摘要：
The mesoporous carbons with abundant Fe-Co sites were prepared through one-step carbonization of a MOF materials (ZIF-67) with sodium iron ethylenediaminetetraacetic acid [NaFe(III)EDTA], which can facilitate the nucleation and growth of highly dispersed palladium active sites. The robust synergistic interaction between Pd and FeCo metal with moderate work functions is responsible for the enhanced catalytic activity. Interfacing Pd nano-particles with FeCo sites has been demonstrated for the first time to boost the heterogeneous catalysis of hydrogen production from formic acid, affording the high turnover frequency (TOF) value of 1288 h- 1 at 303 K. The Pd-Fe-Co sites also help to achieve outstanding catalysis performance of in situ hydrogenating phenol. The 91.1 % of the conversion of phenol and 92.7 % of the selectivity of cyclohexanone has been obtained with formic acid as H-donor.
摘要：
Modification of fly ash geopolymer with steel slag: Preparation of steel slag-fly ash geopolymer paste using steel slag andvarying dosages of NaOH-Na2SiO3 as variables. The study aims to investigate the workability, strength, and strengthening mechanismof this paste material, as well as to assess its mechanical properties and water stability in stabilized gravel. The results showed thatincorporating steel slag could decrease the fluidity and setting time of fly ash geopolymer while increasing its strength. When the steelslag and activator was 30% and 18%, respectively, the compressive strength at 7 and 28 days was the highest, reaching 19.3 and 24.9MPa, respectively. The strength of geopolymer-stabilized gravel was equivalent to that of cement-stabilized gravel. When thegeopolymer content is modified to 6%, the unconfined compressive strength at 7 and 28 days is 5.2 and 6.1 MPa, respectively. After28 days of curing, the water stability has significantly improved, with a water stability coefficient exceeding 0.9. The addition of steelslag can enhance the reactivity of the reaction system, facilitate the formation of C-(A)-S-H gel, increase the bonding strength, and fillthe internal pores, resulting in a 23.3% reduction in porosity, a denser structure, and improved strength.
作者机构：
[Yu, Shaoyi; Cheng, Yunhui; Xu, Zhou; Yang, Xingyu; Yao, Li; Jia, Pei; Xing, Keyu; Dai, Shiqin] Hunan Provincial Key Laboratory of Cytochemistry, School of Food Science and Bioengineering, Changsha University of Science & Technology, Changsha 410114, Hunan, China;[Jiao, Yanna] Technology Center of Changsha Customs District, Changsha 410116, Hunan, China;[Cheng, Yunhui] School of Food Science and Engineering, Qilu University of Technology, Jinan 250353, China;[Xu, Zhou] State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha 410004, Hunan, China. Electronic address: xz_jnu@126.com
通讯机构：
[Xu, Zhou] S;State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha 410004, Hunan, China. Electronic address:
摘要：
Aflatoxin B1 (AFB1) can accumulate in different organs or tissues and seriously harm humans. Traditional magnetic relaxation switching (MRS) sensors have relatively low sensitivity, but are complex to use. Rapid small-trace molecule analysis in complex samples is challenging. In this study, we used a gadolinium-based metal-organic framework (Gd-MOF) and ultra-small superparamagnetic iron oxide (USPIO) assembly to develop a magnetic resonance tuning-magnetic relaxation switching (MRET-MRS) sensor to improve conventional MRS sensor sensitivity and simplify operational steps in complex samples. Importantly, the local magnetic field generated by USPIO interfered with Gd-MOF electron spin fluctuation and directly affected dipole-dipole interactions between Gd electrons and water molecules, thus rendering relaxation signal changes more sensitive. The sensitivity (0.54pgmL(-1)) was 833 times more sensitive than that of a conventional MRS sensor (0.45ngmL(-1)). Finally, a convenient one-step detection approach can be achieved by mixing antigen/antibody functionalized Gd-MOF/USPIO and target samples.
作者机构：
[Safari, Farzaneh] Changsha Univ Sci & Technol, Int Coll Engn, Changsha 410004, Peoples R China.;[Nieto, Juan J.] Univ Santiago de Compostela, Dept Stat Math Anal & Optimizat, CITMAga, Santiago De Compostela 15782, Spain.
