In order to optimize gob-side entry in fully-mechanized working face in moderate-thick-coal seams, we adopt a new attempt to pack roadside by pumping ordinary concrete, which is very important for the development of g...In order to optimize gob-side entry in fully-mechanized working face in moderate-thick-coal seams, we adopt a new attempt to pack roadside by pumping ordinary concrete, which is very important for the development of gob-side entry technology. The concrete has a long initial setting time and a low initial strength. So it is difficult to control the surrounding rock. In this paper, we analyze the effect of using roadside cable to reinforce supporting in gob-side entry surrounding rock controlling based on elas-tic-plastic and material mechanics knowledge. And then we propose a scheme that cable is used to reinforce roadside supporting and a single hydraulic prop is used as the temporary supporting in gob side. Using the numerical simulation software FLAC2D, we numerically simulated supporting scheme. Results of both the 2D modeling and the industrial test on No.3117 face in Jingang Mine prove that the scheme is feasible. The results show that the technology of protecting the roadway in gob-entry retained efficiently make up the deficiency of roadside packing with ordinary concrete, effectively control the roof strata and acquire a good result of retaining roadway.展开更多
The model and analysis of the cantilever beam adhesion problem under the action of electrostatic force are given. Owing to the nonlinearity of electrostatic force, the analytical solution for this kind of problem is...The model and analysis of the cantilever beam adhesion problem under the action of electrostatic force are given. Owing to the nonlinearity of electrostatic force, the analytical solution for this kind of problem is not available. In this paper, a systematic method of generating polynomials which are the exact beam solutions of the loads with di?erent distributions is provided. The polynomials are used to approximate the beam displacement due to electrostatic force. The equilibrium equation o?ers an answer to how the beam deforms but no information about the unstuck length. The derivative of the functional with respect to the unstuck length o?ers such information. But to compute the functional it is necessary to know the beam deformation. So the problem is iteratively solved until the results are converged. Galerkin and Newton-Raphson methods are used to solve this nonlinear problem. The e?ects of dielectric layer thickness and electrostatic voltage on the cantilever beam stiction are studied. The method provided in this paper exhibits good convergence. For the adhesion problem of cantilever beam without electrostatic voltage, the analytical solution is available and is also exactly matched by the computational results given by the method presented in this paper.展开更多
A single-phase full-color emitting phosphor Sr_(2)Ca_(2)La(PO_(4))_(3)O:Eu^(2+),Tb^(3+),Mn^(2+) was synthesized by the high temperature solid-state method.The phase formation,luminescence properties,thermal stability,...A single-phase full-color emitting phosphor Sr_(2)Ca_(2)La(PO_(4))_(3)O:Eu^(2+),Tb^(3+),Mn^(2+) was synthesized by the high temperature solid-state method.The phase formation,luminescence properties,thermal stability,and energy transfer from Eu^(2+)to Tb^(3+) and Eu^(2+)to Mn^(2+) in Sr_(2)Ca_(2)La(PO_(4))_(3)O were investigated in details.Tunable emission color from blue to blueish green or orange can be observed under 365 nm near-ultraviolet excitation based on the energy transfer from Eu^(2+) to Tb^(3+)or Mn^(2+) ions by varying the ratio of Eu^(2+)/Tb^(3+)or Eu^(2+)/Mn^(2+) ions.White light was obtained with chromaticity coordinates of(0.3558,0.3500)in the Sr_(2)Ca_(2)La(PO_(4))_(3)O:0.04Eu^(2+),0.08Tb^(3+),0.40Mn^(2+) phosphor,suggesting their potential applications in white light emitting diodes.展开更多
OBJECTIVE: To systematically evaluate the efficacy and safety of blood pricking and cupping in the treatment of nonspecific low back pain(NLBP).METHODS:The China National Knowledge Infrastructure Database(CNKI), Wanfa...OBJECTIVE: To systematically evaluate the efficacy and safety of blood pricking and cupping in the treatment of nonspecific low back pain(NLBP).METHODS:The China National Knowledge Infrastructure Database(CNKI), Wanfang Med Online Database(Wanfang), China Science and Technology Journal Database(VIP), Pub Med, Web of Science,EMBase, and Cochrane Library databases were searched from inception to October 31, 2021, for randomized controlled trials(RCTs) of the treatment of NLBP by blood pricking and cupping. The quality of each included study was evaluated according to the Cochrane Systematic Assessor’s Manual evaluation criteria, while the Meta-analysis was performed using RevMan 5.4software.RESULTS: A total of 13 thirteen RCTs included a total of 1088 subjects. The visual analogue scale scores indicated that blood pricking and cupping was superior to the other treatments at relieving NLBP pain [mean difference(MD) =-1.43;95% confidence interval(CI):-2.31 to 0.54;Z = 3.15;P = 0.002). The Oswestry Disability Index score of blood pricking and cupping was superior to that of the control group in terms of improving NLBP dysfunction(MD =-6.25;95%CI:-8.37 to-4.31);Z = 5.77;P < 0.000 01). 7 RCTs mentioned no adverse reactions, while one study reported mild syncope [7%(n = 3), all in the 17-30 years group] that was gradually relieved after rest. CONCLUSIONS: Blood pricking and cupping therapy can safely and effectively reduce pain and improve functional impairment in patients with NLBP. However, this study included limited high-grade studies with a small overall sample size;therefore, further high-quality large-sample RCTs are needed to improve clinical evidence.展开更多
