We investigate a wavelength-division-multiplexing passive optical network(WDM-PON) with centralized lightwave and direct detection. The system is demonstrated for symmetric 10 Gbit/s differential phase-shift keying(DP...We investigate a wavelength-division-multiplexing passive optical network(WDM-PON) with centralized lightwave and direct detection. The system is demonstrated for symmetric 10 Gbit/s differential phase-shift keying(DPSK) downstream signals and on-off keying(OOK) upstream signals,respectively. A wavelength reused scheme is employed to carry the upstream data by using a reflective semiconductor optical amplifier(RSOA) as an intensity modulator at the optical network unit(ONU). The constant-intensity property of the DPSK modulation format can keep high extinction ratio(ER) of downstream signal and reduce the crosstalk to the upstream signal. The bit error rate(BER) performance of our scheme shows that the proposed 10 Gbit/s symmetric WDM-PON can achieve error free transmission over 25-km-long fiber transmission with low power penalty.展开更多
Electrosorption technology was used to treat the reused comprehensive wastewater from iron and steel industry. A problem of relatively high conductivity of wastewater which greatly affects the reuse was examined, and ...Electrosorption technology was used to treat the reused comprehensive wastewater from iron and steel industry. A problem of relatively high conductivity of wastewater which greatly affects the reuse was examined, and industrial test was conducted for the reused water advanced deionization and purification in a comprehensive wastewater treatment plant o{ WISCO [Wuhan Iron and Steel （Group） Corporation]. The results of the on-site in- dustrial test showed a satisfactory treatment performance for the reused water even at a flow rate of 1 000 L/h in a standard 500 L/h unit. The average conductivity decreased by about 70%, from 580--780 μS/cm to 100--350 μS/cm. The average removal efficiency of CI and Ca2＋ was about 75% and 68%, respectively, and CODcr of the treated wa- ter was also reduced in some degree while the pH value was almost unchanged. The energy consumption was as low as 0.6 kWh/t, which was remarkably superior to the conventional technologies. Therefore, it is entirely feasible that the novel eleetrosorption technology can be used in enhanced desalination and purification treatment of reused com- prehensive wastewater in iron and steel industry.展开更多
In orthogonal frequency division multiple access（OFDMA） relay system,for supporting relay transmission,the base station（BS）-the relay station（RS） link must consume an extra part of resource,which may result in s...In orthogonal frequency division multiple access（OFDMA） relay system,for supporting relay transmission,the base station（BS）-the relay station（RS） link must consume an extra part of resource,which may result in serious resource shortage.In order to improve resource utilization,this paper proposes a dynamic resource allocation scheme in adaptive frequency reused OFDMA-relay system based on adaptive modulation and coding（AMC） technology.In this scheme,relay nodes have two independent antennas and operate in decode-and-forward（DF） and full-duplex mode.Then the BS and RSs share the same subcarriers by spatial multiplexing by two independent antennas.The resource allocation problem is formulated for system downlink throughput maximization.Since the optimal solution couldn＇t be obtained easily,a sub-optimal algorithm is proposed.The adaptive frequency reused algorithm with two independent antennas RS improves the system throughput about 24.3 % compared with the orthogonal frequency allocation with single-antenna model,and increases the system throughput 10.4 % compared with adaptive frequency reused algorithms with single-antenna RS.It is proved that both of the RS with two-antenna model and adaptive frequency reused scheme can improve the system throughput significantly.展开更多
Femtocell is a promising technology to improve network performance with low-power and cost-beneficial small base stations. However, the interference-limited reality in femtocell networks makes interference and resourc...Femtocell is a promising technology to improve network performance with low-power and cost-beneficial small base stations. However, the interference-limited reality in femtocell networks makes interference and resource management the key to achieving the benefits of femtocell networks. In this paper, the following contributions are made step by step： first, on the basis of the interference temperature model （ITM） in cognitive radio （CR） technique and the network architecture of the third generation partnership project （3GPP） long term evolution advanced （LTE-A）, the problem model of optimizing the capacity of the femtocell-reused subchannel is established under the frequency partitioning strategy, jointly considering the average interference constraint and the instantaneous interference constraint. Second, utilizing the convex theory, optimal power allocation of the femtocell-reused subchannel is derived. Third, under Rayleigh fading channel, closed-form expressions of the subchannel reusable probability and capacity are derived. At last, numerical results are conducted to confirming our analytical results, which could provide theoretical guidance for frequency resource allocation of femtocell network deployments.展开更多
Flotation is the most common method to recover valuable minerals by selective adsorption of collectors on target mineral surfaces.However,in subsequent hydrometallurgy of mineral flotation concentrates,the adsorbed co...Flotation is the most common method to recover valuable minerals by selective adsorption of collectors on target mineral surfaces.However,in subsequent hydrometallurgy of mineral flotation concentrates,the adsorbed collectors must be desorbed since it can adversely affect the efficiency of metallurgical process and produce wastewater.ZL,as a fatty acid mixture,is a typical industrially used collector for scheelite flotation in China.Sodium oleate(NaOL)has similar fatty acid group as ZL.In this study,the desorption behavior of NaOL/ZL from scheelite surface by a physical method of stirring at a low temperature was investigated.NaOL desorption tests of single mineral showed that a desorption rate of 77.75% for NaOL from scheelite surface into pulp was achieved in a stirring speed of2500 r/min at 5℃in a neutral environment.Under the above desorption condition,in the pulp containing desorbed collector by adding extra 30% normal NaOL dosage,the scheelite recovery reached about 95% in the single mineral flotation test.Desorption and reuse of ZL collector for the flotation of real scheelite ore showed only a 75%normal dosage of ZL could produce a qualified rough concentrate.The atomic force microscope(AFM)tests showed that after desorption treatment of low temperature and strong stirring,the dense strip-like structure of NaOL on the scheelite surface was destroyed to be speck-like.Molecular dynamics simulations(MDS)demonstrated that the adsorption energy between NaOL and scheelite surface was more negative at 25℃(-13.39 kcal/mol)than at 5℃(-11.50 kcal/mol)in a neutral pH,indicating that a low temperature was beneficial for the desorption of collector from mineral surface.Due to its simplicity and economy,the method we proposed of desorption of collector from mineral surface and its reuse for flotation has a great potential for industrial application.展开更多
