journal of Minerals,Metallurgy and Materials 2020年第3期27卷 301-309页

作者： Xiao-hui Li Jue Kou Ti-chang Sun shi-chao wu Yong-qiang Zhao School of Civil and Resource Engineering University of Science and Technology Beijing

Effects of calcium compounds on the carbothermic reduction of vanadium titanomagnetite concentrate(VTC) were investigated. It was found that calcium compounds had great effects on the metallization rate of the reduction product, the order of the metallization rate of reduction product being CaCO3 > no additive > CaSO4 > CaCl2, which indicated that the addition of CaCO3 was more conducive to promoting the reduction of iron than other calcium compounds. Gas analysis showed that there were mainly two processes in the carbothermic reduction of VTC, a solid–solid and a solid–gas reaction. The concentrations of CO and CO2 were highest when CaCO3 was added, while that in a roasting system decreased the most when CaCl2 was added. X-ray diffraction(XRD) analysis showed that calcium compounds could change the reduction process of ilmenite in VTC. The phase compositions of the reduction products were changed from metallic iron(Fe) and anosovite(FeTi2O5) to metallic iron(Fe) and perovekite(CaTiO3) when calcium compounds were added. Additionally, CaSO4 and CaCl2 could significantly promote the growth of metallic iron particles, though the existence of Fe-bearing Mg2TiO4 in reduction products was not conducive to the reduction of iron. The formation of FeS would further hinder the reduction of iron after adding CaSO4.

关键词： vanadium titanomagnetite concentrate calcium compounds carbothermic reduction metallic iron perovekite

Effect of additives on iron recovery and dephosphorization by reduction roasting-magnetic separation of refractory high-phosphorus iron ore

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International Journal of Minerals,Metallurgy and Materials 2021年第12期28卷 1908-1916页

作者： shi-chao wu Zheng-yao Li Ti-chang Sun Jue Kou Xiao-hui Li School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China

The effect of CaCO_(3),Na_(2)CO_(3),and CaF_(2) on the reduction roasting and magnetic separation of high-phosphorus iron ore containing phosphorus in the form of Fe_(3)PO_(7) and apatite was *** results revealed that Na_(2)CO_(3) had the most significant effect on iron recovery and dephosphorization,followed by CaCO_(3),the effect of CaF_(2) was *** mechanisms of CaCO_(3),Na_(2)CO_(3),and CaF_(2) were investigated using X-ray diffraction(XRD),scanning electron microscopy and energy dispersive spectrometry(SEM-EDS).Without additives,Fe_(3)PO_(7) was reduced to elemental phosphorus and formed an iron-phosphorus alloy with metallic *** addition of CaCO_(3) reacted with Fe_(3)PO_(7) to generate an enormous amount of Ca_(3)(PO_(4))_(2) and promoted the reduction of iron ***,the growth of iron particles was *** the addition of Na_(2)CO_(3),the phosphorus in Fe_(3)PO_(7) migrated to nepheline and Na_(2)CO_(3) improved the reduction of iron oxides and growth of iron ***,the recovery of iron and the separation of iron and phosphorus were the *** contrast,CaF_(2) reacted with Fe_(3)PO_(7) to form fine Ca_(3)(PO_(4))2 particles scattered around the iron particles,making the separation of iron and phosphorus difficult.

关键词： alloy phosphorus separation

Phase-dependent double optomechanically induced transparency in a hybrid optomechanical cavity system with coherently mechanical driving

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Chinese Physics B 2019年第7期28卷 233-242页

作者： shi-chao wu Li-Guo Qin Jian Lu Zhong-Yang Wang Shanghai Advanced Research Institute Chinese Academy of Sciences Shanghai 201210 China School of Mathematics Physics and Statistics Shanghai University Of Engineering Science Shanghai 201620 China University of Chinese Academy of Sciences Beijing 100049 China

We propose a scheme that can generate tunable double optomechanically induced transparency in a hybrid optomechanical cavity *** this system, the mechanical resonator of the optomechanical cavity is coupled with an additional mechanical resonator and the additional mechanical resonator can be driven by a weak external coherently mechanical driving *** show that both the intensity and the phase of the external mechanical driving field can control the propagation of the probe field, including changing the transmission spectrum from double windows to a *** study also provides an effective way to generate intensity-controllable, narrow-bandwidth transmission spectra, with the probe field modulated from excessive opacity to remarkable amplification.

