bluuebunny/crossref_metadata_2025 huggingface dataset:
Deformation of Lotus-Type Porous Copper in Rolling
Authors: Utsunomiya Hiroshi , Yukimoto Tsuyoshi , Sakai Tetsuo , Suzuki Shinsuke , Nakajima Hideo
Published: July 2010

Although forming of porous metal is demanded for industrial applications, the deformation characteristics have not been investigated sufficiently. In this study, lotus-type porous copper is processed by multi-pass cold rolling. At the early stage of rolling, the elongation of the porous copper in the rolling direction is small, and the porosity decreases almost linearly with the total reduction in thickness. It is found that pass schedule with small rolls and with small reduction per pass is effective to suppress pore closure. Hardness of the porous copper increases almost linearly with total reduction. If the effective total reduction is considered, the hardness change is similar to that of a nonporous copper.
High Purity Ti2AlC Powder Prepared by a Novel Method
Authors: Zhu Jian Feng , Qi Guo Quan , Wang Fen , Yang Hai Bo
Published: July 2010

Ti2AlC powders with high purity were successfully synthesized via high energy milling and heat treatment of Ti, C and Al powders. The effects of composition and thermal treatment on the formation and purity of Ti2AlC were examined in detail. The results shown a mechanically induced self-propagating reaction (MSR) was triggered to form Ti3AlC2, TiC and TiAlx during the high energy milling. When the as-milled powders were heat treated, Ti2AlC was initially formed by the reaction between TiAl and TiC. With continuously increasing temperature, Ti2AlC was also produced by the reaction between TiAl and Ti3AlC2.
Fabrication and Microstructure of Fe-Al Intermetallic Compound Powders by Mechanical Alloying
Authors: Jiang Tao , Jin Hai Yun
Published: July 2010

The Fe-Al intermetallic compound powders were fabricated by mechanical alloying and heat treatment process. In this research, the phase composition and microstructure of the Fe-Al intermetallic compound powders produced by different milling time and heat treatment at 800oC and 1000oC were investigated. The XRD patterns results showed that the Fe-Al intermetallic compound powders were fabricated by mechanical alloying for 60h. After heat treatment at 800oC and 1000oC, the Fe-Al intermetallic compound powders transformed into the Fe3Al powders. With the increase of milling time, the mechanical alloying extent of Fe-Al intermetallic compound powders would be increased remarkably, and the particles sizes decreased remarkably. The microstructure showed that the mean particles size of the Fe-Al intermetallic compound powders after milling for 60h was rather fine and about 4-5μm. The microstructures showed that mean particles size of the Fe3Al intermetallic compound powders produced by heat treatment at 800oC and 1000oC was also about 4-5μm.
Study on the Erosion Wear Properties of Reaction-Bonded SiC
Authors: Lu Zhen Lin , Xing Zhi Guo , Zhou Yong Xin , Xie Hui
Published: July 2010

The erosion wear behaviors and mechanism of reaction-bonded silicon carbide were studied by jet erosion wear tester and SEM surface analysis in this paper. The results show that the erosive wear rate of reaction-bonded silicon carbide would be increased and then decreased with the increase of erosion angle and would reach the peak value when the erosion angle is at 60º. It is lower than that of high chromium cast iron at all of test erosion angle. The reaction bonded SiC will show better erosion wear behaviors when the SiC particle size matches with the amount of free silicon. The erosion wear mechanism of reaction bonded SiC was analyzed.
Effect of SiC Particle Sizes on Erosion Wear Behaviour of SiC/Epoxy Resin Composite
Authors: Lu Zhen Lin , Xing Zhi Guo , Xie Hui , Zhou Yong Xin
Published: July 2010

The effect of SiC particles sizes on erosion wear behaviour of SiC/epoxy resin composite was studied on self-made slurry erosion wear tester. The results show that the erosion wear rate of SiC/epoxy resin composite would be decreased with the increase of SiC particle sizes. With the increase of impact angle, the erosion wear rate would be increased first, and then decreased, it would be peak value when the erosion wear test was carried out at 60° impact angle. When SiC particles were mixed with different sizes, the erosion wear rate of SiC/epoxy resin composite would be lowest. The erosion wear mechanism of SiC/epoxy resin composite was analyzed by observation of worn surface morphology.
Preferential Oxidation of CO over Pt Catalysts Supported on Mesoporous Aluminosilicates in the Presence of H2
Authors: Nakanishi Ryosuke , Inukai Keiichi , Maeda Masaki , Suzuki Masaya , Tai Yutaka
Published: July 2010

. Preferential oxidation (PROX) of CO in the presence of H2 is an important reaction to maintain stable operation of polymer electrolyte fuel cells (PEFCs) since their anode catalyst can be poisoned by trace amount of CO. In this study, we examined PROX reactions mediated by Pt catalysts prepared using several mesoporous silica and aluminosilicate supports such as imogolite (IM), allophane (AP), silica aerogel (SAG), and an amorphous hydroxyl aluminosilicate developed in our research group (HAS). The selectivity of CO oxidation gradually decreased from 80 to 60 % with increasing temperature from 323 to 473 K for Pt/HAS catalyst whereas it increased with temperature from 10 to 40 % for Pt/IM, Pt/AP, Pt/SAG catalysts. These results indicate that Pt supported on HAS may be effective for low-temperature PROX reactions.
Improvement of Oxidation Resistance of SiC/C (Graphite) Composites by Silicon Infiltration in Surface
Authors: Li Hong Wei , Zhang Qin , Jin Zhi Hao , Wang Ji Ping , Jin Hai Yun
Published: July 2010