We study the effects of electrolyte temperature on DNA molecule translocation experimentally without and with a temperature gradient across nanopore membranes.The same temperatures on both electrolyte chambers are fir...We study the effects of electrolyte temperature on DNA molecule translocation experimentally without and with a temperature gradient across nanopore membranes.The same temperatures on both electrolyte chambers are first considered.The DNA molecule translocation time is measured to be 2.44 ms at 2°C in both chambers,which is 1.57 times longer than at 20°C.Then the temperature difference effect is characterized in both chambers.The results show that the DNA translocation speed can be slowed down as long as one side temperature is lowered,irrespective of the temperature gradient direction.This indicates that the thermophoretic driving force generated by a temperature gradient has no obvious effect on the threading speed of DNA molecules,while the main reason for the slowed DNA translocation speed is the increased viscosity.Interestingly,the capture rate of DNA molecules is enhanced under a temperature gradient condition,and the capture rate during DNA translocation from hot side at 21°C to cold one at 2°C is 1.7 times larger than that under the condition of both chambers at 20°C.Finally,an optimized configuration is proposed to acquire higher capture rates and lower DNA translocation speeds.展开更多
When developing high performance lithium-ion batteries,high capacity is one of the key indicators.In the last decade,the progress of two-dimensional(2 D) materials has provided new opportunities for boosting the stora...When developing high performance lithium-ion batteries,high capacity is one of the key indicators.In the last decade,the progress of two-dimensional(2 D) materials has provided new opportunities for boosting the storage capacity.Here,based on first-principles calculation method,we predict that MnN monolayer,a recently proposed 2 D nodal-loop halfmetal containing the metallic element Mn,can be used as a super high-capacity lithium-ion batteries anode.Its theoretical capacity is above 1554 mA-h/g,more than four times that of graphite.Meanwhile,it also satisfies other requirements for a good anode material.Specifically,we demonstrate that MnN is mechanically,dynamically,and thermodynamically stable.The configurations before and after lithium adsorption exhibit good electrical conductivity.The study of Li diffusion on its surface reveals a very low diffusion barrier(~ 0.12 eV),indicating excellent rate performance.The calculated average open-circuit voltage of the corresponding half-cell at full charge is also very low(~0.22 V),which facilitates higher operating voltage.In addition,the lattice changes of the material during lithium intercalation are very small(~ 1.2%-~4.8%),which implies good cycling performance.These results suggest that 2 D MnN can be a very promising anode material for lithium-ion batteries.展开更多
In the present study, Schwann cells were isolated from the sciatic nerve of neonatal mice and purified using dispase and collagenase. Results showed that after the first round of purification with dispase, most of the...In the present study, Schwann cells were isolated from the sciatic nerve of neonatal mice and purified using dispase and collagenase. Results showed that after the first round of purification with dispase, most of the Schwann cells appeared round in shape and floated in culture solution after 15 minutes. In addition, cell yield and cell purity were higher when compared to the collagenase group. After the second round of purification, the final cell yield for the dispase group was higher than that for the collagenase group, but no significant difference was found in cell purity. Moreover, similar results in cell quantity and purity were observed in adult Sprague-Dawley rats. These findings indicate that purification with dispase can result in the rapid isolation of Schwann cells with a high yield and purity.展开更多
The purpose of this article is to identify the effect of land use pattern on rainfall runoff and runoff sediment relations in Zichang Watershed of the Loess Plateau. From 1986 to 1997, many farmlands changed into g...The purpose of this article is to identify the effect of land use pattern on rainfall runoff and runoff sediment relations in Zichang Watershed of the Loess Plateau. From 1986 to 1997, many farmlands changed into grassland or woodland, especially the farmland in steep slope positions or far away from the river. The change of land use pattern altered the rainfall runoff and runoff sediment relationships, and led to higher slope of trend curves(STCs) of annual rainfall runoff mass curve and runoff sediment mass curve in 1990s than that in 1980s. It is implied that more soil and water loss yielded in 1990s. In order to reduce soil loss, more attentions should be paid to land use pattern and some grass or other herbaceous filter strips should be built along rivers.展开更多
基金support from the National Nature Science Foundation of China (No50874124)
文摘In order to optimize gob-side entry in fully-mechanized working face in moderate-thick-coal seams, we adopt a new attempt to pack roadside by pumping ordinary concrete, which is very important for the development of gob-side entry technology. The concrete has a long initial setting time and a low initial strength. So it is difficult to control the surrounding rock. In this paper, we analyze the effect of using roadside cable to reinforce supporting in gob-side entry surrounding rock controlling based on elas-tic-plastic and material mechanics knowledge. And then we propose a scheme that cable is used to reinforce roadside supporting and a single hydraulic prop is used as the temporary supporting in gob side. Using the numerical simulation software FLAC2D, we numerically simulated supporting scheme. Results of both the 2D modeling and the industrial test on No.3117 face in Jingang Mine prove that the scheme is feasible. The results show that the technology of protecting the roadway in gob-entry retained efficiently make up the deficiency of roadside packing with ordinary concrete, effectively control the roof strata and acquire a good result of retaining roadway.
