Residual stress is one of the main factors affecting the mechanical properties of materials, such as their strength, plasticity and surface integrity. For instance, tensile stress conditions can adversely affect mater...Residual stress is one of the main factors affecting the mechanical properties of materials, such as their strength, plasticity and surface integrity. For instance, tensile stress conditions can adversely affect material performance or component life, while compressive stress conditions can improve material fatigue strength. During the processing of integrated aviation structures, machining deformation caused by residual stress has become one of the most prominent manufacturing problems. Therefore, it is very important to measure and evaluate the stress for real applications.This paper reviews the research of residual stress measurement methods over the past five years by classifying them according to the measurement methods appearing in each stage. The existing problems and difficulties of each measurement technology are summarized, and future trends are forecasted. This paper provides a reference for further in-depth study of residual stress measurement technologies.展开更多
This paper involves a series of destructive full-scale load tests on long bored piles instrumented with strain gauges along the shafts,including two compression and two tension loading tests.The load-displacement resp...This paper involves a series of destructive full-scale load tests on long bored piles instrumented with strain gauges along the shafts,including two compression and two tension loading tests.The load-displacement response,axial force,skin friction,and the thresholds of the slip displacement for fully mobilizing the skin resistances in different soils are discussed.Moreover,the theoretical solution for estimating the pile tip settlement under compression was adopted to analyze the test results.It was found that the measured skin frictions for the piles under compression were about 6% to 42% higher than the estimated values of the cone penetration tests(CPTs),whereas the measured skin frictions in the uplift cases were about 16% to 50% smaller than the estimated values.In addition,the average limited skin frictions for the tension piles were about 0.36 to 0.78 times the average ultimate skin frictions for the piles under compression.It also can be indicated that the skin friction along the pile depth approached the limited state,and decreased from a peak value with increasing loads.展开更多
Many of the sedimentary basins in western China were formed through the superposition and compounding of at least two previously developed sedimentary basins and in general they can be termed as complex superimposed b...Many of the sedimentary basins in western China were formed through the superposition and compounding of at least two previously developed sedimentary basins and in general they can be termed as complex superimposed basins. The distinct differences between these basins and monotype basins are their discontinuous stratigraphic sedimentation, stratigraphic structure and stratigraphic stress-strain action over geological history. Based on the correlation of chronological age on structural sections, superimposed basins can be divided into five types in this study： （1） continuous sedimentation type superimposed basins, （2） middle and late stratigraphic superimposed basins, （3） early and late stratigraphic superimposed basins, （4） early and middle stratigraphic superimposed basins, and （5） long-term exposed superimposed basins. Multiple source-reservoir-caprock assemblages have developed in such basins. In addition, multi-stage hydrocarbon generation and expulsion, multiple sources, polycyclic hydrocarbon accumulation and multiple-type hydrocarbon reservoirs adjustment, reformation and destruction have occurred in these basins. The complex reservoirs that have been discovered widely in the superimposed basins to date have remarkably different geologic features from primary reservoirs, and the root causes of this are folding, denudation and the fracture effect caused by multiphase tectonic events in the superimposed basins as well as associated seepage, diffusion, spilling, oxidation, degradation and cracking. Based on their genesis characteristics, complex reservoirs are divided into five categories： （1） primary reservoirs, （2） trap adjustment type reservoirs, （3） component variant reservoirs, （4） phase conversion type reservoirs and （5） scale-reformed reservoirs.展开更多
For industrial computed tomography systems, generation II scan mode has a large field of view but time consuming and generation III has a small field of view but fast. In order to realize the rapid ICT test of large ...For industrial computed tomography systems, generation II scan mode has a large field of view but time consuming and generation III has a small field of view but fast. In order to realize the rapid ICT test of large objects, a scan mode based on generation III called large field of view scan was discussed and its reconstruction algorithm based on FBP was deduced. The validity of the algorithm was verified by the results of computer simulation and experiments. Analysis showed that the effective scan field of view could be improved by more than 90% compared with that of generation III.展开更多
