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Preparation and properties of high-energy-density aluminum/boroncontaining gelled fuels

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Chinese Journal of Chemical Engineering 2024年第1期65卷 230-242页

作者： Yi chen kang Xue Yang Liu Lun Pan Xiangwen Zhang Ji-Jun Zou Key Laboratory for Green Chemical Technology of the Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Collaborative Innovative Center of Chemical Science and Engineering(Tianjin) Tianjin 300072China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China Zhejiang Institute of Tianjin University Ningbo 315201China

Energetic nanofluid fuel has caught the attention of the field of aerospace liquid propellant for its high energy density(HED), but it suffers from the inevitable solid-liquid phase separation problem. To resolve this problem, herein we synthesized the high-Al-/B-containing(up to 30%(mass)) HED gelled fuels, with low-molecular-mass organic gellant Z, which show high net heat of combustion(NHOC), density, storage stability, and thixotropic properties. The characterizations indicate that the application of energetic particles to the gelled fuels obviously destroys their fibrous network structures but can provide the new particle-gellant gelation microstructures, resulting in the comparable stability between 1.0%(mass) Z/JP-10 + 30%(mass) Al or B and pure JP-10 gelled fuel. Moreover, the gelled fuels with high-content Al or B exhibit high shear-thinning property, recovery capability, and mechanical strength, which are favorable for their storage and utilization. Importantly, the prepared 1.0%(mass) Z/JP-10 + 30%(mass) B(or 1.0%(mass) Z/JP-10 + 30%(mass) Al) shows the density and NHOC 1.27 times(1.30) and 1.43 times(1.21)higher than pure JP-10, respectively. This work provides a facile and valid approach to the manufacturing of HED gelled fuels with high content of energetic particles for gel propellants.

关键词： Gelled fuels Energetic aluminum/boron Low-molecular-mass organic gellant Fuel property

Text Difficulty Study:Do Machines Behave the Same as Humans Regarding Text Difficulty?

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Machine Intelligence Research 2024年第2期21卷 283-293页

作者： Bowen chen Xiao ding Yi Zhao Bo Fu Tingmao Lin Bing Qin Ting Liu Research Center for Social Computing and Information Retrieval Harbin Institute of TechnologyHarbin 150001China Fundamental Technology Center China Construction Bank Financial Technology Co.Ltd.Beijing 100033China

With the emergence of pre-trained models,current neural networks are able to give task performance that is comparable to ***,we know little about the fundamental working mechanism of pre-trained models in which we do not know how they approach such performance and how the task is solved by the *** example,given a task,human learns from easy to hard,whereas the model learns ***,difficulty-insensitive learning leads to great success in natural language processing(NLP),but little attention has been paid to the effect of text difficulty in *** propose a human learning matching index(HLM Index)to investigate the effect of text *** results show:1)LSTM gives more human-like learning behavior than ***,UID-SuperLinear gives the best evaluation of text difficulty among four text difficulty *** nine tasks,some tasks’performance is related to text difficulty,whereas others are not.2)Model trained on easy data performs best in both easy and medium test data,whereas trained on hard data only performs well on hard test data.3)Train the model from easy to hard,leading to quicker convergence.

关键词： Cognition inspired natural language processing psycholinguistics explainability text difficulty curriculum learning

Changes in global land surface frozen ground and freeze-thaw processes during 1950-2020 based on ERA5-Land data

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Advances in Climate Change Research 2024年第2期15卷 265-274页

作者： Yong YANG Ren-Sheng chen Yong-Jian ding Hong-Yuan LI Zhang-Wen LIU Qilian Alpine Ecology and Hydrology Research Station Key Laboratory of Ecological Safety and Sustainable Development in Arid LandsNorthwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 73000China State Key Laboratory of Cryospheric Sciences Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 73000China Shandong Provincial Key Laboratory of Water and Soil Conservation and Environmental Protection College of Resources and EnvironmentLinyi UniversityLinyi 276000China

Frozen ground(FG)plays an important role in global and regional climates and environments through changes in land freeze-thaw processes,which have been conducted mainly in different ***,the changes in land surface freeze-thaw processes under climate change on a global scale are still *** on ERA5-Land hourly land skin temperature data,this study evaluated changes in the global FG area,global land surface first freeze date(FFD),last freeze date(LFD)and frost-free period(FFP)from 1950 to *** results show that the current FG areas(1991-2020 mean)in the Northern Hemisphere(NH),Southern Hemisphere(SH),and globe are 68.50×10^(6),9.03×10^(6),and 77.53×10^(6)km^(2),which account for 72.4%,26.8%,and 60.4%of the exposed land(excluding glaciers,ice sheets,and water bodies)in the NH,SH and the globe,respectively;further,relative to 1951-1980,the FG area decreased by 1.9%,8.8%,and 2.8%,*** FG at lower latitudes degrades to intermittently FG,and intermittently FG degrades to non-frozen ground,which caused the global FG boundary to retreat to higher latitudes from 1950 to *** annual FG areas in the NH,SH,and globe all show significant decreasing trends(p<0.05)from 1950 to 2020 at-0.32×10^(6),-0.22×10^(6),and-0.54×10^(6)km^(2)per decade,*** FFP prolongation in the NH is mainly influenced by LFD advance,while in the SH it is mainly controlled by FFD *** prolongation trend of FFP in the NH(1.34 d per decade)is larger than that in the SH(1.15 d per decade).

