Mangrove wetlands distribution status identification, changing trend analyzation and carbon storage assessment of China

This research investigates the ecological importance,changes,and status of mangrove wetlands along China’s coastline.Visual interpretation,geological surveys,and ISO clustering unsupervised classification methods are employed to interpret mangrove distribution from remote sensing images from 2021,utilizing ArcGIS software platform.Furthermore,the carbon storage capacity of mangrove wetlands is quantified using the carbon storage module of InVEST model.Results show that the mangrove wetlands in China covered an area of 278.85 km2 in 2021,predominantly distributed in Hainan,Guangxi,Guangdong,Fujian,Zhejiang,Taiwan,Hong Kong,and Macao.The total carbon storage is assessed at 2.11×10^(6) t,with specific regional data provided.Trends since the 1950s reveal periods of increase,decrease,sharp decrease,and slight-steady increases in mangrove areas in China.An important finding is the predominant replacement of natural coastlines adjacent to mangrove wetlands by artificial ones,highlighting the need for creating suitable spaces for mangrove restoration.This study is poised to guide future mangroverelated investigations and conservation strategies.

单轴加载下含共面双节理双层复合类岩试样的力学行为与破坏特征

为研究节理与层理面对裂隙层状岩体裂纹演化的共同作用,对不同层理面倾角下,含多角度共面双节理的双层复合类岩试样进行单轴压缩试验和数字图像相关试验。由试验结果可知,层理面和节理对应力−应变曲线特征和强度参数有显著影响。试件的破坏模式分为4种不同类型。层理面的存在抑制了岩桥区域裂纹的贯通,层理面倾角的变化对裂纹扩展路径和破坏模式的转变有较大影响。对于层理面倾角为30°和45°的试件,节理倾角越大,层理面对试件破坏特征的影响越小。此外,观测到一种从层理面上萌生并且更容易在试件上层扩展的拉伸裂纹。

Investigation of erosion behavior of 304 stainless steel under solid–liquid jet flow impinging at 30°

This work carried out liquid-solid two-phase jet experiments and simulations to study the erosion behavior of 304 stainless steel at 30° impingement.The single-phase impinging jet was simulated using dense grid by one-way coupling of solid phase due to its dilute distribution.The simulation results agreed well with experiments.It was found that after impinging particle attrition occurred and particles became round with decreasing length-ratio and particle breakage occurred along the "long" direction.Both experiment and simulations found that the erosion generated on the sample could be divided into three regions that were nominated as stagnant region,cutting transition region and wall jet region.Most particle-wall impacts were found to occur in the cutting transition region and the wall jet region.In the cutting transition region,holes and lip-shaped hogbacks were generated in the same direction as the flow imping.In the wall jet region,furrows and grooves were generated.The averaged grooves depth tended to become constant with the progress of impinging and reach the steady state of erosion in the end.In addition,it was found that impinging effect increased erosion and anti-wear rate.

Investigation of erosion-corrosion behavior of Q235B steel in liquid-solid flows

This work aims to investigate the erosion-corrosion behavior of Q235B steel in liquid-solid two-phase flows.The weight loss rate,surface morphology and electrochemical parameters of Q235B steel at different temperatures(20℃,30℃,40℃)and flow velocities(6 m/s,7 m/s,8 m/s,9 m/s,10 m/s)were studied separately.The results show that the weight loss rate of Q235B steel specimens after erosion-corrosion increases with increasing flow velocity and temperature.For the erosion-corrosion process,the corrosion rates of specimens increase with increasing flow velocity.The results of surface morphology show that the circular pits with clear edges are distributed randomly over specimen surface at low flow velocity,but the pit edge becomes vague at high flow velocity.With temperature increasing,the erosion-corrosion damage became serious as shown by the aggregation of large and small pits on specimen surface.The working mechanism of erosion-corrosion is found to vary with flow velocity and temperature.The relationships among erosion-corrosion components are quantitatively represented and show that synergy dominates the progress of material loss.Corrosion enhances erosion that is a dominant component in the synergy.The inactions of erosion-corrosion can be described by"synergistic"and"additive"behavior.The results show that"additive"effect becomes more significant with increasing flow velocity but decreases with increasing temperature,while"synergistic"effect is not sensitive to flow velocity and temperature.