通讯机构：
[Nieto, JJ ] U;Univ Santiago de Compostela, Dept Stat Math Anal & Optimizat, CITMAga, Santiago De Compostela 15782, Spain.
关键词：
Wu-Zha n g system;Non-linear equatio n s;Dispersion;Surface velocity
摘要：
We study the implementation of a numerical method to solve the time fractional (2 + 1)-dimensional Wu- Zhang system focusing on properties of trigonometric basis functions (TBFs). The approximation of the system describing dispersive long waves by appropriate discretization of the system and Grunwald difference operators is discussed and a linear system of the resulting discrete systems is given. This process includes a presentation of a general framework to approximate the solution by a mesh-free scheme which is stable and converges. Finally, various numerical experiments are present to illustrate the exceptional effect of fractional-order on the WZ system.
摘要：
Considerable photovoltaic (PV) panels are installed on building roof, which are exposed to lightning strike at a high risk. Lightning electromagnetic (EM) field will induce a high voltage, which can damage the electronic devices of PV system. By using the method of moments, the EM coupling among the lightning channel and roof structure is modeled, and the induced voltage of PV array is calculated. The influences of building structure, roof material, and shape are discussed. The induced voltage is strongly dependent on the induced current on rooftop generated by the lightning EM field. Since the induced current produces an opposite magnetic field, it weakens the original lightning magnetic field and the presence of roof can lower the induced voltage. Occasionally, the induced voltage becomes higher for the roof with many crossbars and supporting legs, especially for the metal rooftop. The voltage rises as the roof height increases. Compared to the sloped roof, the distance between the flat roof and PV array is greater, and the effect of roof is relatively minor. To reduce the induced voltage, the arrangement of PV panels is investigated. The results can provide guidance for lightning protection design of rooftop PV system.
摘要：
In order to improve the flame-retardant performance of insulating paper and reduce the fire risk, hydroxyethyl diphosphate and dicyandiamide were used to modify starch to prepare a new starch-based flame retardant (SHPD). The combustion, mechanical, and electrical properties of SHPD treated flame-retardant insulating paper were investigated. The results showed that when the impregnation concentration of SHPD was 25.0%, the limiting oxygen index of the insulating paper was increased from 18.3% to 38.3% and reached the level of UL-94 V-0. The tensile index and burst index of the flame-retardant insulating papers were only 10.17% and 12.5% lower than that of the control insulating paper. The ring crush strength and alternating current breakdown strength in air of the flame-retardant insulating papers were 63.3% and 1.8% higher than that of the control insulating paper. The SHPD flame retardant has a good application prospect in insulating paper.
期刊：
CALPHAD-COMPUTER COUPLING OF PHASE DIAGRAMS AND THERMOCHEMISTRY,2024年84:102666 ISSN：0364-5916
通讯作者：
Huixin Liu<&wdkj&>Shiyi Wen
作者机构：
[Hui Yang; Shipeng Huang; Xiangyang Yin; Peiqiong Zhou; Qianhui Min; Yuling Liu; Yong Du] State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan, 410083, China;[Huixin Liu] School of Energy and Mechanical Engineering, Hunan University of Humanities, Science and Technology, Loudi, Hunan, 417000, China;School of Metallurgy and Environment, Central South University, Changsha, Hunan, 410083, China;[Changfa Du] School of Mathematics and Statistics, Changsha University of Science and Technology, Changsha, Hunan, 410114, China;School of Mechanical Engineering, University of South China, Hengyang, Hunan, 421001, China
通讯机构：
[Huixin Liu; Shiyi Wen] S;School of Energy and Mechanical Engineering, Hunan University of Humanities, Science and Technology, Loudi, Hunan, 417000, China<&wdkj&>State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan, 410083, China<&wdkj&>School of Metallurgy and Environment, Central South University, Changsha, Hunan, 410083, China
摘要：