关键词： Frozen ground Freeze-thaw processes Frost-free period First freeze date Global warming

Composite structure Al_(2)O_(3)/Al_(2)O_(3)-YAG:Ce/YAG ceramics with high color spatial uniformity for white laser lighting

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Journal of Advanced Ceramics 2024年第2期13卷 189-197页

作者： Pengfei Sang Le Zhang Jian kang Mingzhou Li Shiwei chen Peng Yang Bingheng Sun Yang Li Wieslaw Strek Hao chen Jiangsu Key Laboratory of Advanced Laser Materials and Devices School of Physics and Electronics EngineeringJiangsu Normal UniversityXuzhou 221116China Jiangsu Xiyi Advanced Materials Research Institute of Industrial Technology Xuzhou 221400China Xuzhou EAGLED Technology Co. Ltd.Xuzhou 221116China Xuzhou kangna Advanced Materials Technology Co. Ltd.Xuzhou 221116China Xuzhou Fuchang Electronic Technology Co. Ltd.Xuzhou 221116China Shanghai Institute of Optics Fine Mechanics Chinese Academy of SciencesShanghai 201800China School of Material Science and Engineering Shanghai Institute of TechnologyShanghai 201418China State Key Laboratory of Crystal Materials Shandong UniversityJinan 250100China Institute of Low Temperature and Structure Research Polish Academy of SciencesWroclaw 50-422Poland

Composite ceramic phosphor(CCP)is a candidate light-conversion material to obtain the high-quality laser lighting *** based on the transmissive configuration model could not simultaneously meet the requirements of angular color uniformity and high thermal *** this study,a novel composite structure ceramic was designed,including Al_(2)O_(3)-YAG:Ce/YAG layered ceramic with a size of 1 mm×1 mm for lighting,and Al_(2)O_(3) ceramic(φ=16.0 mm)was used as the wrapping material due to its outstanding thermal *** prepared ceramics exhibited excellent thermal performance and no yellow ring *** this design,we achieved the match of the intensity distribution of the blue and yellow lights,resulting in a high angular color uniformity of 0.9 with a view angle of±80°.All ceramics showed no luminous saturation phenomenon,even the laser power density was increased up to 47.51 W/mm^(2).A high-brightness white-light source with a luminous flux of 618 lm,a luminous efficiency of 126 lm/W,a CCT of 6615 K,and a CRI of 69.9 was obtained in the transmissive *** particular,the surface temperature of the ceramic was as low as 74.1℃ under a high laser radiation(47.51 W/mm^(2)).These results indicate that Al_(2)O_(3)/Al_(2)O_(3)-YAG:Ce/YAG composite structure ceramic is a promising luminescent material in the high-power laser lighting applications.

关键词： Al_(2)O_(3)/Al_(2)O_(3)-YAG:Ce/YAG angular color uniformity high thermal stability high-power laser lighting

Maximizing the scattering of multiwavelength phonons in novel biphasic high-entropy ZrCoSb-based half-Heusler alloys

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Journal of Materiomics 2024年第1期10卷 45-56页

作者： Rongchun chen Yu Yan Guangshu Li Ruonan Min Huijun kang Enyu Guo Zongning chen Xiong Yang Tongmin Wang Key Laboratory of Solidification Control and Digital Preparation Technology(Liaoning Province) School of Materials Science and EngineeringDalian University of TechnologyDalian116024China Ningbo Institute of Dalian University of Technology Ningbo315000China