Airblasts,as one common phenomenon accompanied by rapid movements of landslides or rock/snow avalanches,commonly result in catastrophic damages and are attracting more and more scientific attention.To quantitatively a...Airblasts,as one common phenomenon accompanied by rapid movements of landslides or rock/snow avalanches,commonly result in catastrophic damages and are attracting more and more scientific attention.To quantitatively analyze the intensity of airblast initiated by landslides,the Wangjiayan landslide,occurred in the Wenchuan earthquake,is selected here with the landslide propagation and airblast evolution being studied using FLUENT by introducing the Voellmy rheological law.The results reveal that:(1)For the Wangjiayan landslide,its whole travelling duration is only 12 s with its maximum velocity reaching 36 m/s at t=10 s;(2)corresponding to the landslide propagation,the maximum velocity,28 m/s,of the airblast initiated by the landslide also appears at t=10 s with its maximum pressure reaching594.8 Pa,which is equivalent to violent storm;(3)under the attack of airblast,the load suffered by buildings in the airblast zone increases to 1300 Pa at t=9.4 s and sharply decreased to-7000 Pa as the rapid decrease of the velocity of the sliding mass at t=10 s,which is seriously unfavorable for buildings and might be the key reason for the destructive collapse of buildings in the airblast zone of the Wangjiayan landslide.展开更多
Measurement of residual stress is significant to ensure safety, reliability and the life of composites, and currently has been a hot issue in scientific research. The fabrication processes such as ...Measurement of residual stress is significant to ensure safety, reliability and the life of composites, and currently has been a hot issue in scientific research. The fabrication processes such as machining, and heat treatment inherit either kind of residual stress which had either positive consequences or negative ones, for example, the fatigue limit of a component enhances by compressive stress, whereas corrosion resistance gets reduced by tensile stress. This study is aimed at a brief overview of the recent advancement in this field to help researchers in the in-depth study of measuring residual stress. It helps them in selecting the most appropriate techniques among destructive methods i.e., mainly Contour, ring core, deep hole-drilling method, and non-destructive techniques i.e., diffraction, ultrasonic method, depending on their requirements and applications. For each available technique, working methodology, physical limitations, and applications are discussed. At the end of this paper, future trends regarding an assessment of residual stress have been forecasted.展开更多
A field study on the behavior of three destructive piles in soft soils subjected to axial load was presented.All the three piles with different diameters were base-grouted and installed with strain gauges along the pi...A field study on the behavior of three destructive piles in soft soils subjected to axial load was presented.All the three piles with different diameters were base-grouted and installed with strain gauges along the piles.The complete load transfer behavior of the base-grouted pile was analyzed using measured results.Moreover,the thresholds of the relative pile-soil displacement for fully mobilizing skin frictions in different soils were investigated,and pile tip displacements needed to fully mobilize tip resistances were analyzed.The results of the full-scale loading tests show that the skin frictions are close to the ultimate values when the pile-soil relative displacements are 1%-3% of pile diameter,and the pile tip displacements needed to fully mobilize the tip resistances are about 1.3%-2.0% of pile diameter.The load transmission curve of the soils around the pile tip corresponds to a softening model when the pile is loaded to failure.展开更多
