Hydraulic-electric rock fragmentation(HERF)plays a significant role in improving the efficiency of high voltage pulse rock breaking.However,the underlying mechanism of HERF remains unclear.In this study,considering th...Hydraulic-electric rock fragmentation(HERF)plays a significant role in improving the efficiency of high voltage pulse rock breaking.However,the underlying mechanism of HERF remains unclear.In this study,considering the heterogeneity of the rock,microscopic thermodynamic properties,and shockwave time domain waveforms,based on the shockwave model,digital imaging technology and the discrete element method,the cyclic loading numerical simulations of HERF is achieved by coupling electrical,thermal,and solid mechanics under different formation temperatures,confining pressure,initial peak voltage,electrode bit diameter,and loading times.Meanwhile,the HERF discharge system is conducive to the laboratory experiments with various electrical parameters and the resulting broken pits are numerically reconstructed to obtain the geometric parameters.The results show that,the completely broken area consists of powdery rock debris.In the pre-broken zone,the mineral cementation of the rock determines the transition of type CⅠcracks to type CⅡand type CⅢcracks.Furthermore,the peak pressure of the shockwave increased with initial peak voltage but decreased with electrode bit diameter,while the wave front time reduced.Moreover,increasing well depth,formation temperature and confining pressure augment and inhibit HERF,but once confining pressure surpassed the threshold of 60 MPa for 152.40,215.90,and 228.60 mm electrode bits,and 40 MPa for 309.88 mm electrode bits,HERF is promoted.Additionally,for the same kind of rock,the volume and width of the broken pit increase with higher initial peak voltage and rock fissures will promote HERF.Eventually,the electrode drill bit with a 215.90 mm diameter is more suitable for drilling pink granite.This research contributes to a better microscopic understanding of HERF and provides valuable insights for electrode bit selection,as well as the optimization of circuit parameters for HERF technology.展开更多
Objective:To investigate the clinical efficacy of metoprolol succinate extended-release tablets in the treatment of post-myocardial infarction ventricular arrhythmias.Methods:The clinical data of 84 patients with post...Objective:To investigate the clinical efficacy of metoprolol succinate extended-release tablets in the treatment of post-myocardial infarction ventricular arrhythmias.Methods:The clinical data of 84 patients with post-myocardial infarction ventricular arrhythmia included in the study were collected and they were divided into Groups A and B with 42 cases each using the randomization method.Group A was treated with oral glucosamine hydrochloride,while Group B was administered oral metoprolol succinate extended-release tablets.Combined indicators were used to evaluate the improvement of clinical indicators,therapeutic effects,and the incidence of adverse reactions in the two groups.Results:The baseline data of the two groups of patients were not statistically significant(Pall>0.05);after treatment,the QT dispersion,corrected QT dispersion,and heart rate of Group B were lower than that of Group A(Pall=0.000<0.001);the 2 total clinical effectiveness of Group B was 95.24%,which was significantly higher than 80.95%in Group A(χ=4.087,P=0.043<0.05);the total incidence of adverse reactions in Group B was 4.76%,which was significantly lower than 219.04%in Group A(χ=4.087,P=0.043<0.05).Conclusion:In the treatment of post-myocardial infarction ventricular arrhythmia,the use of metoprolol succinate extended-release tablets can effectively correct the QT dispersion of patients,improve their heart rate,increase clinical effectiveness,and reduce the incidence of adverse reactions.展开更多
High-voltage electric pulse(HVEP)is an innovative low-energy and high-efficiency technique.However,the underlying physics of the electrical breakdown within the rock,and the coupling mechanism between the various phys...High-voltage electric pulse(HVEP)is an innovative low-energy and high-efficiency technique.However,the underlying physics of the electrical breakdown within the rock,and the coupling mechanism between the various physical fields involved in HVEP still need to be further understood.In this study,we establish a 2D numerical model of multi-physical field coupling of the electrical breakdown of porous rock with randomly distributed pores to investigate the effect of pore characteristics(porosity,pore media composition)on the partial electrical breakdown of rock(i.e.the generation of a plasma channel inside the rock).Our findings indicate that the generation of a plasma channel is directionally selective and extends in the direction of a weak electrical breakdown intensity.As the porosity of the rock increases,so does the intensity of the electric field in the‘electrical damage’region—the greater the porosity,the greater the effectiveness of rock-breaking.As the fraction of pore fluid(S_(water)/S_(air))gradually declines,the generation time of the plasma channel decreases,and the efficacy of rock-breaking by HVEP increases.In addition,in this study,we conducted an indoor experiment utilizing an electric pulse drill to break down the rock in order to recreate the growth mode of the plasma channel in the rock.Moreover,the experimental results are consistent with the simulation results.In addition,the development of this type of partial electrical breakdown is confirmed to be related to electrode polarity and pore characteristics via the experiment of the symmetrical needle-needle electrode arrangement,which further demonstrates the mechanism of partial electrical breakdown.This research is significant for comprehending the process of electric impulse rock-breaking and gives theoretical guidance and technological support for advancing electric impulse drilling technology.展开更多