The thermoelectric(TE)performance of p-type ZrCoSb-based half-Heusler(HH)alloys has been improved tremendously in recent years;however,it remains challenging to find suitable n-type ZrCoSb-based HH alloys due to their high lattice thermal conductivity(κ_(L)).In this work,n-type Zr_(1−x)Ta_(x)Co_(1−x)Ni_(x)Sb HH alloys were firstly designed by multisite *** evolution of the Raman peak proved that alloy scattering,phonon softening,anharmonicity,entropy-driven disorder,and precipitates had a combined effect on decreasingκ_(L)by 46.7%compared to that of pristine ***,Hf_(0.75)Zr_(0.25)NiSn_(0.99)Sb_(0.01)was introduced into Zr_(0.88)Ta_(0.12)Co_(0.88)Ni_(0.12)Sb to further suppressκ_(L).Remarkably,the grain size of the biphasic HH alloys was refined by at least one order of magnitude.A biphasic high-entropy HH alloy with y=0.2 exhibited the minimumκ_(L)of∼2.44 W/(m·K)at 923 K,reducing by 67.7%compared to that of ***,(Zr_(0.88)Ta_(0.12)Co_(0.88)Ni_(0.12)Sb)_(0.9)(Hf_(0.75)Zr_(0.25)NiSn_(0.99)Sb_(0.01))_(0.1)exhibited the highest TE figure of merit(∼0.38)at 923 *** cooperation between the entropy and biphasic microstructure resulted in multiscale defects,refined grains,and biphasic interfaces,which maximized the scattering of the multiwavelength phonons in HH *** work provides a new strategy for further reducing the grain size andκ_(L)of medium-and high-entropy HH alloys.

关键词： Biphasic half-Heusler alloys Thermoelectric properties Entropy engineering Multiscale defects

MoS_(x) nanowire networks derived from[Mo_(3)S_(13)]^(2−) clusters for efficient electrocatalytic hydrogen evolution

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Nano Research 2024年第8期17卷 6910-6915页

作者： Haoxuan Yu Junan Pan kang chen Wang Chao Zechao Zhuang Sizhuo Feng Jianmei chen Lingbin Xie Longlu Wang Qiang Zhao College of Electronic and Optical Engineering&College of Flexible Electronics(Future Technology) Nanjing University of Posts and Telecommunications9 Wenyuan RoadNanjing 210023China Department of Chemical Engineering Columbia UniversityNew YorkNY 10027USA Institute of Advanced Materials(IAM)&Institute of Flexible Electronics(Future Technology) Nanjing University of Posts and Telecommunications9 Wenyuan RoadNanjing 210023China

Precise design and synthesis of sub-nano scale catalysts with controllable electronic and geometric structures are pivotal for enhancing the hydrogen evolution reaction(HER)performance of molybdenum sulfide(MoS_(2))and unraveling its structure−activity *** leveraging transition molybdenum polysulfide clusters as functional units for multi-level ordering,we successfully designed and synthesized MoS_(x)nanowire networks derived from[Mo_(3)S_(13)]^(2−) clusters via evaporationinduced self-assembly,which exhibit enhanced HER activity attributed to a high density of active sites and dynamic evolution behavior under cathodic ***_(x) nanowire networks electrode yields a current density of 100 mA·cm^(−2) at 142 mV in 0.5 M H_(2)SO_(4).This work provides an attractive prospect for optimizing catalysts at the sub-nano scale and offers insights into a strategy for designing catalysts in various gas evolution reactions.

关键词： MoS_(x) nanowire networks [Mo_(3)S_(13)]^(2−)clusters hydrogen evolution reaction(HER) sub-nano scale

Epimedin B exhibits pigmentation by increasing tyrosinase family proteins expression,activity,and stability

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Journal of Pharmaceutical Analysis 2024年第1期14卷 69-85页

作者： chen Hong Yifan Zhang Lili Yang Haoyang Xu kang cheng Zhi Lv Kaixian chen Yiming Li Huali Wu Department of TCM Chemistry School of PharmacyShanghai University of Traditional Chinese MedicineShanghai200000China Department of Dermatology Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese MedicineShanghai200000China International Education College Shanghai University of Traditional Chinese MedicineShanghai200000China Shanghai Inoherb Cosmetics Co. Ltd.Shanghai200000China

Epimedin B(EB)is one of the main flavonoid ingredients present in Epimedium brevicornum Maxim.,a traditional herb widely used in *** previous study showed that EB was a stronger inducer of melanogenesis and an activator of tyrosinase(TYR).However,the role of EB in melanogenesis and the mechanism underlying the regulation remain ***,as an extension to our previous investigation,we provide comprehensive evidence of EB-induced pigmentation in vivo and in vitro and elucidate the melanogenesis mechanism by assessing its effects on the TYR family of proteins(TYRs)in terms of expression,activity,and *** results showed that EB increased TYRs expression through microphthalmia-associated transcription factor-mediated p-Akt(referred to as protein kinase B(PKB))/glycogen synthase kinase 3β(GSK3β)/β-catenin,p-p70 S6 kinase cascades,and protein 38(p38)/mitogen-activated protein(MAP)kinase(MAPK)and extracellular regulated protein kinases(ERK)/MAPK pathways,after which EB increased the number of melanosomes and promoted their maturation for melanogenesis in melanoma cells and human primary melanocytes/skin ***,EB exerted repigmentation by stimulating TYR activity in hydroquinone-and N-phenylthiourea-induced TYR inhibitive models,including melanoma cells,zebrafish,and ***,EB ameliorated monobenzone-induced depigmentation in vitro and in vivo through the enhancement of TYRs stability by inhibiting TYR misfolding,TYR-related protein 1 formation,and retention in the endoplasmic reticulum and then by downregulating the ubiquitination and proteolysis *** data conclude that EB can target TYRs and alter their expression,activity,and stability,thus stimulating their pigmentation function,which might provide a novel rational strategy for hypopigmentation treatment in the pharmaceutical and cosmetic industries.

