System Reliability Analysis Method Based on T-S FTA and HE-BN

For high-reliability systems in military,aerospace,and railway fields,the challenges of reliability analysis lie in dealing with unclear failure mechanisms,complex fault relationships,lack of fault data,and uncertainty of fault states.To overcome these problems,this paper proposes a reliability analysismethod based on T-S fault tree analysis(T-S FTA)and Hyper-ellipsoidal Bayesian network(HE-BN).The method describes the connection between the various systemfault events by T-S fuzzy gates and translates them into a Bayesian network(BN)model.Combining the advantages of T-S fault tree modeling with the advantages of Bayesian network computation,a reliability modeling method is proposed that can fully reflect the fault characteristics of complex systems.Experts describe the degree of failure of the event in the form of interval numbers.The knowledge and experience of experts are fused with the D-S evidence theory to obtain the initial failure probability interval of the BN root node.Then,the Hyper-ellipsoidal model(HM)constrains the initial failure probability interval and constructs a HE-BN for the system.A reliability analysismethod is proposed to solve the problem of insufficient failure data and uncertainty in the degree of failure.The failure probability of the system is further calculated and the key components that affect the system’s reliability are identified.The proposedmethod accounts for the uncertainty and incompleteness of the failure data in complex multi-state systems and establishes an easily computable reliability model that fully reflects the characteristics of complex faults and accurately identifies system weaknesses.The feasibility and accuracy of the method are further verified by conducting case studies.

Climate change trend and causes of tropical cyclones affecting the South China Sea during the past 50 years

Tropical cyclones(TCs)in the South China Sea(SCS)cause serious disasters and loss every year to the coastal and inland areas of southern China.The types of TCs are usually difficult to forecast,and studies on the understanding of the TCs affecting the SCS are lacking.In this study,the authors use the TC data during 1965–2017 from two best-track datasets to analyse the climatic characteristics in terms of the frequency,the track activity,and the influencing indexes of the TCs affecting the SCS and investigate the possible causes.The results show that,during 1965–2017,there were 535 TCs affecting the SCS,mainly occurring from June to November of each year,with the annual average frequency exhibiting a significant downward trend.Meanwhile,the frequency of the track activity in most areas of the SCS also demonstrate a remarkable decreasing trend but an increase in the Gulf of Tonkin and the Taiwan Strait.The large-scale environmental anomalous westerlies and the decrease of humidity in the mid-and low-level over the northern part of the SCS are likely the main causes for the decrease in frequency and the track activity.In addition,the analysis using the cyclone activity index shows that the influence of the before mentioned TCs in southern China gradually decreases,while the influence of TCs in the SCS show a decreasing trend during past decades.

Constraining the crustal structure under the central and western Tian Shan based on teleseismic receiver functions and gravity anomalies

The Tian Shan is a vast range that spans several countries in Asia.Understanding its evolutionary history may provide valuable insights into intracontinental orogenic dynamics.In this study,we explored the crustal characteristics of the Tian Shan and their relationships to the tectonic evolution of the region.A new H-stacking method that combines the P receiver function and gravity anomalies was used to estimate the thickness and ratio of P-to S-wave velocities(Vp/Vs)for 91 broadband seismic stations in the central and western Tian Shan.Our results revealed significant lateral variations in crustal thickness and Vp/Vs.A—45-km-thick crust and an intermediate-high Vp/Vs(-1.74-1.84)were found in the Kazakh Shield and Tarim Basin,which we interpreted to indicate a mafic crystalline basement and lower crust.The central Tian Shan varied greatly in crustal thickness(40-64 km)and Vp/Vs ratio(1.65-2.00).which may be due to crustal shortening,mafic underplating,and crustal melting.In contrast,we observed a relatively thin crust(42-50 km)with an intermediate Vp/Vs ratio(-1.78)in the western Tian Shan.The differences in the crustal structures between the western and central Tian Shan imply that the Talas-Fergana Fault may be trans-lithospheric.

