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Unintentional forking analysis in wireless blockchain networks 被引量:3
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作者 Qilie Liu Yinyi Xu +2 位作者 Bin Cao Lei Zhang Mugen Peng 《Digital Communications and Networks》 SCIE CSCD 2021年第3期335-341,共7页
The forking problem plays a key role in the security issue,which is a major concern in the blockchain system.Although many works studied the attack strategy,consensus mechanism,privacy-protecting and security performa... The forking problem plays a key role in the security issue,which is a major concern in the blockchain system.Although many works studied the attack strategy,consensus mechanism,privacy-protecting and security performance analysis,most of them only address the intentional forking caused by a malicious attacker.In fact,without any attacker,unintentional forking still remains due to transmission delay and failure,especially in wireless network scenarios.To this end,this paper investigates the reason for generating unintentional forking and derives the forking probability expression in Wireless Blockchain Networks(WBN).Furthermore,in order to illustrate the unintentional forking on the blockchain system,the performances in terms of resource utilization rate,block generation time,and Transaction Per Second(TPS)are investigated.The numerical results show that the target difficulty of hash algorithm in generating a new block,the delay time of broadcasting,the network scale,and the transmission failure probability would affect the unintentional forking probability significantly,which can provide a reliable basis for avoiding forking to save resource consumption and improving system performance. 展开更多
关键词 Wireless blockchain network unintentional forking Proof-of-Work /10.1016/j.dcan.2020.12.005Stochastic theory
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Unintentional modulation microstructure enlargement 被引量:1
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作者 SUN Liting WANG Xiang HUANG Zhitao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2022年第3期522-533,共12页
Radio frequency fingerprinting(RFF)is a technology that identifies the specific emitter of a received electromagnetic signal by external measurement of the minuscule hardware-level,device-specific imperfections.The RF... Radio frequency fingerprinting(RFF)is a technology that identifies the specific emitter of a received electromagnetic signal by external measurement of the minuscule hardware-level,device-specific imperfections.The RFF-related information is mainly in the form of unintentional modulation(UIM),which is subtle enough to be effectively imperceptible and is submerged in the intentional modulation(IM).It is necessary to minimize the influence of the IM and expand the slight differences between emitters for successful RFF.This paper proposes a UIM microstructure enlargement(UMME)method based on feature-level adaptive signal decomposition(ASD),accompanied by autocorrelation and cross-correlation analysis.The common IM part is evaluated by analyzing a newly-defined benchmark feature.Three different indexes are used to quantify the similarity,distance,and dependency of the RFF features from different devices.Experiments are conducted based on the real-world signals transmitted from 20 of the same type of radar in the same working mode.The visual image qualitatively shows the magnification of feature differences;different indicators quantitatively describe the changes in features.Compared with the original RFF feature,recognition results based on the Gaussian mixture model(GMM)classifier further validate the effectiveness of the proposed algorithm. 展开更多
关键词 radio frequency fingerprinting(RFF) unintentional modulation(UIM) adaptive signal decomposition(ASD) variational mode decomposition(VMD) similarity measurement
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Comparison of GaN/AlGaN/AlN/GaN HEMTs Grown on Sapphire with Fe-Modulation-Doped and Unintentionally Doped GaN Buffer:Material Growth and Device Fabrication 被引量:1
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作者 巩稼民 王权 +4 位作者 闫俊达 刘峰奇 冯春 王晓亮 王占国 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第11期99-103,共5页