关键词： Epimedin B Melanosome Tyrosinase Melanogenesis

Two Monte Carlo-based simulators for imaging-system modeling and projection simulation of flat-panel X-ray source

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Nuclear Science and Techniques 2024年第7期35卷 31-46页

作者： Meng-Ke Qi Ting He Yi-Wen Zhou Jing kang Zeng-Xiang Pan Song kang Wang-Jiang Wu Jun chen Ling-Hong Zhou Yuan Xu School of Biomedical Engineering Southern Medical UniversityGuangzhou510515China State Key Laboratory of Optoelectronic Materials and Technologies Guangdong Province Key Laboratory of Display Material and TechnologySchool of Electronics and Information TechnologySun Yat-sen UniversityGuangzhou510275China Department of Radiotherapy Guangdong Provincial People’s Hospital(Guangdong Academy of Medical Sciences)Southern Medical UniversityGuangzhou510515China

The advantages of a flat-panel X-ray source(FPXS)make it a promising candidate for imaging *** imaging-system modeling and projection simulation are critical for analyzing imaging performance and resolving overlapping projection issues in *** conventional analytical ray-tracing approach is limited by the number of patterns and is not applicable to FPXS-projection ***,the computation time of Monte Carlo(MC)simulation is independent of the size of the patterned arrays in *** study proposes two high-efficiency MC projection simulators for FPXS:a graphics processing unit(GPU)-based phase-space sampling MC(gPSMC)simulator and GPU-based fluence sampling MC(gFSMC)*** two simulators comprise three components:imaging-system modeling,photon initialization,and physical-interaction simulations in the ***-system modeling was performed by modeling the FPXS,imaging geometry,and *** gPSMC simulator samples the initial photons from the phase space,whereas the gFSMC simulator performs photon initialization from the calculated energy spectrum and fluence *** entire process of photon interaction with the geometry and arrival at the detector was simulated in parallel using multiple GPU kernels,and projections based on the two simulators were *** accuracies of the two simulators were evaluated by comparing them with the conventional analytical ray-tracing approach and acquired projections,and the efficiencies were evaluated by comparing the computation *** results of simulated and realistic experiments illustrate the accuracy and efficiency of the proposed gPSMC and gFSMC simulators in the projection calculation of various phantoms.

关键词： Flat-panel X-ray source(FPXS) Imaging-system modeling Projection simulation Monte Carlo-based simulators

Ultrafast Response and Threshold Adjustable Intelligent Thermoelectric Systems for Next‑Generation Self‑Powered Remote IoT Fire Warning

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Nano-Micro Letters 2024年第11期16卷 413-428页

作者： Zhaofu ding Gang Li Yejun Wang Chunyu Du Zhenqiang Ye Lirong Liang Long‑cheng Tang Guangming chen College of Materials Science and Engineering&College of Civil and Transportation Engineering Shenzhen UniversityShenzhen 518055People’s Republic of China College of Material Chemistry and Chemical EngineeringKey Laboratory of Organosilicon Chemistry and Material Technology of MoEHangzhou Normal UniversityHangzhou 311121People’s Republic of China

Fire warning is vital to human life,economy and ***,the development of effective warning systems faces great challenges of fast response,adjustable threshold and remote ***,we propose an intelligent self-powered remote IoT fire warning system,by employing single-walled carbon nanotube/titanium carbide thermoelectric composite *** flexible films,prepared by a convenient solution mixing,display p-type characteristic with excellent high-temperature stability,flame retardancy and TE(power factor of 239.7±15.8μW m^(-1) K^(-2))*** comprehensive morphology and structural analyses shed light on the underlying *** the assembled TE devices(TEDs)exhibit fast fire warning with adjustable warning threshold voltages(1–10 mV).Excitingly,an ultrafast fire warning response time of~0.1 s at 1 mV threshold voltage is achieved,rivaling many state-of-the-art ***,TE fire warning systems reveal outstanding stability after 50 repeated cycles and desired durability even undergoing 180 days of air ***,a TED-based wireless intelligent fire warning system has been developed by coupling an amplifier,analogto-digital converter and Bluetooth *** combining TE characteristics,high-temperature stability and flame retardancy with wireless IoT signal transmission,TE-based hybrid system developed here is promising for next-generation self-powered remote IoT fire warning applications.

关键词： Thermoelectric Self-powered IoT fire warning Ultrafast response Threshold adjustable