Dynamic Fatigue Reliability Analysis of Transmission Gear Considering Failure Dependence

Multiple failuremodes and strength degradation are usually inherent in the gear transmission system,which brings new challenges for conducting fatigue reliability analysis and design.This paper proposes a novel dynamic fatigue reliability analysis method for failure dependence and strength degradation based on the combination of theCopula function and Gamma process.Firstly,the dynamic simulation model of the gear transmission system is established to obtain the dynamic stress-time history.The Gamma process is then used to describe the strength degradation to establish the dynamic stress-strength interference model.The marginal distribution functions of tooth contact fatigue and dedendumbending fatigue are calculated respectively based on the dynamic interferencemodel.Finally,the joint distribution of the two failure modes can be obtained by the t-Copula function to characterize the failure dependence,and so the dynamic fatigue reliability considering failure dependence can be estimated.The effectiveness of the proposed method is illustrated with examples.The results reveal the temporal law of reliability and the effects of failure dependence on dynamic fatigue reliability.

Simultaneous Determination of Three Components in Herba Taxilli from Different Host Trees by HPLC

[Objectives] To establish a HPLC method for the simultaneous determination of three components( namely,quercetin,quercitrin and avicularin) in Herba Taxilli. [Methods]Agilent C18 liquid chromatography column( column size: 150 mm × 4. 6 mm,5 m) was used;mobile phase Dacetonitrile∶ water = 22∶ 78; flow rate: 1. 0 m L/min; column temperature: 35℃; injection volume: 10 μL; detection wavelength: 254 nm. [Results]The injection volume of quercetin,quercitrin and avicularin was in a good linear relationship with the peak area in the range of 0. 22-4. 4 μg( R = 1),0. 096-3. 84 μg( R = 0. 999 6),and 0. 106-5. 3 μg( R = 0. 999 9),and the average sample recovery was 99. 32%,100. 53%,and 98. 96%,respectively. [Conclusions]The stability and reproducibility of the established method for determining the content of Herba Taxilli in this experiment are good,and it is expected to provide reference for its quality control and evaluation.

Multi-objective optimization design of anti-roll torsion bar using improved beluga whale optimization algorithm

Purpose – This study aims to reduce the redundant weight of the anti-roll torsion bar brought by thetraditional empirical design and improving its strength and stiffness.Design/methodology/approach – Based on the finite element approach coupled with the improved belugawhale optimization (IBWO) algorithm, a collaborative optimization method is suggested to optimize the designof the anti-roll torsion bar structure and weight. The dimensions and material properties of the torsion bar weredefined as random variables, and the torsion bar’s mass and strength were investigated using finite elements.Then, chaotic mapping and differential evolution (DE) operators are introduced to improve the beluga whaleoptimization (BWO) algorithm and run case studies.Findings – The findings demonstrate that the IBWO has superior solution set distribution uniformity,convergence speed, solution correctness and stability than the BWO. The IBWO algorithm is used to optimizethe anti-roll torsion bar design. The error between the optimization and finite element simulation results wasless than 1%. The weight of the optimized anti-roll torsion bar was lessened by 4%, the maximum stress wasreduced by 35% and the stiffness was increased by 1.9%.Originality/value – The study provides a methodological reference for the simulation optimization process ofthe lateral anti-roll torsion bar.

Crustal and uppermost mantle structure of SE Tibetan plateau from Rayleigh-wave group-velocity measurements

A shear-wave velocity model of the crust and uppermost mantle beneath the SE Tibetan plateau was derived by inverting Rayleigh-wave group-velocity mea- surements of periods between 10 and 70 s. Rayleigh-wave group-velocity dispersions along more than 3,000 inter- station paths were measured based on analysis of telese- ismic wavelbrm data recorded by temporary seismic stations. These observations were then utilized to construct 2D group-velocity maps in the period range of 10-70 s. Tile new group-velocity maps have an enhanced resolution compared with previous global and regional group-velocity models in this region because of the denser and more uniform data coverage. The lateral resolution across the region is about 0.5° for the periods used in this study. Local dispersion curves were then inverted for a 3D shear-wave velocity model of the region by applying a linear inversion scheme. Our 3D shear-wave model confirms the presence of low-velocity zones （LVZs） in the crust beneath the northern part of this region. Our irnaging shows that the upper-middle crustal LVZ beneath the Tengchong region is isolated from these LVZs beneath the eastern and northern part of this region. The upper-middle crustal LVZ may be regarded as evidence of a rnagma chamber in the crust beneath the Tengchong Volcanoes. Our model also reveals a slow lithospheric structure beneath Tengchong and a fast shield-like mantle beneath the stable Yangtze block.