文摘The model and analysis of the cantilever beam adhesion problem under the action of electrostatic force are given. Owing to the nonlinearity of electrostatic force, the analytical solution for this kind of problem is not available. In this paper, a systematic method of generating polynomials which are the exact beam solutions of the loads with di?erent distributions is provided. The polynomials are used to approximate the beam displacement due to electrostatic force. The equilibrium equation o?ers an answer to how the beam deforms but no information about the unstuck length. The derivative of the functional with respect to the unstuck length o?ers such information. But to compute the functional it is necessary to know the beam deformation. So the problem is iteratively solved until the results are converged. Galerkin and Newton-Raphson methods are used to solve this nonlinear problem. The e?ects of dielectric layer thickness and electrostatic voltage on the cantilever beam stiction are studied. The method provided in this paper exhibits good convergence. For the adhesion problem of cantilever beam without electrostatic voltage, the analytical solution is available and is also exactly matched by the computational results given by the method presented in this paper.
基金Project supported by the Natural Science Research of Jiangsu Higher Education Institutions of China (19KJA150011,18KJB140002,17KJA460004)。
文摘A single-phase full-color emitting phosphor Sr_(2)Ca_(2)La(PO_(4))_(3)O:Eu^(2+),Tb^(3+),Mn^(2+) was synthesized by the high temperature solid-state method.The phase formation,luminescence properties,thermal stability,and energy transfer from Eu^(2+)to Tb^(3+) and Eu^(2+)to Mn^(2+) in Sr_(2)Ca_(2)La(PO_(4))_(3)O were investigated in details.Tunable emission color from blue to blueish green or orange can be observed under 365 nm near-ultraviolet excitation based on the energy transfer from Eu^(2+) to Tb^(3+)or Mn^(2+) ions by varying the ratio of Eu^(2+)/Tb^(3+)or Eu^(2+)/Mn^(2+) ions.White light was obtained with chromaticity coordinates of(0.3558,0.3500)in the Sr_(2)Ca_(2)La(PO_(4))_(3)O:0.04Eu^(2+),0.08Tb^(3+),0.40Mn^(2+) phosphor,suggesting their potential applications in white light emitting diodes.
基金Supported by the National Natural Science Foundation of China:Novel Dynamic Regulation Method of Acupoint Stimulation Based on Injectable Magnetic Gel for Myocardial Ischemia-Reperfusion Injury (No. 82074560)Effect Evaluation of Different Combinations of Acupuncture Techniques (No. 8207152951)the Shaanxi Province Innovation Capacity Support Program Project:Exploring the Mechanism of Moxibustion on Diarrheal Irritable Bowel Syndrome based on the"Intestinal Flora-Intestinal Mucosal Immunity"Pathway (No. 2020KJXX-075)。
文摘OBJECTIVE: To systematically evaluate the efficacy and safety of blood pricking and cupping in the treatment of nonspecific low back pain(NLBP).METHODS:The China National Knowledge Infrastructure Database(CNKI), Wanfang Med Online Database(Wanfang), China Science and Technology Journal Database(VIP), Pub Med, Web of Science,EMBase, and Cochrane Library databases were searched from inception to October 31, 2021, for randomized controlled trials(RCTs) of the treatment of NLBP by blood pricking and cupping. The quality of each included study was evaluated according to the Cochrane Systematic Assessor’s Manual evaluation criteria, while the Meta-analysis was performed using RevMan 5.4software.RESULTS: A total of 13 thirteen RCTs included a total of 1088 subjects. The visual analogue scale scores indicated that blood pricking and cupping was superior to the other treatments at relieving NLBP pain [mean difference(MD) =-1.43;95% confidence interval(CI):-2.31 to 0.54;Z = 3.15;P = 0.002). The Oswestry Disability Index score of blood pricking and cupping was superior to that of the control group in terms of improving NLBP dysfunction(MD =-6.25;95%CI:-8.37 to-4.31);Z = 5.77;P < 0.000 01). 7 RCTs mentioned no adverse reactions, while one study reported mild syncope [7%(n = 3), all in the 17-30 years group] that was gradually relieved after rest. CONCLUSIONS: Blood pricking and cupping therapy can safely and effectively reduce pain and improve functional impairment in patients with NLBP. However, this study included limited high-grade studies with a small overall sample size;therefore, further high-quality large-sample RCTs are needed to improve clinical evidence.