The complicated geological conditions will bring great challenges to the drillstring of horizontal wells for the reason that the increase of the well depth in Sichuan-Chongqing region.Since drillstring failure and fri...The complicated geological conditions will bring great challenges to the drillstring of horizontal wells for the reason that the increase of the well depth in Sichuan-Chongqing region.Since drillstring failure and friction during drilling are generally caused by drillstring vibration,great importance must be attached to computer simulation methods for the prediction of drillstring vibration.A finite element model considering axial,lateral and torsional vibration is established.In order to verify the established numerical model,an indoor experimental device based on the similarity principle was established.The vibration characteristics of three shale gas horizontal wells drillstrings are described.The reasons for the large difference in vibration characteristics between the three wells were discussed by changing the well structure,BHA(bottom hole assembly)and drilling parameters.The simulation results show that the depth of ultra-deep well 3 is only 1.27 times of that of medium-deep well 2,but the fluctuation of WOB(weight on bit)is 2.8 times.The primary factor for the great difference of WOB fluctuation is the change of vertical section depth,the secondary factor is the change of the horizontal section length.Additionally,the reasonable range of speeds has been proposed and applied in the field.The advantage of this numerical analysis method is that it can judge the vibration and friction torque of drillstring in horizontal wells with arbitrary structure,drilling parameters and BHA.This method has certain guiding significance to the field practice.展开更多
The origin of the Ryukyu Current(RC)and the formation of its subsurface velocity core were investigated using a 23-year(1993–2015)global Hybrid Coordinate Ocean Model(HYCOM)dataset.The volume transport of the RC come...The origin of the Ryukyu Current(RC)and the formation of its subsurface velocity core were investigated using a 23-year(1993–2015)global Hybrid Coordinate Ocean Model(HYCOM)dataset.The volume transport of the RC comes from the Kuroshio eastward branch(KEB)east of Taiwan and part of the North Pacific Subtropical Gyre(p-NPSG).From the surface to 2000m depth,the KEB(p-NPSG)transport contributes 41.5%(58.5%)to the mean total RC transport.The KEB originally forms the subsurface velocity core of the RC east of Taiwan due to blockage of the subsurface Kuroshio by the Ilan Ridge(sill depth:700 m).Above 700m,the Kuroshio can enter the East China Sea(ECS)over the Ilan Ridge,meanwhile,the blocked Kuroshio below 700m turns to the right and flows along the Ryukyu Islands.With the RC flowing northeastward,the p-NPSG contribution strengthens the subsurface maximum structure of the RC owing to the blockage of the Ryukyu Ridge.In the surface layer,the p-NPSG cannot form a stable northeastward current due to frequent disturbance by mesoscale eddies and water exchange through the gaps(with net volume transport into ECS)between the Ryukyu Islands.展开更多
Objective Clinical immunohistochemistry plays an increasingly important role in pathologic diagnosis. We investigated the usefulness of an immunohistochemical panel of glypican-3 (GPC3), hepatocyte paraffin antigen-1 ...Objective Clinical immunohistochemistry plays an increasingly important role in pathologic diagnosis. We investigated the usefulness of an immunohistochemical panel of glypican-3 (GPC3), hepatocyte paraffin antigen-1 (HepPar-1), arginase-1 (Arg-1), cytokeratin-19 (CK19), and human epithelial membrane antigen (EMA) for the differential diagnosis of liver tumors. Methods Two hundred and thirty-five immunohistochemical sections of hepatocellular carcinoma (HCC;120 cases), intrahepatic cholangiocarcinoma (ICC;50 cases), combined hepatocellular and cholangiocarcinoma (CHC;17 cases), metastatic adenocarcinoma (20 cases), and benign liver lesions (28 cases) were obtained from the Department of Pathology at Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China. The sensitivity and specificity of the combined biomarkers GPC3/HepPar-1/Arg-1/CK19/EMA for the differential diagnosis of HCC, ICC, and CHC were calculated and analyzed retrospectively. Results The combined biomarkers GPC3+/CK19– had the highest specificity (98.3%) for diagnosing HCC, with a sensitivity of 60.0%. The specificity of GPC3–/HepPar-1–/Arg-1–/CK19+/EMA+ for diagnosing ICC was 93.0%, with a sensitivity of 76.0%. The specificity of GPC3+/HepPar-1+/Arg-1+/CK19+/EMA+ for diagnosing CHC was 95.9%, with a sensitivity of 52.9%. Conclusion The combined biomarkers GPC3/HepPar-1/Arg-1/CK19/EMA greatly improved the specificity of liver tumor diagnosis. We believe that clinical pathological work could improve the original determination of liver nodules.展开更多
In this study, the short-term offshore extension of Brahmaputra-Ganges(BG) and Irrawaddy freshwater plumes to the central northern Bay of Bengal(BoB) was investigated based on in situ and satellite observations. In th...In this study, the short-term offshore extension of Brahmaputra-Ganges(BG) and Irrawaddy freshwater plumes to the central northern Bay of Bengal(BoB) was investigated based on in situ and satellite observations. In the summer and winter of 2015, two significant freshening events with periods of weeks were observed from a moored buoy at 15°N, 90°E in the BoB. Soil Moisture Active Passive(SMAP) satellite sea surface salinity compares well with the in situ data and shows that these freshening events are directly related to the short-term offshore extension of the BG and Irrawaddy freshwater, respectively. These data combined with the altimeter sea level anomaly data show that the offshore extending plumes result from freshwater modulated by eddies. During summer, the BG freshwater is modulated by a combination of three closely located eddies: a large anticyclonic eddy(ACE) off the northwestern BoB coast and two cyclonic eddies in the northern BoB. Consequently, the freshwater extends offshore from the river mouth and forms a long and narrow tongue-shaped plume extending southwestward to the central BoB. During winter, the Irrawaddy freshwater is modulated by two continuous ACEs evolved from Rossby wave propagating westward from the Irrawaddy Delta off Myanmar, forming a tongueshaped plume extending to the central BoB. Strong salinity fronts are formed along the boundaries of these tongue-shaped plumes. These findings confirm good capability of the SMAP data to investigate the short-term offshore extension of the BG and Irrawaddy freshwater. This study provides direct evidences of the pathways of the offshore extension of the BG and Irrawaddy freshwater and highlights the role of eddies in the northern BoB freshwater plume variability.展开更多