AlGaN/GaN high electron mobility transistors (HEMTs) grown on Fe-modulation-doped (MD) and unintentionally doped (UID) GaN buffer layers are investigated and compared. Highly resistive GaN buffers (10^9Ω·... AlGaN/GaN high electron mobility transistors (HEMTs) grown on Fe-modulation-doped (MD) and unintentionally doped (UID) GaN buffer layers are investigated and compared. Highly resistive GaN buffers (10^9Ω·cm) are induced by individual mechanisms for the electron traps' formation: the Fe MD buffer (sample A) and the UID buffer with high density of edge-type dislocations (7.24×10^9cm^-2, sample B). The 300K Hall test indicates that the mobility of sample A with Fe doping (2503cm^2V^-1s^-1) is much higher than sample B (1926cm^2V^-1s^-1) due to the decreased scattering effect on the two-dimensional electron gas. HEMT devices are fabricated on the two samples and pulsed I–V measurements are conducted. Device A shows better gate pinch-off characteristics and a higher threshold voltage (-2.63V) compared with device B (-3.71V). Lower gate leakage current |IGS| of device A (3.32×10^-7A) is present compared with that of device B (8.29×10^-7A). When the off-state quiescent points Q_2 (V GQ2=-8V, V DQ2=0V) are on, V th hardly shifts for device A while device B shows +0.21V positive threshold voltage shift, resulting from the existence of electron traps associated with the dislocations in the UID-GaN buffer layer under the gate. Under pulsed I–V and transconductance G m–V GS measurement, the device with the Fe MD-doped buffer shows more potential in improving reliability upon off-state stress. 展开更多
关键词 GAN in HEMT is Comparison of GaN/AlGaN/AlN/GaN HEMTs Grown on Sapphire with Fe-Modulation-Doped and unintentionally Doped GaN Buffer:Material Growth and Device Fabrication of Fe with on
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Intentional and unintentional impacts of anaesthesia: insights from experiments in pain and injury
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作者 James W.M.Kang 《Neural Regeneration Research》 SCIE CAS CSCD 2017年第12期1985-1986,共2页
The study of brain function in the presence of pain and injury is a rapidly expanding field of experimental research.Clinically,the presence of pain and injury is often accompanied by reports of behavioural change and... The study of brain function in the presence of pain and injury is a rapidly expanding field of experimental research.Clinically,the presence of pain and injury is often accompanied by reports of behavioural change and altered cognition.Even in a highly controlled environment such as the surgical operating theatre postoperative behavioural changes including posttraumatic stress disorder,depression,chronic fatigue, 展开更多
关键词 INTENTIONAL unintentional impacts ANAESTHESIA insights from experiments pain and injury
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Long-term monitoring of PCDD/PCDF and other unintentionally produced POPs-Concepts and case studies from Europe 被引量:8
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作者 REINMANN Jürgen WEBER Roland HAAG Roland 《Science China Chemistry》 SCIE EI CAS 2010年第5期1017-1024,共8页
During the start-up and unstable combustion periods,even the state-of-the-art incinerators emit polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/PCDF) in stack gases at concentrations that are up to 1000 times... During the start-up and unstable combustion periods,even the state-of-the-art incinerators emit polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/PCDF) in stack gases at concentrations that are up to 1000 times higher than normal operation. Therefore,incinerators and other sources with variation of PCDD/PCDF release into air cannot be reliably monitored by the conventional short-term sampling that covers only 0.1%to 0.2%of the yearly operating time.A more comprehensive monitoring regime is required.This paper describes different applications of continuous PCDD/PCDF sampling in some European countries.The cases demonstrate that flexible regimes for continuous sampling can be crafted and applied by governments or regional/local authorities.Such regimes range from a countrywide,continuous requirement for selected facility types(e.g.,waste incinerators) to a facility-specific regime that applies,for example,to new facilities for a defined time period until the facility has demonstrated continuous compliance with regulatory limits. Countries implementing the Stockholm Convention are suggested to evaluate in their Best available technology/Best environmental practice(BAT/BEP) activities the usefulness of long-term sampling by,for example,designating institutes related to the environmental ministry or regional authorities to supervise long-term sampling regimes at relevant facilities in their country/areas,beginning with priority sources(e.g.,facilities used for destruction of persistent organic pollutants(POPs) or hazardous waste processing) . This paper presents and discusses the results of the AMESA long-term monitoring system having demonstrated that in addition to PCDD/PCDF all other unintentionally produced POPs listed in the Stockholm Convention could be supervised. 展开更多
关键词 PCDD/PCDF PCB continuous sampling unintentionalLY PRODUCED POPS Stockholm CONVENTION BAT/BEP
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Global trends and regional differences in non-transport unintentional injuries mortality among children and adolescents, 1990 to 2019: results from the Global Burden of Disease 2019 study 被引量:1
