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Using WGM2012 to Compute Gravity Anomaly Corrections of Leveling Observations in China

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Journal of Geodesy and Geoinformation Science 2023年第1期6卷 88-94页

作者： Yanhui cai li ZHANG xu MA National Quality Inspecting and Testing Center of Surveying and Mapping Beijng 100830China

Gravity Anomaly Correction(GAC)is a very important term in leveling data processing.In most cases,it is troublesome for field surveyors to measure gravity when leveling.In this paper,based on the complete Bouguer Gravity Anomaly(BGA)map of WGM2012,the feasibility of replacing in-situ gravity surveying in China is investigated.For leveling application,that is to evaluate the accuracy of WGM2012 in China.Because WGM2012 is organized with a standard rectangle grid,two interpolation methods,bilinear interpolating and Inverse Distance Weighted(IDW)interpolating,are proposed.Four sample areas in China,i.e.,Hanzhong,Chengdu,linzhi and Shantou,are selected to evaluate the systems bias and precision of WGM2012.Numerical results show the average system bias of WGM2012 BGA in west China is about-100.1 mGal(1 mGal=10^(-5) m/s^(2))and the standard deviation is about 30.7 mGal.Tests in Shantou indicate the system bias in plain areas is about-130.4 mGal and standard deviation is about 6.8 mGal.All these experiments means the accuracy of WGM2012 is limited in high mountain areas of western China,but in plain areas,such as Shantou,WGM2012 BGA map is quite good for most leveling applications after calibrating the system bias.

关键词： Bouguer Gravity Anomaly(BGA) Gravity Anomaly Correction(GAC) precise leveling WGM2012 bilinear Interpolation Inverse Distance Weighted(IDW)interpolation

Amorphous alloys for electrocatalysis:The significant role of the amorphous alloy structure

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Nano Research 2023年第4期16卷 4277-4288页

作者： Xingyun li Weizheng cai Dong-Sheng li Jun xu Huabing Tao Bin liu School of Chemical and Biomedical Engineering Nanyang Technological University62 Nanyang DriveSingapore 637459Singapore Department of Biomaterials College of MaterialsXiamen UniversityXiamen 361005China Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials College of Materials and Chemical EngineeringChina Three Gorges UniversityYichang 443002China Fujian Provincial Key Laboratory for Soft Functional Materials Department of PhysicsResearch Institute for Biomimetics and Soft MatterXiamen UniversityXiamen 361005China State Key Laboratory of Physical Chemistry of Solid Surfaces Collaborative Innovation Center of Chemistry for Energy Materials(iChEM)College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Division of Chemical and Biological Chemistry School of Physical and Mathematical SciencesNanyang Technological University21 Nanyang LinkSingapore 637371Singapore

Amorphous alloys,also known as metallic glasses,are solid metallic materials having long-range disordered atomic structures.Compared to crystalline alloys,amorphous alloys not only have metallic characters,but also possess several distinct properties associated to the amorphous structure,such as isotropy,composition flexibility,unsaturated surface,etc.As a result,amorphous alloys offer a class of highly promising materials for catalyzing electrochemical reactions.In this minireview,the preparation,characterization and electrocatalytic performances of a variety of metallic amorphous alloy materials are summarized.The influences of the amorphous alloy structure on different electrochemical reactions are discussed.Finally,a summary on the advantages and challenges of amorphous alloys in electrocatalysis is provided,along with some perspectives about the future research directions.

关键词： amorphous alloys electrocatalysis nonperiodic atomic structure isotropy metastability

Fenton-reaction-triggered metabolism of acetaminophen for enhanced cancer therapy

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Chinese Chemical Letters 2023年第2期34卷 376-381页

作者： Fanwen Sun Yayun Peng Yanping li Menghan xu Ting cai State Key Laboratory of Natural Medicines Department of PharmaceuticsChina Pharmaceutical UniversityNanjing 210009China

Acetaminophen(APAP), a classic nonsteroidal anti-inflammatory drug(NSAID), has attracted much attention due to the overdose-induced hepatotoxicity in the past several decades. N-Acetyl-p-benzoquinone imine(NAPQI), the P450-dependent metabolism of APAP, leads to GSH depletion, protein binding, mitochondrial oxidative stress, and eventually the liver injury. Herein, we develop a Fe-based metal-organic framework(MOF) to deliver and transform acetaminophen into toxic “chemo” drug through the cascade reaction for enhanced cancer therapy. In the acidic tumor microenvironment, the Fe-based MOF collapses and releases abundant Fe ions to generate hydroxyl radicals(·OH) via Fenton reaction, subsequently catalyzing nontoxic APAP into toxic NAPQI. Meanwhile, NAPQI depletes intracellular glutathione(GSH) rapidly, leading to alleviating the antioxidant ability of cancer cells and amplifying Fenton activity. The intracellular oxidative stress and the toxic metabolite of APAP can provide a synergistic effect on antitumor activity.