The locations(longitudes and latitudes)of the tropical cyclones(TCs)making landfall on the Chinese mainland from 1949 to 2008 are investigated in detail by using ArcGis and FORTRAN routine.The southeast coastline[110 ...The locations(longitudes and latitudes)of the tropical cyclones(TCs)making landfall on the Chinese mainland from 1949 to 2008 are investigated in detail by using ArcGis and FORTRAN routine.The southeast coastline[110 to 122°E)with most landfall TCs was selected as the key region,which was divided into 12 subsections with 1°intervals of longitude.The study period was from July to September in each year.The result showed that the average sustaining time of TCs making landfall on the subsections east of 118°E is longer than those west of 118°E.Before landfall,the averaged TC intensity in the subsections east of118°E is stronger than that west of it.After landfall,however,the difference between the west and east is not significant.The index of destructive potential for the period before/after landfall was defined as TDP1/TDP2.The maximum of TDP1/TDP2 occurred in the subsection of[119,120°E)/[110,111°E).The ENSO impact on the frequency and average location of landfall TC over the whole region at 110 to 122°E is not obvious,but the effect varies with specific subsections.There is little differences of averaged TDP1 in the subsections between different phases of ENSO events,but the averaged TDP2 is larger in the warm events than that in the cold events.The rainstorm days of each station caused by TCs in different subsections were counted respectively.The results suggested that the rainstorm days of the subsections east of 118°E are much more than those west of 118°E.The larger values are primarily distributed at the subsections of[119,120°E)and[110,111°E).展开更多
This article describes the importance of detecting grain deviation caused by knots and reviews the main methods used in measuring grain orientation surrounding knots. It discusses the potential of using Diffusion Tens...This article describes the importance of detecting grain deviation caused by knots and reviews the main methods used in measuring grain orientation surrounding knots. It discusses the potential of using Diffusion Tensor Magnetic Resonance Imaging to track and map the grain deviation caused by knots.展开更多
In this study,the Radio Direction Finding method is proposed for the detection of electromagnetic signals,in the VLF band,to try to anticipate the occurrence of potentially destructive geophysical events.The experimen...In this study,the Radio Direction Finding method is proposed for the detection of electromagnetic signals,in the VLF band,to try to anticipate the occurrence of potentially destructive geophysical events.The experimentation concerns the interception of electromagnetic anomalies in Sierra Leone,in the five-day time window,associated with seismic events that could potentially generate tsunamis.The area of investigation is Sierra Leone,whose coastline is subjected to tidal wave hazards triggered by earthquakes generated in the Mid-Atlantic Ridge.Although Sierra Leone is not affected by recurrent earthquakes,there is nevertheless a low probability,estimated at 2 percent,of the occurrence of destructive earthquakes in the next 50 years.Also in estimates,the risk of rogue and potentially damaging waves is estimated to strike the Sierra Leone coast at least once in the next 10 years.The Radio Direction Finding experiment carried out continuously 24/7,has shown a close relationship between increased radio-anomalies,in the frequencies of 6,000 Hz,a time window between electromagnetic anomaly detection and the imminence of an earthquake,and higher frequency times for the risk of earthquake occurrence in the Mid-Atlantic Ridge.展开更多
目的探讨快速破坏性髋关节骨关节炎(RDHOA)是否与体重身高指数(body mass index,BMI)、骨密度(bone mineral density,BMD)有关。方法对比分析8例快速破坏性髋关节骨关节炎患者与8例健康老年人的BMI、跟骨BMD。结果快速破坏性髋关节骨关...目的探讨快速破坏性髋关节骨关节炎(RDHOA)是否与体重身高指数(body mass index,BMI)、骨密度(bone mineral density,BMD)有关。方法对比分析8例快速破坏性髋关节骨关节炎患者与8例健康老年人的BMI、跟骨BMD。结果快速破坏性髋关节骨关节炎与健康老年人的BMI、跟骨BMD数据差异无统计学意义。结论快速破坏性髋关节骨关节炎与患者的体重身高指数、骨密度无关。展开更多
The SPAD reading may be used in estimating total nitrogen content (N) in leaves and even in estimating grape yield in grapevines. The objective of this study was to estimate total N content in leaves and grape yield u...The SPAD reading may be used in estimating total nitrogen content (N) in leaves and even in estimating grape yield in grapevines. The objective of this study was to estimate total N content in leaves and grape yield using the SPAD-502 in grapevines submitted to nitrogen fertilization in soils with clayey and sandy texture. In 2008, two experiments were installed in the Southern region of Brazil. In experiment 1, Cabernet Sauvignon grapevines were planted in a soil with clayey texture and with application of 10, 20, 40 and 80 kg·N·ha-1·year-1. In experiment 2, Cabernet Sauvignon grapevines were planted in a soil with sandy texture and with the application of 0, 10, 15, 20, 40, 80 and 120 kg·N·ha-1·year-1. In the grapevines of the two experiments and during the period from 2008 to 2010, SPAD readings were made on leaves throughout the flowering period and at change in color of the berries using the portable chlorophyll meter Minolta-SPAD-502. The leaves were collected, dried, ground and submitted to analysis of the total N content. In addition, grape yield per hectare was evaluated. The SPAD-502 readings estimated the total N content in flowering and at change in color of the berries in the Cabernet Sauvignon grapevines grown on soils with clayey texture and sandy texture, especially in the first year of evaluation. However, the precision of the SPAD-502 readings is low, with there being no relationship between the SPAD-502 readings and grape yield.展开更多