Diffusion study of the Ni–Si–V system is significant for the establishment of kinetic database of Ni-based alloys. In this work, the diffusion couple experiment combined with the numerical inverse method was adopted to evaluate the diffusivities and atomic mobilities for the Ni–Si–V fcc phase with high throughput. We prepared 12 fcc Ni–Si–V diffusion couples, which were annealed at 1273, 1373 and 1473 K, and their composition profiles after annealing were then measured by EPMA (Electron Probe Microanalysis). Subsequently, inputting the measured composition profiles as well as the available thermodynamic descriptions into the numerical inverse method incorporated in the CALTPP (CALculation of ThermoPhysical Properties) software, the composition- and temperature-dependent diffusivities and atomic mobilities for the Ni–Si–V fcc phase were simultaneously evaluated. In order to verify the reliability of the present evaluations, the CALTPP-simulated diffusion behaviors such as composition profiles and diffusion paths were compared with the measured ones, demonstrating reasonable agreements with each other. Meanwhile, the high-throughput determinations of diffusivities were confirmed by the ones obtained by the Matano-Kirkaldy method. Furthermore, applying the presently obtained diffusivities and atomic mobilities in combination with thermodynamic descriptions of the Ni–Si–V fcc phase, their diffusion flux, two-dimensional composition profile, activation energy and pre-frequency factor were predicted. It is expected that the presently obtained diffusivities and atomic mobilities of the Ni–Si–V fcc phase can contribute to the establishment of kinetic database of Ni-based alloys for their high-efficiency material design.
摘要：
Developing robust and efficient nonprecious metal-based electrocatalysts toward hydrogen evolution reaction (HER) is a big challenge for green and sustainable energy since insufficient catalytic activity and poor stability of current catalysts cannot meet the application requirements. This work reports a freestanding HER electrode FeNiCuAlMo prepared by arc-melting and chemical dealloying methods. The HER performance firstly improves and then declines with the increase of dealloying time. When the dealloying time is 3 h, the electrode shows optimal catalytic performance. The fabricated electrode is composed of AlMo3 and Al5CuMo2, where micro-sized AlMo3 particles are embedded in cellular dendritic Al5CuMo2. Impressively, it displays excellent HER performance, including a small overpotential of 173 mV at a current density of 500 mA/cm2 and outstanding long-term stability for 100 h of continuous hydrogen evolution at 1000 mA/cm2 in an alkaline electrolyte without obvious attenuation. The intrinsic activity of the electrodes combined intermetallic compounds with hierarchical porous structure provides several effects, including enhanced massive active sites, electrolyte access, electron transport, and fast gas release that contribute jointly to enhancing HER activities. The micro-sized AlMo3 particles provide robust framework for the dendritic Al5CuMo2 active sites center, allowing the exposure of enough active sites and simultaneously maintaining good stability. The highly stable and active electrocatalytic HER property makes it as a promising candidate for practical hydrogen production.
期刊：
Journal of Alloys and Compounds,2024年976:173160 ISSN：0925-8388
通讯作者：
Ouyang, LZ;Zhang, JR
作者机构：
[Qin, Chenglei; Zhong, Hao; Wang, Hui; Ouyang, Liuzhang; Liu, Jiangwen] South China Univ Technol, Sch Mat Sci & Engn, Guangzhou 510641, Peoples R China.;[Qin, Chenglei; Zhong, Hao; Wang, Hui; Ouyang, Liuzhang; Liu, Jiangwen] South China Univ Technol, Key Lab Adv Energy Storage Mat Guangdong Prov, Guangzhou 510641, Peoples R China.;[Zhong, Hao] Guangzhou High Tech Zone Inst Energy Technol, Guangzhou 510000, Peoples R China.;[Chen, Kang] Changsha Univ Sci & Technol, Sch Energy & Power Engn, Key Lab Efficient & Clean Energy Utilizat, Changsha 410111, Peoples R China.;[Lang, Chengguang] Sun Yat sen Univ Shenzhen, Sch Adv Energy, Shenzhen 518107, Peoples R China.
通讯机构：
[Zhang, JR ] L;[Ouyang, LZ ] S;South China Univ Technol, Sch Mat Sci & Engn, Guangzhou 510641, Peoples R China.;South China Univ Technol, Key Lab Adv Energy Storage Mat Guangdong Prov, Guangzhou 510641, Peoples R China.;Lishui Univ, Dept Chem, Lishui 323000, Peoples R China.
