On the Signed Domination Number of the Cartesian Product of Two Directed Cycles

Let D be a finite simple directed graph with vertex set V(D) and arc set A(D). A function ?is called a signed dominating function (SDF) if ?for each vertex . The weight ?of f is defined by . The signed domination number of a digraph D is . Let Cm × Cn denotes the cartesian product of directed cycles of length m and n. In this paper, we determine the exact values of gs(Cm × Cn) for m = 8, 9, 10 and arbitrary n. Also, we give the exact value of gs(Cm × Cn) when m, ?(mod 3) and bounds for otherwise.

Direct Regeneration of Spent Lithium-Ion Battery Cathodes:From Theoretical Study to Production Practice

Direct regeneration method has been widely concerned by researchers in the field of battery recycling because of its advantages of in situ regeneration,short process and less pollutant emission.In this review,we firstly analyze the primary causes for the failure of three representative battery cathodes(lithium iron phosphate,layered lithium transition metal oxide and lithium cobalt oxide),targeting at illustrating their underlying regeneration mecha-nism and applicability.Efficient stripping of material from the collector to obtain pure cathode material has become a first challenge in recycling,for which we report several pretreatment methods currently available for subsequent regeneration processes.We review and discuss emphatically the research progress of five direct regeneration methods,including solid-state sintering,hydrothermal,eutectic molten salt,electrochemical and chemical lithiation methods.Finally,the application of direct regeneration technology in production practice is introduced,the problems exposed at the early stage of the industrialization of direct regeneration technol-ogy are revealed,and the prospect of future large-scale commercial production is proposed.It is hoped that this review will give readers a comprehensive and basic understanding of direct regeneration methods for used lithium-ion batteries and promote the industrial application of direct regeneration technology.

A Note on Directed 5-Cycles in Digraphs

In this note, it is proved that if α≥0.24817, then any digraph on n vertices with minimum outdegree at least αn contains a directed cycle of length at most 5.

A review of recent researches on Bunsen reaction for hydrogen production via S–I water and H2S splitting cycles

The Bunsen reaction is the center reaction for both the sulfur–iodine water splitting cycle for hydrogen production and the novel hydrogen sulfide splitting cycle for hydrogen and sulfuric acid production from the sulfur-containing gases.This paper reviews the research progress of the Bunsen reaction in recent 10–15 years.Researches were initially focused on the optimization of the operating conditions of the conventional Bunsen reaction requiring excessive water and iodine to improve the products separation efficiency and to avoid the side reactions and iodine vapor deposition.Alternative methods including electrochemical methods,precipitation methods,and non-aqueous solvent methods had their respective advantages,but still faced challenges.In development of the technology of H2S splitting cycle,dissolving iodine in toluene solvent could render the Bunsen reaction to occur with the flowable I2 stream at ambient temperature such that the side reactions and iodine vaporization can be avoided and the corrosion hazard lessened.It also prevented the Bunsen reaction from using excessive iodine and water.The products from the Bunsen reaction including HI,H2SO4,H2O,and toluene could be directly electrolyzed.

Identification of Milankovitch Cycles and Calculation of Net Primary Productivity of Paleo-peatlands using Geophysical Logs of Coal Seams

Individual coal seams formed in paleo-peatlands represent sustained periods of terrestrial carbon accumulation and a key environmental indicator attributed to this record is the rate of carbon accumulation.Determining the rate of carbon accumulation requires a measure of time contained within the coal.This study aimed to determine this rate via the identification of Milankovitch orbital cycles in the coals.The geophysical log is an ideal paleoclimate proxy and has been widely used in the study of sedimentary records using spectral analysis.Spectral analyses of geophysical log from thick coal seams can be used to identify the Milankovitch cycles and to calculate the period of the coal deposition.By considering the carbon loss during coalification,the long-term average carbon accumulation rate and net primary productivity(NPP)of paleo-peatlands in coal seams can be obtained.This review paper presents the procedures of analysis,assessment of results and interpretation of geophysical logs in determining the NPP of paleo-peatlands.