This book collects Zhu Jing's 11 new short stories written in the last three years.These stories tell about the complex and destructive power in intimate relationships,as well as women's contradictions and ess...This book collects Zhu Jing's 11 new short stories written in the last three years.These stories tell about the complex and destructive power in intimate relationships,as well as women's contradictions and essential loneliness in this era as they grow up.展开更多
Olefin solution polymerization can be used to obtain high-performance polyolefin materials that cannot be obtained via other polymerization processes.Polyolefin elastomers(POE)are a typical example.Due to cost,only a ...Olefin solution polymerization can be used to obtain high-performance polyolefin materials that cannot be obtained via other polymerization processes.Polyolefin elastomers(POE)are a typical example.Due to cost,only a few linear a-olefins(e.g.,1-butene,1-hexene,and 1-octene)are used as comonomers in solution polymerization in industry.However,a-olefin comonomers with other structures may have different effects on polymerization in comparison with common linear ones.Moreover,the properties of the corresponding materials may differ significantly.In this work,copolymers of ethylene with linear and endcyclized a-olefins are synthesized using a metallocene catalyst.The copolymerization of ethylene with linear a-olefins results in a higher turn-over frequency(TOF)and lower incorporation than copolymerization with end-cyclized a-olefins,which may indicate that end-cyclized a-olefins have a higher coordination probability and lower insertion rate.In this reaction,the comonomer is distributed randomly in the polymer chain and efficiently destroys crystallization.End-cyclized a-olefins exhibit a much stronger crystallization destructive capacity(CDC)in the copolymer than linear a-olefins,possibly because linear a-olefins act mainly in the radial direction of the main chain of the polymer,while end-cyclized a-olefins act mainly in the axial direction of the main chain.展开更多
Allometric equations are important for quantifying biomass and carbon storage in terrestrial forest ecosystems.However,equations for dry deciduous woodland ecosystems,an important carbon sink in the lowland areas of E...Allometric equations are important for quantifying biomass and carbon storage in terrestrial forest ecosystems.However,equations for dry deciduous woodland ecosystems,an important carbon sink in the lowland areas of Ethiopia have not as yet been developed.This study attempts to develop and evaluate species-specific allometric equations for predicting aboveground biomass(AGB)of dominant woody species based on data from destructive sampling for Combretum collinum,Combretum molle,Combretum harotomannianum,Terminalia laxiflora and mixed-species.Diameter at breast height ranged from 5 to 30 cm.Two empirical equations were developed using DBH(Eq.1)and height(Eq.2).Equation 2 gave better AGB estimations than Eq.1.The inclusion of both DBH and H were the best estimate biometric variables for AGB.Further,the equations were evaluated and compared with common generic allometric equations.The result showed that our allometric equations are appropriate for estimating AGB.The development and application of empirical species-specific allometric equations is crucial to improve biomass and carbon stock estimation for dry woodland ecosystems.展开更多
BACKGROUND Non-secretory multiple myeloma(MM)is a rare condition that accounts for only 3%of MM cases and is defined by normal serum and urine immunofixation and a normal serum free light chain ratio.Non-secretory MM ...BACKGROUND Non-secretory multiple myeloma(MM)is a rare condition that accounts for only 3%of MM cases and is defined by normal serum and urine immunofixation and a normal serum free light chain ratio.Non-secretory MM with multiple extramedullary plasmacytomas derived from endobronchial lesions is extremely rare and can be misdiagnosed as metastasis of solid cancer.CASE SUMMARY A 36-year-old man presented with progressive facial swelling and nasal congestion with cough.Various imaging studies revealed an endobronchial mass in the left bronchus and a large left maxillary mass with multiple destructive bone metastatic lesions.He initially presented with lung cancer and multiple metastases.However,pathologic reports showed multiple extramedullary plasmacytomas in the left maxilla and the left bronchus.There was no change in the serum and urine monoclonal protein levels,and no abnormalities were observed in laboratory examinations,including hemoglobin,calcium,and creatinine levels.The bone marrow was hypercellular,with 13.49%plasma cells.The patient was diagnosed with non-secretory MM expressed as multiple extramedullary plasmacytomas with endobronchial lesions in a rare location.Radiation therapy for symptomatic lesions with high-dose dexamethasone was started,and the size of the left maxillary sinus lesion dramatically decreased.In the future,chemotherapy will be administered to control lesions in other areas.CONCLUSION We present a rare case of non-secretory MM with multiple extramedullary plasmacytoma with an endobronchial lesion.展开更多