SiC/C (graphite) composite ceramics with 20vol% flake graphite were fabricated by Plasma Activated Sintering (PAS) firstly; the composites treated by silicon infiltration in surface were oxidized from 800oC to 1500oC. Effect of silicon infiltration on the oxidation resistance of SiC/C (graphite) composites was characterized by TG/DTA, SEM and XRD. The results show that the graphite in surface of composites reacted with silicon to form a dense SiC film about 30μm-in-thickness. The oxidation resistance temperature was increased from 600oC to 1300oC. Below 1300oC, the surface of composites by silicon filtration was oxidized to form a dense continuous oxide film to hider the oxidation of graphite in matrix. At 1500oC, the surface oxide film was heavy damaged, and many micropores were produced; inner graphite was oxidized above 1300oC again.
Synthesis of SiOC Base Fibers from Silicone Resin with Low Carbon Content and Control of Surface Functionality by Metal Chloride Treatment in Vapor
Authors: Narisawa Masaki , Satoh Yayoi , Sumimoto Ryuichi , Kamegawa Takashi , Yamashita Hiromi
Published: July 2010

Melt spinnable silicone resin with a low carbon content was spun to fiber form with an averaged diameter of 16.8 m. When the resin fiber was cured by SiCl4 vapor and pyrolyzed at 1273K in inert atmosphere, Si-O-C fiber with smooth surface was obtained. The measured tensile strength was relatively low. The fiber, however, showed oxidation resistance during high temperature exposure under an air flow. When the fiber was cured by TiCl4 with an increased vapor pressure at 313K, 40% mass gain was observed after the curing. SiO2-TiO2 fiber was obtained by pyrolysis in an air flow, while SiOC-TiO2 fiber was obtained by pyrolysis in an inert atmosphere. Structure of TiO2 and the resulting fiber surface morphology strongly depended on the temperature and the atmosphere during the pyrolysis.
Synthesis and Characterization of Poly(ether ketone) Containing Side Sulfonic Acid Group for Proton Exchange Membrane Fuel Cell
Authors: Seo Dong Wan , Lim Young Don , Lee Soon Ho , Hong Tae Whan , Ur Soon Chul , Kim Il Ho , Kim Whan Gi
Published: July 2010

Poly(ether ketone)s (PEK) containing 25-75 mol % valeric acid were prepared with bisphenol A, 4,4-dichlorobenzophenone and 4,4-Bis(4-hydroxylphenyl)valeric acid using potassium carbonate in DMAc (dimethyl acetami de) at 165 °C. Copolymers containing carboxylacid group were reduced to hydroxy group by BH3 solution 1M in THF and NaBH4 co-catalyst. Sulfonated poly(ether ketone)s (S-PEK) were obtained by reaction of 1,3-propanesultone and the reduced copolymer (PEK-OH) with sodium methoxide. A series of copolymers were studied by 1H-NMR spectroscopy, differential scanning calorimeter (DSC), and thermo gravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymers with water and methanol. The S-PEK membranes exhibited proton conductivities from 1.31  10-3 to 3.52  10-3 S/cm, water swell from 12.70 to 35.50 %, IEC from 0.45 to 0.75 meq/g and methanol diffusion coefficients from 3.65  10-7 to 5.10  10-7 cm2/S at 25 °C.
Effect of Solution Temperature on Microstructure of 2205 Duplex Stainless Steel Welded Joints
Authors: Qiao Yuan Yuan , Zou De Ning , Li Jiao , Han Ying
Published: July 2010

The various temperature solution experiments were carried out in this paper, which for 2205 duplex stainless steel joints welded by manual arc welding. The evolutions of microstructure in pre/post solution treatment and the contents of ferrite phase were conducted by using optical microscope and ferrite scope detector. The analysis results in the welded, the heat affected and the base metal regions show that suitable solution treatment is effective to adjust the welded microstructure condition. The austenite in each region transformed into ferrite when the temperature enhanced from 1050 to 1200°C. This resulted in increasing the volume of ferrite and coarsening the grain. All microstructure characteristics of the three regions were taken into account, it deduced that the feasible solution temperature range was 1050~1100°C for 2205 duplex stainless steel welded joint.
Improvement of the Dry Friction and Wear Properties of the Si/SiC by Doping with Ni and PbO
Authors: Sang Ke Zheng , Wang Wen Chao , Geng Gang Qiang
Published: July 2010

The composite of silicon carbide with nickel and lead oxide was prepared by reaction sintered method. The phase compositions of the composites were studied by XRD, SEM and EDX. Friction and wear properties of the composites in dry conditions at the temperatures 15°C, 300°C and 600°C were tested using a pin-on-disk tribometer. The results showed that NiSi2 was formed and located between the SiC particles during sintering process. However the PbO was remained and distributed uniformly in the composites besides a little of Pb4SiO6 were formed. Friction coefficient of the composites decreased with the increase of the temperature and was about 0.2 at 600°C. And wear resistance of the composites was improved at all test temperatures comparing with that of the Si/SiC.
Fabrication and Thermal Property of AlN/ Epoxy Composites
Authors: Jin Hai Yun , Shi Hui Cheng , He Bo , Gao Nai Kui , Peng Zeng Ren
Published: July 2010

AlN filled epoxy composites were fabricated. The microstructure of composites was observed by SEM. The thermal conductivity was also measured. The results showed that microstructure of AlN/ epoxy composites was different with monolithic epoxy, it had some crystal-like characteristics. The grain size of AlN/ epoxy composites decreased with increasing AlN contents, and the thermal conductivity of composites increased with increasing AlN content. The thermal conductivity of 40wt. % AlN/ epoxy was about 3 times of monolithic epoxy.
Electroless Copper Plating on Ti3SiC2 Powder Surface Using Ascorbic Acid as a Reducing Agent
Authors: Cui Ya Ru , Xu Yun Hua , Li Kai Mao , Li Xiao Ming , Yang Jun , Wang Juan
Published: July 2010