Thermochemical splitting of CO_(2) on perovskites for CO production: A review

Energy supply dominated by fossil energy has been and remains the main cause of carbon dioxide emissions,the major greenhouse gas leading to the current grave climate change challenges.Many technical pathways have been proposed to address the challenges.Carbon capture and utilization(CCU) represents one of the approaches and thermochemical CO_(2) splitting driven by thermal energy is a subset of the CCU,which converts the captured CO_(2) into CO and makes it possible to achieve closed-loop carbon recirculation.Redox-active catalysts are among the most critical components of the thermochemical splitting cycles and perovskites are regarded as the most promising catalysts.Here we review the latest advancements in thermochemical cycles based on perovskites,covering thermodynamic principles,material modifications,reaction kinetics,oxygen pressure control,circular strategies,and demonstrations to provide a comprehensive overview of the topical area.Thermochemical cycles based on such materials require the consideration of trade-off between cost and efficiency,which is related to actual material used,operation mode,oxygen removal,and heat recovery.Lots of efforts have been made towards improving reaction rates,conversion efficiency and cycling stability,materials related research has been lacking-a key aspect affecting the performance across all above aspects.Double perovskites and composite perovskites arise recently as a potentially promising addition to material candidates.For such materials,more effective oxygen removal would be needed to enhance the overall efficiency,for which thermochemical or electrochemical oxygen pumps could contribute to efficient oxygen removal as well as serve as means for inert gas regeneration.The integration of thermochemical CO_(2) splitting process with downstream fuel production and other processes could reduce costs and increase efficiency of the technology.This represents one of the directions for the future research.

A new production component method for natural gas development planning

Based on an analysis of the limitations of conventional production component methods for natural gas development planning,this study proposes a new one that uses life cycle models for the trend fitting and prediction of production.In this new method,the annual production of old and new wells is predicted by year first and then is summed up to yield the production for the planning period.It shows that the changes in the production of old wells in old blocks can be fitted and predicted using the vapor pressure model(VPM),with precision of 80%e95%,which is 6.6%e13.2%higher than that of other life cycle models.Furthermore,a new production prediction process and method for new wells have been established based on this life cycle model to predict the production of medium-to-shallow gas reservoirs in western Sichuan Basin,with predication error of production rate in 2021 and 2022 being 6%and 3%respectively.The new method can be used to guide the medium-and long-term planning or annual scheme preparation for gas development.It is also applicable to planning for large single gas blocks that require continuous infill drilling and adjustment to improve gas recovery.

Production forecasting methods for different types of gas reservoirs

Hydrocarbon production in oil and gas fields generally progresses through stages of production ramp-up,plateau(peak),and decline during field development,with the whole process primarily modeled and forecasted using lifecycle models.SINOPEC's conventional gas reservoirs are dominated by carbonates,low-permeability tight sandstone,condensate,volcanic rocks,and medium-to-high-permeability sandstone.This study identifies the optimal production forecasting models by comparing the fitting coefficients of different models and calculating the relative errors in technically recoverable reserves.To improve forecast precision,it suggests substituting exponential smoothing method-derived predictions for anomalous data caused by subjective influences like market dynamics and maintenance activities.The preferred models for carbonate gas reservoir production forecasts are the generalized Weng's,Beta,Class-I generalized mathematical,and Hu-Chen models.The Vapor pressure and Beta models are optimal for forecasting the annual productivity of wells(APW)from gas-bearing low-permeability tight sandstone reservoirs.The Wang-Li,Beta,and Yu QT tb models are apt for moderate-to-small-reserves,single low-permeability tight sandstone gas reservoirs.The Rayleigh,Hu-Chen,and generalized Weng's models are suitable for condensate gas reservoirs.For medium-to-high-permeability sandstone gas reservoirs,the lognormal,generalized gamma,and Beta models are recommended.

