目的:探讨乳腺锥光束CT(Cone Beam Breast CT,CBBCT)平扫在乳腺病灶筛查及性质评估中的应用价值。方法:收集2020年6月~2022年6月在本院接受乳腺结节切除术的患者178例作为研究对象,分别采用锥光束乳腺CT平扫、数字乳腺X射线摄影(Digital...目的:探讨乳腺锥光束CT(Cone Beam Breast CT,CBBCT)平扫在乳腺病灶筛查及性质评估中的应用价值。方法:收集2020年6月~2022年6月在本院接受乳腺结节切除术的患者178例作为研究对象,分别采用锥光束乳腺CT平扫、数字乳腺X射线摄影(Digital Mammography,DM)进行术前检查,对比其乳腺结节检出率、乳腺癌诊断准确率的差别。结果:CBBCT平扫、DM对乳腺腺体分型的Kappa值为0.611,P<0.05,两种检查方式之间对乳腺腺体类型的评估结果具有一致性。178例患者中,经病理证实共227个病灶(119个恶性、108个良性),其中DM检出160个病灶、检出率为70.48%;CBBCT平扫检出227个病灶,检出率为100%。CBBCT平扫的乳腺结节检出率高于DM,差异有统计学意义(P<0.05)。CBBCT平扫诊断乳腺癌的灵敏性为86.11%、特异性为97.10%;DM诊断乳腺癌的灵敏性为72.09%、特异性为90.88%。CBBCT平扫、DM诊断乳腺癌的灵敏度、特异度差异无统计学意义(P>0.05)。ROC曲线显示,CBBCT平扫诊断乳腺癌的效能优于DM(P<0.05)。结论:CBBCT平扫有助于乳腺结节检出率、乳腺癌诊断率的提升,是一种理想的术前检查手段。展开更多
To ensure compacted backfilling, it is essential to ensure the reliability of the performance of a solid backfill support, key equipment for integrating backfilling and mining. To evaluate the backfilling performance ...To ensure compacted backfilling, it is essential to ensure the reliability of the performance of a solid backfill support, key equipment for integrating backfilling and mining. To evaluate the backfilling performance of a backfill support, the concept of backfill and operation properties is proposed in this study. Moreover, it is elaborated in terms of five aspects, namely, structural property, supporting property, tamping property, mechanical response property, and geological adaptation property, which are specifically reflected by 14 indexes including the supporting intensity and vertical roof gap. Seven separate evaluation indexes are selected to build a backfill and operation properties based system for evaluating the design schemes of the backfill support via a multi-index comprehensive evaluation method; then, the evaluation method and process together with measures to control the backfill and operation properties are proposed. By using this system, 11 schemes for optimizing the ZC5200/14.5/3 backfill support at Zhaizhen Coal Mine are evaluated, and scheme #10 is found to show superior vertical roof gap and other backfill and operation properties, thus demonstrating the reasonability of the evaluation system. On this basis, the backfill support research framework of designing initial scheme, optimizing design scheme, selecting the best evaluation indexes, evaluating optimizing scheme, and evaluating operation properties is built; this should serve as an important reference for further studies on the roof controlling performance of a backfill support.展开更多
The paper considers a multivariate partially linear model under independent errors,and investigates the asymptotic bias and variance-covariance for parametric component βand nonparametric component F(·)by the ...The paper considers a multivariate partially linear model under independent errors,and investigates the asymptotic bias and variance-covariance for parametric component βand nonparametric component F(·)by the GJS estimator and Kernel estimation.展开更多
In the present study, polyvoltine germplasm stock ofAndhra Pradesh State Sericulture Research and Development, Institute (APSSRDI) was evaluated for its performance based on quantitative and qualitative traits. Twen...In the present study, polyvoltine germplasm stock ofAndhra Pradesh State Sericulture Research and Development, Institute (APSSRDI) was evaluated for its performance based on quantitative and qualitative traits. Twenty-one oval and 10 peanut cocoon shaped lines were reared in different seasons of the year. Since the polyvoltines are non-diapausing, six generations were reared and evaluated for various economically important traits based on evaluation index and sub-ordinate function statistical methods. Ten top ranked lines obtained by using both the methods were identified as potential parental strains. Among oval lines, APMI4, APMI 1, APMIS, APMW9, and APMI9, and among peanut lines APMD5, APMDI, APMD3, APMD9 and APMD8 were selected as base material. The identified high yielding lines will be used in various breeding programmes as initial parents for the synthesis of superior polyvoltine breeds/hybrids.展开更多
Ground improvement has been used on many construction sites to densify granular materials, in other word, to improve soil properties and reduce potential settlement. This work presents a case study of ground improveme...Ground improvement has been used on many construction sites to densify granular materials, in other word, to improve soil properties and reduce potential settlement. This work presents a case study of ground improvement using rapid impact compaction (RIC). The research site comprises the construction of workshop and depots as part of railway development project at Batu Gajah-Ipoh, Malaysia. In-situ testing results show that the subsurface soil comprises mainly of sand and silty sand through the investigated depth extended to 10 m. Groundwater is approximately 0.5 m below the ground surface. Evaluation of improvement was based on the results of pre- and post-improvement cone penetration test (CPT). Interpretation software has been used to infer soil properties. Load test was conducted to estimate soil settlement. It is found that the technique succeeds in improving soil properties namely the relative density increases from 45% to 70%, the friction angle of soil is increased by an average of 3°, and the soil settlement is reduced by 50%: The technique succeeds in improving soil properties to approximately 5.0 m in depth depending on soil uniformity with depth.展开更多