Biological soil crust distribution in Artemisia ordosica communities along a grazing pressure gradient in Mu Us Sandy Land, Northern China

This study investigated the distribution pattern of biological soil crust （BSC） in Artemisia ordosica communities in Mu Us Sandy Land. Three experimental sites were selected according to grazing pressure gradient. In each experimental site, the total vegetation cover, A. ordosica cover, BSC cover, litter-fall cover, BSC degree of fragmentation, BSC thickness and soil properties were investigated in both fixed and semi-fixed sand dunes and simultaneously analyzed in the laboratory. The results showed that at the same grazing pressure, BSC cover and composition were significantly affected by the fixation degree of sand dunes. In addition, BSC cover in the fixed sand dunes was 83.74% on average, whereas it is proportionally dominated by 28% mosses, 21% lichens, and 51% algae. Meanwhile, BSC cover in the semi-fixed sand dunes was 23.54% on average, which is proportionally domi- nated by 6.3% mosses, 2.5% lichens, and 91.2% algae. Fine sand, organic matter, and total nitrogen （N） contents in the fixed sand dunes were all significantly higher than those in the semi-fixed sand dunes. Litter-fall cover de- creased along the grazing pressure gradient, whereas BSC fragmentation degree increased. Fine sand content decreased along with the increase of grazing pressure, whereas medium sand content increased in both fixed and semi-fixed dunes. The organic matter and total N contents in the no grazing site were significantly higher than those in light and normal grazing sites. However, there were no significant differences between the light and normal grazing sites. In addition, there were also no significant differences in BSC thickness between the light and normal grazing sites in the fixed sand dunes. However, a significant decrease was observed in both BSC cover and thick- ness in the normal grazing site. The BSC in the semi-fixed dunes was more sensitive to disturbance.

Efficient oneM2M Protocol Conversion Platform Based on NB-IoT Access

The protocol is the foundation of IoT technology, which plays an important role in the IoT device interworking and interoperability. The 5 G wireless communication system provides large-scale NB-IoT terminals access with F-RAN, and the vertical industry applications need support for the device management. As one of the most influential protocol in the IoT application, the oneM2M protocol not only has a complete architecture, but also has an interface with other IoT protocols. Therefore, to bridge the gap between the operator and industrial enterprises, the main contributions of this paper are as follows: Firstly, a general multi-protocol conversion method is proposed based on oneM2M platform where the protocol classification is used in different scenarios. Secondly, the F-RAN architecture of oneM2M platform is designed and implemented with NB-IoT device access. Thirdly, a multiplexing scheme to process the device information is proposed for interworking proxy entity(IPE), which improves the conversion efficiency for different protocols. Finally, the feasibility and efficiency of the scheme are verified.

Scale-dependent effects of habitat fragmentation on the genetic diversity of Actinidia chinensis populations in China

Spatial scale partly explains the differentiated effects of habitat fragmentation on plant biodiversity,but the mechanisms remain unclear.To investigate the effects of habitat fragmentation on genetic diversity at different scales,we sampled Actinidia chinensis Planch.at broad and fine scales,China.The broad-scale sampling included five mountain populations and one oceanic island population(Zhoushan Archipelago),and the fine-scale sampling covered 11 lake islands and three neighboring land populations in Thousand-Island Lake(TIL).These populations were genotyped at 30 microsatellite loci,and genetic diversity,gene flow,and genetic differentiation were evaluated.Genetic differentiation was positively related to geographical distance at the broad scale,indicating an isolation-bydistance effect of habitat fragmentation on genetic diversity.The oceanic population differed from the mainland populations and experienced recent bottleneck events,but it showed high gene flow with low genetic differentiation from a mountain population connected by the Yangtze River.At the fine scale,no negative genetic effects of habitat fragmentation were found because seed dispersal with water facilitates gene flow between islands.The population size of A.chinensis was positively correlated with the area of TIL islands,supporting island biogeography theory,but no correlation was found between genetic diversity and island area.Our results highlight the scale-dependent effects of habitat fragmentation on genetic diversity and the importance of connectivity between island-like isolated habitats at both the broad and fine scales.