Forecasting grain production costs in the backdrop of economic cycles

This research indicates that with the changes in economic cycles, China's production costs are experiencing "wave-shaped" spiral growth. From 2004 to 2008, China's grain production costs increased rapidly, with the primary driving force the rapid growth of labor, land and material costs. In the middle stage of industrialization, China's grain production costs will experience spiral growth following economic cyclical fluctuations, entering relative stability after a certain period. From 2009 to around 2012, grain production costs will drop, but average production costs may be higher than in the current upward cycle. From 2013 to around 2020, grain production costs will rise again and be much higher than in the current upward cycle.

Geometric Origin of Staggered Fermion：Direct Product K—Cycle

Staggered formalism of lattice fermion can be cast into a form of direct product K-cycle in noncommutative geometry. We prove the correspondence between this staggered K-cycle and a canonically defined K-cycle for finitely generated Abelian groups where a lattice appears as a special case.

Evaluation of Corrosion Product Activity in a Typical PWR with Extended Cycles and Flow Rate Perturbations

Effect of flow rate perturbations has been studied using the modified computer program CPAIR-P for time dependent corrosion rates in Pressurized Water Reactors (PWRs) having extended cycles. In these simulations, a decrease in the corresponding saturation values of corrosion product activity (CPA) is observed for higher pH values. Comparison of CPA’s behavior has been done for constant flow-rate case as well as for transients with elevated 10B levels (~40%) in dissolved boric acid in coolant in two operating cycles. When the flow rate is decreased in the first cycle, the saturation value of CPA attains new higher values. Also, in the second operating cycle, the saturation values are about 12% higher when compared with the values in the first cycle.

Tailoring microstructure evolution and mechanical properties of a high-performance alloy steel through controlled thermal cycles of a direct laser depositing process

Direct laser deposition(DLD),as a popular metal additive manufacturing process,shows advantages of technical flexibility and high efficiency to gain a high-performance alloy steel component.However,during the processing of DLD,the deposited steel layer is affected by the subsequent layer depositing.The DLD block shows different microstructure and mechanical properties at the bottom,middle and top of the deposited parts.To date,there are few research works about the effects of inter-layer interval time and laser power on the microstructure evolution and mechanical properties of the deposited layers.In this study,the idle time and laser power layer by layer during DLD of 12CrNi2 steel were controlled to cause the deposited layers to maintain a high cooling rate,while the bottom deposited layer was subjected to a weak tempering effect.Results show that a high proportion of martensite is produced,which improves the strength of the deposited layer.Under the laser scanning strategy of laser power 2,500 W,scanning velocity 5 mm·s^(-1),powder feeding rate 11 g·min^(-1),overlap rate 50%,and a laser power difference of 50 W and a 2 min interval,the tensile strength of the deposited layer of 12CrNi2 steel is in the range of 873-1,022 MPa,and the elongation is in the range of 16.2%-18.9%.This study provides a method to reduce the tempering effect of the subsequent deposition layers on the bottom layers,which can increase the proportion of martensite in the low-alloy high-strength steel,so as to improve the yield strength of the alloy steel.

有向图上基于层次树索引的最大cycle truss社区搜索

社区搜索旨在从信息网络中找出包含用户查询顶点的高内聚连通子图,cycle truss是一种基于cycle三角形的社区搜索模型,而现有的基于索引的cycle truss社区搜索方法存在索引空间大、搜索效率低、社区内聚性低的缺点。为了解决这一问题,提出一种基于层次树索引的最大cycle truss社区搜索方法。首先,提出了k-cycle truss分解算法,并引入了两个重要的概念:cycle三角连通与k-层次等价。基于k-层次等价设计了层次树索引TreeCIndex与表结构索引SuperTable,在此基础上,并基于这两个新的索引,提出了两个高效的cycle truss社区搜索算法。在4个真实数据集上与已有的基于TrussIndex与EquiTruss的社区搜索算法进行了比较,实验结果表明,TreeCIndex与SuperTable比TrussIndex与EquiTruss节省至少41.5%的空间,索引构建的时间节省8.2%至98.3%,且搜索最大cycle truss社区的效率分别高出了一个和两个数量级。

Leveraging Robust Artificial Intelligence for Mechatronic Product Development—A Literature Review