Fipronil is an insecticide with low residual activity and high efficacy at low concentrations.Due to its widespread use and long half-life,fipronil can persist during wastewater treatment and is found even in surface ...Fipronil is an insecticide with low residual activity and high efficacy at low concentrations.Due to its widespread use and long half-life,fipronil can persist during wastewater treatment and is found even in surface waters.When released into the environment,it can accumulate over time and can lead to concentrations in soil and plant tissues that are harmful to both target and non-target organisms.As the reuse of treated wastewater and sewage sludge presents challenges and opportunities for farmers,this study investigates the effects of irrigation with environmentally relevant doses of fipronil on zucchini plants and their main insect pest,Aphis gossypii.Traces of fipronil were found in the zucchini leaves,but not in the flowers,after 35-days of cumulative exposure.A decrease in nymph-to-adult survival and a dose-dependent reduction in the fecundity of A.gossypii feeding on contaminated host plants was observed.Also,aphids feeding on contaminated host plants exhibited the same mortality rate as the control group when exposed to an acute dose of fipronil.However,when natural pyrethrins were used,there was a significant increase in resistance to this insecticide.Our results demonstrate the potential for fipronil to accumulate in plant tissues and highlight the risk of changes in insecticide susceptibility in insect pests.This suggests a need for a holistic approach to the complex dynamics of wastewater reuse in agriculture.展开更多
Sedimentation sludge water(SSW),a prominent constituent of wastewater from drinking water treatment plants,has received limited attention in terms of its treatment and utilization likely due to the perceived difficult...Sedimentation sludge water(SSW),a prominent constituent of wastewater from drinking water treatment plants,has received limited attention in terms of its treatment and utilization likely due to the perceived difficulties associated with managing SSW sludge.This study comprehensively evaluated the water quality of SSW by comparing it to a well-documented wastewater(filter backwash water(FBW)).Furthermore,it investigated the pollutant variations in the SSW during pre-sedimentation process,probed the underlying reaction mechanism,and explored the feasibility of employing a pilot-scale coagulation-sedimentation process for SSW treatment.The levels of most water quality parameters were generally comparable between SSW and FBW.During the pre-sedimentation of SSW,significant removal of turbidity,bacterial counts,and dissolved organic matter(DOM)was observed.The characterization of DOM components,molecular weight distributions,and optical properties revealed that the macromolecular proteinaceous biopolymers and humic acids were preferentially removed.The characterization of particulates indicated that high surface energy,zeta potential,and bridging/adsorption/sedimentation/coagulation capacities in aluminum residuals of SSW,underscoring its potential as a coagulant and promoting the generation and sedimentation of inorganic-organic complexes.The coagulation-sedimentation process could effectively remove pollutants from low-turbidity SSW([turbidity]0<15 NTU).These findings provide valuable insights into the water quality dynamics of SSW during the pre-sedimentation process,facilitating the development of SSW quality management and enhancing its reuse rate.展开更多
In dynamic scenes,the pose estimation and map consistency of visual simultaneous localisation and mapping(visual SLAM)are affected by intermittent changes in object motion states.An adaptive motion-state estimation an...In dynamic scenes,the pose estimation and map consistency of visual simultaneous localisation and mapping(visual SLAM)are affected by intermittent changes in object motion states.An adaptive motion-state estimation and feature-reuse mechanism is proposed which restores features once objects become stationary.Camera ego-motion is com-pensated via projection-based point-to-point red-green-blue-depth(RGB-D)Iterative Closest Point;the alignment residual yields a short-term jitter score.An Extended Kalman Filter fuses the centre-pixel trajectory and depth of the object,using depth innovation as strong evidence to suppress false triggers.Applied adaptive decision thresholds involve resolution,ego-motion intensity,jitter,and reference depth,and are combined with dual/single triggering and hysteresis to achieve robust switching.When an object is considered static,its feature points are reused.On the Bonn RGB-D Dynamic Dataset(BONN)and TUM RGB-D SLAM Dataset and Benchmark(TUM),the proposed method matches or exceeds baselines:In intermittent-motion-dominated BONN sequences Placing_non_box,it re-duces the root-mean-square of the absolute trajectory error(ATE-RMSE)by 27%relative to the baseline,remains comparable to Ellipsoid-SLAM on TUM,and consistently outperforms ORB-SLAM3 in dynamic scenes.The hysteresis counter reading on Placing_non_box2 shows that the proposed method can reduce the motion-state misclassification rate by nearly 40%.From the ablation experiment results,we confirm that adaptive thresholds yield the most significant optimisation effect.The approach improves robustness and map completeness in dynamic environments without degrading performance in low-dynamic settings.展开更多
Photonuclear data are increasingly used in fundamental nuclear research and technological applications.These data are generated using advanced γ-ray sources.The Shanghai laser electron gamma source(SLEGS)is a new las...Photonuclear data are increasingly used in fundamental nuclear research and technological applications.These data are generated using advanced γ-ray sources.The Shanghai laser electron gamma source(SLEGS)is a new laser Compton scattering γ-ray source at the Shanghai Synchrotron Radiation Facility.It delivers energy-tunable,quasi-monoenergetic gamma beams for high-precision photonuclear measurements.This paper presents the flat-efficiency detector(FED)array at SLEGS and its application in photoneutron cross-section measurements.Systematic uncertainties of the FED array were determined to be 3.02%through calibration with a ^(252)Cf neutron source.Using ^(197)Au and ^(159)Tb as representative nuclei,we demonstrate the format and processing methodology for raw photoneutron data.The results validate SLEGS’capability for high-precision photoneutron measurements.展开更多
This study presents a holistic framework for sustainable urban design,using the proposed redevelopment design of Berlin’s Tegel Airport as a case study.The research addresses the need for comprehensive,real-world app...This study presents a holistic framework for sustainable urban design,using the proposed redevelopment design of Berlin’s Tegel Airport as a case study.The research addresses the need for comprehensive,real-world applications of sustainable urban design principles in the context of climate change and urban challenges.The proposed framework integrates multiple sustainability elements,including adaptive reuse,innovative energy systems,and a’resource community’concept.Key features include mixed-use development,a phased approach,and innovative mobility solutions.The study demonstrates the practical application of urban resilience theory,adaptive reuse concepts,circular economy principles,and compact city theory.Findings reveal the potential for significant environmental benefits,including reduced energy consumption and improved resource efficiency.The framework shows promise in fostering social cohesion through mixed-use spaces and community-centered design.Economic implications include creating local job opportunities and the potential for long-term cost savings through efficient resource management.However,challenges such as initial implementation costs and the need for stakeholder coordination are identified.The study contributes to sustainable urban planning by bridging the theoretical concepts and practical implementation gap.It offers a model for transforming urban brownfields into sustainable communities,providing valuable insights for urban planners,policymakers,and developers.Future research directions include longitudinal studies of implemented projects and comparative analyses across diverse urban contexts.展开更多