We report the first near real-time inverted echo sounder(IES)observation in the South China Sea(Fig.1).Although the first IES observation in the South China Sea was in 2005,and the near real-time IES observation modul...We report the first near real-time inverted echo sounder(IES)observation in the South China Sea(Fig.1).Although the first IES observation in the South China Sea was in 2005,and the near real-time IES observation module was first developed in 2012(http://www.po.gso.uri.edu/dynamics/IES/hist.html),the real-time IES has never been deployed in the South China Sea until the reporting of observations in this study.IES is a bottom-mounted mooring that records the round-trip acoustic travel time from the bottom to the surface and back(τ).展开更多
With the development of the greenhouse grape cultivation area,the supporting greenhouse grape varieties appear to be single.At present,there are few researches on the selection of grape varieties suitable for two-harv...With the development of the greenhouse grape cultivation area,the supporting greenhouse grape varieties appear to be single.At present,there are few researches on the selection of grape varieties suitable for two-harvest-a-year cultivation in greenhouses.In order to meet the needs of fruit growers for the diversity of greenhouse grape varieties,experimental studies had been carried out.Through three consecutive years of two-harvest-a-year production of six grape varieties of‘Jingxiangyu’,‘Ruidukemei’,‘Xiangfei’,‘Jingyan’,‘Zaomanao’and‘Hanxiangmi’,the first crop of greenhouse grapes matured from May to July,and the second crop matured during the New Year s Day and Spring Festival.Through the investigation and analysis of their phenological periods,fruit economic characteristics and economic benefits,it was found that the four varieties of‘Jingxiangyu’,‘Ruidukemei’,‘Xiangfei’and‘Jingyan’performed well under greenhouse cultivation conditions,and thus can be used as supporting fine varieties for large-scale promotion.展开更多
A novel voltammetric sensor based on gold nanoparticles (GNPs) and single-walled carbon nanotubes (SWNTs) composite was developed. The nanocomposite modified electrode was characterized using atoms force microscope (A...A novel voltammetric sensor based on gold nanoparticles (GNPs) and single-walled carbon nanotubes (SWNTs) composite was developed. The nanocomposite modified electrode was characterized using atoms force microscope (AFM). The electrochemical behavior of meclofenoxate hydrochloride (MFX) was investigated on this sensor. The results indicated that the GNPs/SWNTs modified electrode exhibited efficient electrocatalytic oxidation for MFX with relatively high sensitivity, and stability. Using square wave voltammetry (SWV), the GNPs/SWNTs modified electrode exhibited a linear voltammetric response for MFX in the concentration range of 5.0 × 10–7 – 2.0 × 10–5mol·L–1, with the limit of detection (LOD) of 1.0 × 10–7 mol·L–1. The sensor was applied to determine MFX in finished drug with a satisfactory result.展开更多
As Internet technology progresses rapidly,the development of new media has become an important factor affecting the socialization process of college students.It is favoured by students because of its unique value in t...As Internet technology progresses rapidly,the development of new media has become an important factor affecting the socialization process of college students.It is favoured by students because of its unique value in the content,form,speed,and effect of communication.New media technology is a double-edged sword,which not only provides a colourful learning and living environment for college students but also impacts the socialization process of college students with its unique charm.In the process of socialization of college students,it not only has a positive impact but also has a negative impact.With the rapid development of mobile terminal technology,WeChat,Microblog,Tik Tok,KuaiShou and other new media applications are increasingly becoming a social factor,which influences the development of college students’moral cognition,values,social communication and personality characteristics.They have changed the way college students’study,life,communication,and thinking.As an important base of college students’education,schools should actively explore countermeasures to promote the benign development of college students’socialization.展开更多
Food systems are already a major contributor to land degradation,and changes in global diets will exacerbate this situation[1].Population growth and affluent dietary patterns result in changes in land demand and land-...Food systems are already a major contributor to land degradation,and changes in global diets will exacerbate this situation[1].Population growth and affluent dietary patterns result in changes in land demand and land-use patterns,and up to 40% of global arable land and more than 30% of global food-crop production are used for animal feed[2].Furthermore,food-feed competition can result in an inadequate food supply[3].展开更多
Acute kidney injury(AKI)leads to unacceptably high mortality due to difficulties in timely intervention and less efficient renal delivery of therapeutic drugs.Here,a series of polyvinylpyrrolidone(PVP)-curcumin nanopa...Acute kidney injury(AKI)leads to unacceptably high mortality due to difficulties in timely intervention and less efficient renal delivery of therapeutic drugs.Here,a series of polyvinylpyrrolidone(PVP)-curcumin nanoparticles(PCurNP)are designed to meet the renal excretion threshold(~45 kDa),presenting a controllable delivery nanosystem for kidney targeting.Renal accumulation of the relatively small nanoparticles,^(89)Zr-PCurNP M10 with the diameter between 5 and 8 nm,is found to be 1.7 times and 1.8 times higher than the accumulation of^(89)Zr-PCurNP M29(20-50 nm)and M40(20-50 nm)as revealed by PET imaging.Furthermore,serum creatinine analysis,kidney tissues histology,and tubular injury scores revealed that PCurNP M10 efficiently treated cisplatin-induced AKI.Herein,PCurNP offers a novel and simple strategy for precise PET image-guided drug delivery of renal protective materials.展开更多