Ground movements due to longwall mining operations have the potential to damage the hydrological balance within as well as outside the mine permit area in the form of increased surface ponding and changes to hydrogeol...Ground movements due to longwall mining operations have the potential to damage the hydrological balance within as well as outside the mine permit area in the form of increased surface ponding and changes to hydrogeological properties. Recently, the Office of Surface Mining, Reclamation and Enforcement(OSMRE) in the USA, has completed a public comment period on a newly proposed rule for the protection of streams and groundwater from adverse impacts of surface and underground mining operations(80 FR 44435). With increased community and regulatory focus on mining operations and their potential to adversely affect streams and groundwater, now there is a greater need for better prediction of the possible effects mining has on both surface and subsurface bodies of water. With mining induced stress and strain within the overburden correlated to changes in the hydrogeological properties of rock and soil, this paper investigates the evaluation of the hydrogeological system within the vicinity of an underground mining operation based on strain values calculated through a surface deformation prediction model. Through accurate modeling of the pre- and post-mining hydrogeological system, industry personnel can better depict mining induced effects on surface and subsurface bodies of water aiding in the optimization of underground extraction sequences while maintaining the integrity of water resources.展开更多
In this paper, the earthquake hazard parameters (λ m,b and M max) from the maximum likelihood method for the raw catalogue and declustered catalogues have been used to discuss the effect of the aftershocks on the ear...In this paper, the earthquake hazard parameters (λ m,b and M max) from the maximum likelihood method for the raw catalogue and declustered catalogues have been used to discuss the effect of the aftershocks on the earthquake hazard estimation. The declustered catalogues have been compiled from the raw catalogues by deleting the aftershocks in different time interval after main shock according to the criteria for the aftershock activity period. As an example, Hebei seismic zone is taken to show the effect of the aftershock on the earthquake hazard assessment because three strong earthquakes with the aftershocks occurred from 1966 to 1976. The results have been shown that the effect of the aftershocks on the parameters λ m,b is significant. The difference between the clustered and declustered catalogues has reached in seismic activity rate and recurrence period, at most, 45% and 90%, respectively. But the difference in M max is smaller. Based on this, the suggestion that the aftershocks should be omitted in the estimation of the earthquake hazard could be made, but how long the aftershocks activity duration is still left to the future research.展开更多
To study the relationship between zooplankton community structure and environmental factors and water quality in the Harbin Section of the Songhua River,investigations were carried out in June,August,and October 2011....To study the relationship between zooplankton community structure and environmental factors and water quality in the Harbin Section of the Songhua River,investigations were carried out in June,August,and October 2011.Canonical correspondence analysis(CCA) and saprobic indices were used to process and analyze the data.Seasonal variability was identified as a significant source of variation,which explains the fluctuation in zooplankton density.In autumn,the dry season,water residence time increased and zooplankton biomass and abundance accumulated in the slow flowing waters.Zooplankton abundance increased when food conditions improved.Therefore,the total zooplankton abundance in autumn is much higher than that in spring and summer.According to the saprobic indices,all the sample sites had mesosaprobic water and water quality was worse in autumn.CCA revealed that temperature accounted for most of the spatial variation in the zooplankton community.Moreover,pH,dissolved oxygen saturation,and turbidity were important factors affecting zooplankton community distribution.展开更多