Accurate retrieval of casting 3D models is crucial for process reuse.Current methods primarily focus on shape similarity,neglecting process design features,which compromises reusability.In this study,a novel deep lear...Accurate retrieval of casting 3D models is crucial for process reuse.Current methods primarily focus on shape similarity,neglecting process design features,which compromises reusability.In this study,a novel deep learning retrieval method for process reuse was proposed,which integrates process design features into the retrieval of casting 3D models.This method leverages the comparative language-image pretraining(CLIP)model to extract shape features from the three views and sectional views of the casting model and combines them with process design features such as modulus,main wall thickness,symmetry,and length-to-height ratio to enhance process reusability.A database of 230 production casting models was established for model validation.Results indicate that incorporating process design features improves model accuracy by 6.09%,reaching 97.82%,and increases process similarity by 30.25%.The reusability of the process was further verified using the casting simulation software EasyCast.The results show that the process retrieved after integrating process design features produces the least shrinkage in the target model,demonstrating this method’s superior ability for process reuse.This approach does not require a large dataset for training and optimization,making it highly applicable to casting process design and related manufacturing processes.展开更多
Memory-unsafe programming languages,such as C/C++,are often used to develop system programs,rendering the programs susceptible to a variety of memory corruption attacks.Among these threats,just-in-time return-oriented...Memory-unsafe programming languages,such as C/C++,are often used to develop system programs,rendering the programs susceptible to a variety of memory corruption attacks.Among these threats,just-in-time return-oriented programming(JIT-ROP)stands out as an advanced method for conducting code-reuse attacks,effectively circumventing code randomization safeguards.JIT-ROP leverages memory disclosure vulnerabilities to obtain reusable code fragments dynamically and assemble malicious payloads dynamically.In response to JIT-ROP attacks,several re-randomization implementations have been developed to prevent the use of disclosed code.However,existing re-randomization methods require recurrent re-randomization during program runtime according to fixed time windows or specific events such as system calls,incurring significant runtime overhead.In this paper,we present the design and implementation of PtrProxy,an efficient re-randomization approach on the AArch64 platform.Unlike previous methods that necessitate frequent runtime rerandomization or reply on unreliable triggering conditions,this approach triggers the re-randomization process by detecting the code page harvest operation,which is a fundamental operation of the JIT-ROP at-tacks,making our method more efficient and reliable than previous approaches.We evaluate PtrProxy on benchmarks and real-world applications.The evaluation results show that our approach can effectively protect programs from JIT-ROP attacks while introducing marginal runtime overhead.展开更多
The reuse of green sand in casting production is hindered by the accumulation of oolitic deposits,primarily composed of clay binder with surface degradation,which may adversely affect the the moulding sand performance...The reuse of green sand in casting production is hindered by the accumulation of oolitic deposits,primarily composed of clay binder with surface degradation,which may adversely affect the the moulding sand performance.Currently,there is a lack of standardized methods for quantifying the oolitic content.Accurate measurement of oolitic content is of great significance to the reuse of green sand.Attempts to determine oolitic content using potassium hydroxide(KOH)and phosphoric acid(H_(3)PO_(4))methods encounter challenges due to their excessive reactions with SiO_(2) in the sand.In this study,an improved method for measuring the oolitic content of green sand with repeated approximations was proposed.This method judges the chemical activity of the sample surface through the change of its mass to accurately obtain the mass of the reaction oolitic deposits.The test result of the used sand samples from the foundry shows that the oolitic deposits are completely removed after reacting with KOH solution three times at 300℃ for 20 min.SEM and EDS also show that after three times of reactions,the surface of green sand becomes smooth and the content of Al-containing oolitic deposits is very low.This indicates that the method can accurately control the extent of the reaction.Implementation of this method at Huangshi Dongbei Casting Co.,Ltd.has yielded consistent and reliable test results,effectively mirroring variations in green sand oolitic content on the production line.This new method is expected to be widely adopted to improve the efficiency and quality of reused green sand in casting operations.展开更多
Eton Systems-a member of TMAS,the Swedish Textile Machinery Association-is taking part in the current Microfactories System Innovation project which is working on the development of a fully automated workflow for seco...Eton Systems-a member of TMAS,the Swedish Textile Machinery Association-is taking part in the current Microfactories System Innovation project which is working on the development of a fully automated workflow for second hand garments.Eton is contributing its well-proven transport system for material handling to the project,which also involves spe-cialists at the Swedish School of Textiles in Boras,the Au-tomation Region innovation cluster at Mälardalen University and the national collaboration platform iHubs Sweden.展开更多
With digital coding technology,reconfigurable intelligent surfaces(RISs)become powerful real-time sys-tems for manipulating electromagnetic(EM)waves.However,most automatic RIS designs involve exten-sive numerical simu...With digital coding technology,reconfigurable intelligent surfaces(RISs)become powerful real-time sys-tems for manipulating electromagnetic(EM)waves.However,most automatic RIS designs involve exten-sive numerical simulations of the unit,including the passive pattern and active devices,requiring high data acquisition and training costs.In addition,for passive patterns,the widely employed random pixe-lated method presents design efficiency and effectiveness challenges due to the massive pixel combina-tions and blocked excitation current flow in discrete patterns.To overcome these two critical problems,we propose a versatile RIS design paradigm with efficient topology representation and a separate design architecture.First,a non-uniform rational B-spline(NURBS)is introduced to represent continuous pat-terns and solve excitation current flow issues.This representation makes it possible to finely tune con-tinuous patterns with several control points,greatly reducing the pattern solution space by 20-fold and facilitating RIS optimization.Then,employing multiport network theory to separate the passive pat-tern and active device from the unit,the separate design architecture significantly reduces the dataset acquisition cost by 62.5%.Through multistep multiport calculation,the multistate EM responses of the RIS under different structural combinations can be quickly obtained with only one prediction of pattern response,thereby achieving dataset and model reuse for different RIS designs.With a hybrid continuous-discrete optimization algorithm,three examples—including two typical high-performance RISs and an ultra-wideband multilayer RIS—are provided to validate the superiority of our paradigm.Our work offers an efficient solution for RIS automatic design,and the resulting structure is expected to boost RIS appli-cations in the fields of wireless communication and sensing.展开更多