Cu-coated Ti3SiC2 powder was fabricated by electroless copper plating method from CuSO4 using poisonless ascorbic acid (C6H6O4(OH)2) as reducing agent. Sensibilization and activation on Ti3SiC2 powder surface was performed by Sn-Ag catalyst system. Surfactants lauryl sodium sulfate (SDS) and Polysorbate 80 (Tween-80) were used as modifiers to control copper particle sizes and shapes. It is found that good pretreatment and activation can obtain fully-formed copper coating. The optimal copper deposition rate can reach to 2.053 g.dm-2.h-1 at 80°C . The best coating effect can be obtained in the samples modifying with 12g/L SDS+8ml/L Tween-80.
Dynamic and Static Properties of Wood-Plastic Composites Made of Recycled High-Density Polyethylene
Authors: Yu Gui Wen , Hu Ying Cheng , Gu Ji You
Published: July 2010

Three different nondestructive testing (NDT) methods were used on the wood-plastic composites (WPC), which were made of either recycled or virgin high-density polyethylene (HDPE) with poplar fibers as filler. The values of dynamic Young’s modulus of WPC based on recycled or virgin HDPE were measured by the different NDT methods, and the values of static bending modulus of elasticity (MOE) were also determined by three point bending test according to ASTM D790-03. The paper analyzed the variability of the dynamic young’s modulus of WPC based on recycled or virgin HDPE obtained with different NDT methods, and the correlativity was also estimated between the dynamic Young’s modulus and the static MOE of WPC based on recycled HDPE. These results suggest that WPC can be made of recycled HDPE, and the NDT methods can be appropriate to estimate the dynamic Young’s modulus of WPC based on recycled HDPE.
Synergistic Effects of Ferric Stearate, Ferrocene and NiDBC
Authors: Zhao Zhao , Luo Xue Gang , Lin Xiao Yan
Published: July 2010

The synergistic effects of ferric stearate, ferrocene and nickel N,N-dibuty dithiocarbamate (NiDBC) on photocatalysis were studied. Absorption intensities and redox abilities of these pholocatalyst compounds were investigated by Diffuse Reflectance Spectroscopy (DRS) and cyclic voltammetry. The study indicated that adding Ferric stearate to either ferrocene or NiDBC reduced the absorption intensity at the range of 400-550nm. Mixed with NiDBC, the absorbance ranges of ferric stearate and ferrocene were both broadened from 200-550nm to 200-700nm. The results of cyclic voltammetry indicated that redox ability of ferrocene was inhibited by ferric stearate. Furthermore, accession of NiDBC may enhance the inhibition. NiDBC reduced the redox ability of ferric stearate as well.
Adsorption of Hazardous Heavy Metals Using Reactive Inorganic Agents in Synthetic Wastewater
Authors: Kim Jong Oh , Lee Jin Woo
Published: July 2010

This study focused on the adsorption characteristics of hazardous heavy metals using reactive inorganic agents in synthetic wastewater. Basic properties of five reactive agents were analyzed by zeta potential, particle size, XRF and SEM. Zeta potential of five adsorbents was 45, 7, 14, -2 and 45 mV, respectively. Average particle size was in the range of 1.4 to 9㎛. By XRF analysis, main components were Na, Al, Si, S and Fe in reactive agents and no great differences in Mg, K, Ca and Ti components. As, Zn, Ni, Cu, Cr, Cd and Pb were used as target heavy metals. Adsorption capacity of Pb and Cu was in the order: TN 315Ny-T3>TN820L>TN315NY.
Fixed Bed Column Filled with Rice Husk for the Removal of Cu (II) from Aqueous Solution
Authors: Deng Zai Fang , Luo Xue Gang , Lin Xiao Yan
Published: July 2010

The performance of low-cost adsorbent such as rice husk fixed bed column in removing copper from aqueous solution were studied in this work. Different column design parameters like bed height, flow rate and initial concentration were calculated. It was found that at 10 mg/L concentration of Cu (Ⅱ) and at flow rate 5 mL/min with different bed depths such as 9, 12 and 15 cm, the breakthrough time increases from 150 to 260 min; the breakthrough time increases from 125 to 780 min with decreasing of flow rate from 15 to 5 mL/min and decreased from 260 to 50 min when initial concentration increased from 7 to 50 mg/L.
Study on the Energy Conversion from the Dynamic Load of Vehicles on the Road Using Piezoelectric Materials
Authors: Lee Jae Yun , Lee Moon Kyu , Oh Jae Geun , Kim Kwang Soo
Published: July 2010

Many researchers have studied the harvesting from discarded energy such as solar energy, wind and vibration because of the exhaustion of fossil fuel and the environmental pollution. Particularly, vibration-based energy harvesting has increasingly received an attention in last decade. Therefore, the aim of study is to analyze the characteristics of piezoelectric materials to be used in the energy conversion system on vehicle road. At first, the dynamic loads of vehicle on the road are measured with respect to the weight and speed prior to analyzing the characteristics of piezoelectric materials. Then, the energy conversion amount of piezoelectric element is quantified for its size and type under the load profiles. The vehicle dynamic load is the average of 200kgf. The result indicates that the dynamic vehicle load is less affected by the speed. The generated voltage is 1.8kV, and extracted energy is 0.11mJ from one under the load of 8kgf applied on piezoelectric element. The power extracted from one passenger vehicle is able to operate a sensor and transmit acquisition data.
AFM Studies on the Effect of Crystalline Interphase on Adhesion of Polyurethane Thin Film to Al Substrate
Authors: Kim Jang Soon , Lee Ok Hyoung , Lim Yun Soo
Published: July 2010