The Yushu Ms 7.1 earthquake occurred on April 14,2010 in Qinghai Province,China.It induced a mass of secondary geological disasters,such as collapses,landslides,and debris flows.Risk assessment maps are important for ...The Yushu Ms 7.1 earthquake occurred on April 14,2010 in Qinghai Province,China.It induced a mass of secondary geological disasters,such as collapses,landslides,and debris flows.Risk assessment maps are important for geological disaster prevention and mitigation,and also can serve as a guide for post-earthquake reconstruction.Firstly,a hazard assessment index system of secondary geological disasters in the earthquake region was built in this paper,which was based on detailed analysis of environmental and triggering factors closely related to geological disasters in the study area.GIS technology was utilized to extract and analyze the assessment index.Hazard assessment maps of secondary geological disasters were obtained by spatial modeling and overlaying analysis.Secondly,an analysis of the vulnerability of hazard bearing bodies in the area was conducted,important information,such as, population density,percentage of arable land, industrial and agricultural outputs per unit area were regarded as assessment indices to evaluate socioeconomic vulnerability.Thirdly,the risk level of secondary geological disasters of the area was obtained by the formula:Risk=Hazard×Vulnerability. Risk assessment maps were categorized into four levels,including"low","moderate","high"and"very high".These results show that some urban areas are at very high risk,including Jiegu,Chengwen,Xiaxiula and Sahuteng towns.This research can provide some references and suggestions to improve decisionmaking support for emergency relief and post- earthquake reconstruction in the study area.展开更多
Longwall mining is one of the most acclaimed and widely used in underground method for coal extraction. The interaction of powered supports with the roof is the key issue in strata mechanics of longwall mining. Contro...Longwall mining is one of the most acclaimed and widely used in underground method for coal extraction. The interaction of powered supports with the roof is the key issue in strata mechanics of longwall mining. Controlled caving of rock mass is a prerequisite pro thriving exploitation of coal deposits by longwall retreat with caving technique and support resistance has evolved as the most promising and effective scientific tool to predict various aspects related to strata mechanics of such workings. Load density,height of caving block, distance of fractured zone ahead of the face, overhang of goaf and mechanical strength of the debris above and below the support base have been found to influence the magnitude of load on supports. Designing powered support has been attempted at the different countries in different methods. This paper reviews the mechanism of roof caving and the conventional approaches of caving behaviour and support resistance requirement in the context of major strata control experiences gained worldwide. The theoretical explanation of the mechanism of roof caving is still continuing with consistently improved understanding through growing field experiences in the larger domain of geo-mining conditions and state-of-art strata mechanics analysis and monitoring techniques.展开更多
In order to make more available methods for natural jadeite quality evaluation,this study applied rigorous coupled wave theory to calculate and simulate the reflection characteristics of various natural jadeites,and e...In order to make more available methods for natural jadeite quality evaluation,this study applied rigorous coupled wave theory to calculate and simulate the reflection characteristics of various natural jadeites,and establish evaluation standard based on the relationship between refractive index and reflectivity and responses of reflection efficiency to refractive index,grating thickness and incident angles,etc.The results suggest that reflection efficiency varies significantly as a function of the natural jadeite quality,which can provide a new method to evaluate natural jadeite.展开更多