Degradation of atrazine and changes in soil biological indices throughout dendroremediation using poplars

Dendroremediation,a novel strategy for cleaning up contaminants from the environment by using special woody plant species and microbes,is a popular phytoremediation approach.It is a cost-effective and environmentally friendly method that is being increasingly adopted.Poplar species(Populus L.)have been suggested for use in remediation because of their characteristics of high biomass production,fast growth,and potential for removing pollutants.Our environment is often contaminated by toxic substances produced by human activities,and remediation of contamination is therefore a global issue.Atrazine is one of the most widely used herbicides in China.In the present study,‘I-69/55’poplar(P.deltoides cv.‘I-69/55’)and hybrid poplar(Populus deltoides×nigra,DN34)grown in pots were assayed for their ability to remediate atrazine-contaminated soils.The degradation dynamics of atrazine were assessed with a high-performance liquid chromatography system using materials from a greenhouse with different rhizosphere environments.We studied the dynamic variation in microbes and microbial biomass carbon to elucidate the rhizosphere effects and mechanism of remediation of atrazine-contaminated soil by poplar.Our four treatments included a control with uncontaminated soil without a tree,atrazine pollution without a tree,atrazine pollution with‘I-69/55’poplar,and atrazine pollution with hybrid poplar.Hybrid poplar showed potential for remediation of atrazine-contaminated soil,and the degradation of atrazine in the rhizosphere was faster than that in non-rhizosphere soil.Atrazine significantly inhibited bacteria growth in nonrhizosphere soil.The high concentration of bacteria in the hybrid poplar rhizosphere might be key to atrazine degradation.Trends of change among fungi and actinomyces did not correspond to trends in atrazine degradation throughout the trial period.Further research is needed to predict the effects of atrazine on cultivable microorganisms in various soils.Atrazine had significant inhibitory effects on microbial biomass carbon in non-rhizosphere soil,and the rhizosphere environment of poplars enhanced the recovery of microbial biomass carbon.The potential for hybrid poplar as a dendroremediation material needs further study.

Crustal structure beneath the central and western North China from receiver function analysis

The North China Craton(NCC)is one of the oldest cratons on earth.Several important tectonic transformations of MesozoicCenozoic tectonic regime led to the destruction of the North China craton.The knowledge of crustal structure can provide important constraints for the formation and evolution of cratons.New maps of sediment thickness,crustal thickness(H)and v_(P)/v_(S)(κ)in the central and western NCC were obtained using sequential H-κstacking.P-wave receiver functions are calculated using teleseismic waveform data recorded by 405 stations from Chin Array project.Benefiting from the densely distribution of temporary seismic stations,our results reveal details of the crustal structure in the study area.The thickness of sedimentary layer in North China ranges from 0–6.4 km,and the thickest sedimentary layer is in Ordos block and its surroundings(about 2.8–6 km);The thickness of sedimentary layer in the Mongolia fold belt and Yinshan orogenic belt is relatively thin(less than 1 km).The crustal thickness of the study area varies between 27–48 km,of which the crust of the North China Plain is about 30–33 km,the central NCC is about 33–40 km,and the Ordos block is 40–48 km thick.The average v_(P)/v_(S)ratios in the study area is mostly between 1.66 and 1.90,and that in the Yanshan-Taihang mountain fold belt is between 1.70 and 1.85,and that in the Ordos block is between 1.65 and 1.90,with an average value of 1.77,indicating the absence of a thick basaltic lower crust.The obvious negative correlation between crustal thickness and average v_(P)/v_(S)ratio within Ordos and Central Asia orogenic belt may be related to magmatic underplating during the crustal formation.There is no significant correlation between the crustal thickness and the v_(P)/v_(S)ratio in the Lüliang-Taihang mountain fold belt,which may be related to the multiple geological processes such as underplating and crustal extension and thinning in this area.The lack of correlation between crust thickness and topography in the central orogenic belt and the North China Basin indicates the topography of these areas are controlled not only by crustal isostatic adjustment but also by the lithospheric mantle processes.