基金supported by the National Basic Research Program of China("973"Project)(Grant Nos.2011CB707601 and 2011CB707605)the National Natural Science Foundation of China(Grants Nos.50925519 and 51375092)+1 种基金supported by the Scientific Research Foundation of Graduate School of Southeast University(Grant No.YBJJ1004)supported by the Fundamental Research Funds for the Central Universities and the Innovative Project for Graduate Students of Jiangsu Province(Grant No.KYLX_0100)
文摘We study the effects of electrolyte temperature on DNA molecule translocation experimentally without and with a temperature gradient across nanopore membranes.The same temperatures on both electrolyte chambers are first considered.The DNA molecule translocation time is measured to be 2.44 ms at 2°C in both chambers,which is 1.57 times longer than at 20°C.Then the temperature difference effect is characterized in both chambers.The results show that the DNA translocation speed can be slowed down as long as one side temperature is lowered,irrespective of the temperature gradient direction.This indicates that the thermophoretic driving force generated by a temperature gradient has no obvious effect on the threading speed of DNA molecules,while the main reason for the slowed DNA translocation speed is the increased viscosity.Interestingly,the capture rate of DNA molecules is enhanced under a temperature gradient condition,and the capture rate during DNA translocation from hot side at 21°C to cold one at 2°C is 1.7 times larger than that under the condition of both chambers at 20°C.Finally,an optimized configuration is proposed to acquire higher capture rates and lower DNA translocation speeds.
基金Project supported by the Scientific Research Fund of Jiangxi Provincial Education Department,China(Grant No.GJJ190962)the National Natural Science Foundation of China(Grant Nos.11904153,51962010,61961027,12064026,and 12064014)Jiangxi Province Natural Science Foundation,China(Grant No.20202BABL211008)。
文摘When developing high performance lithium-ion batteries,high capacity is one of the key indicators.In the last decade,the progress of two-dimensional(2 D) materials has provided new opportunities for boosting the storage capacity.Here,based on first-principles calculation method,we predict that MnN monolayer,a recently proposed 2 D nodal-loop halfmetal containing the metallic element Mn,can be used as a super high-capacity lithium-ion batteries anode.Its theoretical capacity is above 1554 mA-h/g,more than four times that of graphite.Meanwhile,it also satisfies other requirements for a good anode material.Specifically,we demonstrate that MnN is mechanically,dynamically,and thermodynamically stable.The configurations before and after lithium adsorption exhibit good electrical conductivity.The study of Li diffusion on its surface reveals a very low diffusion barrier(~ 0.12 eV),indicating excellent rate performance.The calculated average open-circuit voltage of the corresponding half-cell at full charge is also very low(~0.22 V),which facilitates higher operating voltage.In addition,the lattice changes of the material during lithium intercalation are very small(~ 1.2%-~4.8%),which implies good cycling performance.These results suggest that 2 D MnN can be a very promising anode material for lithium-ion batteries.
基金supported by the National Natural Science Foundation of China, No. 30872630, 81000522 and 30973050Shanghai Shenkang Laboratory Funding, No. SHDC12007706
文摘In the present study, Schwann cells were isolated from the sciatic nerve of neonatal mice and purified using dispase and collagenase. Results showed that after the first round of purification with dispase, most of the Schwann cells appeared round in shape and floated in culture solution after 15 minutes. In addition, cell yield and cell purity were higher when compared to the collagenase group. After the second round of purification, the final cell yield for the dispase group was higher than that for the collagenase group, but no significant difference was found in cell purity. Moreover, similar results in cell quantity and purity were observed in adult Sprague-Dawley rats. These findings indicate that purification with dispase can result in the rapid isolation of Schwann cells with a high yield and purity.
文摘The purpose of this article is to identify the effect of land use pattern on rainfall runoff and runoff sediment relations in Zichang Watershed of the Loess Plateau. From 1986 to 1997, many farmlands changed into grassland or woodland, especially the farmland in steep slope positions or far away from the river. The change of land use pattern altered the rainfall runoff and runoff sediment relationships, and led to higher slope of trend curves(STCs) of annual rainfall runoff mass curve and runoff sediment mass curve in 1990s than that in 1980s. It is implied that more soil and water loss yielded in 1990s. In order to reduce soil loss, more attentions should be paid to land use pattern and some grass or other herbaceous filter strips should be built along rivers.
