1 INTRODUCTIONThe determination of the solids hold-up and local solidfluxes is of paramount importance in the study ofthe hydrodynamics of a two-phase flow.Several tech-niques have been used during the past decades(Ta...1 INTRODUCTIONThe determination of the solids hold-up and local solidfluxes is of paramount importance in the study ofthe hydrodynamics of a two-phase flow.Several tech-niques have been used during the past decades(Table1).These methods can be classified in two groups,depending on their possible disturbance of the two-展开更多
Objective To provide basis of reference values for relevant parameters of Chinese Reference Man. Methods Eighteen kinds of major organ or tissue samples, including muscle, rib, liver, and so on, were obtained from 4 a...Objective To provide basis of reference values for relevant parameters of Chinese Reference Man. Methods Eighteen kinds of major organ or tissue samples, including muscle, rib, liver, and so on, were obtained from 4 areas (Hebei, Shanxi, Jiangsu, and Sichuan provinces) with different dietary patterns in China in autopsy of 16 healthy adult men, who had just encountered sudden deaths. At the same time, whole blood samples were collected from 10 volunteers living in each of these areas. The concentrations of 56 elements in these samples were detected by using Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), and Graphite Furnace Atomic Absorption Spectrometry (GF-AAS) techniques. Based on obtained concentrations and reference values of these organ or tissue weights for Chinese Reference Man, the relative elemental burdens in these organs or tissues as well whole body were also estimated. Results The concentrations of 56 elements in 18 main organs or tissues were determined all together and their elemental organ or tissue and whole body burdens were estimated. Furthermore, the distributions of important elements for radiation protection in these organs or tissues were emphatically discussed. Conclusion By summing with past related results, the total results obtained from the series of research may provide more reliable and better representative basis of these reference values for Chinese Reference Man than before.展开更多
When gob-side entry retaining is implemented in deep coal seams threatened by rockburst, the cementbased supporting body beside roadway will bear greater roof pressure and strong impact load. Then the supporting body ...When gob-side entry retaining is implemented in deep coal seams threatened by rockburst, the cementbased supporting body beside roadway will bear greater roof pressure and strong impact load. Then the supporting body may easily deform and fail because of its low strength in the early stage. This paper established the roadside support mechanical model of gob-side entry retaining. Based on this model,we proposed and used the soft–strong supporting body as roadside support in the gob-side entry retaining. In the early stage of roof movement, the soft–strong supporting body has a better compressibility, which can not only relieve roof pressure and strong impact load, but also reduce the supporting resistance and prevent the supporting body from being crushed. In the later stage, with the increase of the strength of the supporting body, it can better support the overlying roof. The numerical simulation results and industrial test show that the soft–strong supporting body as roadside support can be better applied into the gob-side entry retaining in deep coal seams threatened by rockburst.展开更多
The properties of the low-lying states of a negative donor center trapped by a spherical quantum dot, which is subjected to a parabolic potential confinement, are investigated in the absence of magnetic field. The cal...The properties of the low-lying states of a negative donor center trapped by a spherical quantum dot, which is subjected to a parabolic potential confinement, are investigated in the absence of magnetic field. The calculations have been performed by means of the exact diagonalization of the Hamiltonian matrix within the effective-mass approximation. We find that there is only one bound state the D^- center in a spherical parabolic quantum dot in the absence of magnetic field. The binding energy of the ground state is obtained as a function of the dot size. Moreover, the critical confined potential radius value at which the negative donor center changes from unbound to bound is obtained.展开更多
Non-HFE hereditary haemochromatosis （HH） refers to a genetically heterogeneous group of iron overload disorders that are unlinked to mutations in the HFE gene. The four main types of non-HFE HH are caused by mutatio...Non-HFE hereditary haemochromatosis （HH） refers to a genetically heterogeneous group of iron overload disorders that are unlinked to mutations in the HFE gene. The four main types of non-HFE HH are caused by mutations in the hemojuvelin, hepcidin, transferrin receptor 2 and ferroportin genes. Juvenile haemochromatosis is an autosomal recessive disorder and can be caused by mutations in either hemojuvelin or hepcidin. Ar~ adult onset form of HH similar to HFE-HH is caused by homozygosity for mutations in transferrin receptor 2. The autosomal dominant iron overload disorder ferroportin disease is caused by mutations in the iron exporter ferroportin. The clinical characteristics and molecular basis of the various types of non-HFE haemochromatosis are reviewed. The study of these disorders and the molecules involved has been invaluable in improving our understanding of the mechanisms involved in the regulation of iron metabolism.展开更多