基金the financial support from Science Challenge Project of China (No. TZ2016006-0103 and No.TZ2016006-0107-02)Liao Ning Revitalization Talents Program of China (No. XLYC1807230)+2 种基金Science Fund for Creative Research Groups of NSFC (No. 51621064)the Fundamental Research Funds for the Central Universities of China (No. DUT17RC(3)105)National Natural Science Foundation of China (No. 51975096)。
文摘Residual stress is one of the main factors affecting the mechanical properties of materials, such as their strength, plasticity and surface integrity. For instance, tensile stress conditions can adversely affect material performance or component life, while compressive stress conditions can improve material fatigue strength. During the processing of integrated aviation structures, machining deformation caused by residual stress has become one of the most prominent manufacturing problems. Therefore, it is very important to measure and evaluate the stress for real applications.This paper reviews the research of residual stress measurement methods over the past five years by classifying them according to the measurement methods appearing in each stage. The existing problems and difficulties of each measurement technology are summarized, and future trends are forecasted. This paper provides a reference for further in-depth study of residual stress measurement technologies.
基金Project(No.51078330)supported by the National Natural Science Foundation of China
文摘This paper involves a series of destructive full-scale load tests on long bored piles instrumented with strain gauges along the shafts,including two compression and two tension loading tests.The load-displacement response,axial force,skin friction,and the thresholds of the slip displacement for fully mobilizing the skin resistances in different soils are discussed.Moreover,the theoretical solution for estimating the pile tip settlement under compression was adopted to analyze the test results.It was found that the measured skin frictions for the piles under compression were about 6% to 42% higher than the estimated values of the cone penetration tests(CPTs),whereas the measured skin frictions in the uplift cases were about 16% to 50% smaller than the estimated values.In addition,the average limited skin frictions for the tension piles were about 0.36 to 0.78 times the average ultimate skin frictions for the piles under compression.It also can be indicated that the skin friction along the pile depth approached the limited state,and decreased from a peak value with increasing loads.
基金the National Key Fundamental Research Plan "973" Project(2006CB202308) for funds for this paper
文摘Many of the sedimentary basins in western China were formed through the superposition and compounding of at least two previously developed sedimentary basins and in general they can be termed as complex superimposed basins. The distinct differences between these basins and monotype basins are their discontinuous stratigraphic sedimentation, stratigraphic structure and stratigraphic stress-strain action over geological history. Based on the correlation of chronological age on structural sections, superimposed basins can be divided into five types in this study： （1） continuous sedimentation type superimposed basins, （2） middle and late stratigraphic superimposed basins, （3） early and late stratigraphic superimposed basins, （4） early and middle stratigraphic superimposed basins, and （5） long-term exposed superimposed basins. Multiple source-reservoir-caprock assemblages have developed in such basins. In addition, multi-stage hydrocarbon generation and expulsion, multiple sources, polycyclic hydrocarbon accumulation and multiple-type hydrocarbon reservoirs adjustment, reformation and destruction have occurred in these basins. The complex reservoirs that have been discovered widely in the superimposed basins to date have remarkably different geologic features from primary reservoirs, and the root causes of this are folding, denudation and the fracture effect caused by multiphase tectonic events in the superimposed basins as well as associated seepage, diffusion, spilling, oxidation, degradation and cracking. Based on their genesis characteristics, complex reservoirs are divided into five categories： （1） primary reservoirs, （2） trap adjustment type reservoirs, （3） component variant reservoirs, （4） phase conversion type reservoirs and （5） scale-reformed reservoirs.