Effect of rain enrichment on soil respiration of Nitraria sphaerocarpa community in a hyperarid area

In order to analyze the effect of rain enrichment on soil respiration rate of a Nitraria sphaerocarpa community, we measured soil respiration rate in bare and vegetated areas in a hyperarid area （Dunhuang） during the growing season. Results show that rain enrichment can increase bare and vegetated soil respiration rates. The more rainfall enrichment, the greater the increment and the longer duration time effect for soil respiration rate. 200% （16 mm） and 300% （24 mm） of rain enrichment can significantly increase bare soil respiration rates by 90% and 106% （P〈0.01）, respectively. By contrast, areas with 100% （8 mm）, 200% （16 mm） and 300% （24 mm） of rain enrichment can significantly increase shrub area respiration rates by 68%, 157% and 205% （P〈0.01）, respectively. The response time of bare and vegetated soil respiration to rainfall enrichment is asynchronous. Response variable of soil respiration in vegetated soil is higher （118%） than in bare soil. There was significant positive correlation between soil respiration rate and soil water content during the growing season （P〈0.01）. For every 1 mm increment of precipitation, soil respiration rate increased by 0.01 and 0.04 pmol/（m2.s）, respectively in vegetated and bare soils.

An Alternative-Service Recommending Algorithm Based on Semantic Similarity

With the development of the Internet of Things(Io T), people's lives have become increasingly convenient. It is desirable for smart home(SH) systems to integrate and leverage the enormous information available from IoT. Information can be analyzed to learn user intentions and automatically provide the appropriate services. However, existing service recommendation models typically do not consider the services that are unavailable in a user's living environment. In order to address this problem, we propose a series of semantic models for SH devices. These semantic models can be used to infer user intentions. Based on the models, we proposed a service recommendation probability model and an alternative-service recommending algorithm. The algorithm is devoted to providing appropriate alternative services when the desired service is unavailable. The algorithm has been implemented and achieves accuracy higher than traditional Hidden Markov Model(HMM). The maximum accuracy achieved is 68.3%.

枸杞专用品种选育研究展望

综述了枸杞产业的重要性,枸杞专用品种选育及开发现状,并提出了枸杞育种中存在的问题及解决途径,最后对选育专用枸杞品种进行展望。

Tectonic activity and earthquake risk in the Chengnanhe fault zone in Weihai city,Shandong province,China,obtained by using an integrated prospecting technique in geophysics and geology

For city planning and reducing potential earthquake risk,it’s necessary to detect the information of the buried faults in an urban area especially,including the location and activities.An integrated technique with geophysical and geological methods,including the shallow seismic reflection profile,electrical resistivity measurement,geologic borehole section,and exploration trench,was used to detect the Chengnanhe fault,which is one of the two main faults passing through the Weihai urban area in Shandong province,China.The results show that it is a normal fault striking with E-W direction,and it is relatively inactive and stable.By using the thermoluminescence(TL)dating,we found that the Chengnanhe fault initiated in mid-Pleistocene and there was no offset after late Pleistocene.Such an integrated technique with multiple geological and geophysical methods provides a significant assessment of earthquake risk for city planning in urban areas.

A New Distinguish Method of Blending Coals Slagging Characteristic

The slagging characteristic of coal effects the safe operation of boiler unit directly, the study on coal slagging is paid more and more attention by scholars of the world. Because of the complexity of coal characteristic, the blending coals slagging characteristic is more complex than single coal. The study method of blending coals characteristic is the same as the single coal method, but the simple method can’t distinguish the blending coals slagging characteristic well and truly. This paper gives the new distinguish method of blending coals slagging characteristic based on experimentation condition, it is the rate of slag and furnace refuse. The rate of slagging on furnace wall and the refuse on furnace bottom has utilized to distinguish the slagging characteristic of coal. The result shows that the rate of slag and furnace refuse method has better veracity.