Decarbonizing offshore oil and gas platforms has become a critical challenge in the energy transition.In this article,we propose the following two models for decarbonizing offshore oil and gas platforms to facilitate ...Decarbonizing offshore oil and gas platforms has become a critical challenge in the energy transition.In this article,we propose the following two models for decarbonizing offshore oil and gas platforms to facilitate highly challenging energy transitions:(1)repurposing decommissioned platforms as offshore wind-hydrogen hubs and(2)integrating offshore wind power and hydrogen production systems into operational platforms.This study is conducted to systematically assess the feasibility of the proposed models and further examine their technological challenges,systemic risks,and possible mitigation pathways.The results showed that wind turbines,reverse osmosis desalination,and alkaline water electrolysis have high levels of maturity,whereas subsea hydrogen pipelines and liquid/compressed hydrogen carriers remain comparatively immature.Both models can significantly lower costs,strengthen energy resilience,and reduce emissions.However,large-scale deployment is generally constrained by high capital costs,integration complexity,and fragmented regulatory frameworks.The findings highlight that reusing offshore infrastructure to integrate offshore wind power and hydrogen production systems offers cost and environmental advantages over conventional decommissioning,while integrated supply systems can ensure long-term stability through multi-energy complementarity.The study provides strategic insights for advancing low-carbon transformation and guiding the sustainable and resilient development of offshore energy systems.展开更多
Although ray tracing produces high-fidelity, realistic images, it is considered computationally burdensome when implemented on a high rendering rate system. Perception-driven rendering techniques generate images with ...Although ray tracing produces high-fidelity, realistic images, it is considered computationally burdensome when implemented on a high rendering rate system. Perception-driven rendering techniques generate images with minimal noise and distortion that are generally acceptable to the human visual system, thereby reducing rendering costs. In this paper, we introduce a perception-entropy-driven temporal reusing method to accelerate real-time ray tracing. We first build a just noticeable difference(JND) model to represent the uncertainty of ray samples and image space masking effects. Then, we expand the shading gradient through gradient max-pooling and gradient filtering to enlarge the visual receipt field. Finally, we dynamically optimize reusable time segments to improve the accuracy of temporal reusing. Compared with Monte Carlo ray tracing, our algorithm enhances frames per second(fps) by 1.93× to 2.96× at 8 to 16 samples per pixel, significantly accelerating the Monte Carlo ray tracing process while maintaining visual quality.展开更多
The paper presents an innovative approach to studying the reuse of a decommissioned natural gas production platformfor the seasonal storage and extraction of a hydrogen-methane(H2-CH4)mixture froma depleted reservoir....The paper presents an innovative approach to studying the reuse of a decommissioned natural gas production platformfor the seasonal storage and extraction of a hydrogen-methane(H2-CH4)mixture froma depleted reservoir.The reuse plan involves removing outdated equipment from the platform’s decks while retaining essential components such as wellheads and separators.Exploiting a depleted reservoir for the injection of an H_(2)-CH_(4) mixture requires a thorough understanding of its specific characteristics.This paper focuses on the engineering approach adopted in the basic design phase for such a conversion,providing recommendations and HSE guidelines.Given the hazardous nature of substances like hydrogen in the gas mixture,the paper also examines potential risk scenarios,particularly those involving containment loss.A qualitative and quantitative assessment of these risks is conducted to evaluate their impact on the structure and equipment.The results of this assessment serve as a foundation for later studies on layout optimization and domino effect prevention.Additionally,some critical scenarios are simulated using an innovative approach known as the Source Box Accident Model(SBAM),which was proposed in previous works.SBAM leverages Computational Fluid Dynamics(CFD)but decouples the accidental phenomenon into a release phase and a dispersion phase.This method overcomes the challenges conventional CFD tools face in assessing congested plant configurations,providing more precise estimations of gas cloud behavior.The simulation results indicate that the released gas remains within the platform deck domain,and the flammable cloud is significantly smaller than what traditional,simplified tools predict.展开更多
The paper analyzes the definite place of industrial building in the history of urban development. Due to the development of urban economy and the transition of the traditional industrial structure, many historic citie...The paper analyzes the definite place of industrial building in the history of urban development. Due to the development of urban economy and the transition of the traditional industrial structure, many historic cities and towns both at home and abroad have witnessed a large scale "demolition" and abandonment of industrial buildings in urban renewal during last 30 years. Consequently, it has been leading to the discontinuity of urban cultural and historic context. The paper discusses and expounds the clas...展开更多
基金the Alexander von Humboldt Foundation for their support
文摘We investigate a wavelength-division-multiplexing passive optical network(WDM-PON) with centralized lightwave and direct detection. The system is demonstrated for symmetric 10 Gbit/s differential phase-shift keying(DPSK) downstream signals and on-off keying(OOK) upstream signals,respectively. A wavelength reused scheme is employed to carry the upstream data by using a reflective semiconductor optical amplifier(RSOA) as an intensity modulator at the optical network unit(ONU). The constant-intensity property of the DPSK modulation format can keep high extinction ratio(ER) of downstream signal and reduce the crosstalk to the upstream signal. The bit error rate(BER) performance of our scheme shows that the proposed 10 Gbit/s symmetric WDM-PON can achieve error free transmission over 25-km-long fiber transmission with low power penalty.