文摘For industrial computed tomography systems, generation II scan mode has a large field of view but time consuming and generation III has a small field of view but fast. In order to realize the rapid ICT test of large objects, a scan mode based on generation III called large field of view scan was discussed and its reconstruction algorithm based on FBP was deduced. The validity of the algorithm was verified by the results of computer simulation and experiments. Analysis showed that the effective scan field of view could be improved by more than 90% compared with that of generation III.
基金supported by the National Natural Science Foundation of China(42322702,42177131)。
文摘Airblasts,as one common phenomenon accompanied by rapid movements of landslides or rock/snow avalanches,commonly result in catastrophic damages and are attracting more and more scientific attention.To quantitatively analyze the intensity of airblast initiated by landslides,the Wangjiayan landslide,occurred in the Wenchuan earthquake,is selected here with the landslide propagation and airblast evolution being studied using FLUENT by introducing the Voellmy rheological law.The results reveal that:(1)For the Wangjiayan landslide,its whole travelling duration is only 12 s with its maximum velocity reaching 36 m/s at t=10 s;(2)corresponding to the landslide propagation,the maximum velocity,28 m/s,of the airblast initiated by the landslide also appears at t=10 s with its maximum pressure reaching594.8 Pa,which is equivalent to violent storm;(3)under the attack of airblast,the load suffered by buildings in the airblast zone increases to 1300 Pa at t=9.4 s and sharply decreased to-7000 Pa as the rapid decrease of the velocity of the sliding mass at t=10 s,which is seriously unfavorable for buildings and might be the key reason for the destructive collapse of buildings in the airblast zone of the Wangjiayan landslide.
文摘Measurement of residual stress is significant to ensure safety, reliability and the life of composites, and currently has been a hot issue in scientific research. The fabrication processes such as machining, and heat treatment inherit either kind of residual stress which had either positive consequences or negative ones, for example, the fatigue limit of a component enhances by compressive stress, whereas corrosion resistance gets reduced by tensile stress. This study is aimed at a brief overview of the recent advancement in this field to help researchers in the in-depth study of measuring residual stress. It helps them in selecting the most appropriate techniques among destructive methods i.e., mainly Contour, ring core, deep hole-drilling method, and non-destructive techniques i.e., diffraction, ultrasonic method, depending on their requirements and applications. For each available technique, working methodology, physical limitations, and applications are discussed. At the end of this paper, future trends regarding an assessment of residual stress have been forecasted.
基金Project(51078330) supported by the National Natural Science Foundation of China
文摘A field study on the behavior of three destructive piles in soft soils subjected to axial load was presented.All the three piles with different diameters were base-grouted and installed with strain gauges along the piles.The complete load transfer behavior of the base-grouted pile was analyzed using measured results.Moreover,the thresholds of the relative pile-soil displacement for fully mobilizing skin frictions in different soils were investigated,and pile tip displacements needed to fully mobilize tip resistances were analyzed.The results of the full-scale loading tests show that the skin frictions are close to the ultimate values when the pile-soil relative displacements are 1%-3% of pile diameter,and the pile tip displacements needed to fully mobilize the tip resistances are about 1.3%-2.0% of pile diameter.The load transmission curve of the soils around the pile tip corresponds to a softening model when the pile is loaded to failure.
基金National Science&Technology Pillar Program during the 11th Five-Year Plan Period(2008BAK50B02)National Basic Research Program of China(973 Program:2010CB428401)
文摘The locations(longitudes and latitudes)of the tropical cyclones(TCs)making landfall on the Chinese mainland from 1949 to 2008 are investigated in detail by using ArcGis and FORTRAN routine.The southeast coastline[110 to 122°E)with most landfall TCs was selected as the key region,which was divided into 12 subsections with 1°intervals of longitude.The study period was from July to September in each year.The result showed that the average sustaining time of TCs making landfall on the subsections east of 118°E is longer than those west of 118°E.Before landfall,the averaged TC intensity in the subsections east of118°E is stronger than that west of it.After landfall,however,the difference between the west and east is not significant.The index of destructive potential for the period before/after landfall was defined as TDP1/TDP2.The maximum of TDP1/TDP2 occurred in the subsection of[119,120°E)/[110,111°E).The ENSO impact on the frequency and average location of landfall TC over the whole region at 110 to 122°E is not obvious,but the effect varies with specific subsections.There is little differences of averaged TDP1 in the subsections between different phases of ENSO events,but the averaged TDP2 is larger in the warm events than that in the cold events.The rainstorm days of each station caused by TCs in different subsections were counted respectively.The results suggested that the rainstorm days of the subsections east of 118°E are much more than those west of 118°E.The larger values are primarily distributed at the subsections of[119,120°E)and[110,111°E).