Stevens-Johnson syndrome(SJS)and toxic epidermal necrolysis(TEN)are rare but severe diseases.This study aimed to validate the predictive ability of risk models in patients with SJS/TEN and propose possible refinement ...Stevens-Johnson syndrome(SJS)and toxic epidermal necrolysis(TEN)are rare but severe diseases.This study aimed to validate the predictive ability of risk models in patients with SJS/TEN and propose possible refinement in China.Patients in the Department of Dermatology of Huashan Hospital from January 2008 to January 2019 were included.Results showed that the severity-of-illness score for TEN(SCORTEN)had a good discrimination(area under the receiver operating characteristic curve(AUC),0.78),and it was superior to auxiliary score(AS)and ABCD-10,which indicates age,bicarbonate level,cancer,dialysis,and 10%involved body surface area(AUC,0.69 and 0.68,respectively).The calibration of SCORTEN(Hosmer-Lemeshow goodness-of-fit test,P=0.69)was also better than that of AS(P=0.25)and ABCD-10(P=0.55).SCORTEN and ABCD-10 were similar(Brier score(BS),0.04 and 0.04)in terms of accuracy of predictions.In addition,the imaging appearance of pulmonary consolidation on computed tomography was associated with high mortality.Refined models were formed using the variables and this imaging appearance.The refined AS and ABCD-10 models were similar in discrimination compared with the original SCORTEN(0.74 vs.0.78,P=0.23;0.74 vs.0.78,P=0.30,respectively).Therefore,SCORTEN showed good discrimination performance,calibration,and accuracy,and refined AS or ABCD-10 model may be an option when SCORTEN variables are not available.展开更多
Double shoulder drill pipe joint(DSJ)is a novel thread structure which appears in recent years.Its strength reduced efficiently while the structure design is not appropriately,for the DSJ’s mechanical behaviors weren...Double shoulder drill pipe joint(DSJ)is a novel thread structure which appears in recent years.Its strength reduced efficiently while the structure design is not appropriately,for the DSJ’s mechanical behaviors weren’t well studied.In this paper a 3D whole structure finite element model of DSJ was established based on the Principle of Virtual Work,and validated the model’s computing results by experimental results.The authors analyzed the stress and strain distribution with the 3D whole structure finite element model’s computing results under torque moment,compression force,tension load,and bend moment.And then acquired the DSJ’s mechanical behaviors under each load.The research works of this paper refer accordance to recognize and design the DSJ.展开更多
Cu-based metal organic frameworks(MOFs)are regarded as promising sensing materials,which have abundant metal sites,large surface area and simple synthesis processes.In this work,a novel three-dimensional flower-like C...Cu-based metal organic frameworks(MOFs)are regarded as promising sensing materials,which have abundant metal sites,large surface area and simple synthesis processes.In this work,a novel three-dimensional flower-like Cu-MOF was synthesized,which was combined with ultra-thin MXene nanosheets to construct a novel electrochemical sensor for H_(2)O_(2).展开更多
Stick-slip vibration presents one of the major causes of drilling problems,such as premature tool failures,low drilling efficiency and poor wellbore quality.The objective of this work is to investigate the influences ...Stick-slip vibration presents one of the major causes of drilling problems,such as premature tool failures,low drilling efficiency and poor wellbore quality.The objective of this work is to investigate the influences of rotary table speed(RTS)on stick-slip phenomenon of the drilling system.In this study,the drilling system is treated as a lumped torsional pendulum model of which the bit/rock interaction is regarded as Coulomb friction.By analyzing cases with different RTS,two types of vibrations on the bit are found:stick-slip vibration and uniform motion.With an increase in the RTS,the stick-slip vibration on the drill bit disappears once the RTS arrives at its critical value.For the cases that stick-slip vibrations occur,the phase trajectories converge toward a limit cycle.For the cases that stick-slip vibration does not appear,the drill bit tends to stabilize at a uniform motion and the phase trajectories correspond to contracting spirals observed in the phase plane.展开更多
Graphene （G） was prepared by reducing graphene oxide （GO） with hydrazine hydrate. SnO-graphene com- posites with different amounts of graphene were prepared via hydrothermal method. SnO-G composites were character...Graphene （G） was prepared by reducing graphene oxide （GO） with hydrazine hydrate. SnO-graphene com- posites with different amounts of graphene were prepared via hydrothermal method. SnO-G composites were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The effects of the graphene content in the composites and the hydrothermal temperature on the gas-sensing re- sponses of the materials to formaldehyde vapor were investigated. The gas-sensing selectivity of the sensor based on SnO-1% G （100 ℃, 10 h） composite to five kinds of gases （1000 × 10^-6） was also studied. The results revealed that the sensor based on SnO-1% G （100 ℃, 10 h） exhibited high response to formal- dehyde vapor when the operating temperature of the sensor was 133 ℃ and the response to 0.001 × 10^-6 formaldehyde attained 3.9. The response time and recovery time for 0.001 × 10^-6 formaldehyde were 24 and 12 s, respectively.展开更多
In this paper,we prove the existence of solutions to the Fu-Yau equation on com-pact Kähler manifolds.As an application,we give a class of non-trivial solutions of the modified Strominger system.
基金supported by the National Natural Science Foundation of China(Nos.52034006,52004229,52225401,and 52274231)the Regional Innovation Cooperation Project of Sichuan Province(No.2022YFQ0059)+3 种基金Science and Technology Cooperation Project of the CNPC-SWPU Innovation Alliance(No.2020CX040301)Natural Science Foundation of Sichuan Province(No.2023NSFSC0431)Science and Technology Strategic Cooperation Project between Nanchong City and Southwest Petroleum University(No.SXHZ004)Research and innovation Fund for Graduate Students of Southwest Petroleum University(No.2022KYCX058).