基金Item Sponsored by Preferred Scientific Research Foundation for Returned Overseas Chinese Scholars,Ministry of Human Resources and Social Security of China([2007]170)
文摘Electrosorption technology was used to treat the reused comprehensive wastewater from iron and steel industry. A problem of relatively high conductivity of wastewater which greatly affects the reuse was examined, and industrial test was conducted for the reused water advanced deionization and purification in a comprehensive wastewater treatment plant o{ WISCO [Wuhan Iron and Steel （Group） Corporation]. The results of the on-site in- dustrial test showed a satisfactory treatment performance for the reused water even at a flow rate of 1 000 L/h in a standard 500 L/h unit. The average conductivity decreased by about 70%, from 580--780 μS/cm to 100--350 μS/cm. The average removal efficiency of CI and Ca2＋ was about 75% and 68%, respectively, and CODcr of the treated wa- ter was also reduced in some degree while the pH value was almost unchanged. The energy consumption was as low as 0.6 kWh/t, which was remarkably superior to the conventional technologies. Therefore, it is entirely feasible that the novel eleetrosorption technology can be used in enhanced desalination and purification treatment of reused com- prehensive wastewater in iron and steel industry.
基金supported by the National Natural Science Foundation of China (61071108)the Central Universities Basic Scientific Research Special Fund (SWJTU09ZT14)
文摘In orthogonal frequency division multiple access（OFDMA） relay system,for supporting relay transmission,the base station（BS）-the relay station（RS） link must consume an extra part of resource,which may result in serious resource shortage.In order to improve resource utilization,this paper proposes a dynamic resource allocation scheme in adaptive frequency reused OFDMA-relay system based on adaptive modulation and coding（AMC） technology.In this scheme,relay nodes have two independent antennas and operate in decode-and-forward（DF） and full-duplex mode.Then the BS and RSs share the same subcarriers by spatial multiplexing by two independent antennas.The resource allocation problem is formulated for system downlink throughput maximization.Since the optimal solution couldn＇t be obtained easily,a sub-optimal algorithm is proposed.The adaptive frequency reused algorithm with two independent antennas RS improves the system throughput about 24.3 % compared with the orthogonal frequency allocation with single-antenna model,and increases the system throughput 10.4 % compared with adaptive frequency reused algorithms with single-antenna RS.It is proved that both of the RS with two-antenna model and adaptive frequency reused scheme can improve the system throughput significantly.
基金The National Science and Technology Special Project，The National Natural Science Foundation of China
文摘Femtocell is a promising technology to improve network performance with low-power and cost-beneficial small base stations. However, the interference-limited reality in femtocell networks makes interference and resource management the key to achieving the benefits of femtocell networks. In this paper, the following contributions are made step by step： first, on the basis of the interference temperature model （ITM） in cognitive radio （CR） technique and the network architecture of the third generation partnership project （3GPP） long term evolution advanced （LTE-A）, the problem model of optimizing the capacity of the femtocell-reused subchannel is established under the frequency partitioning strategy, jointly considering the average interference constraint and the instantaneous interference constraint. Second, utilizing the convex theory, optimal power allocation of the femtocell-reused subchannel is derived. Third, under Rayleigh fading channel, closed-form expressions of the subchannel reusable probability and capacity are derived. At last, numerical results are conducted to confirming our analytical results, which could provide theoretical guidance for frequency resource allocation of femtocell network deployments.
基金financially supported by the National Natural Science Foundation of China(Nos.52304314 and U23A20602)the Open Fund of the Key Laboratory of Mineral Metallurgical Resources Utilization and Pollution Control,Ministry of Ecology and Environment+3 种基金China(No.HB202406)the Fundamental Research Funds for the Central Universities of Central South University,China(Nos.CX20240021 and 2024ZZTS0008)the Innovation and Entrepreneurship Funding Project for College Students of Central South UniversityChina(No.S202410533166)。
文摘Flotation is the most common method to recover valuable minerals by selective adsorption of collectors on target mineral surfaces.However,in subsequent hydrometallurgy of mineral flotation concentrates,the adsorbed collectors must be desorbed since it can adversely affect the efficiency of metallurgical process and produce wastewater.ZL,as a fatty acid mixture,is a typical industrially used collector for scheelite flotation in China.Sodium oleate(NaOL)has similar fatty acid group as ZL.In this study,the desorption behavior of NaOL/ZL from scheelite surface by a physical method of stirring at a low temperature was investigated.NaOL desorption tests of single mineral showed that a desorption rate of 77.75% for NaOL from scheelite surface into pulp was achieved in a stirring speed of2500 r/min at 5℃in a neutral environment.Under the above desorption condition,in the pulp containing desorbed collector by adding extra 30% normal NaOL dosage,the scheelite recovery reached about 95% in the single mineral flotation test.Desorption and reuse of ZL collector for the flotation of real scheelite ore showed only a 75%normal dosage of ZL could produce a qualified rough concentrate.The atomic force microscope(AFM)tests showed that after desorption treatment of low temperature and strong stirring,the dense strip-like structure of NaOL on the scheelite surface was destroyed to be speck-like.Molecular dynamics simulations(MDS)demonstrated that the adsorption energy between NaOL and scheelite surface was more negative at 25℃(-13.39 kcal/mol)than at 5℃(-11.50 kcal/mol)in a neutral pH,indicating that a low temperature was beneficial for the desorption of collector from mineral surface.Due to its simplicity and economy,the method we proposed of desorption of collector from mineral surface and its reuse for flotation has a great potential for industrial application.