Polyurethanes crystallized at the aluminum surface, but the crystalline interphase varied with polyol OH number. Early stage of spherulite formation was characterized using AFM after removing amorphous polyurethane. The crystallite shapes of polyurethanes were correlated with the bond strength measured from indentation debonding. Interestingly, the samples involving non-specific shape of crystallites displayed high bond strength, while the polyurethanes with rod-like crystallite poorly adhered to aluminum substrate. Although crystallite shape did not unequivocally relate to bond strength, the results propose that there is a probable correlation.
Effect of Silicon Carbide Susceptor and Nickel Catalyst Content on Microwave Enhanced Thermal Conversion of Glycerol Waste
Authors: Hawangchu Yotwadee , Atong Duangduen , Sricharoenchaikul Viboon
Published: July 2010

Glycerol waste is by-product from the manufacturing of biodiesel by transesterification method containing impurities such as fatty acid, alcohol, spent catalyst, soap and water. Conversion of this waste to value added fuel products would not only improve economic of biodiesel production but also reduce environmental impact from this process. In this work, thermal conversion of glycerol waste by microwave that induced the heat required for initiating the reaction was carried out in a fixed bed quartz reactor using silicon carbide as the bed medium for microwave receptor as well as supporter for nickel catalyst. For non-catalytic reaction at 220W (700°C), carbon and hydrogen conversions were 22.89% and 19.59%, respectively. Gas production was 0.12 L/min syngas, 0.07 L/min H2, 0.82 MJ/m3 of LHV, and 1.27 H2/CO. In catalytic test, the highest syngas, H2, and LHV of 0.41 L/min, 0.23 L/min, and 9.18 MJ/m3, respectively, were obtained from 1%Ni/SiC while the highest H2/CO of 2.72 was obtained from 0.5%Ni/SiC. The 1%Ni/SiC test also resulted in the highest conversion of carbon and hydrogen as much as 79.50% and 83.26%, respectively. For comparison between fresh and regenerated catalysts, it was found that fresh catalyst performed significantly better that regenerated one in term of higher total conversion which may due to sodium deposition on spent catalyst surface.
Optical and Electrical Properties of Large Area SnO2: F Thin Films by Spray Pyrolysis
Authors: Zhao Gao Yang , Ren Yang , Gao Yun , Shen Jie
Published: July 2010

SnO2:F transparent conductive thin films with the area of 500×500mm2 were deposited on glass substrates by spray pyrolysis using SnCl4•5H2O and HF as the starting material and dopant respectively in methanol. The effects of HF concentration on the crystallized status, microstructures, transmittance, conductivity and low emissivity performances of the films have been studied. The results indicated that when HF content was excessive the solution presented strong acidity and it was difficult to obtain the uniform and dense films. However, when HF content was less, the conductivity of the film was poor. In this paper, The optimal mount of dopant HF was investigated and the molar ratio of Sn to F is 1:0.5. And also the uniform and dense SnO2:F transparent conductive oxide thin films can be obtained, whose resistivity reached 6.36×10-4Ω•cm, and the average transmittance in visible region was 80%.The low emissivity of this film was 0.25, which could be used as the Low-E glass.
Synthesis of Ti2AlC/Al2O3 Nanocomposites by High Energy Milling and Heat Treatment
Authors: Zhu Jian Feng , Qi Guo Quan , Yang Hai Bo , Wang Fen
Published: July 2010

Ti2AlC/Al2O3 nanocomposites were synthesized by high energy milling with Ti, C, Al and TiO2 as initial materials. The formation and evolution of phases in high energy milling and following heat treatment were investigated by X-ray diffractometer (XRD). The results show that the raw materials of Ti, C, Al and TiO2 were pulverized to ultrafine particles, and some of them transformed to amorphous phase. When the as-milled powders were heat treated in vacuum atmosphere, TiC was firstly produced and released large amount of reactive heat, which resulted in the reaction between Ti and Al to produce intermediate phases of the TixAly (TiAl3, TiAl, and Ti3Al) intermetallics. The reaction between Al and TiO2 produced Al2O3 phase. The TixAly intermetallics and the residual Ti and Al transformed to TiAl equilibrium phase. Finally, the TiAl intermetallics and the TiC reacted to yield Ti2AlC, which produced Ti2AlC/Al2O3 nanocomposite together with the former in-situ formed Al2O3.
Non-Emulsifiers Multi-Liquid-Crystallized-Phase Opalescence Glaze
Authors: Wang Fen , Li Qiang , Luo Hong Jie , Zhu Jian Feng
Published: July 2010

A multiphase opaque glaze with opalescent color was prepared in a basic composition glaze system with some phase separation agent. Effects of the B2O3/P2O5 ratio on the opacifying power and microstructure of the glaze, and opalescent mechanism were studied with scanning electron microscope (SEM), X-ray diffraction (XRD) and colorimeter. The results indicate that the droplets of the liquid phase separation and the crystals precipitated out in the glaze enhance the refraction and the scattering to light, resulting in glaze opacifying. With the mol ratio of B2O3/P2O5 as 1:2 in the selected composition and fired at 1200oC, the glaze possessed the highest whiteness. It is testified that a function transformation existed in glaze, which results in a multiphase coexistence, together with the size, content, contribution of the droplets and crystals have great influence not only on the opacity and the whiteness, but also on the bright and jade likeness of the glaze. The mathematical relation of opacity intensity and the characteristics of the particles in the glaze were also established based on the related analysis.
Algebraic string bracket as a Poisson bracket
Authors: Abbaspour Hossein , Tradler Thomas , Zeinalian Mahmoud
Published: July 2010