Performance of BCC-CSM Models with Different Horizontal Resolutions in Simulating Extreme Climate Events in China

In this study,the performance of the Beijing Climate Center(BCC)Climate System Model version 1.1(BCCCSM1.1)(280-km resolution)and the BCC-CSM1.1 m(110-km resolution)in simulating extreme climate events over China in the last 40 years is compared.Both models capture the main spatial distribution features of heavy precipitation(R95T),the number of consecutive wet days(CWD),the annual count of days with precipitation≥1 mm(R1),the maximum consecutive 5-day precipitation(Rx5),and the numbers of frost days(FD)and summer days(SU).The BCC-CSM1.1 m has a better ability to simulate the detailed distribution of extreme climate events than the BCCCSM1.1,including R95T,CWD,R1,and the simple precipitation intensity index(SDII).However,the BCCCSM 1.1 m does not show an improvement in simulating the number of days with extreme precipitation(R90N),the number of consecutive dry days(CDD),the heat wave duration index(HWDI),the warm day frequency(TX90 P),and cold night frequency(TN10P).This indicates that the simulation of the R95T,CWD,R1,and SDII climate events is more sensitive to the resolution of the model.The improved BCC-CSM1.1 m is used to explore the projection of extreme climate change in China during the 21 st century under the RCP4.5(Representative Concentration Pathways)and RCP8.5 scenarios.The results show that extreme precipitation will increase dramatically over North and Southwest China in the late 21 st century.The CWD index will decrease on the Tibetan Plateau and in northeastern and central China and will increase in other parts of China;R1 will increase in northern China and decrease in southern China;Rx5 will increase dramatically in southern China;FD will decrease and SU will increase over China in the late 21 st century under both emission scenarios,with larger amplitudes in RCP8.5.

Evaluation and Projection of Extreme High Temperature Indices in Southwestern China Using NEX-GDDP-CMIP6

Based on the recently released NASA Earth Exchange Global Daily Downscaled Projections(NEX-GDDP)Coupled Model Intercomparison Project Phase 6(CMIP6) dataset and the gridded observational daily dataset CN05.1, this study evaluates the performance of 26 CMIP6 models in simulating extreme high temperature(EHT) indices in southwestern China and estimates future changes in the EHT indices under the Shared Socioeconomic Pathways(SSPs) SSP1-2.6, SSP2-4.5, and SSP5-8.5 using 11 optimal CMIP6 models. Five EHT indices are employed:annual maximum value of daily maximum temperature(TXX), high temperature days(T35), warm days(TX90P),heat wave frequency(HWF), and heat wave days(HWD). The main results are as follows.(1) NEX-GDDP-CMIP6 is highly capable of simulating the spatial patterns of TXX and T35 in southwestern China but it presents a weaker ability to simulate the spatial patterns of TX90P, HWF, and HWD.(2) The simulated time series of T35, TX90P, HWF,and HWD in southwestern China exhibit consistent upward trends with the observations. The linear trends of increase in TX90P and HWD are much greater than those of increase in TXX, T35, and HWF.(3) The estimated increases in TXX and T35 in southwestern China are significantly greater in Chongqing and the adjacent areas of Sichuan than in the other regions. Spatial distributions of the increases in TX90P, HWF, and HWD generally show higher values in the west and lower values in the east.(4) In the three different scenarios, the projected future TXX,T35, TX90P, and HWD in southwestern China all display a continuous increase with time and radiative forcing levels, whereas HWF initially increases but then decreases under the SSP5-8.5 scenario. By the end of the 21st century, under the SSP5-8.5 scenario, TXX and T35 are projected to increase by 6.0℃ and 45.0 days, respectively. The duration of individual heat waves is also expected to increase.

Non-native species in marine protected areas: Global distribution patterns

Marine protected areas(MPAs)across various countries have contributed to safeguarding coastal and marine environments.Despite these efforts,marine non-native species(NNS)continue to threaten biodiversity and ecosystems,even within MPAs.Currently,there is a lack of comprehensive studies on the inventories,distribution patterns,and effect factors of NNS within MPAs.Here we show a database containing over 15,000 occurrence records of 2714 marine NNS across 16,401 national or regional MPAs worldwide.To identify the primary mechanisms driving the occurrence of NNS,we utilize model selection with proxies representing colonization pressure,environmental variables,and MPA characteristics.Among the environmental predictors analyzed,sea surface temperature emerged as the sole factor strongly associated with NNS richness.Higher sea surface temperatures are linked to increased NNS richness,aligning with global marine biodiversity trends.Furthermore,human activities help species overcome geographical barriers and migration constraints.Consequently,this influences the distribution patterns of marine introduced species and associated environmental factors.As global climate change continues to alter sea temperatures,it is crucial to protect marine regions that are increasingly vulnerable to intense human activities and biological invasions.