关键词： double optomechanically induced transparency hybrid optomechanical cavity system pump– probe spectroscopy mechanical driving

Effect of perioperative chemotherapy on resection of isolated pulmonary metastases from colorectal cancer:A single center experience

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World Journal of Gastrointestinal Oncology 2024年第8期16卷 3457-3470页

作者： Zhao Gao Xuan Jin Ying-chao wu shi-Jie Zhang shi-Kai wu Xin Wang Department of Medical Oncology Peking University First HospitalBeijing 10000China Department of General Surgery Peking University First HospitalBeijing 10000China Department of Thoracic Surgery Peking University First HospitalBeijing 10000China

BACKGROUND Numerous studies have assessed surgical resection as a standard treatment option for patients with colorectal cancer(CRC)and resectable pulmonary metastases(PM).However,the role of perioperative chemotherapy after complete resection of isolated PM from patients with CRC patients remains *** hypothesize that perioperative chemotherapy does not provide significant survival benefits for patients undergoing resection of PM from *** To determine whether perioperative chemotherapy affects survival after radical resection of isolated PM from *** We retrospectively collected demographic,clinical,and pathologic data on patients who underwent radical surgery for isolated PM from *** survival(CSS)and disease-free survival were calculated using Kaplan-Meier ***-group differences were compared using the log-rank *** multivariate analysis,Cox regression was utilized when *** This study included 120 patients with a median age of 61.6 *** 5-year CSS rate was 78.2%,with 36.7% experiencing *** resection for isolated PM resulted in a 5-year CSS rate of 50.0% for second *** chemotherapy(P=0.079)did not enhance survival *** associated with improved survival included fewer metastatic lesions[hazard ratio(HR):2.51,P=0.045],longer disease-free intervals(HR:0.35,P=0.016),and wedge lung resections(HR:0.42,P=0.035).Multiple PM predicted higher recurrence risk(HR:2.22,P=0.022).The log-rank test showed no significant difference in CSS between single and repeated metastasectomy(P=0.92).CONCLUSION Perioperative chemotherapy shows no survival benefit post-PM resection in ***-free intervals and fewer metastatic lesions predict better *** metastasectomy is warranted for eligible patients.

关键词： Pulmonary metastasis Colorectal cancer Perioperative chemotherapy Survival Repeated pulmonary metastasectomy

Dynamical switchable quantum nonreciprocity induced by off-resonant chiral two-photon driving

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 31-37页

作者： Da-Wei Liu Zi-Hao Li shi-Lei chao Ying wu Liu-Gang Si School of Physics and Institute for Quantum Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China

Optical nonreciprocity,which refers to the direction-dependent emission,scattering and absorption of photons,plays a very important role in quantum engineering and quantum information ***,we propose an all-optical approach to achieve the optical dynamical switchable quantum nonreciprocity by an off-resonant chiral two-photon driving in a single microring cavity,which differs from the conventional nonreciprocal *** is shown that the optical field with time-dependent statistical properties can be generated and the nonreciprocity flips periodically,with switchable photon blockade and photon-induced tunneling *** find that the dynamical system is robust and immune to the parameter variations,which loosens the parameter range of ***,the time window for one-way quantum information is sufficiently wide and *** work opens a new idea for the current quantum nonreciprocal research,which can facilitate a memory functionality and be used for future inmemory superconducting quantum *** other nonreciprocal quantum devices,i.e.,dynamical switchable nonreciprocal squeezing and entanglement,may be inspired by our method,which is expected to have important applications in future quantum technology.

关键词： dynamical switchable nonreciprocity single-photon source chiral two-photon driving

Adverse effect of niobium and boron on hot deformation behavior of sulfur-containing steel

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Journal of Iron and Steel Research International 2024年第1期31卷 252-263页

作者： Guo-ning He shi-qi Wan Bo Jiang chao-lei Zhang Ya-zheng Liu Chun-jing wu School of Materials Science and Engineering University of Science and Technology BeijingBeijing100083China Institute for Advanced Materials and Technology University of Science and Technology BeijingBeijing100083China

The hot deformation behaviors of sulfur-containing gear steel 20MnCr5 containing three different contents of Nb and B(0,0.021%Nb,and 0.024%Nb-0.0022%B)were *** compression and tenssion tests were carried out by Gleeble3800 at the austenite region from 850 to 1150℃and the adverse effects of Nb and B were analyzed by the fracture,microstructure and precipitate *** compression tests showed that the proportions of instable area in hot processing maps of 0.021%Nb and Nb-B steels were higher and the deformability of Nb free steel was *** tensile deformation experiments showed that the reduction areas of Nb free,0.021%Nb and Nb-B steels were 92%-99%,84%-98%and 67%-97%,*** addition of Nb or Nb and B inhibited the dynamic recrystallization during hot deformation,and consequently,more deformed grains were then formed in 0.021%Nb and Nb-B steels thus to obtain the microstructure with worse uniformity and then deteriorate the *** addition,the interaction between inclusions and microalloyed elements was also *** particles of 0.021%Nb and Nb-B steels dynamically precipitated during deformation and precipitated together with MnS thus to worsen the deformability,resulting in the decrease of reduction area.