In this paper we construct a Lie algebra representation of the algebraic string bracket on negative cyclic cohomology of an associative algebra with appropriate duality. This is a generalized algebraic version of the main theorem of [AZ] which extends Goldman’s results using string topology operations.The main result can be applied to the de Rham complex of a smooth manifold as well as to the Dolbeault resolution of the endomorphisms of a holomorphic bundle on a Calabi–Yau manifold.
Behaviour of an Impact Attenuator for Formula SAE Car under Dynamic Loading
Authors: Boria Simonetta
Published: July 2010

A Formula SAE car must have structural devices that able to absorb most of the kinetic energy by means of progressive crushing therefore minimizing the forces and decelerations transferred to the occupant during frontal collisions. This paper presents the prediction of dynamic behaviour of an impact attenuator for a Formula SAE car under frontal impact conditions by using numerical and experimental approaches. The impact attenuator construction is a combination of sandwich panels and aluminium inner sheets. Firstly, the analysis of sandwich structures is carried out to better understand their behaviour and model them properly in the numerical simulation using LS-DYNA. In order to obtain the best configuration for the impact attenuator in terms of maximum absorbed energy, minimum deceleration and weight saving, its length and the number of inner sheets are optimised. Finally, a crash-test is performed on the impact attenuator to compare the experimental results with the numerical ones. The results obtained show that the impact attenuator is able to absorb the total impact energy with progressive and plastic deformation to contain the average deceleration as below 20 g.
Heavy Truck Occupant Safety Analysis using Finite Element Simulation
Authors: Ahmed R. Asad , Patra Abani K.
Published: July 2010

Numerical simulation of automotive crashes plays an important role in reducing the cost and time taken for predicting the results of a collision. The subject of interior crash protection has received much attention for automobiles than commercial vehicles like heavy trucks. This paper presents a Finite Element simulation of a heavy truck cab for safety analysis of its occupant during frontal collisions. The dashboard of the cab is modelled along with a steering column, floor and a roof top. Two type of acceleration pulses are used to calculate the Head Injury Criteria, Neck Injury and chest injury levels of the occupant. Three different scenarios of occupant namely without seatbelt, with seatbelt, and with both airbag and seatbelt are detailed. The results of simulation have demonstrated that the use of safety restraints has reduced the occupants injury to considerable levels.
Measurements and modelling of snowmelt and turbulent heat fluxes over shrub tundra
Authors: Bewley D. , Essery R. , Pomeroy J. , Ménard C.
Published: July 2010

Abstract. Measurements of snowmelt and turbulent heat fluxes were made during the snowmelt periods of two years at two neighbouring tundra sites in the Yukon, one in a sheltered location with tall shrubs exposed above deep snow and the other in an exposed location with dwarf shrubs covered by shallow snow. The snow was about twice as deep in the valley as on the plateau at the end of each winter and melted out about 10 days later. The site with buried vegetation showed a transition from air-to-surface heat transfers to surface-to-air heat transfers as bare ground became exposed during snowmelt, but there were daytime transfers of heat from the surface to the air at the site with exposed vegetation even while snow remained on the ground. A model calculating separate energy balances for snow and exposed vegetation, driven with meteorological data from the sites, is found to be able to reproduce these behaviours. Averaged over 30-day periods the model gives about 8 Wm−2 more sensible heat flux to the atmosphere for the valley site than for the plateau site. Sensitivity of simulated fluxes to model parameters describing vegetation cover and density is investigated.
Source modeling and inversion with near real-time GPS: a GITEWS perspective for Indonesia
Authors: Babeyko A. Y. , Hoechner A. , Sobolev S. V.
Published: July 2010

Abstract. We present the GITEWS approach to source modeling for the tsunami early warning in Indonesia. Near-field tsunami implies special requirements to both warning time and details of source characterization. To meet these requirements, we employ geophysical and geological information to predefine a maximum number of rupture parameters. We discretize the tsunamigenic Sunda plate interface into an ordered grid of patches (150×25) and employ the concept of Green's functions for forward and inverse rupture modeling. Rupture Generator, a forward modeling tool, additionally employs different scaling laws and slip shape functions to construct physically reasonable source models using basic seismic information only (magnitude and epicenter location). GITEWS runs a library of semi- and fully-synthetic scenarios to be extensively employed by system testing as well as by warning center personnel teaching and training. Near real-time GPS observations are a very valuable complement to the local tsunami warning system. Their inversion provides quick (within a few minutes on an event) estimation of the earthquake magnitude, rupture position and, in case of sufficient station coverage, details of slip distribution.
Cardiovascular Burden of the V142I Transthyretin Variant
Authors: Selvaraj Senthil , Claggett Brian , Shah Svati H. , Mentz Robert J. , Khouri Michel G. , Manichaikul Ani W. , Khan Sadiya S. , Rich Stephen S. , Mosley Thomas H. , Levitan Emily B. , Arora Pankaj , Goyal Parag , Haring Bernhard , Eaton Charles B. , Cheng Richard K. , Wells Gretchen L. , Manson JoAnn E. , Fontana Marianna , Solomon Scott D.
Published: May 2024

Importance

Individual cohort studies concur that the amyloidogenic V142I variant of the transthyretin (TTR) gene, present in 3% to 4% of US Black individuals, increases heart failure (HF) and mortality risk. Precisely defining carrier risk across relevant clinical outcomes and estimating population burden of disease are important given established and emerging targeted treatments.