基金funding from MUR under the umbrella of the PRIMA-Partnership for Research&Innovation in the Mediterranean Area through the research project SAFE"Sustainable water reuse practices improving safety in agriculture,food and environment"support from the CERCA Institute through the CERCAGINYS programme,funded by the Spanish Ministry of Science and Innovationsupport from the Economy and Knowledge Department of the Catalan Government through a Consolidated Research Groups(ICRA-ENV-2021 SGR 01282 and ICRA-TECH 2021 SGR 01283)。
文摘Fipronil is an insecticide with low residual activity and high efficacy at low concentrations.Due to its widespread use and long half-life,fipronil can persist during wastewater treatment and is found even in surface waters.When released into the environment,it can accumulate over time and can lead to concentrations in soil and plant tissues that are harmful to both target and non-target organisms.As the reuse of treated wastewater and sewage sludge presents challenges and opportunities for farmers,this study investigates the effects of irrigation with environmentally relevant doses of fipronil on zucchini plants and their main insect pest,Aphis gossypii.Traces of fipronil were found in the zucchini leaves,but not in the flowers,after 35-days of cumulative exposure.A decrease in nymph-to-adult survival and a dose-dependent reduction in the fecundity of A.gossypii feeding on contaminated host plants was observed.Also,aphids feeding on contaminated host plants exhibited the same mortality rate as the control group when exposed to an acute dose of fipronil.However,when natural pyrethrins were used,there was a significant increase in resistance to this insecticide.Our results demonstrate the potential for fipronil to accumulate in plant tissues and highlight the risk of changes in insecticide susceptibility in insect pests.This suggests a need for a holistic approach to the complex dynamics of wastewater reuse in agriculture.
基金supported by the Ministry of Science and Technology of China (Nos.2021YFC3200904,and 2022YFC3203705)the National Natural Science Foundation of China (Nos.52070184,and 52270012)the Nanning Scientific Research and Technology Development Project (No.ZC20223238).
文摘Sedimentation sludge water(SSW),a prominent constituent of wastewater from drinking water treatment plants,has received limited attention in terms of its treatment and utilization likely due to the perceived difficulties associated with managing SSW sludge.This study comprehensively evaluated the water quality of SSW by comparing it to a well-documented wastewater(filter backwash water(FBW)).Furthermore,it investigated the pollutant variations in the SSW during pre-sedimentation process,probed the underlying reaction mechanism,and explored the feasibility of employing a pilot-scale coagulation-sedimentation process for SSW treatment.The levels of most water quality parameters were generally comparable between SSW and FBW.During the pre-sedimentation of SSW,significant removal of turbidity,bacterial counts,and dissolved organic matter(DOM)was observed.The characterization of DOM components,molecular weight distributions,and optical properties revealed that the macromolecular proteinaceous biopolymers and humic acids were preferentially removed.The characterization of particulates indicated that high surface energy,zeta potential,and bridging/adsorption/sedimentation/coagulation capacities in aluminum residuals of SSW,underscoring its potential as a coagulant and promoting the generation and sedimentation of inorganic-organic complexes.The coagulation-sedimentation process could effectively remove pollutants from low-turbidity SSW([turbidity]0<15 NTU).These findings provide valuable insights into the water quality dynamics of SSW during the pre-sedimentation process,facilitating the development of SSW quality management and enhancing its reuse rate.
文摘In dynamic scenes,the pose estimation and map consistency of visual simultaneous localisation and mapping(visual SLAM)are affected by intermittent changes in object motion states.An adaptive motion-state estimation and feature-reuse mechanism is proposed which restores features once objects become stationary.Camera ego-motion is com-pensated via projection-based point-to-point red-green-blue-depth(RGB-D)Iterative Closest Point;the alignment residual yields a short-term jitter score.An Extended Kalman Filter fuses the centre-pixel trajectory and depth of the object,using depth innovation as strong evidence to suppress false triggers.Applied adaptive decision thresholds involve resolution,ego-motion intensity,jitter,and reference depth,and are combined with dual/single triggering and hysteresis to achieve robust switching.When an object is considered static,its feature points are reused.On the Bonn RGB-D Dynamic Dataset(BONN)and TUM RGB-D SLAM Dataset and Benchmark(TUM),the proposed method matches or exceeds baselines:In intermittent-motion-dominated BONN sequences Placing_non_box,it re-duces the root-mean-square of the absolute trajectory error(ATE-RMSE)by 27%relative to the baseline,remains comparable to Ellipsoid-SLAM on TUM,and consistently outperforms ORB-SLAM3 in dynamic scenes.The hysteresis counter reading on Placing_non_box2 shows that the proposed method can reduce the motion-state misclassification rate by nearly 40%.From the ablation experiment results,we confirm that adaptive thresholds yield the most significant optimisation effect.The approach improves robustness and map completeness in dynamic environments without degrading performance in low-dynamic settings.
基金supported by National Key Research and Development Program of China(Nos.2022YFA1602404 and 2023YFA1606901)the National Natural Science Foundation of China(Nos.12275338,12388102,and U2441221)the Key Laboratory of Nuclear Data Foundation(JCKY2022201C152).
文摘Photonuclear data are increasingly used in fundamental nuclear research and technological applications.These data are generated using advanced γ-ray sources.The Shanghai laser electron gamma source(SLEGS)is a new laser Compton scattering γ-ray source at the Shanghai Synchrotron Radiation Facility.It delivers energy-tunable,quasi-monoenergetic gamma beams for high-precision photonuclear measurements.This paper presents the flat-efficiency detector(FED)array at SLEGS and its application in photoneutron cross-section measurements.Systematic uncertainties of the FED array were determined to be 3.02%through calibration with a ^(252)Cf neutron source.Using ^(197)Au and ^(159)Tb as representative nuclei,we demonstrate the format and processing methodology for raw photoneutron data.The results validate SLEGS’capability for high-precision photoneutron measurements.