The present research intends to address in a comprehensive, transversal, and interdisciplinary manner the chronic patient management process in the research project named "PRO DOMO SUD" in order to identify operatio...The present research intends to address in a comprehensive, transversal, and interdisciplinary manner the chronic patient management process in the research project named "PRO DOMO SUD" in order to identify operational inefficiencies, thus demonstrating that these are largely attributable to incurred costs and, thus, evaluate possible solutions for providing effective and appropriate responses by healthcare and social services. Can patients/older people be treated, monitored, and managed successfully with mobile and wearable technologies? The project involved three different groups of patients/participants: Patients with heart failure shock in "Home Monitoring Scenario"; Patients with different pathologies in "Virtual Ward Scenario"; Patients with limited mobility due to Neurological and Orthopaedic disease in "Rehabilitation Scenario". Due to the complexity of the issue, the methodological approach adopted must be multidimensional and interdisciplinary, addressing the complexity of the chronic patient from all viewpoints, not reducing it, yet analysing, understanding, rearranging, and managing it in an organic manner. The three different scenarios were allowed to identify several impacts on organizational and clinic management of chronic diseases, the tests showed significant improvements in quality of life of patients enrolled in the project. The data deriving from the three scenario demonstrate that wearable divide and ICT, in general, can empower both patients and physician personnel allowing them to be active part in the chronic disease management process. The PRO DOMO SUD experience derived from the Living Lab, this is a new paradigm for industrial research and development activities which allows the final users to actively collaborate with the designers and technicians in the development and test of new products and services aimed to them. The Living Labs stimulate social innovation by transferring research results from the closed industrial laboratory towards real life contexts where citizens and users become co-developers.展开更多
In this paper, for the generalized linear models (GLMs) with diverging number of covariates, the asymptotic properties of maximum quasi-likelihood estimators (MQLEs) under some regular conditions are developed. Th...In this paper, for the generalized linear models (GLMs) with diverging number of covariates, the asymptotic properties of maximum quasi-likelihood estimators (MQLEs) under some regular conditions are developed. The existence, weak convergence and the rate of convergence and asymptotic normality of linear combination of MQLEs and asymptotic distribution of single linear hypothesis teststatistics are presented. The results are illustrated by Monte-Carlo simulations.展开更多
With the rapid development of nanotechnology and increasingly broad bio-application of engineered nanomaterials, their bio- hazards have become a serious public concern. It is believed that the chemical nature, partic...With the rapid development of nanotechnology and increasingly broad bio-application of engineered nanomaterials, their bio- hazards have become a serious public concern. It is believed that the chemical nature, particle size, morphology, and surface chemistry of nanomaterials are key parameters that influence their toxicity. Although cultured ceils have been widely used to evaluate nanomaterial toxicity, it remains unclear whether the passage of these cells affects the evaluation results. In the pre- sent study, Ba/F3 cells transfected with the BCR-ABL gene were subcultured to study the effect of passage number on cell sta- bility and their cellular responses upon exposure to nanomaterials. The results demonstrated that proliferation, cellular senes- cence, BCR-ABL gene expression, cell cycle and apoptosis were stable across multiple passages. Senescence and BCR-ABL gene expression of cells from different passage cells were unchanged when treated with silver nanoparticles (AgNPs). In addi- tion, the cells at multiple passage numbers were all arrested in the G2/M phase and apoptosis was induced by the AgNPs. These nanoparticles could enter cells via endocytosis and localize in the cndosomes, which were also not influenced by passage number. These data suggest that short-term passage would not affect cultured cell stability and toxicity assessment using these cells would be consistent when maintained appropriately.展开更多
Soil degradation is a serious environmental problem in Ethiopia. However, little information is documented on indicators such as variations in soil properties across different landforms in a catchment. This study was ...Soil degradation is a serious environmental problem in Ethiopia. However, little information is documented on indicators such as variations in soil properties across different landforms in a catchment. This study was aimed to assess soil properties and their changes across sites with different erosion statuses, and identify landscape positions that require prior management attention in the Mai-Negus catchment, northern Ethiopia. Three types of erosion-status sites(stable, eroding and aggrading) were identified using reconnaissance surveys, and then the corresponding soil samples were collected