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作者 Yunfei Liu Yanhui Dong +8 位作者 Xiaojin Yan Ning Ma Jiajia Dang Jingshu Zhang Panliang Zhong Luo Li Zhiyong Zou Yi Song Jun Ma 《Chinese Medical Journal》 SCIE CAS CSCD 2022年第17期2056-2065,共10页
Background::Non-transport unintentional injuries(NTUIs)are major public concerns,especially among children and adolescents in low-and middle-income countries.With environmental and cognitive changes,a recent systemati... Background::Non-transport unintentional injuries(NTUIs)are major public concerns,especially among children and adolescents in low-and middle-income countries.With environmental and cognitive changes,a recent systematic description of global trends and regional differences concerning NTUIs is urgently needed for the global agenda of relevant policy-making and intervention target findings.Methods::We used mortality,population,and socio-demographic-index(SDI)data from Global Burden of Disease 2019 to analyze the trends of NTUIs mortality.We applied the slope index of inequality(SII)and relative index of inequality(RII)to measure the absolute and relative inequality between countries and territories.The concentration curve and concentration index(CI)were also used to measure the inequality.We conducted a sensitivity analysis to make our findings credible.Results::In 2019,there were 205,000 deaths due to NTUIs among children and adolescents aged 5 to 24 years,which decreased from 375,000 in 1990.In 2019,the age-standardized mortality rate(ASMR)was 8.13 per 100,000,ranging from the lowest in the Netherlands(0.90 per 100,000)to the highest in the Solomon Islands(29.34 per 100,000).The low-middle SDI group had the highest ASMR of NTUIs,while the low SDI group had the slowest decrease.After excluding the death caused by"exposure to forces of nature"and"other unintentional injuries",drowning accounted for the most deaths in almost every SDI group,gender,and age group,but the major causes of death varied in different subgroups.For example,animal contact was a major cause in low and low-middle SDI groups but less in high SDI groups,while high and high-middle SDI groups had a higher proportion of deaths for foreign body and poisonings.The SII showed a declining trend,but the RII and CI did not,which might indicate that inequality was persistent.Similar results were found in the sensitivity analysis.Conclusions::Despite the declining trend of the mortality rate and the narrowing gap between countries,there were still a large number of children and adolescents dying from NTUIs,and those experiencing social-economic disadvantages remained at high mortality.Embedding the prevention of NTUIs into sustainable development goals might contribute to the progress of reducing death and inequalities,which ensures that no one is left behind. 展开更多
关键词 Children and adolescents Non-transport unintentional injuries Socio-demographic-index Inequality analysis Foreign body Poisoning Global Burden of Disease Cause of death Developing countries DROWNING
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Correction to“Downregulation of FoxM1 inhibits the viability and invasion of gallbladder carcinoma cells,partially dependent on the induction of cellular senescence”
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作者 Jie Tao Xin-Sen Xu +1 位作者 Yan-Zhou Song Chang Liu 《World Journal of Gastroenterology》 SCIE CAS 2021年第26期4246-4247,共2页
We corrected the mistake of Figure 3,and replaced the incorrect images with the correct ones.The“adenovirus”was a typographical error in writing,and should be revised to“lentivirus”.
关键词 CORRECTION unintentional MISTAKE Error SORTING Figure
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Human Aspects of Smart Technologies'Security:The Role of Human Failure
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作者 Mohammad Aldabbas Bemd Teufel 《Journal of Electronic Science and Technology》 CAS CSCD 2016年第4期311-318,共8页
Security of smart technologies like smart grids and crowd energy systems cannot rely only on technical solutions, humans play a significant role in failure, security culture, information security, cyber security, trus... Security of smart technologies like smart grids and crowd energy systems cannot rely only on technical solutions, humans play a significant role in failure, security culture, information security, cyber security, trust and sharing, and perceptions and concern. This paper investigates security issues in smart technologies and the related role of human failure, whether it is intentional or unintentional.Methods that help reducing this failure are discussed. A human oriented framework for failure reduction is presented in order to enhance security. 展开更多
关键词 Crowd energy human role intentional failure SECURITY smart grids unintentional failure.
