摘要：
In order to improve the seismic performance of adjacent buildings, two types of tuned inerter damper (TID) damping systems for adjacent buildings are proposed, which are composed of springs, inerter devices and dampers in serial or in parallel. The dynamic equations of TID adjacent building damping systems were derived, and the H2 norm criterion was used to optimize and adjust them, so that the system had the optimum damping performance under white noise random excitation. Taking TID frequency ratio and damping ratio as optimization parameters, the optimum analytical solutions of the displacement frequency response of the undamped structure under white noise excitation were obtained. The results showed that compared with the classic TMD, TID could obtain a better damping effect in the adjacent buildings. Comparing the TIDs composed of serial or parallel, it was found that the parallel TIDs had more significant advantages in controlling the peak displacement frequency response, while the H2 norm of the displacement frequency response of the damping system under the coupling of serial TID was smaller. Taking the adjacent building composed of two ten-story frame structures as an example, the displacement and energy collection time history analysis of the adjacent building coupled with the optimum design parameter TIDs were carried out. It was found that TID had a better damping effect in the full-time range compared with the classic TMD. This paper also studied the potential power of TID in adjacent buildings, which can be converted into available power resources during earthquakes.
摘要：
This article studies a multiagile earth observation satellite system, in which a group of satellites provides observation services to acquire images of targets on the earth's surface. In this system, the large-scale multiobjective task scheduling problem is studied by jointly optimizing the task assignment scheme and the observation window allocation to maximize the total profit of all executed tasks on all satellites and the loading balance among satellites. Note, however, that it is challenging to solve this problem since the task assignment scheme and the observation window allocation are tightly coupled. Therefore, a bilevel optimization problem is formulated, where the tasks are assigned at the upper level and the observation windows are allocated at the lower level. In this way, the observation windows are allocated based on the given task assignment scheme, thus decoupling the task assignment scheme and the observation window allocation. Furthermore, the observation windows can be allocated in parallel on different satellites to improve computational efficiency. Subsequently, a bilevel evolutionary algorithm is proposed. Specifically, at the upper level, an initialization strategy is devised to efficiently generate feasible task assignment schemes by constructing the candidate satellite set for each task, and then a constrained multiobjective evolutionary algorithm is adopted to optimize the task assignment schemes. In addition, at the lower level, for each task assignment scheme, a greedy strategy is proposed to allocate the observation windows to as many tasks as possible on each satellite and a local search method is suggested to further improve the observation window allocation. Experiments on a diverse set of instances involving up to 1000 tasks demonstrate that the proposed algorithm exhibits better or at least competitive performance against other compared algorithms on each instance.
摘要：
Aesthetic expectations often constitute the primary focus in marketing nature-based tourist destinations. However, academic research has insufficiently explored the disparity between tourists' aesthetic expectations and the actual aesthetic quality maintenance in shaping satisfaction. Employing the Expectation Confirmation Theory, this study utilized structural equation modeling techniques to analyze survey data (n = 446). It proposed and tested an Aesthetic Expectation Confirmation Model to examine the relationship between aesthetic expectations, experiential qualities, and tourist satisfaction in the Zhangjiajie National Forest Park. The empirical findings show that aesthetic expectations have a direct, negative impact on satisfaction, while aesthetic expectation confirmation has a positive direct impact on satisfaction. Moreover, aesthetic expectation confirmation also plays a mediating role in the influence of aesthetic expectations and experiential quality on satisfaction. Specifically, aesthetic expectations indirectly impact satisfaction negatively through aesthetic expectation confirmation, whereas aesthetic experiential qualities have a positive, indirect impact on satisfaction through the same process. These findings offer theoretical contributions to the literature on forest recreation aesthetics and hold practical significance for the planning and management of destination aesthetics.
关键词：
integrated circuit;RTL code;code security;code obfuscation;XML syntax tree
摘要：
As the most widely used description code in digital circuits and system on chip (SoC), the security of register transfer level (RTL) code is extremely critical. Code obfuscation is a typical method to ensure the security of RTL code, but popular obfuscation methods are not fully applicable to RTL code. In addition, some RTL code obfuscation tools also have issues with incomplete functionality or obfuscation errors. In view of the above issues, this paper studies the RTL code security problem represented by obfuscation. Based on the extensible markup language (XML) syntax tree generated by parsing RTL code, a complete RTL code refactoring model is constructed, and four targeted RTL code obfuscation methods are proposed, namely: Layout obfuscation; Parameter obfuscation; Critical path obfuscation; Code increment obfuscation. Utilizing the developed obfuscation tool, an assessment of the performance and effectiveness of the obfuscation methods is conducted, alongside testing the equivalence between the obfuscated code and the source code. The experimental results show that the proposed obfuscation methods have higher practicability and reliability, and have the characteristics of high obfuscation coverage that can be stable at over 98% and preservation of compiler indicative Comments.
