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Computer Modeling in Engineering & Sciences 2024年第8期140卷 1405-1427页

作者： Sen-Hui Wang Xi Kang Cheng Wang tian-bing ma Xiang He Ke Yang School of Mechatronics Engineering Anhui University of Science and TechnologyHuainan232001China Institute of Energy Hefei Comprehensive National Science CenterHefei230031China

Accurately predicting the remaining useful life(RUL)of bearings in mining rotating equipment is vital for mining *** research aims to distinguish the features associated with the RUL of bearings and propose a prediction model based on these selected *** study proposes a hybrid predictive model to assess the RUL of rolling element *** proposed model begins with the pre-processing of bearing vibration signals to reconstruct sixty time-domain *** hybrid model selects relevant features from the sixty time-domain features of the vibration signal by adopting the RReliefF feature selection ***,the extreme learning machine(ELM)approach is applied to develop a predictive model of RUL based on the optimal *** model is trained by optimizing its parameters via the grid search *** training datasets are adjusted to make them most suitable for the regression model using the cross-validation *** proposed hybrid model is analyzed and validated using the vibration data taken from the public XJTU-SY rolling element-bearing *** comparison is constructed with other traditional *** experimental test results demonstrated that the proposed approach can predict the RUL of bearings with a reliable degree of accuracy.

关键词： Bearing degradation remaining useful life estimation RReliefF feature selection extreme learning machine

Synthesis of straight-chain C_(49)H_(100) alkane using a modular splicing strategy

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Journal of Energy Chemistry 2024年第5期92卷 414-421页

作者： bing ma Jingqing tian Xueling Lang Shutao Lei Bolong Li Chen Zhao Shanghai Key Laboratory of Green Chemistry and Chemical Processes School of Chemistry and Molecular EngineeringEast China Normal UniversityShanghai 200062China School of materials Science and Engineering Nankai UniversityTianjin 300350China

Ultra-long n-alkanes are highly valuable in both scientific research and as major constituents of specialty high-melting-point *** conventional methods(e.g.,Fischer–Tropsch(FT),ethylene oligomerization,and polyethylene cracking)typically resulting in wide n-alkane distributions,the elaborate design strategy presented herein allows the direct synthesis of pure,long n-alkanes using a modular splicing method with acetone,furfural,and fatty acid anhydrides or acyl chlorides as *** herein approach is based on a simple four-step catalytic reaction scheme involving C–C chain elongation and C–O bond *** synthesized pure n-alkanes had a carbon chain length as high as C_(49)(total yield of 49%).The synthesis approach also allows to selectively prepare n-alkanes with even and odd carbon numbers ranging from C15 to C_(49).This process represents a great breakthrough in the synthesis of long-chain pure n-alkanes,surpassing the carbon number limitations reported in previous methodologies.

关键词： Straight-chain alkane Aldol condensation F-Cacylation Hydrodeoxygenation

Capturing metal clusters at the strong-interaction region to reverse Ostwald ripening

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Science China materials 2024年第4期67卷 1363-1364页

作者： Shuheng tian Ding ma Beijing National Laboratory for Molecular Sciences New Cornerstone Science LaboratoryCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

High-temperature interactions induce sintering of metal nanoparticles(NPs) on heterogeneous catalyst surfaces, leading to reduced surface area and active site loss through Ostwald ripening [1]. This irreversible deactivation necessitates costly catalyst replacement, notably impacting metals like copper in hydrogenation and reforming reactions [2].

关键词： catalyst reforming irreversible

Numerical investigation on characteristics of interfacial wave of liquid film in gas-liquid two-phase flow using OpenFOAM

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Chinese Journal of Aeronautics 2024年第2期37卷 233-248页

作者： Xiaoqi ma Yueshe WANG Jiaming tian State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’an 710049China

Liquid film cooling as an advanced cooling technology is widely used in space *** operation of liquid film along the rocket combustion inner wall is crucial for thermal protection of rocket *** stability of liquid film is mainly determined by the characteristics of interfacial wave,which is rarely investigated right *** to improve the stability of thin film has become a hot *** view of this,an advanced model based on the conventional Volume of Fluid(VOF)model is adopted to investigate the characteristics of interfacial wave in gas-liquid flow by using OpenFOAM,and the mechanism of formation and development of wave is revealed intuitively through numerical *** effects from gas velocity,surface tension and dynamic viscosity of liquid(three factors)on the wave are studied *** can be found that the gas velocity is critical to the formation and development of wave,and four modes of droplets generation are illustrated in this ***,a gas vortex near the gas-liquid interface can induce formation of wave easily,so changing the gas vortex state can regulate formation and development of ***’s more,the change rules of three factors influencing on the interfacial wave are obtained,and the surface tension has a negative effect on the formation and development of wave only when the surface tension coefficient is above the critical value,whereas the dynamic viscosity has a positive effect in this ***,the maximum height and maximum slope angle of wave will level off as the gas velocity ***,the maximum slope angle of wave is usually no more than 38°,no matter what happens to the three factors.