文摘Hydraulic-electric rock fragmentation(HERF)plays a significant role in improving the efficiency of high voltage pulse rock breaking.However,the underlying mechanism of HERF remains unclear.In this study,considering the heterogeneity of the rock,microscopic thermodynamic properties,and shockwave time domain waveforms,based on the shockwave model,digital imaging technology and the discrete element method,the cyclic loading numerical simulations of HERF is achieved by coupling electrical,thermal,and solid mechanics under different formation temperatures,confining pressure,initial peak voltage,electrode bit diameter,and loading times.Meanwhile,the HERF discharge system is conducive to the laboratory experiments with various electrical parameters and the resulting broken pits are numerically reconstructed to obtain the geometric parameters.The results show that,the completely broken area consists of powdery rock debris.In the pre-broken zone,the mineral cementation of the rock determines the transition of type CⅠcracks to type CⅡand type CⅢcracks.Furthermore,the peak pressure of the shockwave increased with initial peak voltage but decreased with electrode bit diameter,while the wave front time reduced.Moreover,increasing well depth,formation temperature and confining pressure augment and inhibit HERF,but once confining pressure surpassed the threshold of 60 MPa for 152.40,215.90,and 228.60 mm electrode bits,and 40 MPa for 309.88 mm electrode bits,HERF is promoted.Additionally,for the same kind of rock,the volume and width of the broken pit increase with higher initial peak voltage and rock fissures will promote HERF.Eventually,the electrode drill bit with a 215.90 mm diameter is more suitable for drilling pink granite.This research contributes to a better microscopic understanding of HERF and provides valuable insights for electrode bit selection,as well as the optimization of circuit parameters for HERF technology.
文摘Objective:To investigate the clinical efficacy of metoprolol succinate extended-release tablets in the treatment of post-myocardial infarction ventricular arrhythmias.Methods:The clinical data of 84 patients with post-myocardial infarction ventricular arrhythmia included in the study were collected and they were divided into Groups A and B with 42 cases each using the randomization method.Group A was treated with oral glucosamine hydrochloride,while Group B was administered oral metoprolol succinate extended-release tablets.Combined indicators were used to evaluate the improvement of clinical indicators,therapeutic effects,and the incidence of adverse reactions in the two groups.Results:The baseline data of the two groups of patients were not statistically significant(Pall>0.05);after treatment,the QT dispersion,corrected QT dispersion,and heart rate of Group B were lower than that of Group A(Pall=0.000<0.001);the 2 total clinical effectiveness of Group B was 95.24%,which was significantly higher than 80.95%in Group A(χ=4.087,P=0.043<0.05);the total incidence of adverse reactions in Group B was 4.76%,which was significantly lower than 219.04%in Group A(χ=4.087,P=0.043<0.05).Conclusion:In the treatment of post-myocardial infarction ventricular arrhythmia,the use of metoprolol succinate extended-release tablets can effectively correct the QT dispersion of patients,improve their heart rate,increase clinical effectiveness,and reduce the incidence of adverse reactions.
基金supported by National Natural Science Foundation of China(Nos.52034006,52004229,52225401 and52274231)Regional Innovation Cooperation Project of Sichuan Province(No.2022YFQ0059)+1 种基金Natural Science Foundation of Sichuan Province(No.23NSFSC2099)Science and Technology Strategic Cooperation Project between Nanchong City and Southwest Petroleum University(No.SXHZ004)。
文摘High-voltage electric pulse(HVEP)is an innovative low-energy and high-efficiency technique.However,the underlying physics of the electrical breakdown within the rock,and the coupling mechanism between the various physical fields involved in HVEP still need to be further understood.In this study,we establish a 2D numerical model of multi-physical field coupling of the electrical breakdown of porous rock with randomly distributed pores to investigate the effect of pore characteristics(porosity,pore media composition)on the partial electrical breakdown of rock(i.e.the generation of a plasma channel inside the rock).Our findings indicate that the generation of a plasma channel is directionally selective and extends in the direction of a weak electrical breakdown intensity.As the porosity of the rock increases,so does the intensity of the electric field in the‘electrical damage’region—the greater the porosity,the greater the effectiveness of rock-breaking.As the fraction of pore fluid(S_(water)/S_(air))gradually declines,the generation time of the plasma channel decreases,and the efficacy of rock-breaking by HVEP increases.In addition,in this study,we conducted an indoor experiment utilizing an electric pulse drill to break down the rock in order to recreate the growth mode of the plasma channel in the rock.Moreover,the experimental results are consistent with the simulation results.In addition,the development of this type of partial electrical breakdown is confirmed to be related to electrode polarity and pore characteristics via the experiment of the symmetrical needle-needle electrode arrangement,which further demonstrates the mechanism of partial electrical breakdown.This research is significant for comprehending the process of electric impulse rock-breaking and gives theoretical guidance and technological support for advancing electric impulse drilling technology.
文摘The complicated geological conditions will bring great challenges to the drillstring of horizontal wells for the reason that the increase of the well depth in Sichuan-Chongqing region.Since drillstring failure and friction during drilling are generally caused by drillstring vibration,great importance must be attached to computer simulation methods for the prediction of drillstring vibration.A finite element model considering axial,lateral and torsional vibration is established.In order to verify the established numerical model,an indoor experimental device based on the similarity principle was established.The vibration characteristics of three shale gas horizontal wells drillstrings are described.The reasons for the large difference in vibration characteristics between the three wells were discussed by changing the well structure,BHA(bottom hole assembly)and drilling parameters.The simulation results show that the depth of ultra-deep well 3 is only 1.27 times of that of medium-deep well 2,but the fluctuation of WOB(weight on bit)is 2.8 times.The primary factor for the great difference of WOB fluctuation is the change of vertical section depth,the secondary factor is the change of the horizontal section length.Additionally,the reasonable range of speeds has been proposed and applied in the field.The advantage of this numerical analysis method is that it can judge the vibration and friction torque of drillstring in horizontal wells with arbitrary structure,drilling parameters and BHA.This method has certain guiding significance to the field practice.