期刊：
Journal of Materials in Civil Engineering,2024年36(2):04023543 ISSN：0899-1561
通讯作者：
Dong, HW
作者机构：
[Huang, Tuo; Qin, Haoyun; Wang, Zhaoyang; Liu, Hongfu] Changsha Univ Sci & Technol, Changsha 410114, Peoples R China.;[Cao, Zhonglu; Dong, HW; Dong, Hongwu] China Commun Construct Co CCCC First Harbor Engn, Tianjin Port Engn Inst Co Ltd, 1002 Dagu South Rd, Tianjin 300222, Peoples R China.;[Cao, Zhonglu; Dong, HW; Dong, Hongwu] China Commun Construct Co CCCC First Harbor Engn, Tianjin 300461, Peoples R China.
通讯机构：
[Dong, HW ] C;China Commun Construct Co CCCC First Harbor Engn, Tianjin Port Engn Inst Co Ltd, 1002 Dagu South Rd, Tianjin 300222, Peoples R China.;China Commun Construct Co CCCC First Harbor Engn, Tianjin 300461, Peoples R China.
摘要：
To objectively characterize the time-temperature-stress equivalence of viscoelastic properties of asphalt mixture, the triaxial compressive creep test was carried out on an AC-13 asphalt mixture under the conditions of different temperatures and stress states in this paper and the nonlinear variation law of creep deformation was obtained. According to the characteristics of similar creep curves and the principle of time-temperature equivalence, two methods were used to shift the creep compliance under different confining pressure, temperature, and axial stress conditions, and the change of temperature and stress shift factors with confining pressure were obtained; in addition, the creep compliance principal curve was fitted by the Prony series and its principal surface was established. On this basis, the multiple stress creep recovery test under different confining pressures was conducted to measure the parameters of Schapery’s nonlinear viscoelastic model and their variation law with the triaxial stress ratio was obtained, which accurately characterized the synergistic effect of confining pressure and axial stress.
摘要：
High-temperature hazards of asphalt pavement and pollution from car exhaust are two major problems that need to be solved in road construction. In this paper, a multifunctional composite coating has been prepared from the perspective of reducing road temperature and car exhaust degradation. The principle of heat-reflecting coating is used to reduce the road surface temperature. At the same time, the TiO2 aqueous solution with photocatalytic degradation effect is added to the heat-reflective coating material to achieve the purpose of degrading automobile exhaust degradation, creating a new type of multifunctional coating that has both cooling and exhaust degradation effects. In addition, by changing the amount of carbon black, a multi-functional coating with the best coloring is selected, so that it has better functionality and has the most suitable shade for the road surface. Finally, the cooling effect and the exhaust gas reduction effect are examined through indoor and outdoor tests and the slip resistance of the coating is tested using the pendulum method. The results show that the functional coating group has a certain ability of cooling and exhaust gas degradation compared to the normal control group without coating. For the functional coating group with different carbon black content, the functional coating (G2) with 0.9% carbon black content has the strongest overall functionality. The cooling and exhaust gas reduction effects proved to be the best. The surface cooling rate is 5.4 degrees C, while the internal cooling rate is 4.3 degrees C. The cumulative degradation efficiency of CO and NO is found to be 27.77%, and 73.75%, respectively.
摘要：
This study aimed to develop a method to determine nonlinear viscoelastic properties of subgrade soil using the light weight deflectometer (LWD) test. Firstly, a constitutive model was developed to accurately characterize the nonlinear viscoelastic behavior of subgrade soil. A User-Defined Material Subroutine (UMAT) was coded to define this constitutive model in ABAQUS, which was verified by the virtual triaxial test analysis. Secondly, a numerical model was developed to simulate the LWD test, which considered the true LWD load pattern and the constitutive nature of subgrade soil. The sensitivity analysis demonstrated that the viscoelastic parameters significantly affected the deflection-time history curves. Subsequently, a batch calculation program was developed via MATLAB and ABAQUS to automatically compute the dynamic responses of subgrade in the LWD test. A total of 42,057 groups of subgrade deflection data were calculated under the LWD load, covering a wide range of nonlinear viscoelastic parameters. Finally, two machine-learning approaches (i.e., artificial neural network [ANN] and convolutional neural network [CNN]) were proposed to backcalculate these viscoelastic parameters of soil from the LWD load–deflection-time history data. The results showed that the CNN approach was much more accurate than the ANN approach for the backcalculation of the nonlinear viscoelastic properties of subgrade.