关键词： Interfacial wave Gas-liquid Two-phase flow VOF model OpenFOAM

Progress on immuno-microenvironment and immune-related therapies in patients with pseudomyxoma peritonei

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Cancer Biology & Medicine 2024年第7期21卷 586-605页

作者： Qidi Zhao tian Wei Ru ma Yubin Fu Rui Yang Yandong Su Yang Yu bing Li Yan Li School of Clinical Medicine Tsinghua UniversityBeijing 100084China Department of Surgical Oncology Beijing Tsinghua Changgung HospitalSchool of Clinical MedicineTsinghua UniversityBeijing 102218China Department of Peritoneal Cancer Surgery Bejing Shijitan HospitalCapital Medical UniversityBejing 100038China

Pseudomyxoma peritonei(PMP) is an indolent malignant syndrome. The standard treatment for PMP is cytoreductive surgery combined with intraperitoneal hyperthermic chemotherapy(CRS + HIPEC). However, the high recurrence rate and latent clinical symptoms and signs are major obstacles to further improving clinical outcomes. Moreover, patients in advanced stages receive little benefit from CRS + HIPEC due to widespread intraperitoneal metastases. Another challenge in PMP treatment involves the progressive sclerosis of PMP cell-secreted mucus, which is often increased due to activating mutations in the gene coding for guanine nucleotide-binding protein alpha subunit(GNAS). Consequently, the development of other PMP therapies is urgently needed. Several immune-related therapies have shown promise, including the use of bacterium-derived non-specific immunogenic agents, radioimmunotherapeutic agents, and tumor cell-derived neoantigens, but a well-recognized immunotherapy has not been established. In this review the roles of GNAS mutations in the promotion of mucin secretion and disease development are discussed. In addition, the immunologic features of the PMP microenvironment and immune-associated treatments are discussed to summarize the current understanding of key features of the disease and to facilitate the development of immunotherapies.

关键词： Pseudomyxoma peritonei tumor immuno-microenvironment immune-related therapy mucin 2 GNAS mutation

Hydration lubrication modulated by water structure at TiO2–aqueous interfaces

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Friction 2024年第4期12卷 591-605页

作者： Pingsu ma Yuan LIU Ke HAN Yu tian Liran ma State Key Laboratory of Tribology in Advanced Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China

The nature of solid-liquid interfaces is of great significance in *** advances have been made in lubrication based on hydration ***,a detailed molecular-level understanding is still ***,we investigated water molecule behaviors at the TiO2-aqueous interfaces by the sum-frequency generation vibrational spectroscopy(SFG-VS)and atomic force microscope(AFM)to elucidate the fundamental role of solid-liquid interfaces in *** contributions of water structures and hydration effects were revealed,where water structures played the dominant role in lubrication for TiO2 surfaces of varying hydrophilicity,while hydration effects dominated with the increasing of ion *** lubrication is observed on the initial TiO2 surfaces with strongly H-bonded water molecules compared to the hydrophilic TiO2 surfaces with more disordered *** stable ordered water arrangement with strong hydrogen bonds and the shear plane occurring between the ordered water layer and subsequent water layer may play a significant role in achieving lower *** adsorbed hydrated molecules with the increasing ionic concentration perturb ordered water but lead to the enhancement of hydration effects,which is the main reason for the improved lubrication for both *** work provides more insights into the detailed molecular-level understanding of the mechanism of hydration lubrication.

关键词： hydration lubrication interfacial water structures hydration effects titanium dioxide(TiO2)

Photoinduced superlubricity on TiO_(2) surfaces

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Friction 2024年第3期12卷 428-438页

作者： Ke HAN Liran ma Yu tian Jianbin LUO State Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing 100084China Received:16 September 2022/Revised:28 October 2022/Accepted:27 December 2022The author(s)2022.