关键词： Acetaminophen Metal-organic framework Fenton reaction Cancer therapy Nanocomposite

Water modeling on fluid flow and mixing phenomena in a BOF steelmaking converter

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Journal of Iron and Steel Research(International) 2024年第3期31卷 595-607页

作者： Xin-yu cai Hao-jian Duan Ding-han li Anjun xu li-feng Zhang School of Metallurgical and Ecological Engineering University of Science and Technology Beijing(USTB)Beijing 100083China School of Mechanical and Materials Engineering North China University of TechnologyBeijing 100144China

A 1∶8 physical water model was constructed to investigate the fluid flow and mixing phenomena in the basic oxygen furnace(BOF)converter.The particle image velocimetry was employed to measure the velocity distribution of the bath and the high-speed camera was applied to capture the cavity shape in the combined blowing BOF converter.The mixing time for varied operating conditions was measured by the stimulus-response approach.The cavity depth increased with the decrease in the lance height and the increase in the top gas flow rate while the bottom blowing gas had little influence on the cavity depth.The minimum cavity depth was obtained under the condition of a 69.8 m^(3)/h top gas flow rate,a 287.5 mm lance height and a 0.93 m^(3)/h bottom blowing gas flow rate,which was 161.2 mm.The mixing time decreased as the lance height decreased and the top blowing gas flow rate increased.The mixing time was first decreased and then increased with the increase in the bottom gas flow rate.With the condition of 69.8 m^(3)/h gas flow rate of top blowing,the 287.5 mm lance height and the 0.93 m^(3)/h gas flow rate of bottom blowing,the mixing time in the converter was 48.65 s.The empirical formula between the stirring power and the mixing time in the converter was calculated.

关键词： Water model Fluid flow Particle image velocimetry Mixing time BOF converter

Tailoring sulfur-doped and nitrogen-defective carbon nitride nanosheets for efficient photo-controlled radical polymerizations

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Science China Chemistry 2024年第7期67卷 2325-2334页

作者： xue li Meng Kai xu Yuan Huang Tao cai Key Laboratory of Biomedical Polymers of Ministry of Education College of Chemistry and Molecular SciencesWuhan University Wuhan University Shenzhen Research Institute

Despite the challenges that remain,the synergistic adjustment of various microstructures and photochemical parameters of graphitic carbon nitride(g-C3N4) in photocatalytic reactions holds promises for improving catalytic efficiency and reducing energy consumption.Herein,sulfur-doped and nitrogen-defective g-C3N4(n-SC3Nx) nanosheets were designed and elaborately synthesized.The resultant n-SC3Nxpossessed a precisely defined 2D layer structure with extensive porosity and incremental specific surface area.Enhanced photoinduced electron transfer-reversible addition-fragmentation chain transfer(PET-RAFT) polymerization of vinyl monomers with low dispersity,excellent temporal control and high chain-end fidelity was achieved under mild blue light irradiation in a nondegassed system.Owing to their ultrathin nanostructures with nitrogen defects and sulfur dopants,n-SC3Nxwas capable of catalyzing RAFT polymerization in aqueous solutions at significantly accelerated rates,which were nearly 8 times faster compared to bulk g-C3N4.The ease of separation and efficient reusability in subsequent polymerizations was enabled by the heterogeneous nature of n-SC3Nx.The appeal of this approach was illustrated by the fact that utilizing a reusable and metal-free photocatalyst in aqueous environments allowed for the synthesis of polymers with molecular weight up to 300 kg mol-1and a dispersity of 1.32.

关键词： graphitic carbon nitride nitrogen defects sulfur dopants PET-RAFT polymerization recyclability

Joint Optimization Scheme Based on Beam Selection and Interference Cancellation in Lens Millimeter Wave NOMA Systems

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China Communications 2022年第4期19卷 57-66页

作者： Lei xu Jing cai Jing Chang Hongyu Fang Xiaohui li School of Electronics and Information Engineering Anhui UniversityHefei 230601China