Objectives

To better define the natural history of disease in carriers across mid to late life, assess variant modifiers, and estimate cardiovascular burden to the US population.

Design, Setting, and Participants

A total of 23 338 self-reported Black participants initially free from HF were included in 4 large observational studies across the US (mean [SD], 15.5 [8.2] years of follow-up). Data analysis was performed between May 2023 and February 2024.

Exposure

V142I carrier status (n = 754, 3.2%).

Main Outcomes and Measures

Hospitalizations for HF (including subtypes of reduced and preserved ejection fraction) and all-cause mortality. Outcomes were analyzed by generating 10-year hazard ratios for each age between 50 and 90 years. Using actuarial methods, mean survival by carrier status was estimated and applied to the 2022 US population using US Census data.

Results

Among the 23 338 participants, the mean (SD) age at baseline was 62 (9) years and 76.7% were women. Ten-year carrier risk increased for HF hospitalization by age 63 years, predominantly driven by HF with reduced ejection fraction, and 10-year all-cause mortality risk increased by age 72 years. Only age (but not sex or other select variables) modified risk with the variant, with estimated reductions in longevity ranging from 1.9 years (95% CI, 0.6-3.1) at age 50 to 2.8 years (95% CI, 2.0-3.6) at age 81. Based on these data, 435 851 estimated US Black carriers between ages 50 and 95 years are projected to cumulatively lose 957 505 years of life (95% CI, 534 475-1 380 535) due to the variant.

Conclusions and Relevance

Among self-reported Black individuals, male and female V142I carriers faced similar and substantial risk for HF hospitalization, predominantly with reduced ejection fraction, and death, with steep age-dependent penetrance. Delineating the individual contributions of, and complex interplay among, the V142I variant, ancestry, the social construct of race, and biological or social determinants of health to cardiovascular disease merits further investigation.
The effect of Qi‐Shao‐Tong‐Mai‐An‐Shen herbal paste on coronary heart disease patients with depression and/or anxiety: Study protocol for a randomized controlled trial
Authors: Chen Ying , Xiao Xiang , Li Lin , Si Chao‐Zeng , Jiang Hong , Shao Ming‐Jing , Lu Xiao‐Yan , Zheng Shu‐Liang , Dai Tian‐Gu , He Qing , Huang Li
Published: May 2024

Coronary heart disease (CHD) poses a significant threat to human life and well‐being. The presence of psycho‐cardiology diseases not only exacerbates the progression of CHD but also imposes a substantial financial burden. Consequently, there is a pressing need to prioritize the prevention and management of psycho‐cardiology conditions. Given the complex adverse effects associated with antidepressants, it is imperative to investigate alternative, safer, and more efficacious early interventions for psycho‐cardiology diseases. The trial will randomly divide 99 patients who meet the inclusion criteria into two groups in a ratio of 1:2. Both groups will be administered standard western medicine treatment for CHD. The Qi‐Shao‐Tong‐Mai‐An‐Shen (QSTMAS) group will be treated with an additional 30 mL QSTMAS herbal paste orally twice daily for up to 12 weeks. The primary endpoints are the changes of Generalized Anxiety Disorder‐7 and Patient Health Questionnaire‐9 scores after the intervention for 12 weeks. The secondary endpoints include the scores of Traditional Chinese medicine syndromes, 6‐min walking test, Insomnia severity index sleep scale, laboratory tests, and other examinations of both groups after the intervention for 12 weeks. The QSTMAS herbal paste exhibits potential and promise as a treatment modality for mild‐to‐moderate psychological disorders within the department of cardiology. The implementation of a rigorous trial design will facilitate an objective and scientific assessment of the clinical effectiveness and safety of combining QSTMAS herbal paste with standard western medicine for CHD patients with depression and/or anxiety. Trial Registration: China Clinical Trial Registry, ChiCTR2200065179. Registered 31 October 2022.
Modifying the Backbone Chemistry of PEG‐Based Bottlebrush Block Copolymers for the Formation of Long‐Circulating Nanoparticles
Authors: Grundler Julian , Whang Chang‐Hee , Shin Kwangsoo , Savan N. Anna , Zhong Mingjiang , Saltzman W. Mark
Published: May 2024

Nanoparticle physicochemical properties have received great attention in optimizing the performance of nanoparticles for biomedical applications. For example, surface functionalization with small molecules or linear hydrophilic polymers is commonly used to tune the interaction of nanoparticles with proteins and cells. However, it is challenging to control the location of functional groups within the shell for conventional nanoparticles. Nanoparticle surfaces composed of shape‐persistent bottlebrush polymers allow hierarchical control over the nanoparticle shell but the effect of the bottlebrush backbone on biological interactions is still unknown. The synthesis is reported of novel heterobifunctional poly(ethylene glycol) (PEG)‐norbornene macromonomers modified with various small molecules to form bottlebrush polymers with different backbone chemistries. It is demonstrated that micellar nanoparticles composed of poly(lactic acid) (PLA)‐PEG bottlebrush block copolymer (BBCP) with neutral and cationic backbone modifications exhibit significantly reduced cellular uptake compared to conventional unmodified BBCPs. Furthermore, the nanoparticles display long blood circulation half‐lives of ≈22 hours and enhanced tumor accumulation in mice. Overall, this work sheds light on the importance of the bottlebrush polymer backbone and provides a strategy to improve the performance of nanoparticles in biomedical applications.
Bilaterally Aligned Electroosmotic Flow Generated by Porous Microneedle Device for Dual‐Mode Delivery
Authors: Wang Gaobo , Kato Kosuke , Ichinose Sae , Inoue Daisuke , Kobayashi Airi , Terui Hitoshi , Tottori Soichiro , Kanzaki Makoto , Nishizawa Matsuhiko
Published: May 2024