Superlubricity control is of great interest in both industry and scientific research,and several methods have been proposed to achieve this *** this work,ultraviolet(UV)light was introduced into titanium dioxide(TiO_(2))and silicon nitride(Si_(3)N_(4))tribosystems to accomplish photoinduced *** friction coefficients(COFs)between Si_(3)N_(4) balls and TiO_(2) plates in the mixtures of sulfuric acid(H^(2)SO_(4))solution and glycerol solution were obviously reduced,and the system entered the superlubricity region(COFmation of silica(SiO_(2))layers on the surfaces of Si_(3)N_(4) balls and the elastohydrodynamic effects were determined to be fundamental to the low friction in this experiment,and the enhancement of the combination between the TiO_(2) surface and the hydroxy group of glycerol by UV illumination was the key to the photoinduced superlubricity in this *** findings showed one method for achieving superlubricity by introducing a light field that could be further applied to special working conditions.

关键词： light control friction superlubricity glycerol titanium dioxide(TiO_(2))

Photo-induced grease/oil switched lubricant for friction regulation

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Friction 2024年第8期12卷 1696-1706页

作者： Zheng ZHANG Shuangxi TANG Liran ma Yu tian State Key Laboratory of Tribology in Advanced Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China

Controllable friction regulation has drawn much interest in both scientific and industrial *** there have been many researches on friction regulation by many physical fields and chemical ***-sensitive materials are promising because it is relatively easy to change their properties compared with ***,a new kind of photo-induced grease/oil switched lubricant is designed and shows great reversibility under ultraviolet(UV)and visible(Vis)*** viscosity can change more than 50 times under different irradiation,and the coefficients of friction(COFs)obviously increase under Vis irradiation and decrease under UV irradiation,which performs better than those of the common *** to the experimental results,the phenomena are contributed to the break and reconstruction of the three-dimensional network inside the *** a switchable grease/oil state under different irradiation,this work provides a new principle for designing a smart lubricant with controllable friction regulation.

关键词： photo-induced spiropyran switched lubricant friction regulation

Growth,optical dispersion and magnetic behavior of Dy^(3+) doped yttrium iron garnet crystals

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Journal of Rare Earths 2024年第6期42卷 1110-1117,I0004页

作者： Yating Fang Hui Shen Yudie ma Shijie Liao Shuang Xia tian tian Ding Zhou Yunfeng ma Jiayue Xu Institute of Crystal Growth School of Materials Science and EngineeringShanghai Institute of Technology National Engineering Center of Electromagnetic Radiation Control materials School of Electronic Science and EngineeringUniversity of Electronic Science and Technology of China

Y_(3)Fe_(5)O_(12)(YIG)crystals are highly desirable for the fabrication of mid-infrared isolators with the rapid growth of optical communications,although it is rather challenging to grow large size and high-quality single ***^(3+)doping is expected to improve the optical and magneto-optical prope ***,high quality Dy:YIG crystals and the adjustment of Dy^(3+)on the structure and optical behavior of YIG crystal remain unclear,impeding its practical ***,a series of Y_(3-x)Dy_(x)Fe_(5)O_(12)(x=0,0.5,1.0,1.5,3)solid solution crystals was grown by the flux-Bridgman method and single crystals up to 25 mm were *** the introduction of Dy^(3+),lattice parameters are gradually enlarged from 1.2379 nm(YIG)to 1.2420 nm(DyIG).Typical Dy^(3+)absorption peaks are observed around 1070,1265 and 1670 *** refractive index decreases from 2.37(500 nm)to 2.10(2500 nm)for YIG crystal,and it reduces from 2.47(500 nm)to 2.16(2500 nm)for DyIG *** optical bandgaps remain almost unchanged for Dy:YIG *** optical dispersion of the refractive indices was finely fitted by the Wemple and DiDomenico(WDD)and the Sellmeier models,*** the increase of Dy^(3+)content,the saturation magnetization(Ms)decreases significantly from 23.62 emu/g(YIG)to 5.33 emu/g(DyIG).Small coercive field is persisted for this system,endowing small external magnetic *** results provide valuable references for the manipulation of rare earths on the properties of magnetooptical crystals,which is beneficial to the design of high-performance garnet crystals for the application of optical switching and non-reciprocal related devices.

关键词： magneto-optical crystal Yttrium iron garnet Dy^(3+)doping Crystal growth Optical dispersion Rare earths

Interfacial tribochemical kinetics: A new perspective on superlubricity of diamond-like carbon films

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Science China(Technological Sciences) 2024年第7期67卷 2050-2052页

作者： CHEN WeiQi ma tian-Bao State Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing 100084China

Friction is considered one of the primary challenges affecting the performance of machine operations and is a significant source of energy loss in industrial applications. About 30%of disposable energy is consumed by ... 详细信息

关键词： kinetics friction operations