Non-orthogonal multiple access(NOMA)has been integrated in millimeter-wave(mmWave)Massive MIMO systems to further enhance the spectrum efficiency, but NOMA has not been fully considered in lens mmWave systems. The fusion of these two technologies requires the joint design of beam selection and interference cancellation. In addition, when users follow the spatial cluster distribution, although the user clustering schemes based on K-means algorithm have been applied, the influence of the virtual and actual cluster center users on achievable sum rate has not been differentiated and analyzed in detail. To solve the above problems, a joint optimization scheme is proposed to maximize the achievable sum rate. The optimization problem is NP-hard, which is solved by using the divide-and-conquer approach. Concretely,based on the signal power loss analysis of directional deviation, a beam selection algorithm is designed for inter-cluster interference cancellation based on the Kmeans algorithm. Further for intra-cluster interference cancellation, a power allocation algorithm based on the bisection method is designed to guarantee the fairness of users in each cluster. The simulation results show that the proposed scheme offers a significant performance improvement in terms of both achievable sum rate and energy efficiency, and it is suitable for the large-scale user scenario due to its low complexity.

关键词： lens mmWave systems NOMA user clustering beam selection power allocation

A new system for distinguishing native from exotic species in China

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Journal of Plant Ecology 2023年第2期16卷 213-217页

作者： Song-Zhi xu Han xu cai-Yun Zhao Zhen-Yu li School of life Sciences Nantong UniversityNantong 226019China Institute of Plant Quarantine Chinese Academy of Inspection and QuarantineBeijing 100176China State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China State Key Laboratory of Systematic and Evolutionary Botany Institute of BotanyChinese Academy of SciencesBeijing 100093China

Distinguishing between native and exotic species is important for the study of biogeography and taxonomy,species conservation,vegetation management and analysis of flora and fauna(Bean 2007).Although there is a wide range of definitions of indigenous plants in different countries across the world,most people defined indigenous plants as‘taxa that have originated in a given area without human involvement or that have arrived there without intentional or unintentional intervention of humans from an area in which they are native’(Pysek et al.2004).

关键词： taxonomy originated

Isolation of the cuspidal spectrum:The function field case

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Science China Mathematics 2022年第7期65卷 1331-1342页

作者： li cai Bin xu Yau Mathematical Sciences Center Tsinghua UniversityBeijing 100084China School of Mathematics Sichuan UniversityChengdu 610064China

Isolating cuspidal automorphic representations from the whole automorphic spectrum is a basic problem in the trace formula approach.For example,matrix coefficients of supercuspidal representations can be used as test functions for this.However,they kill a large class of interesting cuspidal automorphic representations.For the case of number fields,multipliers of the Schwartz algebra are used in the recent work(see Beuzart-Plessis et al.(2021))to isolate all the cuspidal spectrum.In particular,they are suitable for the comparison of orbital integrals.These multipliers are then applied to the proof of the Gan-Gross-Prasad conjecture for unitary groups(see Beuzart-Plessis et al.(2021,2022)).In this article,we prove the similar result on isolating the cuspidal spectrum in Beuzart-Plessis et al.(2021)for the function field case.

关键词： cuspidal spectrum Hecke algebra trace formula automorphic representation

Insights into the tribological behavior of choline chloride-urea and choline chloride-thiourea deep eutectic solvents

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Friction 2023年第1期11卷 76-92页

作者： Yuting li Yuan li Hao li Xiaoqiang FAN Han YAN Meng cai Xiaojun xu Minhao ZHU Key Laboratory of Advanced Technologies of Materials(Ministry of Education) School of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China Tribology Research Institute School of Mechanical EngineeringSouthwest Jiaotong UniversityChengdu 610031China

Deep eutectic solvents(DESs)have been considered as novel and economic alternatives to traditional lubricants because of their similar physicochemical performance.In this study,choline chloride(ChCl)DESs were successfully synthesized via hydrogen-bonding networks of urea and thiourea as the hydrogen bond donors(HBDs).The as-synthesized ChCl-urea and ChCl-thiourea DESs had excellent thermal stability and displayed good lubrication between steel/steel tribo-pairs.The friction coefficient and wear rate of ChCl-thiourea DES were 50.1%and 80.6%,respectively,lower than those of ChCl-urea DES for GCr15/45 steel tribo-pairs.However,for GCr15/Q45 steel,ChCl-urea DES decreased the wear rate by 85.0%in comparison to ChCl-thiourea DES.Under ChCl-thiourea DES lubrication,the tribo-chemical reaction film composed of FeS formed at the interfaces and contributed to low friction and wear.However,under high von Mises stress,the film could not be stably retained and serious wear was obtained through direct contact of friction pairs.This illustrated that the evolution of the tribo-chemical reaction film was responsible for the anti-friction and anti-wearproperties of the DESs.

关键词： deep eutectic solvents(DESs) tribo-chemical film von Mises stress lubrication mechanism