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Growth of Semi-Insulating GaN Using N2 as Nucleation Layer Carrier Gas Combining with an Optimized Annealing Time
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作者 周忠堂 邢志刚 +2 位作者 郭丽伟 陈弘 周均铭 《Chinese Physics Letters》 SCIE CAS CSCD 2007年第6期1645-1648,共4页
Semi-insulating (SI) GaN is grown using N2 as the nucleation layer (NL) carrier gas combined with an optimized annealing time by metalorganic chemical vapour deposition. Influence of using 1-12 and N2 as the NL ca... Semi-insulating (SI) GaN is grown using N2 as the nucleation layer (NL) carrier gas combined with an optimized annealing time by metalorganic chemical vapour deposition. Influence of using 1-12 and N2 as the NL carrier gas is investigated in our experiment. It is found that the sheet resistance of unintentionally doped GaN can be increased from 10^4 Ω/sq to 10^10 Ω/sq by changing the NL carrier gas from 1-12 to N2 while keeping the other growth parameters to be constant, however crystal quality and roughness of the tilm are degraded unambiguously. This situation can be improved by optimizing the NL annealing time. The high resistance of GaN grown on NL using N2 as the carrier gas is due to higher density of threading dislocations caused by the higher density of nucleation islands and small statistic diameter grain compared to the one using 1-12 as carrier gas. Annealing the NL for an optimized annealing time can decrease the density of threading dislocation and improve the tilm roughness and interface of AlGaN/GaN without degrading the sheet resistance of as-grown GaN signiticantly. High-quality SI GaN is grown after optimizing the annealing time, and AlGaN/GaN high electron mobility transistors are also prepared. 展开更多
关键词 unintentionalLY DOPED GAN FILMS DISLOCATIONS BUFFER
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Testing the hypothesis of subtypes of nonadherence in schizophrenia and schizoaffective disorder:A prospective study
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作者 Dulcinea Vega Francisco J Acosta Pedro Saavedra 《World Journal of Psychiatry》 SCIE 2020年第11期260-271,共12页
BACKGROUND Nonadherence is a major problem in the treatment of psychotic disorders.It has been hypothesized that nonadherent patients with schizophrenia are not a homogeneous population and subtypes of nonadherence mi... BACKGROUND Nonadherence is a major problem in the treatment of psychotic disorders.It has been hypothesized that nonadherent patients with schizophrenia are not a homogeneous population and subtypes of nonadherence might exist,but this hypothesis has not been specifically tested.AIM To test the hypothesis of subtypes of nonadherence in schizophrenia and schizoaffective disorder.METHODS This prospective study included 110 consecutively admitted patients diagnosed with schizophrenia or schizoaffective disorder.Assessments were performed at baseline and at 6 mo follow-up after discharge.Sociodemographic,clinical,psychopathological and treatment-related variables were evaluated.Adherence was defined as the concurrence of adherence to antipsychotic treatment and outpatient follow-up during the six-month period.Adherence to antipsychotic treatment was defined as the concurrence of objective and subjective adherence.Sixty-four patients(58%)fulfilled nonadherence criteria at the end of the followup period and were categorized according to their subtype of nonadherence.RESULTS In nonadherent patients(n=64),32(50%)fulfilled criteria of intentional nonadherence,and 32(50%)of unintentional nonadherence(UNA).Unintentional nonadherent patients,as compared to intentional nonadherent patients,are characterized by older age,lower educational level,worse cognitive and negative symptoms,greater severity,worse knowledge of their treatment regimen,greater prevalence of supervision of the treatment,lower number of prior hospitalizations and greater use of nonpsychiatric treatment,anticholinergics and hypnotics.Low educational level(OR=26.1;95%CI:2.819-241),worse treatment knowledge at six months(OR per unit=0.904;95%CI:0.853-0.957)and nonpsychiatric treatment at six months(OR=15.8;95%CI:1.790-139)were independently associated to UNA.CONCLUSION Differentiated subtypes of nonadherence according to intentionality seem to exist in patients with schizophrenia and schizoaffective disorder.Our findings suggest the need for differentiated approach,both in future research and in clinical practice. 展开更多
关键词 Adherence HOSPITALIZATION PSYCHOSIS HYPOTHESIS unintentional nonadherence Intentional nonadherence
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Do Functional Problems and Neighborhood Disturbances in and around the Home Trigger Injuries?