The dispersion of particles in turbulent semi-circular duct flows

The flow field in a semi-circular duct is simulated by Large Eddy Simulation(LES)and its particle field is simulated by Lagrange particle tracking method.Reynolds number Reb(based on bulk velocity and hydraulic diameter)is 80,000 and Ret(based on friction velocity and hydraulic diameter)is 3528.Particle diameter dpis chosen as 10,50,100,500 mm corresponding to St as 0.10,2.43,9.72,243.05.The results show that the intensity of the secondary flow near the ceiling is less than that near the floor because the ceiling is curved and able to inhibit the secondary flow.It is found that the difference between the semicircular duct and the square duct is that the secondary flow in a corner of the semi-circular duct is not symmetrical along the diagonal although they have the same generation mechanism.Regarding the particles,small particles(dp≤10 mm)are found to uniformly distribute in the duct,while large particles(dp≥50 mm)preferentially distribute in the corner and floor center.The maximum particles(dp=500mm)fall on the floor quickly and their dispersion mainly depends on the secondary flow near the floor.Particle deposition in the corner depends on particle size due to the effect of secondary flow and gravity.The effect of lift force on particles becomes more significant for 50 and 100 mm particles in comparison with other smaller particles.In the end,the effect of secondary flow is found to be more significant to dominate particle behavior than that of flow fluctuation.

Resonant contribution of the three-body decay processB_(s)→K+K−P in perturbative QCD

We investigate CP violation in the decay process B_(s)→ϕ(ρ,ω)P→K^(+)K^(-)P by considering the interference effects ofϕ→K^(+)K^(-),ρ→K^(+)K^(-),andω→K^(+)K^(-)within the framework of the perturbative QCD method(P refers toπ,K,η,andη′pseudoscalar mesons).We analyze the mixings ofϕ−ρ^(0),ϕ−ω,andω−ρ0 and provide the amplitudes of the quasi-two-body decay processes.The CP violation for the B_(s)→K^(+)K^(-)P decay process is obvious in the ranges of the three vector meson interferences.Meanwhile,the localized CP violation can be found to compare with the experimental results from the three-body decay process at the LHC in the near future.

Nontuberculous mycobacteria in China:incidence and antimicrobial resistance spectrum from a nationwide survey

Background:Information on the prevalence and resistance spectrum of nontuberculous mycobacteria(NTM)in China is mainly based on regional or local data.To estimate the proportion of NTM cases in China,a national survey of NTM pulmonary disease was carried out based on acid-fast positive sputum samples collected in 2013.

Age-period-cohort analysis of pulmonary tuberculosis reported incidence, China, 2006-2020

Background:Tuberculosis(TB)poses a severe public health challenge in China and worldwide.This study evaluated the effects of age,period,and birth cohort on reported incidence trends of TB based on population and refined the characteristics of high-risk groups.Methods:Aggregate data that reported pulmonary tuberculosis(PTB)cases from China Tuberculosis Management Information System(TBIMS)from 2006 to 2020 were used to analyze effect coefficients through the age-period-cohort(APC)model based on intrinsic estimator(IE)method,and converted them into relative risk(RR)to estimate trends.Results:A total of 14.82 million cases of PTB were reported in China from 2006 to 2020,showing a continuous downward trend.The reporting rate increased with age by age group,with 70-74 years old being 2-3 times higher than that in 20-24 years old.APC analysis model showed that age effects were bimodal in 20-24 years old[RR=2.29,95%confidence interval(CI):1.73-3.03]and 70-74 years old(RR=1.95,95%CI:1.67-2.27),and lower than the overall average in the groups under 15 years old.Stratified results showed that the risk was higher for women under age 40 than men and higher for men over 40.The risk was higher in urban than in rural areas under 30 years old and slightly higher in rural than in urban between 30 and 64 years old.The risk for 15-34 years old was significantly higher in the east than in other regions.The period effects showed a decreasing trend,and the risk was higher in rural in recent years.Except for cohorts born in 1961-1965 and 2001-2005,where theRR increased,the later the cohort was born,the lower the risk.The cohort 1926-1930 in eastern had the highest risk(RR=3.49,95%CI:2.44-4.98).Conclusions:The reported incidence of PTB continued to decline in China from 2006 to 2020.The young(20-24 years old)and the elderly(70-74 years old)were equally at high risk.There were differences in the age,period and cohort effects on PTB incidence among gender,urban-rural and regions.Our findings better reflected the characteristics of high-risk populations,thus contributing to the development of timely and effective intervention strategies,and providing clues for etiological research.