摘要：
Onsite hydrogen generation by sodium borohydride hydrolysis resolves hydrogen energy supply system challenges. However, the spent-NaBH4 regeneration is still a problem in the closed loop of this irreversible reaction. As the by-product is the key to the problem, NaB(OH)4 is regarded as not the boron source but the hydrogen source of NaBH4 regeneration. Therefore, in this study, inexpensive Al metal and NaB(OH)4 are ball milled under argon to regenerate NaBH4 without additional hydrogen input. However, the ball-milling reaction is hindered by the flexible Al and impact oxide layer, and the NaBH4 yield is only approximately 22 %. Therefore, a brittle intermetallic compound Mg2Al3 is reacted with NaB(OH)4 by ball milling, achieving a NaBH4 yield of over 42 %. The mechanism study shows that the brittleness of the raw material plays an important role in promoting the ball-milling reaction. This study achieves NaBH4 regeneration using only Al as the reducing agent and provides a promising method to promote the mechanochemical regeneration of NaBH4.
期刊：
IEEE Transactions on Medical Imaging,2024年43(2):832-845 ISSN：0278-0062
作者机构：
[Xiaofei Huang; Hongfang Gong] School of Mathematics and Statistics, Changsha University of Science and Technology, Changsha, China
摘要：
Research in medical visual question answering (MVQA) can contribute to the development of computer-aided diagnosis. MVQA is a task that aims to predict accurate and convincing answers based on given medical images and associated natural language questions. This task requires extracting medical knowledge-rich feature content and making fine-grained understandings of them. Therefore, constructing an effective feature extraction and understanding scheme are keys to modeling. Existing MVQA question extraction schemes mainly focus on word information, ignoring medical information in the text, such as medical concepts and domain-specific terms. Meanwhile, some visual and textual feature understanding schemes cannot effectively capture the correlation between regions and keywords for reasonable visual reasoning. In this study, a dual-attention learning network with word and sentence embedding (DALNet-WSE) is proposed. We design a module, transformer with sentence embedding (TSE), to extract a double embedding representation of questions containing keywords and medical information. A dual-attention learning (DAL) module consisting of self-attention and guided attention is proposed to model intensive intramodal and intermodal interactions. With multiple DAL modules (DALs), learning visual and textual co-attention can increase the granularity of understanding and improve visual reasoning. Experimental results on the ImageCLEF 2019 VQA-MED (VQA-MED 2019) and VQA-RAD datasets demonstrate that our proposed method outperforms previous state-of-the-art methods. According to the ablation studies and Grad-CAM maps, DALNet-WSE can extract rich textual information and has strong visual reasoning ability.
摘要：
The low carbon footprint and superior properties of geopolymer make it a potentially suitable alternative to ordinary Portland cement, which has been one of the dominating research focuses in the last decades. However, the mechanisms of geopolymeric reactions and the nanostructure of geopolymer are still questionable. Besides, some undesired properties in geopolymer synthesis limit the field application of geopolymers. This paper focused on the current knowledge of the reaction chemistry and nanostructure of geopolymer and factors affecting metakaolin-based geopolymer synthesis. A systematic summary of the reaction process, chemical bonds in geopolymer, and models of geopolymer were provided to better understand the reaction mechanisms of geopolymerization. Various factors important to geopolymer's properties, including Si/Al ratio, Na/Al ratio, type of alkaline activator and alkali cation, water/solid ratio, and curing condition, were comprehensively reviewed to guide the geopolymer synthesis. Through this review, we hope to promote this field's continued growth and development and encourage the wider adoption of geopolymers as a sustainable alternative to traditional construction materials.