摘要：
In recent years, frequent occurrences of algal blooms due to environmental changes have posed significant threats to the environment and human health. This paper analyzes the reasons of algal bloom from the perspective of environmental factors such as nutrients, temperature, light, hydrodynamics factors and others. Various commonly used algal bloom monitoring methods are discussed, including traditional field monitoring methods, remote sensing techniques, molecular biology-based monitoring techniques, and sensor-based real-time monitoring techniques. The advantages and limitations of each method are summarized. Existing algal bloom prediction models, including traditional models and machine learning (ML) models, are introduced. Support Vector Machine (SVM), deep learning (DL), and other ML models are discussed in detail, along with their strengths and weaknesses. Finally, this paper provides an outlook on the future development of algal bloom warning techniques, proposing to combine various monitoring methods and prediction models to establish a multi-level and multi-perspective algal bloom monitoring system, further improving the accuracy and timeliness of early warning, and providing more effective safeguards for environmental protection and human health.
摘要：
A series of novel porous hydrogen-generation materials with the formulae Al-(BiO)2CO3, Al-4BiNO3(OH)2 center dot BiO(OH), and Al-Bi2(SO4)3 were synthesized by ball milling and spark plasma sintering (SPS). Their hydrogen-production properties were investigated. The results revealed that doping Al-(BiO)2CO3 in aluminium powder was the most effective for improving the hydrogen-generation performance. The hydrogen-conversion yield and maximum hydrogen-generation rate (MHGR) of the Al-(BiO)2CO3 block reached 94.9% and 384.6 mL g-1 min-1, respectively. Mechanism study indicated that (BiO)2CO3 decomposed into Bi2O3 and CO2, and the produced Bi2O3 could react with Al to produce Bi and Al2O3in situ during the SPS process. Herein, the produced CO2 could also form a large number of holes in the bulk sample under the action of sintering pressure to obtain the porous Al-(BiO)2CO3 composite. The hydrogen-generation performance of Al-(BiO)2CO3 was thus substantially enhanced under the synergistic effect of these factors. A series of novel porous hydrogen-generation materials with the formulae Al-(BiO)2CO3, Al-4BiNO3(OH)2 center dot BiO(OH), and Al-Bi2(SO4)3 were synthesized by ball milling and spark plasma sintering (SPS).
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.
摘要：
We investigate the transmission properties of super-Gaussian pulses at a moving temporal boundary. The incident spectrum of super-Gaussian pulses, determined by different shape parameters, affects the reflected and transmitted pulse energy and the sidelobes distribution after crossing the temporal boundary. When the incident pulse is an initial unchirped super-Gaussian pulse or a super-Gaussian pulse with a small chirp parameter, the reflected pulse energy increases and the transmitted pulse energy decreases as the incident pulse shape parameter increases. When the incident pulse with a initial chirp and |C| >= 2, the incident pulse spectrum mainlobe energy increases as the shape parameter increases, resulting in reflected pulse energy decreases and transmitted pulse energy increases. This study also discusses the pulse splitting occurs in the anomalous dispersion region. The super-Gaussian pulse sidelobes can theoretically be removed by creating two temporal boundaries.
摘要：
To investigate the vortex-induced vibration (VIV) of a flexible cable in the uniform flow, experiments were conducted using a flexible cable with an external diameter of 80mm and a length of 10.48m in the wind tunnel. The characteristics of multi-modal VIV, time-frequency and traveling wave behavior of the flexible cable were analyzed. Moreover, the effects of twist direction, diameter and the single/double helical wire on the VIV characteristics of the flexible cable were investigated. It is found that the flexible cable experiences single and multi-modal VIVs in uniform flow at different incoming wind speeds, respectively. For the multi-modal VIV of the flexible cable, the vibration over the time history is dominated by two adjacent modal frequencies and shows a phenomenon of beat vibration. The multi-modal VIV responses of the flexible cable show a mix of standing and traveling wave behaviors, in which the effects of standing wave are more pronounced near both ends and the effects of traveling wave are more dominant in the middle region of the flexible cable. The twist direction of the helical wire has little effect on the VIV responses of the flexible cable. The VIV amplitudes of the flexible cable can be reduced by a single helical wire. With the diameter of the helical wire increases, the suppression effects of the single or double helical wire on the VIV of the flexible cable can be improved. Particularly, the double helical wire with diameter 0.10D can effectively suppress the VIV of the flexible cable.