Mechatronic product development is a complex and multidisciplinary field that encompasses various domains, including, among others, mechanical engineering, electrical engineering, control theory and software engineering. The integration of artificial intelligence technologies is revolutionizing this domain, offering opportunities to enhance design processes, optimize performance, and leverage vast amounts of knowledge. However, human expertise remains essential in contextualizing information, considering trade-offs, and ensuring ethical and societal implications are taken into account. This paper therefore explores the existing literature regarding the application of artificial intelligence as a comprehensive database, decision support system, and modeling tool in mechatronic product development. It analyzes the benefits of artificial intelligence in enabling domain linking, replacing human expert knowledge, improving prediction quality, and enhancing intelligent control systems. For this purpose, a consideration of the V-cycle takes place, a standard in mechatronic product development. Along this, an initial assessment of the AI potential is shown and important categories of AI support are formed. This is followed by an examination of the literature with regard to these aspects. As a result, the integration of artificial intelligence in mechatronic product development opens new possibilities and transforms the way innovative mechatronic systems are conceived, designed, and deployed. However, the approaches are only taking place selectively, and a holistic view of the development processes and the potential for robust and context-sensitive artificial intelligence along them is still needed.

Optimal decision of retailer for replenishment cycle under a deteriorating product supply chain

In order to minimize the total cost of the retailer, an optimal replenishment cycle is studied by considering the deteriorating product, two-level trade credits, the limited storage capacity of their own warehouse and credit-linked order quantity simultaneously. A two-echelon supply chain model, which consists of a supplier and a retailer, is established. Then, the retailer＇s optimal replenishment cycle under all the cases are derived by using the optimization theory and method. On the basis of these, the effects of system parameters on the optimal replenishment cycle are examined by using the numerical studies. The results show that, when the retailer＇s trade credit period is longer （shorter） than the customer＇s trade credit period, the optimal replenishment cycle should he increased （decreased） as the retailer＇s trade credit period increases; if the minimum order quantity is high （low）, the optimal replenishment cycle should be increased （not changed） as the minimum order quantity increases.

Deterioration Mechanism of Sulfate Attack on Concrete under Freeze-thaw Cycles

The experiments of concrete attacked by sulfate solution under freeze-thaw cycles were investigated. The sulfate solution includes two types of 5% Na2SO4 and 5% MgSO4. Through the experiment, microstructural analyses such as SEM, XRD and TGA measurements were performed on the selected samples after freeze-thaw cycles. The corrosion products of the concrete were distinguished and quantitatively compared by the thermal analysis. Besides, the damage mechanism considering the dynamic modulus of elastically of concrete under the coupling effect was also investigated. The experimental results show that, under the action of freeze-thaw cycles and sulfate attack, the main attack products in concrete are ettringite and gypsum. The corrosion products exposed to MgSO4 solution are more than those to Na2SO4 solution. Furthermore, the content of gypsum in concrete is less than that of ettringite in test, and some of gypsum can be observed only after a certain corrosion extent. It is also shown that MgSO4 solution has a promoting effect to the damage of concrete under freeze-thaw cycles. Whereas for Na：SO4 solution, the damage of concrete has restrained before 300 freeze-thaw cycles, but the sulfate attack accelerates the deterioration process in its further test period.

Productivity and nutrient cycling in an agroforestry ecosystem for interplant of pineapple and coconut

In this paper, the biomass productivity and nutrient cycling in an agroforestry system of coconut (Cocus nucifera) interplanted with pineapple (Ananas comosus) had been studied. The result showed that the biomass productivity of this ecosystem was 47 460 kg...hm2...a?1, which was 4.3 times as much as that of pure coconut plantation. In the biological cycling of N, P. K elements, the total annual retention was 559.470 kg...hm?2, the annual return was 410.745 kg...hm?2, the annual uptake was 970.475 kg...hm?2, respectively. The average circulation rate in three nutrient elements (N, P, K) was 42.32%, which was 27.53% more than that in pure coconut stands. Coconut interplanted with pineapple was proved to be one of optimum cultural patterns, which had the higher biomass productivity, and better usage efficiency of environment resources in tropical areas.