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作者 Koustuv Dalal Charli Eriksson 《Health》 2014年第11期1085-1091,共7页
The study has tried to identify whether poor self-rated health and home and neighbourhood environmental problems trigger injuries. The study used data from the Life & Health year 2008 survey, a postal questionnair... The study has tried to identify whether poor self-rated health and home and neighbourhood environmental problems trigger injuries. The study used data from the Life & Health year 2008 survey, a postal questionnaire administered by Statistics Sweden in five administrative regions in central Sweden (Uppsala, S?dermanland, ?rebro, Varmland and V?stmanland). A random sample of 1,060,032 respondents aged 18 - 79 years had participated in the study. ?rebro and Varmland region had the highest proportions of injuries. People at their age between 18 to 24 years—males—tobacco and alcohol addicted had the highest proportions of injuries. Environmental factors such as disturbances in and around home had emerged as major triggering factors for injuries. Physical functional problems such as problem of buying own food, cooking, dressing-up and walking had been emerged as very strong predicting factors of injuries. Policy makers in Sweden could identify the poor neighborhood, disturb living condition through the housing companies and the cooperative housing societies to control injuries and promote safety. 展开更多
关键词 unintentional INJURIES FUNCTIONAL PROBLEMS and LIVELIHOOD Disturbances Sweden
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Factors Associeted with Home Accidents in Childhood at Regional Teaching Hospital of OuéméPlateau
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作者 Caroline Padonou Gilles Bognon +3 位作者 Florence Alihonou Lutécia Zohoun Samuel Kisembo Bavi Gratien Sagbo 《Open Journal of Pediatrics》 2022年第2期358-363,共6页
Introduction: Home accidents (HA) are often unknown in Benin compared to infectious pathologies. The aim of this work was to determine the prevalence and the factors associated with HA in children admitted to the CHUD... Introduction: Home accidents (HA) are often unknown in Benin compared to infectious pathologies. The aim of this work was to determine the prevalence and the factors associated with HA in children admitted to the CHUD-OP. Method: This was a cross-sectional study conducted from August 1<sup>st</sup> to October 31<sup>th</sup> 2021. We studied children aged 0 to 18 who presented with HA to the pediatrics and emergency reception and triage departments at CHUD-OP. We defined HA as “any event occurring inside the home or in the immediate vicinity of the home that resulted in an injury which was not done deliberately. Results: The hospital frequency of HA was 8.4% (61/725). The median age was 5 years with a male to female ratio of 1.6. Trauma was the leading cause of HA (59%) followed by poisoning (23%). Falling was the main mechanism of trauma (80.6%). The toxins causing poisoning were dominated by caustics (28.6%). The age of the children (p = 0.02), the level of education of the mothers (p , and the area they occur (kitchen with p = 0.04 and on the stairs with p = 0.03) were statistically associated with the occurrence of trauma. Conclusion: HA are common among children admitted at CHUD-OP and factors associated with HA are identified. Measures to prevent home accidents among children in the community should be considered. 展开更多
关键词 Caustic Soda Poisoning Home Accidents unintentional Home Accidents Trauma at Home Associated Factors
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Spatial distribution of polychlorinated biphenyls in soil around a municipal solid waste incinerator 被引量:6
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作者 Wenbin Liu Haifeng Li +2 位作者 Zhenyu Tian Huiting Xie Jicheng Hu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2013年第8期1636-1642,共7页
The impact of a typical municipal solid waste incinerator (MSWI) on polychlorinated biphenyl (PCB) concentrations in the surrounding soil was studied. Six stack gas samples were taken from the MSWI and 21 soil sam... The impact of a typical municipal solid waste incinerator (MSWI) on polychlorinated biphenyl (PCB) concentrations in the surrounding soil was studied. Six stack gas samples were taken from the MSWI and 21 soil samples were collected from sampling sites between 300 and 1700 m from the MSWI stack. The total (∑PCB) concentrations of dioxin-like (dl) PCBs and indicator PCBs in the stack gas samples were between 3.41 and 34.3 ng/m3, and the corresponding toxic equivalents (TEQs) ranged from 4.45 to 66.9 pg WHO-TEQ/m3, with a mean of 28.6 pg WHO-TEQ/m3. A total of 2.43 g WHO-TEQ of PCBs per year was calculated to be released into the environment from MSWIs in China. The ∑PCB concentrations in the soil samples ranged from 28.0 to 264.4 pg/g, with mean and median values of 127.6 and 127.7 pg/g, respectively, while the TEQ values were between 0.020 and 0.18 pg WHO-TEQ/g, with mean and median values of 0.074 and 0.062 pg WHO-TEQ/g, respectively. Comparing this study with other studies performed around the world suggest that PCB emission from incinerators has a critical influence on PCB concentrations in the surrounding soil. An exponential function equation is proposed, which indicates a clear decline in ∑PCB concentrations with increasing distance from the stack. A contour map created using an ordinary kriging interpolation technique showed that a limited area (1250 m radius) from the stack was clearly influenced by PCB emission from the MSWI. 展开更多