It is a commonly asked question:how big should the longwall shields be? The answer is a key aspect of a longwall mining feasibility study when the consequences of inadequately rated shields are considered.This paper a...It is a commonly asked question:how big should the longwall shields be? The answer is a key aspect of a longwall mining feasibility study when the consequences of inadequately rated shields are considered.This paper addresses this question based on the measured nature of the loading environment in which shields are required to operate,the various geological and geometrical controls of that environment and the various links between their load rating,a range of other relevant shield design factors and the loss event they are required to prevent a major roof collapse on the longwall face.The paper concludes that despite the tremendous advances that have been made in shield design and load rating over the past50 years,the same drivers that caused longwall miners of the past to seek improved roof control on the longwall face via the use of ever-higher rated shields,are still as relevant today.However at the current time,the limits of the largest available longwall shields have yet to be tested,therefore industry focus for the foreseeable future should possibly be in achieving the maximum level of roof control on the face via their optimum operational use rather than considering further shield rating increases and incurring the inevitable downsides in terms of capital cost and shield weight.展开更多
Huntsman Lake is located within the Middle Run of the Pohick Creek watershed, which is itself located within the much larger Chesapeake Bay watershed. Data collected from both the water column and the lake＇s sediment...Huntsman Lake is located within the Middle Run of the Pohick Creek watershed, which is itself located within the much larger Chesapeake Bay watershed. Data collected from both the water column and the lake＇s sediments indicate that phosphorus-rich bottom sediments are an important internal loading source, and these internal phosphorus loads would continue to adversely impact water quality until and unless sediments are removed or inactivated. The implementation of artificial circulation was anticipated to be able to increase the sequestration of phosphorus within better oxygenated bottom sediments, and was the first lake management strategy deployed in Huntsman Lake. In the first two years after the installation of a whole-lake circulation system, the lake＇s waters are no longer stratified, and the bottom waters are no longer hypoxic and/or anoxic. While there is no evidence of a subsequent reduction in concentrations of nitrogen or chlorophyll-a, average phosphorus concentrations have decreased. However, high variability in the phosphorus data decreases our confidence that this is a sustained improvement. These results are consistent with prior findings, including those from downstream systems, that the reversal of the symptoms of eutrophication can involve lag-periods up to several years, if they are successful at all.展开更多
文摘1 INTRODUCTIONThe determination of the solids hold-up and local solidfluxes is of paramount importance in the study ofthe hydrodynamics of a two-phase flow.Several tech-niques have been used during the past decades(Table1).These methods can be classified in two groups,depending on their possible disturbance of the two-
基金Supported by the National Natural Sciences Foundation of China(30370443)
文摘Objective To provide basis of reference values for relevant parameters of Chinese Reference Man. Methods Eighteen kinds of major organ or tissue samples, including muscle, rib, liver, and so on, were obtained from 4 areas (Hebei, Shanxi, Jiangsu, and Sichuan provinces) with different dietary patterns in China in autopsy of 16 healthy adult men, who had just encountered sudden deaths. At the same time, whole blood samples were collected from 10 volunteers living in each of these areas. The concentrations of 56 elements in these samples were detected by using Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), and Graphite Furnace Atomic Absorption Spectrometry (GF-AAS) techniques. Based on obtained concentrations and reference values of these organ or tissue weights for Chinese Reference Man, the relative elemental burdens in these organs or tissues as well whole body were also estimated. Results The concentrations of 56 elements in 18 main organs or tissues were determined all together and their elemental organ or tissue and whole body burdens were estimated. Furthermore, the distributions of important elements for radiation protection in these organs or tissues were emphatically discussed. Conclusion By summing with past related results, the total results obtained from the series of research may provide more reliable and better representative basis of these reference values for Chinese Reference Man than before.