基金The National Natural Science Foundation of China under contract Nos 41576001,41920104006,41776107,41906023,41621064,41476020 and 41606113the Scientific Research Fund of SIO under contract Nos JG1626,JG1621 and JT1604+2 种基金the Project of State Key Laboratory of Satellite Ocean Environment Dynamics,SIO under contract Nos SOEDZZ1901,SOEDZZ1804 and SOEDZZ1806the National Programme on Global Change and Air-sea Interaction under contract No.GASI-IPOVAI-01-02the Zhejiang Provincial Natural Science Foundation of China under contract No.LQ17D060003
文摘The origin of the Ryukyu Current(RC)and the formation of its subsurface velocity core were investigated using a 23-year(1993–2015)global Hybrid Coordinate Ocean Model(HYCOM)dataset.The volume transport of the RC comes from the Kuroshio eastward branch(KEB)east of Taiwan and part of the North Pacific Subtropical Gyre(p-NPSG).From the surface to 2000m depth,the KEB(p-NPSG)transport contributes 41.5%(58.5%)to the mean total RC transport.The KEB originally forms the subsurface velocity core of the RC east of Taiwan due to blockage of the subsurface Kuroshio by the Ilan Ridge(sill depth:700 m).Above 700m,the Kuroshio can enter the East China Sea(ECS)over the Ilan Ridge,meanwhile,the blocked Kuroshio below 700m turns to the right and flows along the Ryukyu Islands.With the RC flowing northeastward,the p-NPSG contribution strengthens the subsurface maximum structure of the RC owing to the blockage of the Ryukyu Ridge.In the surface layer,the p-NPSG cannot form a stable northeastward current due to frequent disturbance by mesoscale eddies and water exchange through the gaps(with net volume transport into ECS)between the Ryukyu Islands.
基金Supported by grants from National Natural Science Foundation of China(NSFC No.81271600,81671718 and 81873903)+1 种基金the Natural Science Foundation of Hubei Province in China(No.2016CFB687)the Clinical Foundation of Tongji Hospital(No.2015C013)
文摘Objective Clinical immunohistochemistry plays an increasingly important role in pathologic diagnosis. We investigated the usefulness of an immunohistochemical panel of glypican-3 (GPC3), hepatocyte paraffin antigen-1 (HepPar-1), arginase-1 (Arg-1), cytokeratin-19 (CK19), and human epithelial membrane antigen (EMA) for the differential diagnosis of liver tumors. Methods Two hundred and thirty-five immunohistochemical sections of hepatocellular carcinoma (HCC;120 cases), intrahepatic cholangiocarcinoma (ICC;50 cases), combined hepatocellular and cholangiocarcinoma (CHC;17 cases), metastatic adenocarcinoma (20 cases), and benign liver lesions (28 cases) were obtained from the Department of Pathology at Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China. The sensitivity and specificity of the combined biomarkers GPC3/HepPar-1/Arg-1/CK19/EMA for the differential diagnosis of HCC, ICC, and CHC were calculated and analyzed retrospectively. Results The combined biomarkers GPC3+/CK19– had the highest specificity (98.3%) for diagnosing HCC, with a sensitivity of 60.0%. The specificity of GPC3–/HepPar-1–/Arg-1–/CK19+/EMA+ for diagnosing ICC was 93.0%, with a sensitivity of 76.0%. The specificity of GPC3+/HepPar-1+/Arg-1+/CK19+/EMA+ for diagnosing CHC was 95.9%, with a sensitivity of 52.9%. Conclusion The combined biomarkers GPC3/HepPar-1/Arg-1/CK19/EMA greatly improved the specificity of liver tumor diagnosis. We believe that clinical pathological work could improve the original determination of liver nodules.
基金The National Natural Science Foundation of China under contract Nos 41920104006 and 41776107the Key Program of the National Natural Science Foundation of China under contract No. 91647209+4 种基金the Key Special Program on the Science and Technology of Zhejiang Province under contract No. 2015C03015the Scientific Research Fund of SIO under contract Nos JZ2001 and JT1801the Scientific Research Fund of the State Key Laboratory of Satellite Ocean Environment Dynamics,SIO under contract No.SOEDZZ2106the Open Fund of State Key Laboratory of Satellite Ocean Environment Dynamics,Second Institute of OceanographyMNR under contract No. QNHX2114。
文摘In this study, the short-term offshore extension of Brahmaputra-Ganges(BG) and Irrawaddy freshwater plumes to the central northern Bay of Bengal(BoB) was investigated based on in situ and satellite observations. In the summer and winter of 2015, two significant freshening events with periods of weeks were observed from a moored buoy at 15°N, 90°E in the BoB. Soil Moisture Active Passive(SMAP) satellite sea surface salinity compares well with the in situ data and shows that these freshening events are directly related to the short-term offshore extension of the BG and Irrawaddy freshwater, respectively. These data combined with the altimeter sea level anomaly data show that the offshore extending plumes result from freshwater modulated by eddies. During summer, the BG freshwater is modulated by a combination of three closely located eddies: a large anticyclonic eddy(ACE) off the northwestern BoB coast and two cyclonic eddies in the northern BoB. Consequently, the freshwater extends offshore from the river mouth and forms a long and narrow tongue-shaped plume extending southwestward to the central BoB. During winter, the Irrawaddy freshwater is modulated by two continuous ACEs evolved from Rossby wave propagating westward from the Irrawaddy Delta off Myanmar, forming a tongueshaped plume extending to the central BoB. Strong salinity fronts are formed along the boundaries of these tongue-shaped plumes. These findings confirm good capability of the SMAP data to investigate the short-term offshore extension of the BG and Irrawaddy freshwater. This study provides direct evidences of the pathways of the offshore extension of the BG and Irrawaddy freshwater and highlights the role of eddies in the northern BoB freshwater plume variability.