and analyzed. The major soil properties were significantly varied(P ≤ 0.05) among the three erosion-status sites. The highest soil p H, organic carbon, total nitrogen, cation exchange capacity, iron and zinc were recorded from the aggrading sites in the reservoir and valley landforms of the study catchment. A higher bulk density was generally recorded in the eroding sites, whereas a lower value was observed in the aggrading sites. The highest sand content was observed in the eroding sites of the mountain followed by the central ridge landform. The paired mean difference and the correlation matrix of most soil properties between the different erosion statuses also showed significant differences. About 95% of the erosionstatus sites were correctly classified by the discriminant function, indicating that the field survey-based classification was acceptable for decision making. On the basis of this study, suitable interventions should thus be introduced to the prioritized landforms, which are the mountain and central ridge, and eroding sites with severely degraded soil properties across the catchment.展开更多
文摘目的:探讨乳腺锥光束CT(Cone Beam Breast CT,CBBCT)平扫在乳腺病灶筛查及性质评估中的应用价值。方法:收集2020年6月~2022年6月在本院接受乳腺结节切除术的患者178例作为研究对象,分别采用锥光束乳腺CT平扫、数字乳腺X射线摄影(Digital Mammography,DM)进行术前检查,对比其乳腺结节检出率、乳腺癌诊断准确率的差别。结果:CBBCT平扫、DM对乳腺腺体分型的Kappa值为0.611,P<0.05,两种检查方式之间对乳腺腺体类型的评估结果具有一致性。178例患者中,经病理证实共227个病灶(119个恶性、108个良性),其中DM检出160个病灶、检出率为70.48%;CBBCT平扫检出227个病灶,检出率为100%。CBBCT平扫的乳腺结节检出率高于DM,差异有统计学意义(P<0.05)。CBBCT平扫诊断乳腺癌的灵敏性为86.11%、特异性为97.10%;DM诊断乳腺癌的灵敏性为72.09%、特异性为90.88%。CBBCT平扫、DM诊断乳腺癌的灵敏度、特异度差异无统计学意义(P>0.05)。ROC曲线显示,CBBCT平扫诊断乳腺癌的效能优于DM(P<0.05)。结论:CBBCT平扫有助于乳腺结节检出率、乳腺癌诊断率的提升,是一种理想的术前检查手段。
基金Project(2017QNA21)supported by Fundamental Research Funds for the Central Universities,ChinaProject supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),China
文摘To ensure compacted backfilling, it is essential to ensure the reliability of the performance of a solid backfill support, key equipment for integrating backfilling and mining. To evaluate the backfilling performance of a backfill support, the concept of backfill and operation properties is proposed in this study. Moreover, it is elaborated in terms of five aspects, namely, structural property, supporting property, tamping property, mechanical response property, and geological adaptation property, which are specifically reflected by 14 indexes including the supporting intensity and vertical roof gap. Seven separate evaluation indexes are selected to build a backfill and operation properties based system for evaluating the design schemes of the backfill support via a multi-index comprehensive evaluation method; then, the evaluation method and process together with measures to control the backfill and operation properties are proposed. By using this system, 11 schemes for optimizing the ZC5200/14.5/3 backfill support at Zhaizhen Coal Mine are evaluated, and scheme #10 is found to show superior vertical roof gap and other backfill and operation properties, thus demonstrating the reasonability of the evaluation system. On this basis, the backfill support research framework of designing initial scheme, optimizing design scheme, selecting the best evaluation indexes, evaluating optimizing scheme, and evaluating operation properties is built; this should serve as an important reference for further studies on the roof controlling performance of a backfill support.
基金Supported by the Anhui Provincial Natural Science Foundation(11040606M04) Supported by the National Natural Science Foundation of China(10871001,10971097)
文摘The paper considers a multivariate partially linear model under independent errors,and investigates the asymptotic bias and variance-covariance for parametric component βand nonparametric component F(·)by the GJS estimator and Kernel estimation.
基金Project supported by Development of Heterotic Polyvoltine Hybridsof Superior Quantity and Quality, India
文摘In the present study, polyvoltine germplasm stock ofAndhra Pradesh State Sericulture Research and Development, Institute (APSSRDI) was evaluated for its performance based on quantitative and qualitative traits. Twenty-one oval and 10 peanut cocoon shaped lines were reared in different seasons of the year. Since the polyvoltines are non-diapausing, six generations were reared and evaluated for various economically important traits based on evaluation index and sub-ordinate function statistical methods. Ten top ranked lines obtained by using both the methods were identified as potential parental strains. Among oval lines, APMI4, APMI 1, APMIS, APMW9, and APMI9, and among peanut lines APMD5, APMDI, APMD3, APMD9 and APMD8 were selected as base material. The identified high yielding lines will be used in various breeding programmes as initial parents for the synthesis of superior polyvoltine breeds/hybrids.