文摘This study presents a holistic framework for sustainable urban design,using the proposed redevelopment design of Berlin’s Tegel Airport as a case study.The research addresses the need for comprehensive,real-world applications of sustainable urban design principles in the context of climate change and urban challenges.The proposed framework integrates multiple sustainability elements,including adaptive reuse,innovative energy systems,and a’resource community’concept.Key features include mixed-use development,a phased approach,and innovative mobility solutions.The study demonstrates the practical application of urban resilience theory,adaptive reuse concepts,circular economy principles,and compact city theory.Findings reveal the potential for significant environmental benefits,including reduced energy consumption and improved resource efficiency.The framework shows promise in fostering social cohesion through mixed-use spaces and community-centered design.Economic implications include creating local job opportunities and the potential for long-term cost savings through efficient resource management.However,challenges such as initial implementation costs and the need for stakeholder coordination are identified.The study contributes to sustainable urban planning by bridging the theoretical concepts and practical implementation gap.It offers a model for transforming urban brownfields into sustainable communities,providing valuable insights for urban planners,policymakers,and developers.Future research directions include longitudinal studies of implemented projects and comparative analyses across diverse urban contexts.
基金supported by the National Natural Science Foundation of China(Nos.52074246,52275390,52375394)the National Defense Basic Scientific Research Program of China(No.JCKY2020408B002)the Key R&D Program of Shanxi Province(No.202102050201011).
文摘Accurate retrieval of casting 3D models is crucial for process reuse.Current methods primarily focus on shape similarity,neglecting process design features,which compromises reusability.In this study,a novel deep learning retrieval method for process reuse was proposed,which integrates process design features into the retrieval of casting 3D models.This method leverages the comparative language-image pretraining(CLIP)model to extract shape features from the three views and sectional views of the casting model and combines them with process design features such as modulus,main wall thickness,symmetry,and length-to-height ratio to enhance process reusability.A database of 230 production casting models was established for model validation.Results indicate that incorporating process design features improves model accuracy by 6.09%,reaching 97.82%,and increases process similarity by 30.25%.The reusability of the process was further verified using the casting simulation software EasyCast.The results show that the process retrieved after integrating process design features produces the least shrinkage in the target model,demonstrating this method’s superior ability for process reuse.This approach does not require a large dataset for training and optimization,making it highly applicable to casting process design and related manufacturing processes.
基金supported in part by the National Natural Science Foundation of China(62272351,61972297,62172308).
文摘Memory-unsafe programming languages,such as C/C++,are often used to develop system programs,rendering the programs susceptible to a variety of memory corruption attacks.Among these threats,just-in-time return-oriented programming(JIT-ROP)stands out as an advanced method for conducting code-reuse attacks,effectively circumventing code randomization safeguards.JIT-ROP leverages memory disclosure vulnerabilities to obtain reusable code fragments dynamically and assemble malicious payloads dynamically.In response to JIT-ROP attacks,several re-randomization implementations have been developed to prevent the use of disclosed code.However,existing re-randomization methods require recurrent re-randomization during program runtime according to fixed time windows or specific events such as system calls,incurring significant runtime overhead.In this paper,we present the design and implementation of PtrProxy,an efficient re-randomization approach on the AArch64 platform.Unlike previous methods that necessitate frequent runtime rerandomization or reply on unreliable triggering conditions,this approach triggers the re-randomization process by detecting the code page harvest operation,which is a fundamental operation of the JIT-ROP at-tacks,making our method more efficient and reliable than previous approaches.We evaluate PtrProxy on benchmarks and real-world applications.The evaluation results show that our approach can effectively protect programs from JIT-ROP attacks while introducing marginal runtime overhead.
基金financially supported by the National Key Research and Development Program of China(Grant No.2022YFB3706800)the National Natural Science Foundation of China(Grant Nos.51905188 and 51775205).
文摘The reuse of green sand in casting production is hindered by the accumulation of oolitic deposits,primarily composed of clay binder with surface degradation,which may adversely affect the the moulding sand performance.Currently,there is a lack of standardized methods for quantifying the oolitic content.Accurate measurement of oolitic content is of great significance to the reuse of green sand.Attempts to determine oolitic content using potassium hydroxide(KOH)and phosphoric acid(H_(3)PO_(4))methods encounter challenges due to their excessive reactions with SiO_(2) in the sand.In this study,an improved method for measuring the oolitic content of green sand with repeated approximations was proposed.This method judges the chemical activity of the sample surface through the change of its mass to accurately obtain the mass of the reaction oolitic deposits.The test result of the used sand samples from the foundry shows that the oolitic deposits are completely removed after reacting with KOH solution three times at 300℃ for 20 min.SEM and EDS also show that after three times of reactions,the surface of green sand becomes smooth and the content of Al-containing oolitic deposits is very low.This indicates that the method can accurately control the extent of the reaction.Implementation of this method at Huangshi Dongbei Casting Co.,Ltd.has yielded consistent and reliable test results,effectively mirroring variations in green sand oolitic content on the production line.This new method is expected to be widely adopted to improve the efficiency and quality of reused green sand in casting operations.
文摘Eton Systems-a member of TMAS,the Swedish Textile Machinery Association-is taking part in the current Microfactories System Innovation project which is working on the development of a fully automated workflow for second hand garments.Eton is contributing its well-proven transport system for material handling to the project,which also involves spe-cialists at the Swedish School of Textiles in Boras,the Au-tomation Region innovation cluster at Mälardalen University and the national collaboration platform iHubs Sweden.