Direct farm, production base, traceability and food safety in China

With the rapid growth of China＇s economy, rising demand for safety food has been accompanied by frequent food safety scandals. Given that China＇s farming is dominated by millions of small-scale farms, ensuring food safety is a major challenge facing the public and private sectors. The direct farm （DF） program, initiated in 2008, represents one of the government＇s major initiatives to modernize the distribution of fresh fruit and vegetables （FFV） and improve food safety. Under the DF program, participating national and international retailers are expected to establish more direct procurement relationships with farm communities. While it is often claimed that greater participation by retailers in the production and post-harvest processing implied the DF program will lead to improved quality, safety and traceability, systematic evidence remains elu- sive as existing studies are largely narrative, based on case studies, or theoretical inference. Little empirical evidence is available for a broader evaluation of the DF program. This paper aims to fill this gap by assessing the overall performance of a single retailer＇s DF experience with respect to the procurement and food safety of FFV. We use data from a survey of production managers of 35 DF production bases （PBs） spread across 11 provinces, 3 cities and 1 autonomous region in China. The results show a mixture of opportunities and challenges. On one hand, the DF program improves production practices and distribution channels of FFV produced on its PBs, thus facilitating the move of China＇s food system towards improved food safety compliance. On the other hand, significant heterogeneity in the traceability of food and the ability of DF to meet higher safety standards is evident both across major product categories and across household-operated vs. firm-operated PBs. The paper concludes with policy implications.

Influence of Seed Priming on Performance and Water Productivity of Direct Seeded Rice in Alternating Wetting and Drying

Direct seeded rice is promising alternative to traditional transplanting, but requires appropriate crop and water management to maintain yield performance and achieve high water productivity. Present study evaluated the effect of seed priming and irrigation on crop establishment, tillering, agronomic traits, paddy yield, grain quality and water productivity of direct seeded rice in alternate wetting and drying （DSR-AWD） in comparison with direct seeded rice at field capacity （DSR- FC）. Seed priming treatments were osmo-priming with KCI （2.2%）, CaCI2 （2.2%） and moringa leaf extracts （MLE, 3.3%） including hydro-priming as control. Among the treatments, seed osmo-primed with MLE emerged earlier and had higher final emergence, followed by osmo-priming with CaCI2. Tillering emergence rate and number of tillers per plant were the highest for seed priming with CaCI2 in DSR- AWD. Total productive and non-productive tillers, panicle length, biological and grain yields, harvest index were highest for seed priming with MLE or CaCI2 in DSR-AWD. Similarly, grain quality, estimated in terms of normal grains, abortive and chalky grains, was also the highest in DSR-AWD with MLE osmo-priming. Benefit cost ratio and water productivity was also the highest in DSR-AWD for seed priming with MLE. In conclusion, seed priming with MLE or CaCI2 can be successfully employed to improve the direct seeded rice performance when practiced with alternate wetting and drying irrigation.

Theoretical assessment of hydrogen production and multicycle energy conversion via solar thermochemical cycle based on nonvolatile SnO2

A kind of solar thermochemical cycle based on methanothermal reduction of SnO2 is proposed for H2 and CO production. We find that the oxygen release capacity and thermodynamic driven force for methanothermal reduction of SnO2 are large, and suggest CH4 :SnO2 = 2:1 as the feasible reduction condition for achieving high purities of syngas and avoiding vaporization of produced Sn. Subsequently, the amount of H2 and energetic upgrade factors under different oxidation conditions are compared, in which excess water vapor is found beneficial for hydrogen production and fuel energetic upgradation. Moreover, the effect of incom plete recovery of SnO2 on the subsequent cycle is underscored and explained. After accounting for factors such as isothermal operation and cycle stability, CH4 :SnO2 = 2:1 and H2O:Sn = 4:1 are suggested for highest solar-to-fuel efficiency of 46.1% at nonisothermal condition, where the reduction and oxidation temperature are 1400 and 600 K, respectively.