基金Projects(RG148/12AET,RG086/10AET) supported by the UMRG,MalaysiaProject(PS05812010B) supported by the Post Graduate Research Fund,Malaysia
文摘Ground improvement has been used on many construction sites to densify granular materials, in other word, to improve soil properties and reduce potential settlement. This work presents a case study of ground improvement using rapid impact compaction (RIC). The research site comprises the construction of workshop and depots as part of railway development project at Batu Gajah-Ipoh, Malaysia. In-situ testing results show that the subsurface soil comprises mainly of sand and silty sand through the investigated depth extended to 10 m. Groundwater is approximately 0.5 m below the ground surface. Evaluation of improvement was based on the results of pre- and post-improvement cone penetration test (CPT). Interpretation software has been used to infer soil properties. Load test was conducted to estimate soil settlement. It is found that the technique succeeds in improving soil properties namely the relative density increases from 45% to 70%, the friction angle of soil is increased by an average of 3°, and the soil settlement is reduced by 50%: The technique succeeds in improving soil properties to approximately 5.0 m in depth depending on soil uniformity with depth.
基金sponsored by the Appalachian Research Initiative for Environmental Science(ARIES)
文摘Ground movements due to longwall mining operations have the potential to damage the hydrological balance within as well as outside the mine permit area in the form of increased surface ponding and changes to hydrogeological properties. Recently, the Office of Surface Mining, Reclamation and Enforcement(OSMRE) in the USA, has completed a public comment period on a newly proposed rule for the protection of streams and groundwater from adverse impacts of surface and underground mining operations(80 FR 44435). With increased community and regulatory focus on mining operations and their potential to adversely affect streams and groundwater, now there is a greater need for better prediction of the possible effects mining has on both surface and subsurface bodies of water. With mining induced stress and strain within the overburden correlated to changes in the hydrogeological properties of rock and soil, this paper investigates the evaluation of the hydrogeological system within the vicinity of an underground mining operation based on strain values calculated through a surface deformation prediction model. Through accurate modeling of the pre- and post-mining hydrogeological system, industry personnel can better depict mining induced effects on surface and subsurface bodies of water aiding in the optimization of underground extraction sequences while maintaining the integrity of water resources.
文摘In this paper, the earthquake hazard parameters (λ m,b and M max) from the maximum likelihood method for the raw catalogue and declustered catalogues have been used to discuss the effect of the aftershocks on the earthquake hazard estimation. The declustered catalogues have been compiled from the raw catalogues by deleting the aftershocks in different time interval after main shock according to the criteria for the aftershock activity period. As an example, Hebei seismic zone is taken to show the effect of the aftershock on the earthquake hazard assessment because three strong earthquakes with the aftershocks occurred from 1966 to 1976. The results have been shown that the effect of the aftershocks on the parameters λ m,b is significant. The difference between the clustered and declustered catalogues has reached in seismic activity rate and recurrence period, at most, 45% and 90%, respectively. But the difference in M max is smaller. Based on this, the suggestion that the aftershocks should be omitted in the estimation of the earthquake hazard could be made, but how long the aftershocks activity duration is still left to the future research.
基金Supported by the National Natural Science Foundation of China(No.41271106)
文摘To study the relationship between zooplankton community structure and environmental factors and water quality in the Harbin Section of the Songhua River,investigations were carried out in June,August,and October 2011.Canonical correspondence analysis(CCA) and saprobic indices were used to process and analyze the data.Seasonal variability was identified as a significant source of variation,which explains the fluctuation in zooplankton density.In autumn,the dry season,water residence time increased and zooplankton biomass and abundance accumulated in the slow flowing waters.Zooplankton abundance increased when food conditions improved.Therefore,the total zooplankton abundance in autumn is much higher than that in spring and summer.According to the saprobic indices,all the sample sites had mesosaprobic water and water quality was worse in autumn.CCA revealed that temperature accounted for most of the spatial variation in the zooplankton community.Moreover,pH,dissolved oxygen saturation,and turbidity were important factors affecting zooplankton community distribution.