基金The Scientific Research Fund of Second Institute of Oceanography,MNR,under contract Nos QNYC2102,JZ2001 and JT1801the National Natural Science Foundation of China under contract Nos 41920104006,41906023,41806020,41776107,41906024 and 41976001the Project of State Key Laboratory of Satellite Ocean Environment Dynamics,SIO,under contract No.SOEDZZ2106。
文摘We report the first near real-time inverted echo sounder(IES)observation in the South China Sea(Fig.1).Although the first IES observation in the South China Sea was in 2005,and the near real-time IES observation module was first developed in 2012(http://www.po.gso.uri.edu/dynamics/IES/hist.html),the real-time IES has never been deployed in the South China Sea until the reporting of observations in this study.IES is a bottom-mounted mooring that records the round-trip acoustic travel time from the bottom to the surface and back(τ).
基金Excellent Talent Training Fund in Yanqing District,BeijingJinqiao Seed Project in Yanqing District,BeijingOrdos Science and Technology Program.
文摘With the development of the greenhouse grape cultivation area,the supporting greenhouse grape varieties appear to be single.At present,there are few researches on the selection of grape varieties suitable for two-harvest-a-year cultivation in greenhouses.In order to meet the needs of fruit growers for the diversity of greenhouse grape varieties,experimental studies had been carried out.Through three consecutive years of two-harvest-a-year production of six grape varieties of‘Jingxiangyu’,‘Ruidukemei’,‘Xiangfei’,‘Jingyan’,‘Zaomanao’and‘Hanxiangmi’,the first crop of greenhouse grapes matured from May to July,and the second crop matured during the New Year s Day and Spring Festival.Through the investigation and analysis of their phenological periods,fruit economic characteristics and economic benefits,it was found that the four varieties of‘Jingxiangyu’,‘Ruidukemei’,‘Xiangfei’and‘Jingyan’performed well under greenhouse cultivation conditions,and thus can be used as supporting fine varieties for large-scale promotion.
文摘A novel voltammetric sensor based on gold nanoparticles (GNPs) and single-walled carbon nanotubes (SWNTs) composite was developed. The nanocomposite modified electrode was characterized using atoms force microscope (AFM). The electrochemical behavior of meclofenoxate hydrochloride (MFX) was investigated on this sensor. The results indicated that the GNPs/SWNTs modified electrode exhibited efficient electrocatalytic oxidation for MFX with relatively high sensitivity, and stability. Using square wave voltammetry (SWV), the GNPs/SWNTs modified electrode exhibited a linear voltammetric response for MFX in the concentration range of 5.0 × 10–7 – 2.0 × 10–5mol·L–1, with the limit of detection (LOD) of 1.0 × 10–7 mol·L–1. The sensor was applied to determine MFX in finished drug with a satisfactory result.
文摘As Internet technology progresses rapidly,the development of new media has become an important factor affecting the socialization process of college students.It is favoured by students because of its unique value in the content,form,speed,and effect of communication.New media technology is a double-edged sword,which not only provides a colourful learning and living environment for college students but also impacts the socialization process of college students with its unique charm.In the process of socialization of college students,it not only has a positive impact but also has a negative impact.With the rapid development of mobile terminal technology,WeChat,Microblog,Tik Tok,KuaiShou and other new media applications are increasingly becoming a social factor,which influences the development of college students’moral cognition,values,social communication and personality characteristics.They have changed the way college students’study,life,communication,and thinking.As an important base of college students’education,schools should actively explore countermeasures to promote the benign development of college students’socialization.
基金supported by the National Natural Science Foundation of China(42171230)。
文摘Food systems are already a major contributor to land degradation,and changes in global diets will exacerbate this situation[1].Population growth and affluent dietary patterns result in changes in land demand and land-use patterns,and up to 40% of global arable land and more than 30% of global food-crop production are used for animal feed[2].Furthermore,food-feed competition can result in an inadequate food supply[3].
基金supported by the National Natural Science Foundation of China(81601605,21571147,82102121)the Postdoctoral Science Foundation of China(2016M600670)+2 种基金supported by the University of Wisconsin–Madison,the National Institutes of Health(NIBIB/NCI P30CA014520)the Natural Science Foundation of SZU(Grant No.827-000143)the Shenzhen Peacock Plan(KQTD2016053112051497).
文摘Acute kidney injury(AKI)leads to unacceptably high mortality due to difficulties in timely intervention and less efficient renal delivery of therapeutic drugs.Here,a series of polyvinylpyrrolidone(PVP)-curcumin nanoparticles(PCurNP)are designed to meet the renal excretion threshold(~45 kDa),presenting a controllable delivery nanosystem for kidney targeting.Renal accumulation of the relatively small nanoparticles,^(89)Zr-PCurNP M10 with the diameter between 5 and 8 nm,is found to be 1.7 times and 1.8 times higher than the accumulation of^(89)Zr-PCurNP M29(20-50 nm)and M40(20-50 nm)as revealed by PET imaging.Furthermore,serum creatinine analysis,kidney tissues histology,and tubular injury scores revealed that PCurNP M10 efficiently treated cisplatin-induced AKI.Herein,PCurNP offers a novel and simple strategy for precise PET image-guided drug delivery of renal protective materials.
基金This research was supported by a grant from the National Natural Science Foundation of China(No.81673060).