摘要：
This paper proposes a novel concurrent learning -based adaptive boundary observer designed to tackle the joint estimation problem of system states and unknown parameters for a class of hyperbolic partial differential equation systems under the circumstance of unsatisfied persistent excitation conditions. By leveraging concurrent learning technique, an adapted data points selection algorithm is employed concurrently with current data to construct the adaptation law of unknown parameters, which overcomes the limitations imposed by persistent excitation conditions and ensures exponential convergence of estimation errors of unknown parameters under finite excitation conditions. Furthermore, combining the ideas of backstepping and swapping filters on the basis of uncertain estimation, a concurrent learning -based adaptive boundary observer is designed, accompanied by rigorous theoretical analysis and proofs to demonstrate its capability of achieving exponential convergence in estimation. Finally, the corresponding illustrative simulations are given to show the effectiveness of the proposed methodology.
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.
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.
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.
通讯机构：
[Wang, Z ] C;Changsha Univ Sci & Technol, Sch Elect & Informat Engn, State Key Lab Disaster Prevent & Reduct Power Grid, Changsha 410114, Peoples R China.
关键词：
Distribution networks;Electromagnetic potential transformer;Ferromagnetic resonance;Resonance suppression;Flexible grounding
摘要：
When a single line-to-ground (SLG) fault occurs in a distribution network, ferromagnetic resonance is easily triggered by magnetic saturation of the potential transformer (PT) after the fault disappears. To solve this problem, a method is proposed for ferromagnetic resonance suppression (FRS) in distribution networks based on flexible grounding technology. A controllable voltage is injected at the neutral point of the distribution network through a flexible grounding device (FGD) to suppress the neutral point voltage (NPV) of the system to zero, quickly restoring the system to the normal operating state, preventing magnetic saturation of the PT core, destroying the conditions for ferromagnetic resonance in the system, and realising FRS. The proposed method provides a release channel for the charge accumulated in the line-to-ground capacitance, consuming the electromagnetic energy stored in the circuit. Various resonant conditions are simulated in a PSIM 9.1 environment to verify the FRS process and effect of the proposed method. The simulation results show that the proposed method can quickly achieve FRS with a good detuning effect, simple control and a high response speed.
摘要：
Recently, single-layer PtSe(2), possessing high carrier mobility and optical response, has been successfully fabricated. To further expand its application scope and find new physics, in this work, we functionalized it via the adsorption of non-metallic atoms X (X = H, B, C, N, O, and F) to form hybrid systems X-PtSe(2), and their geometrical, mechanical, electronic, and optical properties as well as strain tuning effects were studied deeply. Calculations show that the energy stability of X-PtSe(2) systems is significantly enhanced, and they also hold higher thermal and mechanical stability. Particularly, X-PtSe(2) systems present excellent in-plane tenacity and out-of plane stiffness against deformations, which make them more applicable for designing nanodevices. Intrinsic PtSe(2) is a semiconductor, while the X-PtSe(2) system can be a band-gap narrowed semiconductor or metal, thus expanding the application scope for PtSe(2), and the odd-even effect of electronic phase variation related to the atomic number is found. Besides, the wavelength range of optical adsorption is increased in X-PtSe(2) systems, implying that its optical response region is wide, providing more options for developing optoelectronic devices. Moreover, it is shown that strain can flexibly tune the electronic property of X-PtSe(2) systems, especially enhancing the optical absorption ability substantially, beneficial for their applications in solar devices.
摘要：
For Mandelbrot's cascade (Y-n) in an independent and identically distributed (i.i.d.) random environment xi, we are interested in the a.s. convergence rate of the Mandelbrot's martingale (W-n) to its limit W, where W-n=Y-n/E xi Yn is the normalized partition function. We obtain sufficient conditions under which W-Wn has an exponential convergence rate: W-W-n=o(e(-na)) a.s. for some a > 0 explicitly calculated; we also find conditions under which W-Wn has a polynomial convergence rate: W-W-n=o(n(-alpha)) a.s. for some alpha > 0. Similar conclusions hold for Mandelbrot's cascade in a varying environment.