基金supported by the National Natural Science Foundation of China(Grant No,41171332)the National Science & Technology Pillar Program of China(Grant No.2008BAK50B01-5,2008BAK50B01-6 and O8H80210AR)
文摘The Yushu Ms 7.1 earthquake occurred on April 14,2010 in Qinghai Province,China.It induced a mass of secondary geological disasters,such as collapses,landslides,and debris flows.Risk assessment maps are important for geological disaster prevention and mitigation,and also can serve as a guide for post-earthquake reconstruction.Firstly,a hazard assessment index system of secondary geological disasters in the earthquake region was built in this paper,which was based on detailed analysis of environmental and triggering factors closely related to geological disasters in the study area.GIS technology was utilized to extract and analyze the assessment index.Hazard assessment maps of secondary geological disasters were obtained by spatial modeling and overlaying analysis.Secondly,an analysis of the vulnerability of hazard bearing bodies in the area was conducted,important information,such as, population density,percentage of arable land, industrial and agricultural outputs per unit area were regarded as assessment indices to evaluate socioeconomic vulnerability.Thirdly,the risk level of secondary geological disasters of the area was obtained by the formula:Risk=Hazard×Vulnerability. Risk assessment maps were categorized into four levels,including"low","moderate","high"and"very high".These results show that some urban areas are at very high risk,including Jiegu,Chengwen,Xiaxiula and Sahuteng towns.This research can provide some references and suggestions to improve decisionmaking support for emergency relief and post- earthquake reconstruction in the study area.
文摘Longwall mining is one of the most acclaimed and widely used in underground method for coal extraction. The interaction of powered supports with the roof is the key issue in strata mechanics of longwall mining. Controlled caving of rock mass is a prerequisite pro thriving exploitation of coal deposits by longwall retreat with caving technique and support resistance has evolved as the most promising and effective scientific tool to predict various aspects related to strata mechanics of such workings. Load density,height of caving block, distance of fractured zone ahead of the face, overhang of goaf and mechanical strength of the debris above and below the support base have been found to influence the magnitude of load on supports. Designing powered support has been attempted at the different countries in different methods. This paper reviews the mechanism of roof caving and the conventional approaches of caving behaviour and support resistance requirement in the context of major strata control experiences gained worldwide. The theoretical explanation of the mechanism of roof caving is still continuing with consistently improved understanding through growing field experiences in the larger domain of geo-mining conditions and state-of-art strata mechanics analysis and monitoring techniques.
文摘In order to make more available methods for natural jadeite quality evaluation,this study applied rigorous coupled wave theory to calculate and simulate the reflection characteristics of various natural jadeites,and establish evaluation standard based on the relationship between refractive index and reflectivity and responses of reflection efficiency to refractive index,grating thickness and incident angles,etc.The results suggest that reflection efficiency varies significantly as a function of the natural jadeite quality,which can provide a new method to evaluate natural jadeite.
文摘The present research intends to address in a comprehensive, transversal, and interdisciplinary manner the chronic patient management process in the research project named "PRO DOMO SUD" in order to identify operational inefficiencies, thus demonstrating that these are largely attributable to incurred costs and, thus, evaluate possible solutions for providing effective and appropriate responses by healthcare and social services. Can patients/older people be treated, monitored, and managed successfully with mobile and wearable technologies? The project involved three different groups of patients/participants: Patients with heart failure shock in "Home Monitoring Scenario"; Patients with different pathologies in "Virtual Ward Scenario"; Patients with limited mobility due to Neurological and Orthopaedic disease in "Rehabilitation Scenario". Due to the complexity of the issue, the methodological approach adopted must be multidimensional and interdisciplinary, addressing the complexity of the chronic patient from all viewpoints, not reducing it, yet analysing, understanding, rearranging, and managing it in an organic manner. The three different scenarios were allowed to identify several impacts on organizational and clinic management of chronic diseases, the tests showed significant improvements in quality of life of patients enrolled in the project. The data deriving from the three scenario demonstrate that wearable divide and ICT, in general, can empower both patients and physician personnel allowing them to be active part in the chronic disease management process. The PRO DOMO SUD experience derived from the Living Lab, this is a new paradigm for industrial research and development activities which allows the final users to actively collaborate with the designers and technicians in the development and test of new products and services aimed to them. The Living Labs stimulate social innovation by transferring research results from the closed industrial laboratory towards real life contexts where citizens and users become co-developers.