基金The support of the New Zealand Foundation for Research,Science and Technology (Contract No. C04X0705) is gratefully acknowledged
文摘This article describes the importance of detecting grain deviation caused by knots and reviews the main methods used in measuring grain orientation surrounding knots. It discusses the potential of using Diffusion Tensor Magnetic Resonance Imaging to track and map the grain deviation caused by knots.
文摘In this study,the Radio Direction Finding method is proposed for the detection of electromagnetic signals,in the VLF band,to try to anticipate the occurrence of potentially destructive geophysical events.The experimentation concerns the interception of electromagnetic anomalies in Sierra Leone,in the five-day time window,associated with seismic events that could potentially generate tsunamis.The area of investigation is Sierra Leone,whose coastline is subjected to tidal wave hazards triggered by earthquakes generated in the Mid-Atlantic Ridge.Although Sierra Leone is not affected by recurrent earthquakes,there is nevertheless a low probability,estimated at 2 percent,of the occurrence of destructive earthquakes in the next 50 years.Also in estimates,the risk of rogue and potentially damaging waves is estimated to strike the Sierra Leone coast at least once in the next 10 years.The Radio Direction Finding experiment carried out continuously 24/7,has shown a close relationship between increased radio-anomalies,in the frequencies of 6,000 Hz,a time window between electromagnetic anomaly detection and the imminence of an earthquake,and higher frequency times for the risk of earthquake occurrence in the Mid-Atlantic Ridge.
基金supported by the Ministry of Science and Technology of China(2022YFA1403901)the National Natural Science Foundation of China(11888101 and 12174428)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB28000000)the Chinese Academy of Sciences through the Youth Innovation Promotion Association(2022YSBR-048)。
文摘目的探讨快速破坏性髋关节骨关节炎(RDHOA)是否与体重身高指数(body mass index,BMI)、骨密度(bone mineral density,BMD)有关。方法对比分析8例快速破坏性髋关节骨关节炎患者与8例健康老年人的BMI、跟骨BMD。结果快速破坏性髋关节骨关节炎与健康老年人的BMI、跟骨BMD数据差异无统计学意义。结论快速破坏性髋关节骨关节炎与患者的体重身高指数、骨密度无关。
基金To the CAPES Foundation(Brazilian Federal Agency for Support and Evaluation of Graduate Education)for fi-nancing the project“Prediction of fertilization in grape-vines with the aim of quality grapes and wines in the southern region of Brazil”(National Post Doctorate Pro-gram-PNPD 2007,public notice 034/2007)and for the Post Doctorate fellowship which was granted to the first,second and fifth authorsTo Fapergs(Research Support Foundation of Rio Grande do Sul)for the financial assis-tance(Process no.0903999)To Embrapa Uva e Vinho and the Citrosul company for making vineyards available for performance of the experiments.
文摘The SPAD reading may be used in estimating total nitrogen content (N) in leaves and even in estimating grape yield in grapevines. The objective of this study was to estimate total N content in leaves and grape yield using the SPAD-502 in grapevines submitted to nitrogen fertilization in soils with clayey and sandy texture. In 2008, two experiments were installed in the Southern region of Brazil. In experiment 1, Cabernet Sauvignon grapevines were planted in a soil with clayey texture and with application of 10, 20, 40 and 80 kg·N·ha-1·year-1. In experiment 2, Cabernet Sauvignon grapevines were planted in a soil with sandy texture and with the application of 0, 10, 15, 20, 40, 80 and 120 kg·N·ha-1·year-1. In the grapevines of the two experiments and during the period from 2008 to 2010, SPAD readings were made on leaves throughout the flowering period and at change in color of the berries using the portable chlorophyll meter Minolta-SPAD-502. The leaves were collected, dried, ground and submitted to analysis of the total N content. In addition, grape yield per hectare was evaluated. The SPAD-502 readings estimated the total N content in flowering and at change in color of the berries in the Cabernet Sauvignon grapevines grown on soils with clayey texture and sandy texture, especially in the first year of evaluation. However, the precision of the SPAD-502 readings is low, with there being no relationship between the SPAD-502 readings and grape yield.