关键词： Hot deformation Gear steel Processing map Dynamic recrystallization Microalloying

Active flutter suppression of nonlinear fin-actuator system via inverse system and immersion and invariance method

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Chinese Journal of Aeronautics 2024年第4期37卷 343-362页

作者： Jin LU Zhigang wu chao YANG Chinese Aeronautical Establishment Beijing 100029China School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China

Structural nonlinearities such as freeplay will affect the stability and even flight safety of the fin-actuator *** is a lack of a practical method for designing Active Flutter Suppression (AFS) control laws for nonlinear fin-actuator systems.A design method for the AFS controller of the nonlinear all-movable fin-electromechanical actuator system is established by combining the inverse system and the Immersion and Invariance (I&I) ***,the composite control law combining the inverse system principle and internal model control is used to offset the nonlinearity and dynamics of the actuator,so that its driving torque can follow the ideal ***,the ideal torque of the actuator is designed employing the I&I *** unfavorable oscillation of the fin is suppressed by making the output torque of the actuator track the ideal *** simulation results reveal that the proposed AFS method can increase the flutter speed of the nonlinear finactuator system with freeplay,and a set of controller parameters is also applicable for wider freeplay within a certain *** power required for the actuator does not exceed the power that can be provided by the commonly used aviation *** method can also resist a certain level of noise and external disturbance.

关键词： Aeroelasticity Active flutter suppression Fin-actuator system Freeplay Inverse system Immersion and invariance

Intelligent feedforward gust alleviation based on neural network

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Chinese Journal of Aeronautics 2024年第3期37卷 116-132页

作者： Yitao ZHOU Zhigang wu chao YANG School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China

This paper proposes a neural network-based intelligent feedforward gust alleviation framework,which includes a neural network identification model and a neural network controller.A neural network training dataset is formed by collecting flight data and the gust data encountered during the aircraft flight.A neural network identification model is first trained to accurately predict the aircraft’s ***,based on the output of the identification model and the collected flight data,the parameters of the time-delay neural network controller are obtained through a learning *** simulation results show that the designed intelligent controller has good gust alleviation effects for both continuous turbulence excitation and discrete gust *** example,when the aircraft is 40000 kg and the flight speed is 0.81Ma,the controller achieves a 67.82%reduction in wingtip acceleration and a 35.90%reduction in center of mass acceleration under continuous turbulence *** considering the measurement uncertainties,such as noise existing in the collected data,the trained controller can still achieve an acceptable gust alleviation ***,considering a flight in which the aircraft mass is constantly changing,the intelligent controller,which continuously learns from new flight data,maintains a good gust alleviation effect throughout the flight.

关键词： Gust alleviation Intelligent control Feedforward control Neural networks Time-varying aircraft

Micro-aluminum powder with bi-or tri-component alloy coating as a promising catalyst:Boosting pyrolysis and combustion of ammonium perchlorate

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Defence Technology（防务技术） 2024年第3期33卷 100-113页

作者： chao Wang Ying Liu Mingze wu Jia Li Ying Feng Xianjin Ning Hong Li Ningfei Wang Baolu shi School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

A novel design of micro-aluminum(μAl)powder coated with bi-/tri-component alloy layer,such as:Ni-P and Ni-P-Cu(namely,Al@Ni-P,Al@Ni-P-Cu,respectively),as combustion catalysts,were introduced to release its huge energy inside Al-core and promote rapid pyrolysis of ammonium perchlorate(AP)at a lower temperature in aluminized *** microstructure of Al@Ni-P-Cu demonstrates that a three-layer Ni-P-Cu shell,with the thickness of~100 nm,is uniformly supported byμAl carrier(fuel unit),which has an amorphous surface with a thickness of~2.3 nm(catalytic unit).The peak temperature of AP with the addition of Al@Ni-P-Cu(3.5%)could significantly drop to 316.2℃ at high-temperature thermal decomposition,reduced by 124.3℃,in comparison to that of pure AP with 440.5℃.It illustrated that the introduction of Al@Ni-P-Cu could weaken or even eliminate the obstacle of AP pyrolysis due to its reduction of activation energy with 118.28 kJ/*** laser ignition results showed that the ignition delay time of Al@Ni-P-Cu/AP mixture with 78 ms in air is shorter than that of Al@Ni-P/AP(118 ms),decreased by 33.90%.Those astonishing breakthroughs were attributed to the synergistic effects of adequate active sites on amorphous surface and oxidation exothermic reactions(7597.7 J/g)of Al@Ni-P-Cu,resulting in accelerated mass and/or heat transfer rate to catalyze AP pyrolysis and ***,it is believed to provide an alternative Al-based combustion catalyst for propellant designer,to promote the development the propellants toward a higher energy.

关键词： Micro-aluminum powder(μAl) Nano-sized alloy coating Combustion catalyst Ammonium perchlorate Pyrolysis behavior Ignition and combustion