关键词 unintentional persistent organic pollutants stack gas contour map safe distance
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A matter of time: Temporal variation in the introduction history and population genetic structuring of an invasive lizard 被引量:4
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作者 HalmahMOULE Kirilee CHAPLIN +3 位作者 Rebecca D. BRAY Kimberly A. MILLER Michael B. THOMSON David G. CHAPPLE 《Current Zoology》 SCIE CAS CSCD 2015年第3期456-464,共9页
Invasive species are considered one of the greatest threats to native ecosystems, second only to habitat loss and frag- mentation. Despite this, the temporal dynamics of invasions are poorly understood, with most stud... Invasive species are considered one of the greatest threats to native ecosystems, second only to habitat loss and frag- mentation. Despite this, the temporal dynamics of invasions are poorly understood, with most studies focusing on a single time point, providing us with only a snapshot of the biology and genetics of the invader. We investigated the invasion of Lord Howe Island by the delicate skink Lampropholis delicata and assessed the introduction history and genetic structure of this species over a 5-year period. Using genetic data taken from 2007, and again in 2011/12, we examined changes in the population genetic struc- ture (whether new haplotypes had been introduced to the island, and shifts in haplotype frequencies) of the species on the island between these two time points. No new haplotypes were introduced to the island between 2007 and 2011/12; however, significant shifts in haplotype frequencies across the island were detected. We conclude that the delicate skink is expanding its range into the southern regions of the island and that the haplotype frequencies on Lord Howe Island are still in a state of highly dynamic flux. Our study highlights the importance of considering invasions as dynamic and studying them in such a way that enable us to better manage their impacts 展开更多
关键词 Biological invasion Genetic admixture Lampropholis delicata Lord Howe Island Population genetics unintentional introduction
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Comprehensive monitoring of chlorinated aromatic and heteroaromatic pollutants at sites contaminated by chlorine production processes to inform policy making 被引量:4
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作者 Takumi Takasuga Hiroaki Takemori +3 位作者 Teru Yamamoto Kazuo Higashino Yuko Sasaki Roland Weber 《Emerging Contaminants》 2020年第1期133-142,共10页
The production of chlorine by the chlor-alkali process using graphite electrodes was one of the largest sources of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/PCDFs)in history with estimates in the kg TEQ... The production of chlorine by the chlor-alkali process using graphite electrodes was one of the largest sources of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/PCDFs)in history with estimates in the kg TEQ range for individual factories.In addition,the chlorine production predecessor processes in the former Leblanc soda factories generated large amounts of PCDD/PCDFs,also in kg TEQ range for individual sites.In both processes coal tar,used as pitch binder for electrodes in the chlor-alkali process or tars for sealing chlorine chambers,was the major source for PCDD/PCDFs formation.The complex PAH mixture in the tars which were chlorinated in the processes contained approx.1%dibenzofuran.Therefore in this study we screened the full range of chlorinated aromatic and heteroaromatic compounds in contaminated soils from former chlor-alkali plants in Germany and Japan as well as from a German Leblanc factory,using high resolution time-of-flight mass spectrometry GC-HR-TOF-MS.At all three sites the full range of unintentionally produced persistent organic pollutants(POPs)listed in the Stockholm Convention(PCDFs,PCDDs,PCBs,PCNs,HCB,HCBD and PeCBz)were present at high ppb levels and TEQ was up to several 100,000 ng/kg soil in hot spot areas.Additionally,a wide range of other polychlorinated(PC-)PAHs(PC-phenanthrene/anthracene,PC-pyrene/fluoranthene,PC-benzo(a)anthracene/chrysene)were detected.Some of these compound classes were present in one to two order of magnitude higher concentrations compared to PCDFs.Furthermore,polychlorinated methyldibenzofurans,polychlorinated dimethyl-/ethyl-dibenzofurans,and polychlorinated carbazoles e the N-analogue of dibenzofuran-were detected at levels comparable to PCDFs at all three sites.Polychlorinated benzonitriles were detected in addition to chlorobenzenes as monoaromatic pollutant.Since all three factories have stopped production 50e120 years ago,all detected chlorinated aromatics can be regarded as very persistent.The technologies have been used in several hundred locations globally.These(former)chlorine production sites should be assessed for contamination and their contemporary threat to humans and the environment should be evaluated.The toxicity of most of these polychlorinated PAHs and hetero-PAHs is unknown but due to their related structures,similar toxicity profiles can be expected and need to be investigated.Furthermore,all processes where chlorine and complex organic material are present should be screened for the entire resulting chlorinated pollutant mixture,the detailed fingerprints should be documented,and the overall toxicological risk assessed for individual processes to inform policy making. 展开更多