Prevalence of and risk factors for tuberculosis among healthcare workers in Chinese tuberculosis facilities

Background:China is one of 22 countries with a high tuberculosis(TB)burden in the world.Healthcare workers(HCWs)have a high risk of contracting Mycobacterium tuberculosis infection due to insufficient infection control practices.We conducted a cross-sectional study to explore the prevalence of TB and its associated risk factors among HCWs in Chinese TB facilities.Methods:Two hundred and forty-one TB facilities employing a total of 9663 HCWs were selected from 12 provinces in China to represent healthcare settings at the provincial,prefectural,and county levels.Structured questionnaires were used to collect information on TB infection control practices and HCWs in those facilities.Data was double entered into EpiData 3.1;TB prevalence and associated risk factors were analyzed using SPSS 21.0 with bivariate and multivariate regression models.Results:The results showed that 71 HCWs had been diagnosed with TB,accounting for a prevalence of 760/100000.The multivariate analysis showed that associated risk factors included belonging to the age group of 51 years and above(aOR:6.17,95%CI:1.35-28.28),being a nurse(aOR=3.09,95%CI:1.15-8.32),implementation of 0-9 items of management measures(aOR=2.57,95%CI:1.37-4.80),and implementation of 0-1 items of ventilation measures(aOR=2.42,95%CI:1.31-4.47).Conclusion:This was the first national large sampling survey on TB prevalence among HCWs in China.It was found that the implementation of TB infection control practices in some facilities was poor.The TB prevalence in HCWs was higher than that in the general population.Therefore,TB infection control practices in Chinese medical facilities should be strengthened.

Effect of using electronic medication monitors on tuberculosis treatment outcomes in China: a longitudinal ecological study

Background:In China,an indigenously developed electronic medication monitor(EMM)was designed and used in 138 counties from three provinces.Previous studies showed positive results on accuracy,effectiveness,acceptability,and feasibility,but also found some ineffective implementations.In this paper,we assessed the effect of implementation of EMMs on treatment outcomes.Methods:The longitudinal ecological method was used at the county level with aggregate secondary programmatic data.All the notified TB cases in 138 counties were involved in this study from April 2017 to June 2019,and rifampicinresistant cases were excluded.We fitted a multilevel model to assess the relative change in the quarterly treatment success rate with increasing quarterly EMM coverage rate,in which a mixed effects maximum likelihood regression using random intercept model was applied,by adjusting for seasonal trends,population size,sociodemographic and clinical characteristics,and clustering within counties.

Direct CP violation of three body decay processes from the resonance effect

The physical state of ρ−ω−φ mesons can be mixed using the unitary matrix.The decay processes ω→π^(+)π^(−)and φ→π^(+)π^(−)originate from isospin symmetry breaking.The ρ−ω,ρ−φ,and ω−φ interferences lead to a resonance contribution to produce strong phases.CP violation is considered from isospin symmetry breaking due to the new strong phase of the first order.CP violation can be enhanced greatly for the decay process B^(0)→π^(+)π^(−)η^((′))when the invariant masses of π^(+)π^(−) pairs are in the area around the ω resonance range and φ resonance range in perturbative QCD.We also discuss the possibility of searching for the predicted CP violation at the LHC.

Implementing a new tuberculosis surveillance system in Zhejiang,Jilin and Ningxia:improvements,challenges and implications for China’s National Health Information System

Background:China is still faced with the public health challenge of tuberculosis(TB),and a robust surveillance system is critical for developing evidence-based TB control policies.The Tuberculosis Information Management System(TBIMS),an independent system launched in 2005,has encountered several challenges in meeting the current needs ofTB control.The Chinese government also planned to establish the National Health Information System(NHIS)aggregating data in different areas.The China National Health Commission-Gates TB Project Phase III launched a new TB surveillance system to address these challenges and also as a pilot for the countrywide implementation of the NHIS.This commentary highlights the improvements and challenges in implementing the newTB system and also discusses the implications for the roll-out of the NHIS.

Molecular Characterization and Drug Susceptibility of Mycobacterium Bovis Isolated from Cattle in Xinjiang,China

To the Editor:Bovine tuberculosis (TB)is a zoonotic disease caused by Mycobacterium bovis.It not only seriously influences the raising of livestock but also threatens the health of human beings and other economically important animals.Therefore, the prevention and control of M.boris has great significance for public and animal health.Spoligotyping is the most widely used method for genotyping of M.boris and investigates transmission across different geographical regions.However,its discriminatory power varies widely among countries.Variable number of tandem repeats (VNTR)analysis has emerged as an alternative method for genotyping of bacterial species isolates.