文摘Stevens-Johnson syndrome(SJS)and toxic epidermal necrolysis(TEN)are rare but severe diseases.This study aimed to validate the predictive ability of risk models in patients with SJS/TEN and propose possible refinement in China.Patients in the Department of Dermatology of Huashan Hospital from January 2008 to January 2019 were included.Results showed that the severity-of-illness score for TEN(SCORTEN)had a good discrimination(area under the receiver operating characteristic curve(AUC),0.78),and it was superior to auxiliary score(AS)and ABCD-10,which indicates age,bicarbonate level,cancer,dialysis,and 10%involved body surface area(AUC,0.69 and 0.68,respectively).The calibration of SCORTEN(Hosmer-Lemeshow goodness-of-fit test,P=0.69)was also better than that of AS(P=0.25)and ABCD-10(P=0.55).SCORTEN and ABCD-10 were similar(Brier score(BS),0.04 and 0.04)in terms of accuracy of predictions.In addition,the imaging appearance of pulmonary consolidation on computed tomography was associated with high mortality.Refined models were formed using the variables and this imaging appearance.The refined AS and ABCD-10 models were similar in discrimination compared with the original SCORTEN(0.74 vs.0.78,P=0.23;0.74 vs.0.78,P=0.30,respectively).Therefore,SCORTEN showed good discrimination performance,calibration,and accuracy,and refined AS or ABCD-10 model may be an option when SCORTEN variables are not available.
基金This research is supported by Scientific Research Starting Project of SWPU(No.2017QHZ012)Major Project by Education Office of Sichuan Province(No.17ZA0418)+1 种基金supported by the Natural Science Fund for Outstanding Youth Science Fund(Grant No.51222406)Scientific Research Innovation Team Project of Sichuan Colleges and Universities(2017TD0014).
文摘Double shoulder drill pipe joint(DSJ)is a novel thread structure which appears in recent years.Its strength reduced efficiently while the structure design is not appropriately,for the DSJ’s mechanical behaviors weren’t well studied.In this paper a 3D whole structure finite element model of DSJ was established based on the Principle of Virtual Work,and validated the model’s computing results by experimental results.The authors analyzed the stress and strain distribution with the 3D whole structure finite element model’s computing results under torque moment,compression force,tension load,and bend moment.And then acquired the DSJ’s mechanical behaviors under each load.The research works of this paper refer accordance to recognize and design the DSJ.
基金This work was financially supported by the National Key Research and Development Program of China(No.2016YFA0203101)the National Natural Science Foundation of China(Nos.21974042,21904039,21874080,21645008,21621003,21622506)+1 种基金the Sci-entific Research Fund of Hunan Provincial Education Department(No.18A010)the Science and Technology Department of Hunan Province(Nos.14JJ4030,2020JJ5352).
文摘Cu-based metal organic frameworks(MOFs)are regarded as promising sensing materials,which have abundant metal sites,large surface area and simple synthesis processes.In this work,a novel three-dimensional flower-like Cu-MOF was synthesized,which was combined with ultra-thin MXene nanosheets to construct a novel electrochemical sensor for H_(2)O_(2).
基金This research is supported by the National Natural Science Foundation of China(Grant No.51222406)New Century Excellent Talents in University of China(NCET-12-1061)+2 种基金Scientific Research Innovation Team Project of Sichuan Colleges and Universities(12TD007)Youth Scientific Research Innovation Team Project of Sichuan Province(2014TD0025)the key projects of academic and technical leaders cultivate fund in Sichuan Province,China(2011-441-zxh).
文摘Stick-slip vibration presents one of the major causes of drilling problems,such as premature tool failures,low drilling efficiency and poor wellbore quality.The objective of this work is to investigate the influences of rotary table speed(RTS)on stick-slip phenomenon of the drilling system.In this study,the drilling system is treated as a lumped torsional pendulum model of which the bit/rock interaction is regarded as Coulomb friction.By analyzing cases with different RTS,two types of vibrations on the bit are found:stick-slip vibration and uniform motion.With an increase in the RTS,the stick-slip vibration on the drill bit disappears once the RTS arrives at its critical value.For the cases that stick-slip vibrations occur,the phase trajectories converge toward a limit cycle.For the cases that stick-slip vibration does not appear,the drill bit tends to stabilize at a uniform motion and the phase trajectories correspond to contracting spirals observed in the phase plane.
基金supported by the National Natural Science Foundation of China (No. 61271156)the Natural Science Foundation of Anhui Province (No. 1408085MF114)+1 种基金Innovation Team Project of AHUT (No. TD201204)the research project for university per-sonnel returning from overseas sponsored by the Ministry of Education of China
文摘Graphene （G） was prepared by reducing graphene oxide （GO） with hydrazine hydrate. SnO-graphene com- posites with different amounts of graphene were prepared via hydrothermal method. SnO-G composites were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The effects of the graphene content in the composites and the hydrothermal temperature on the gas-sensing re- sponses of the materials to formaldehyde vapor were investigated. The gas-sensing selectivity of the sensor based on SnO-1% G （100 ℃, 10 h） composite to five kinds of gases （1000 × 10^-6） was also studied. The results revealed that the sensor based on SnO-1% G （100 ℃, 10 h） exhibited high response to formal- dehyde vapor when the operating temperature of the sensor was 133 ℃ and the response to 0.001 × 10^-6 formaldehyde attained 3.9. The response time and recovery time for 0.001 × 10^-6 formaldehyde were 24 and 12 s, respectively.
文摘In this paper,we prove the existence of solutions to the Fu-Yau equation on com-pact Kähler manifolds.As an application,we give a class of non-trivial solutions of the modified Strominger system.