Here, a novel porous microneedle (PMN) device with bilaterally aligned electroosmotic flow (EOF) enabling controllable dual‐mode delivery of molecules is developed. The PMNs placed at anode and cathode compartments are modified with anionic poly‐2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid and cationic poly‐(3‐acrylamidopropyl) trimethylammonium, respectively. The direction of EOF generated by PMN at the cathode compartment is, therefore, reversed from cathode to anode, countering the unwanted cathodal suctioning of interstitial fluid caused by reverse iontophoresis. With the bilateral alignment of EOF, the versatility of the proposed device is evaluated by delivering molecules with different charges and sizes using Franz cell. In addition, a 3D printed probe device is developed to ease practical handling and minimize electrical stimulation by integrating two PMNs in closed proximity. Finally, the performance of the integrated probe device is demonstrated by dual delivery of a variety of molecules (methylene blue, rhodamine B, and fluorescein isothiocyanate–dextran) using pig skin and vaccination using mice with delivered ovalbumin.
Atomic‐Scale Tracking Topological Phase Transition Dynamics of Polar Vortex‐Antivortex Pairs
Authors: Zhu Ruixue , Zheng Sizheng , Li Xiaomei , Wang Tao , Tan Congbing , Yu Tiancheng , Liu Zhetong , Wang Xinqiang , Li Jiangyu , Wang Jie , Gao Peng
Published: May 2024

Non‐trivial topological structures, such as vortex‐antivortex (V‐AV) pairs, have garnered significant attention in the field of condensed matter physics. However, the detailed topological phase transition dynamics of V‐AV pairs, encompassing behaviors like self‐annihilation, motion, and dissociation, have remained elusive in real space. Here, polar V‐AV pairs are employed as a model system, and their transition pathways are tracked with atomic‐scale resolution, facilitated by in situ (scanning) transmission electron microscopy and phase field simulations. This investigation reveals that polar vortices and antivortices can stably coexist as bound pairs at room temperature, and their polarization decreases with heating. No dissociation behavior is observed between the V‐AV phase at room temperature and the paraelectric phase at high temperature. However, the application of electric fields can promote the approach of vortex and antivortex cores, ultimately leading to their annihilation near the interface. Revealing the transition process mediated by polar V‐AV pairs at the atomic scale, particularly the role of polar antivortex, provides new insights into understanding the topological phases of matter and their topological phase transitions. Moreover, the detailed exploration of the dynamics of polar V‐AV pairs under thermal and electrical fields lays a solid foundation for their potential applications in electronic devices.
Activating Iterative Revolutions of the Cancer‐Immunity Cycle in Hypoxic Tumors with a Smart Nano‐Regulator
Authors: Ding Junying , Lu Yang , Zhao Xueze , Long Saran , Du Jianjun , Sun Wen , Fan Jiangli , Peng Xiaojun
Published: May 2024

The activation of sequential events in the cancer‐immunity cycle (CIC) is crucial for achieving effective antitumor immunity. However, formidable challenges, such as innate and adaptive immune resistance, along with the off‐target adverse effects of nonselective immunomodulators, persist. In this study, a tumor‐selective nano‐regulator named PNBJQ has been presented, focusing on targeting two nonredundant immune nodes: inducing immunogenic cancer cell death and abrogating immune resistance to fully activate endogenous tumor immunity. PNBJQ is obtained by encapsulating the immunomodulating agent JQ1 within a self‐assembling system formed by linking a Type‐I photosensitizer to polyethylene glycol through a hypoxia‐sensitive azo bond. Benefiting from the Type‐I photosensitive mechanism, PNBJQ triggers the immunogenic cell death of hypoxic tumors under near‐infrared (NIR) light irradiation. This process resolves innate immune resistance by stimulating sufficient cytotoxic T‐lymphocytes. Simultaneously, PNBJQ smartly responds to the hypoxic tumor microenvironment for precise drug delivery, adeptly addressing adaptive immune resistance by using JQ1 to downregulate programmed death ligand 1 (PD‐L1) and sustaining the response of cytotoxic T lymphocytes. The activatable synergic photoimmunotherapy promotes an immune‐promoting tumor microenvironment by activating an iterative revolution of the CIC, which remarkably eradicates established hypoxic tumors and suppresses distal lesions under low light dose irradiation.
Expanded ROS Generation and Hypoxia Reversal: Excipient‐free Self‐assembled Nanotheranostics for Enhanced Cancer Photodynamic Immunotherapy
Authors: Yang Jing , Ren Bibo , Yin Xuntao , Xiang Lunli , Hua YanQiu , Huang Xue , Wang Haibo , Mao Zhengwei , Chen Wei , Deng Jun
Published: May 2024