期刊：
Journal of Computational Design and Engineering,2024年 ISSN：2288-4300
通讯作者：
Lairong Yin
作者机构：
[Peng Zhang; Yuyu Li; Kejun Tang; Lairong Yin; Long Huang; Hongbing Wang] College of Automotive and Mechanical Engineering, Changsha University of Science and Technology , Changsha 410114, Hunan , China
通讯机构：
[Lairong Yin] C;College of Automotive and Mechanical Engineering, Changsha University of Science and Technology , Changsha 410114, Hunan , China
摘要：
Automated tape placement (ATP) is an important automated process adopted for the fabrication of large composite components. Trajectory planning is the key link of ATP, which directly affects the precision and efficiency of the layup process, and the quality of final products. Presently, most existing trajectory optimization methods for ATP focus on smooth surfaces. Nevertheless, as commercial CAD/CAM software generally uses NURBS (Non-uniform Rational B-Splines) for modelling, the difficulty of finding the solution and the low efficiency associated with the calculation process are inevitable. The discrete methods provide alternatives for designing layup trajectories, whereas their accuracy is seldom analyzed. Furthermore, a path optimization algorithm for eliminating gap problems while preventing wrinkles on discrete models is rarely reported. In this paper, the adjustment of layup trajectories for ATP is considered on triangular meshes. Firstly, the triangular mesh is reconstructed as a Nagata patch to recover the original geometry with good accuracy. Then, a numerical method for tracing desired paths on the Nagata patch set is provided, and the computation efficiency is validated. Next, two optimization methodologies are proposed to improve the layup of composite tapes while avoiding wrinkles. Finally, the presented two strategies are examined on a discrete hyperbolic surface and a discrete freeform surface, and some of the results are delivered.
摘要：
Magnetic nanoporous materials represent a new emerging category of magnetic materials for construction of magnetic resonance sensors. In this study, we adopted the metal-organic framework materials, MIL-101(Fe), as the precursor to prepare series nanoporous-carbon-Fe(3)O(4) (NPC-Fe(3)O(4)) composites. Results showed that Fe(3)O(4) were uniformly distributed in MIL-101(Fe) and the size of MNP was precisely tuned at different pyrolysis temperatures, conferring the optimal NPC-Fe(3)O(4)-450°C composite with dramatically improved T(2) relaxivity. The NPC-Fe(3)O(4)-450°C composite was modified with antibodies and antigens, respectively, for detection of aflatoxin B(1) in various food samples with complicated matrix. Range from 0.010ngmL(-1) to 2.0ngmL(-1), extreme low detection limit of 5.0pgmL(-1), and satisfied recoveries were successfully achieved, indicating excellent anti-matrix effect. These findings offer a new dimension to engineer novel magnetic materials with improved relaxivity for simple and easy sensing of food hazards in complicated food matrix without any purification or separation procedures.
期刊：
Journal of Physics and Chemistry of Solids,2024年188:111891 ISSN：0022-3697
通讯作者：
Jin Zhang
作者机构：
[Xiongcan Zeng; Yi Zhou; Wanhong He; Yinghong Zhou; Guihua Huang; Dujie Feng; Jin Zhang] Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation & Hunan Provincial Key Laboratory of Cytochemistry, School of Chemistry and Chemical Engineering, Changsha University of Science and Technology, Changsha, 410114, PR China;[Mingming Dang] Department of Resources and Environment, Hunan Nonferrous Metals Vocational and Technical College, Zhuzhou, 412000, PR China
通讯机构：
[Jin Zhang] H;Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation & Hunan Provincial Key Laboratory of Cytochemistry, School of Chemistry and Chemical Engineering, Changsha University of Science and Technology, Changsha, 410114, PR China
摘要：
Gd3+-doped Bi4O5I2 with a flower-like structure has been successfully prepared for the first time using a one-step hydrothermal method. The effect of different doping amounts on the photodegradation properties has been investigated. The total removal of ciprofloxacin (CIP) by 3 % Gd–Bi4O5I2 (molar atomic ratio of Gd to Bi = 0.03:1) under visible light irradiation was 94.50 % (within 120 min). The reaction rate constant was 6.3 times higher than that of pure Bi4O5I2. In complex water containing humic acid (HA) and various anions, 3 % Gd–Bi4O5I2 maintained a high total removal rate for CIP. UV–Vis diffuse reflectance spectroscopy and electrochemical tests have shown that doping Gd3+ not only extends the photoresponse range, but also reduces the photonic band gap width. Gd3+ ions act as electron traps to trap excited electrons and promote the separation and migration efficiency of photogenerated electron-hole pairs, improving the performance of Gd–Bi4O5I2 composites for the photocatalytic degradation of CIP.