基金supported by Major Programm of Natural Science Foundation of China under Grant No.71690242the Natural Science Foundation of China under Grant No.11471252the National Social Science Fund of China under Grant No.18BTJ040
文摘In this paper, for the generalized linear models (GLMs) with diverging number of covariates, the asymptotic properties of maximum quasi-likelihood estimators (MQLEs) under some regular conditions are developed. The existence, weak convergence and the rate of convergence and asymptotic normality of linear combination of MQLEs and asymptotic distribution of single linear hypothesis teststatistics are presented. The results are illustrated by Monte-Carlo simulations.
基金supported by the National Key Basic Research Program of China(Grant Nos.2011CB933500 and 2011CB933501)the National Natural Science Foundation of China(Grant Nos.60725101 and 50872021)+3 种基金the International Cooperation Program awarded by MOST(Ministry of Science and Technology) of China(Grant No.2008DFA51180)the Natural Science Foundation of Jiangsu Province in China(Grant Nos.SBE201077305,BK2009013 and BK2009592)the Graduate Research and Innovation Program of Jiangsu Province in China(Grant No.CXZZ-0172)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘With the rapid development of nanotechnology and increasingly broad bio-application of engineered nanomaterials, their bio- hazards have become a serious public concern. It is believed that the chemical nature, particle size, morphology, and surface chemistry of nanomaterials are key parameters that influence their toxicity. Although cultured ceils have been widely used to evaluate nanomaterial toxicity, it remains unclear whether the passage of these cells affects the evaluation results. In the pre- sent study, Ba/F3 cells transfected with the BCR-ABL gene were subcultured to study the effect of passage number on cell sta- bility and their cellular responses upon exposure to nanomaterials. The results demonstrated that proliferation, cellular senes- cence, BCR-ABL gene expression, cell cycle and apoptosis were stable across multiple passages. Senescence and BCR-ABL gene expression of cells from different passage cells were unchanged when treated with silver nanoparticles (AgNPs). In addi- tion, the cells at multiple passage numbers were all arrested in the G2/M phase and apoptosis was induced by the AgNPs. These nanoparticles could enter cells via endocytosis and localize in the cndosomes, which were also not influenced by passage number. These data suggest that short-term passage would not affect cultured cell stability and toxicity assessment using these cells would be consistent when maintained appropriately.
基金the financial support by Deutscher Akademischer Austausch Dienst (DAAD)/Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) (Germany) through the Centre for Development Research (ZEF), University of Bonn (Germany)the support of Aksum University (Ethiopia) for the first author’s field work
文摘Soil degradation is a serious environmental problem in Ethiopia. However, little information is documented on indicators such as variations in soil properties across different landforms in a catchment. This study was aimed to assess soil properties and their changes across sites with different erosion statuses, and identify landscape positions that require prior management attention in the Mai-Negus catchment, northern Ethiopia. Three types of erosion-status sites(stable, eroding and aggrading) were identified using reconnaissance surveys, and then the corresponding soil samples were collected and analyzed. The major soil properties were significantly varied(P ≤ 0.05) among the three erosion-status sites. The highest soil p H, organic carbon, total nitrogen, cation exchange capacity, iron and zinc were recorded from the aggrading sites in the reservoir and valley landforms of the study catchment. A higher bulk density was generally recorded in the eroding sites, whereas a lower value was observed in the aggrading sites. The highest sand content was observed in the eroding sites of the mountain followed by the central ridge landform. The paired mean difference and the correlation matrix of most soil properties between the different erosion statuses also showed significant differences. About 95% of the erosionstatus sites were correctly classified by the discriminant function, indicating that the field survey-based classification was acceptable for decision making. On the basis of this study, suitable interventions should thus be introduced to the prioritized landforms, which are the mountain and central ridge, and eroding sites with severely degraded soil properties across the catchment.