The efficacy of photodynamic therapy (PDT)‐related cancer therapies is significantly restricted by two irreconcilable obstacles, i.e., low reactive oxygen species (ROS) generation capability and hypoxia which constrains the immune response. Herein, this work develops a self‐assembled clinical photosensitizer indocyanine green (ICG) and the HSP90 inhibitor 17‐dimethylaminoethylamino‐17‐demethoxygeldanamycin (17‐DMAG) nanoparticles (ISDN) without any excipient. This work discovers that the hydrophobic interaction forces between ICG and 17‐DMAG promote the photostability of ICG and its intersystem crossing (ISC) process, thereby improving the ROS quantum yield from 0.112 to 0.46. Augmented ROS generation enhances PDT efficacy and further enhances immunogenic cell death (ICD) effects. 17‐DMAG inhibits the HSP90/hypoxia‐inducible factor 1α (HIF‐1α) axis to dramatically reverse the immunosuppressive tumor microenvironment caused by PDT‐aggravated hypoxia. In a mouse model of pancreatic cancer, ISDN markedly improve cytotoxic T lymphocyte infiltration and MHC I and MHC II activation, demonstrating the superior ICD effects in situ tumor and the powerful systematic antitumor immunity generation, eventually achieving vigorous antitumor and recurrence resistance. This study proposes an unsophisticated and versatile strategy to significantly improve PDT efficacy for enhancing systemic antitumor immunity and potentially extending it to multiple cancers.
High‐Entropy Prussian Blue Analogues Enable Lattice Respiration for Ultrastable Aqueous Aluminum‐Ion Batteries
Authors: Du Kai , Liu Yujie , Zhao Yiqi , Li Hui , Liu Hexiong , Sun Chunhao , Han Mingshan , Ma Tianyi , Hu Yuxiang
Published: May 2024

Aqueous aluminum ion batteries (AAIBs) hold significant potential for grid‐scale energy storage owing to their intrinsic safety, high theoretical capacity, and abundance of aluminum. However, the strong electrostatic interactions and delayed charge compensation between high‐charge‐density aluminum ions and the fixed lattice in conventional cathodes impede the development of high‐performance AAIBs. To address this issue, this work introduces, for the first time, high‐entropy Prussian blue analogs (HEPBAs) as cathodes in AAIBs with unique lattice tolerance and efficient multipath electron transfer. Benefiting from the intrinsic long‐range disorder and robust lattice strain field, HEPBAs enable the manifestation of the lattice respiration effect and minimize lattice volume changes, thereby achieving one of the best long‐term stabilities (91.2% capacity retention after 10 000 cycles at 5.0 A g−1) in AAIBs. Additionally, the interaction between the diverse metal atoms generates a broadened d‐band and reduced degeneracy compared with conventional Prussian blue and its analogs (PBAs), which enhances the electron transfer efficiency with one of the best rate performance (79.2 mAh g−1 at 5.0 A g−1) in AAIBs. Furthermore, exceptional element selectivity in HEPBAs with unique cocktail effect can facile tune electrochemical behavior. Overall, the newly developed HEPBAs with a high‐entropy effect exhibit promising solutions for advancing AAIBs and multivalent‐ion batteries.
The Unprecedented Biodegradable Polyzwitterion: A Removal‐Free Patch for Accelerating Infected Diabetic Wound Healing
Authors: Wang Zhuoya , Chen Danyang , Wang Hongying , Bao Siyu , Lang Liping , Cui Chunyan , Song Haotian , Yang Jianhai , Liu Wenguang
Published: May 2024

Zwitterionic polymers have emerged as an important class of biomaterials to construct wound dressings and antifouling coatings over the past decade due to their excellent hydrophilicity. However, all the reported zwitterionic polymers as wound dressings are nondegradable because of noncleavable carbon─carbon bonding backbones, and must be removed periodically after treatment to avoid hypoxia in the wound, thus leading to potential secondary injury. In this work, a biodegradable polyzwitterion patch is fabricated for the first time by ring‐opening polymerization of carboxybetaine dithiolane (CBDS), which is self‐crosslinked via inter‐amide hydrogen bonds and zwitterionic dipole–dipole interactions on the side chains. The unprecedented polyCBDS (PCBDS) patch demonstrates enough ductility owing to the intermolecular physical interactions to fully cover irregular wounds, also showing excellent biodegradability and antifouling performance resulted from the existence of disulfide bonds and carboxybetaine groups. Besides, the PCBDS degradation‐induced released CBDS owns potent antioxidant and antibacterial activities. This PCBDS patch is used as a diabetic wound dressing, inhibiting bacterial adhesion on the external surface, and its degradation products can exactly kill bacteria and scavenge excessive reactive oxygen species (ROS) at the wound site to regulate local microenvironment, including regulation of cytokine express and macrophage polarization, accelerating infected diabetic wound repair, and also avoiding the potential secondary injury.
Robust Layer‐Dependent Valley Polarization and Valley Coherence in Spiral WS2 at Room Temperature
Authors: Li Xiangdong , Tong Tong , Fan Xiaopeng , Qi Minru , Wang Shen , Zhang Guofeng , Chen Ruiyun , Hu Jianyong , Yang Zhichun , Zeng Ganying , Qin Chengbing , Xiao Liantuan , Jia Suotang
Published: May 2024

In the emerging field of valleytronics, it is aimed to coherently manipulate the valley pseudospin as an information‐bearing degree of freedom. The 2D transition‐metal dichalcogenides (TMDCs) provide a unique possibility to generate an excitonic valley pseudospin, opening the way to valley information. Although significant development of valley pseudospin in layered materials has been achieved recently, looking for new TMDCs featuring robust valley phenomenon at room temperature is still desirable for practical applications. Herein, the valley pseudospin of the spiral WS2 with different layer thicknesses at room temperature is investigated by both circular and linear polarization‐resolved photoluminescence spectroscopy. In the experimental results, it is demonstrated that the spiral WS2 emerges robust valley polarization and valley coherence, the degree of circular polarization, and linear polarization gradually increase with the lift of the layer thicknesses, reaching up to 0.91 for valley polarization and 0.94 for valley coherence, respectively. The robust layer‐dependent valley pseudospin may originate from the intrinsic broken inversion symmetry, due to the spiral structure of the multilayer WS2. The robust and near‐unity valley polarization and valley coherence at room temperature in the spiral WS2 may provide a new platform for optical manipulation of the valley pseudospin for further valleytronics applications.