基金supported by the National Basic Research Program of China (No. 2010CB226805)the Taishan Scholar Construction Project of Shandong Province, China+3 种基金the National Natural Science Foundation of China (No. 51344009)the Research Award Fund for Outstanding Young Scientists of Shandong Province (No. BS2012NJ007)the Ground Pressure and Strata Control Innovative Team Fund of SDUST (No. 2010KYTD105)the Natural Science Foundation of Shandong Province (No. ZR2012EEZ002)
文摘When gob-side entry retaining is implemented in deep coal seams threatened by rockburst, the cementbased supporting body beside roadway will bear greater roof pressure and strong impact load. Then the supporting body may easily deform and fail because of its low strength in the early stage. This paper established the roadside support mechanical model of gob-side entry retaining. Based on this model,we proposed and used the soft–strong supporting body as roadside support in the gob-side entry retaining. In the early stage of roof movement, the soft–strong supporting body has a better compressibility, which can not only relieve roof pressure and strong impact load, but also reduce the supporting resistance and prevent the supporting body from being crushed. In the later stage, with the increase of the strength of the supporting body, it can better support the overlying roof. The numerical simulation results and industrial test show that the soft–strong supporting body as roadside support can be better applied into the gob-side entry retaining in deep coal seams threatened by rockburst.
基金National Natural Science Foundation of China under Grant No.10775035
文摘The properties of the low-lying states of a negative donor center trapped by a spherical quantum dot, which is subjected to a parabolic potential confinement, are investigated in the absence of magnetic field. The calculations have been performed by means of the exact diagonalization of the Hamiltonian matrix within the effective-mass approximation. We find that there is only one bound state the D^- center in a spherical parabolic quantum dot in the absence of magnetic field. The binding energy of the ground state is obtained as a function of the dot size. Moreover, the critical confined potential radius value at which the negative donor center changes from unbound to bound is obtained.
文摘Non-HFE hereditary haemochromatosis （HH） refers to a genetically heterogeneous group of iron overload disorders that are unlinked to mutations in the HFE gene. The four main types of non-HFE HH are caused by mutations in the hemojuvelin, hepcidin, transferrin receptor 2 and ferroportin genes. Juvenile haemochromatosis is an autosomal recessive disorder and can be caused by mutations in either hemojuvelin or hepcidin. Ar~ adult onset form of HH similar to HFE-HH is caused by homozygosity for mutations in transferrin receptor 2. The autosomal dominant iron overload disorder ferroportin disease is caused by mutations in the iron exporter ferroportin. The clinical characteristics and molecular basis of the various types of non-HFE haemochromatosis are reviewed. The study of these disorders and the molecules involved has been invaluable in improving our understanding of the mechanisms involved in the regulation of iron metabolism.
文摘It is a commonly asked question:how big should the longwall shields be? The answer is a key aspect of a longwall mining feasibility study when the consequences of inadequately rated shields are considered.This paper addresses this question based on the measured nature of the loading environment in which shields are required to operate,the various geological and geometrical controls of that environment and the various links between their load rating,a range of other relevant shield design factors and the loss event they are required to prevent a major roof collapse on the longwall face.The paper concludes that despite the tremendous advances that have been made in shield design and load rating over the past50 years,the same drivers that caused longwall miners of the past to seek improved roof control on the longwall face via the use of ever-higher rated shields,are still as relevant today.However at the current time,the limits of the largest available longwall shields have yet to be tested,therefore industry focus for the foreseeable future should possibly be in achieving the maximum level of roof control on the face via their optimum operational use rather than considering further shield rating increases and incurring the inevitable downsides in terms of capital cost and shield weight.
文摘Huntsman Lake is located within the Middle Run of the Pohick Creek watershed, which is itself located within the much larger Chesapeake Bay watershed. Data collected from both the water column and the lake＇s sediments indicate that phosphorus-rich bottom sediments are an important internal loading source, and these internal phosphorus loads would continue to adversely impact water quality until and unless sediments are removed or inactivated. The implementation of artificial circulation was anticipated to be able to increase the sequestration of phosphorus within better oxygenated bottom sediments, and was the first lake management strategy deployed in Huntsman Lake. In the first two years after the installation of a whole-lake circulation system, the lake＇s waters are no longer stratified, and the bottom waters are no longer hypoxic and/or anoxic. While there is no evidence of a subsequent reduction in concentrations of nitrogen or chlorophyll-a, average phosphorus concentrations have decreased. However, high variability in the phosphorus data decreases our confidence that this is a sustained improvement. These results are consistent with prior findings, including those from downstream systems, that the reversal of the symptoms of eutrophication can involve lag-periods up to several years, if they are successful at all.