关键词 unintentional POPs PCDD/PCDFs Polychlorinated carbazoles Chlorinated PAHs Complex mixtures Fingerprint
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Dioxin sources to the aquatic environment: Re-assessing dioxins in industrial processes and possible emissions to the aquatic 被引量:1
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作者 Katsuya Kawamoto Roland Weber 《Emerging Contaminants》 2021年第1期52-62,共11页
Releases of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/PCDFs)from industrial or thermal processes to the aquatic environment are considered small compared to emissions to air today.However,industrial pro... Releases of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/PCDFs)from industrial or thermal processes to the aquatic environment are considered small compared to emissions to air today.However,industrial processes have occasionally released PCDD/PCDFs into local aquatic environments..PCDD/PCDF formation and releases were re-examined based on investigations conducted before the introduction of water quality regulations in Japan.Emphasis was given to PCDD/PCDF formation in various industrial processes such as the manufacture of acetylene and caprolactam.In acetylene production,PCDD/PCDFs are formed in the oxidative process using chlorine to remove impurities,with PCDFs formed with the particular chlorine pattern with 1,2,7,8-TetraCDF,2,3,7,8-TetraCDFs and 1,2,3,4,7,8-HexaCDF as maker congeners and low PCDDs levels.This indicates that acetylene production residues contain organochlorines.In caprolactam production,formation of PCDD/PCDFs in the cyclohexane photonitrosation process has been confirmed and the emission factor for PCDD/PCDF releases to water from for caprolactam manufacture was estimated with an emission factor for releases to the aquatic environment of 0.25±0.04 mgTEQ/t.A range of additional processes with PCDD/PCDF release were also found during the Japanese survey.Overall,the formation processes were placed in two categories:(A)chemical synthesis processes and (B)flue gas treatment of high temperature processes.The final effluent water met the PCDD/PCDF limits by applying advanced treatment for PCDD/PCDF removal such as activated carbon treatment.The survey shows that industrial processes involving elemental chlorine or other processes that facilitate chlorination or use chlorinating chemicals should be assessed and controlled for PCDD/PCDFs and other unintentional POPs releases to water.In such surveys,chemicals from the chlorine and organochlorine industry should also be assessed for PCDD/PCDFs and other unintentional POPs contamination as proposed by the UNEP Toolkit.The current study can contribute to the Stockholm Convention implementation of Article 5 of the Stockholm Convention to take measures to reduce the release of UPOPs from anthropogenic sources with the goal of their continuing minimization and,where feasible,ultimate elimination. 展开更多
关键词 PCDD/PCDF Water pollution Industrial sources Acetylene manufacturing Caprolactam manufacturing Pattern unintentional POPs
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A brief review of co-doping
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作者 Jingzhao Zhang Kinfai Tse +2 位作者 Manhoi Wong Yiou Zhang Junyi Zhu 《Frontiers of physics》 SCIE CSCD 2016年第6期81-101,共21页
Dopants and defects are important in semiconductor and magnetic devices. Strategies for controlling doping and defects have been the focus of semiconductor physics research during the past decades and remain critical ... Dopants and defects are important in semiconductor and magnetic devices. Strategies for controlling doping and defects have been the focus of semiconductor physics research during the past decades and remain critical even today. Co-doping is a promising strategy that can be used for effectively tuning the dopant populations, electronic properties, and magnetic properties. It can enhance the solubility of dopants and improve the stability of desired defects. During the past 20 years, significant experimental and theoretical efforts have been devoted to studying the characteristics of co-doping. In this article, we first review the historical development of co-doping. Then, we review a variety of research performed on co-doping, based on the compensating nature of co-dopants. Finally, we review the effects of contamination and surfactants that can explain the general mechanisms of co-doping. 展开更多
关键词 CO-DOPING fully compensated partially compensated non-compensated unintentional \doping SURFACTANT
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新版书目
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《日语学习与研究》 CSSCI 2022年第6期33-33,125,共2页
关键词 Japanese language major motivation reconstruct factor analysis intentional factors unintentional factors
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