基金supported by the National Key Research and Development Program of China(2023YFB3811502)the National Science Foundation of China(62225108)+5 种基金the Fundamental Research Funds for the Central Universities(2242022k60003)the National Natural Science Foundation of China(62288101 and 62201139)the Jiangsu Province Frontier Leading Technology Basic Research Project(BK20212002)the Jiangsu Provincial Scientific Research Center of Applied Mathematics(BK20233002)the Fundamental Research Funds for the Central Universities(2242024RCB0005 and 2242024K30009)the 111 Project(111-2-05).
文摘With digital coding technology,reconfigurable intelligent surfaces(RISs)become powerful real-time sys-tems for manipulating electromagnetic(EM)waves.However,most automatic RIS designs involve exten-sive numerical simulations of the unit,including the passive pattern and active devices,requiring high data acquisition and training costs.In addition,for passive patterns,the widely employed random pixe-lated method presents design efficiency and effectiveness challenges due to the massive pixel combina-tions and blocked excitation current flow in discrete patterns.To overcome these two critical problems,we propose a versatile RIS design paradigm with efficient topology representation and a separate design architecture.First,a non-uniform rational B-spline(NURBS)is introduced to represent continuous pat-terns and solve excitation current flow issues.This representation makes it possible to finely tune con-tinuous patterns with several control points,greatly reducing the pattern solution space by 20-fold and facilitating RIS optimization.Then,employing multiport network theory to separate the passive pat-tern and active device from the unit,the separate design architecture significantly reduces the dataset acquisition cost by 62.5%.Through multistep multiport calculation,the multistate EM responses of the RIS under different structural combinations can be quickly obtained with only one prediction of pattern response,thereby achieving dataset and model reuse for different RIS designs.With a hybrid continuous-discrete optimization algorithm,three examples—including two typical high-performance RISs and an ultra-wideband multilayer RIS—are provided to validate the superiority of our paradigm.Our work offers an efficient solution for RIS automatic design,and the resulting structure is expected to boost RIS appli-cations in the fields of wireless communication and sensing.
基金supported by the Chinese Academy of Engineering,China(Grant No.2024-HZ-31-03).-。
文摘Decarbonizing offshore oil and gas platforms has become a critical challenge in the energy transition.In this article,we propose the following two models for decarbonizing offshore oil and gas platforms to facilitate highly challenging energy transitions:(1)repurposing decommissioned platforms as offshore wind-hydrogen hubs and(2)integrating offshore wind power and hydrogen production systems into operational platforms.This study is conducted to systematically assess the feasibility of the proposed models and further examine their technological challenges,systemic risks,and possible mitigation pathways.The results showed that wind turbines,reverse osmosis desalination,and alkaline water electrolysis have high levels of maturity,whereas subsea hydrogen pipelines and liquid/compressed hydrogen carriers remain comparatively immature.Both models can significantly lower costs,strengthen energy resilience,and reduce emissions.However,large-scale deployment is generally constrained by high capital costs,integration complexity,and fragmented regulatory frameworks.The findings highlight that reusing offshore infrastructure to integrate offshore wind power and hydrogen production systems offers cost and environmental advantages over conventional decommissioning,while integrated supply systems can ensure long-term stability through multi-energy complementarity.The study provides strategic insights for advancing low-carbon transformation and guiding the sustainable and resilient development of offshore energy systems.
基金supported by the National Natural Science Foundation of China (No.U19A2063)the Jilin Provincial Science&Technology Development Program of China (No.20230201080GX)。
文摘Although ray tracing produces high-fidelity, realistic images, it is considered computationally burdensome when implemented on a high rendering rate system. Perception-driven rendering techniques generate images with minimal noise and distortion that are generally acceptable to the human visual system, thereby reducing rendering costs. In this paper, we introduce a perception-entropy-driven temporal reusing method to accelerate real-time ray tracing. We first build a just noticeable difference(JND) model to represent the uncertainty of ray samples and image space masking effects. Then, we expand the shading gradient through gradient max-pooling and gradient filtering to enlarge the visual receipt field. Finally, we dynamically optimize reusable time segments to improve the accuracy of temporal reusing. Compared with Monte Carlo ray tracing, our algorithm enhances frames per second(fps) by 1.93× to 2.96× at 8 to 16 samples per pixel, significantly accelerating the Monte Carlo ray tracing process while maintaining visual quality.
基金funded by the Italian Ministry of Environment and Energy Security(MASE)-Direzione Generale per le Fonti energetiche e Titoli Abilitativi(DGFTA).
文摘The paper presents an innovative approach to studying the reuse of a decommissioned natural gas production platformfor the seasonal storage and extraction of a hydrogen-methane(H2-CH4)mixture froma depleted reservoir.The reuse plan involves removing outdated equipment from the platform’s decks while retaining essential components such as wellheads and separators.Exploiting a depleted reservoir for the injection of an H_(2)-CH_(4) mixture requires a thorough understanding of its specific characteristics.This paper focuses on the engineering approach adopted in the basic design phase for such a conversion,providing recommendations and HSE guidelines.Given the hazardous nature of substances like hydrogen in the gas mixture,the paper also examines potential risk scenarios,particularly those involving containment loss.A qualitative and quantitative assessment of these risks is conducted to evaluate their impact on the structure and equipment.The results of this assessment serve as a foundation for later studies on layout optimization and domino effect prevention.Additionally,some critical scenarios are simulated using an innovative approach known as the Source Box Accident Model(SBAM),which was proposed in previous works.SBAM leverages Computational Fluid Dynamics(CFD)but decouples the accidental phenomenon into a release phase and a dispersion phase.This method overcomes the challenges conventional CFD tools face in assessing congested plant configurations,providing more precise estimations of gas cloud behavior.The simulation results indicate that the released gas remains within the platform deck domain,and the flammable cloud is significantly smaller than what traditional,simplified tools predict.
文摘The paper analyzes the definite place of industrial building in the history of urban development. Due to the development of urban economy and the transition of the traditional industrial structure, many historic cities and towns both at home and abroad have witnessed a large scale "demolition" and abandonment of industrial buildings in urban renewal during last 30 years. Consequently, it has been leading to the discontinuity of urban cultural and historic context. The paper discusses and expounds the clas...