文摘This book collects Zhu Jing's 11 new short stories written in the last three years.These stories tell about the complex and destructive power in intimate relationships,as well as women's contradictions and essential loneliness in this era as they grow up.
文摘Olefin solution polymerization can be used to obtain high-performance polyolefin materials that cannot be obtained via other polymerization processes.Polyolefin elastomers(POE)are a typical example.Due to cost,only a few linear a-olefins(e.g.,1-butene,1-hexene,and 1-octene)are used as comonomers in solution polymerization in industry.However,a-olefin comonomers with other structures may have different effects on polymerization in comparison with common linear ones.Moreover,the properties of the corresponding materials may differ significantly.In this work,copolymers of ethylene with linear and endcyclized a-olefins are synthesized using a metallocene catalyst.The copolymerization of ethylene with linear a-olefins results in a higher turn-over frequency(TOF)and lower incorporation than copolymerization with end-cyclized a-olefins,which may indicate that end-cyclized a-olefins have a higher coordination probability and lower insertion rate.In this reaction,the comonomer is distributed randomly in the polymer chain and efficiently destroys crystallization.End-cyclized a-olefins exhibit a much stronger crystallization destructive capacity(CDC)in the copolymer than linear a-olefins,possibly because linear a-olefins act mainly in the radial direction of the main chain of the polymer,while end-cyclized a-olefins act mainly in the axial direction of the main chain.
文摘Allometric equations are important for quantifying biomass and carbon storage in terrestrial forest ecosystems.However,equations for dry deciduous woodland ecosystems,an important carbon sink in the lowland areas of Ethiopia have not as yet been developed.This study attempts to develop and evaluate species-specific allometric equations for predicting aboveground biomass(AGB)of dominant woody species based on data from destructive sampling for Combretum collinum,Combretum molle,Combretum harotomannianum,Terminalia laxiflora and mixed-species.Diameter at breast height ranged from 5 to 30 cm.Two empirical equations were developed using DBH(Eq.1)and height(Eq.2).Equation 2 gave better AGB estimations than Eq.1.The inclusion of both DBH and H were the best estimate biometric variables for AGB.Further,the equations were evaluated and compared with common generic allometric equations.The result showed that our allometric equations are appropriate for estimating AGB.The development and application of empirical species-specific allometric equations is crucial to improve biomass and carbon stock estimation for dry woodland ecosystems.
基金Supported by the Clinical Medicine Research Institute at Chosun University Hospital (2019)
文摘BACKGROUND Non-secretory multiple myeloma(MM)is a rare condition that accounts for only 3%of MM cases and is defined by normal serum and urine immunofixation and a normal serum free light chain ratio.Non-secretory MM with multiple extramedullary plasmacytomas derived from endobronchial lesions is extremely rare and can be misdiagnosed as metastasis of solid cancer.CASE SUMMARY A 36-year-old man presented with progressive facial swelling and nasal congestion with cough.Various imaging studies revealed an endobronchial mass in the left bronchus and a large left maxillary mass with multiple destructive bone metastatic lesions.He initially presented with lung cancer and multiple metastases.However,pathologic reports showed multiple extramedullary plasmacytomas in the left maxilla and the left bronchus.There was no change in the serum and urine monoclonal protein levels,and no abnormalities were observed in laboratory examinations,including hemoglobin,calcium,and creatinine levels.The bone marrow was hypercellular,with 13.49%plasma cells.The patient was diagnosed with non-secretory MM expressed as multiple extramedullary plasmacytomas with endobronchial lesions in a rare location.Radiation therapy for symptomatic lesions with high-dose dexamethasone was started,and the size of the left maxillary sinus lesion dramatically decreased.In the future,chemotherapy will be administered to control lesions in other areas.CONCLUSION We present a rare case of non-secretory MM with multiple extramedullary plasmacytoma with an endobronchial lesion.
