Water oxidation-a critical yet sluggish step in green hydrogen production-is a major bottleneck for electrolysis efficiency.Traditional catalysts often degrade quickly under the high current densities needed for indus...Water oxidation-a critical yet sluggish step in green hydrogen production-is a major bottleneck for electrolysis efficiency.Traditional catalysts often degrade quickly under the high current densities needed for industrial scale.展开更多
With the continuous deepening of vocational education reform,core literacy,as an important concept of educational reform,has gradually been introduced into English teaching.The cultivation of core literacy requires st...With the continuous deepening of vocational education reform,core literacy,as an important concept of educational reform,has gradually been introduced into English teaching.The cultivation of core literacy requires students not only to master basic language knowledge but also to flexibly use cross-cultural communication skills,innovative thinking,and professional literacy to solve problems in actual work situations.In this context,constructing a vocational English evaluation system based on core literacy has become an urgent need to improve the quality of vocational English teaching and cultivate high-quality applied talents.Therefore,the following will focus on exploring the relevant content of the vocational English evaluation system in order to provide some help.展开更多
Background:Currently,there is a deficiency in a strong risk prediction framework for precisely evaluating the likelihood of severe postoperative complications in patients undergoing elective hepato-pancreatobiliary su...Background:Currently,there is a deficiency in a strong risk prediction framework for precisely evaluating the likelihood of severe postoperative complications in patients undergoing elective hepato-pancreatobiliary surgery subsequent to experiencing breakthrough infection of coronavirus disease 2019(COVID-19).This study aimed to find factors predicting postoperative complications and construct an innovative nomogram to pinpoint patients who were susceptible to developing severe complications following breakthrough infection of COVID-19 after undergoing elective hepato-pancreato-biliary surgery.Methods:This multicenter retrospective cohort study included consecutive patients who underwent elective hepato-pancreato-biliary surgeries between January 3 and April 1,2023 from four hospitals in China.All of these patients had experienced breakthrough infection of COVID-19 prior to their surgeries.Additionally,two groups of patients without preoperative COVID-19 infection were included as comparative controls.Surgical complications were meticulously documented and evaluated using the comprehensive complication index(CCI),which ranged from 0(uneventful course)to 100(death).A CCI value of 20.9 was identified as the threshold for defining severe complications.Results:Among 2636 patients who were included in this study,873 were included in the reference group I,941 in the reference group II,389 in the internal cohort,and 433 in the external validation cohort.Multivariate logistic regression analysis revealed that completing a full course of COVID-19 vaccination>6 months before surgery,undergoing surgery within 4 weeks of diagnosis of COVID-19 breakthrough infection,operation duration of 4 h or longer,cancer-related surgery,and major surgical procedures were significantly linked to a CCI>20.9.A nomogram model was constructed utilizing CCI>20.9 in the training cohort[area under the curve(AUC):0.919,95%confidence interval(CI):0.881–0.957],the internal validation cohort(AUC:0.910,95%CI:0.847–0.973),and the external validation cohort(AUC:0.841,95%CI:0.799–0.883).The calibration curve for the probability of CCI>20.9 demonstrated good agreement between the predictions made by the nomogram and the actual observations.Conclusions:The developed model holds significant potential in aiding clinicians with clinical decisionmaking and risk stratification for patients who have experienced breakthrough infection of COVID-19 prior to undergoing elective hepato-pancreato-biliary surgery.展开更多
Predicting the gas breakthrough pressure of saturated compacted bentonite is crucial for ensuring the long-term safe operation of deep geological repositories for the disposal of high-level radioactive nuclear wastes....Predicting the gas breakthrough pressure of saturated compacted bentonite is crucial for ensuring the long-term safe operation of deep geological repositories for the disposal of high-level radioactive nuclear wastes.In this work,the swelling pressure,water injection,gas injection and mercury intrusion porosimetry(MIP)tests on saturated compacted Gaomiaozi(GMZ)bentonite specimens with a dry density of 1.3 Mg/m^(3),1.4 Mg/m^(3),1.5 Mg/m^(3),1.6 Mg/m^(3) and 1.7 Mg/m^(3) were conducted.Subsequently,the relationships between the swelling pressure and average inter-particle distance,as well as between the gas entry pressure and the maximum effective pore size were analyzed and established.Considering that gas migration and breakthrough are all closely related to the pore structures of the tested geomaterials,a novel gas breakthrough pressure prediction model based on the pore size distribution(PSD)curve was constructed using an existing prediction model based on gas entry pressure and swelling pressure.Finally,based on the test results of the specimens 1.5 Mg/m^(3),1.6 Mg/m^(3) and 1.7 Mg/m^(3),gas breakthrough pressures of the specimens with dry densities of 1.3 Mg/m^(3) and 1.4 Mg/m^(3) were predicted.The results show that the calculated gas breakthrough pressures of 0.76 MPa and 1.28 MPa are very close to the measured values of 0.80 MPa and 1.30 MPa,validating the accuracy of the proposed model.展开更多
Comprehensive studies on CO_(2)breakthrough times and flooding effects are crucial for optimizing CO_(2)flooding strategies.This study utilized numerical simulations to investigate the effects of hydraulic fractures,p...Comprehensive studies on CO_(2)breakthrough times and flooding effects are crucial for optimizing CO_(2)flooding strategies.This study utilized numerical simulations to investigate the effects of hydraulic fractures,permeability,and CO_(2)injection rates on CO_(2)breakthrough times and cumulative oil production.Nonlinear relationships among the respective variables were established,with Sobol method analysis delineating the dominant control factors.The key findings indicate that although hydraulic fracturing shortens CO_(2)breakthrough time,it concurrently enhances cumulative oil production.The orientation of hydraulic fractures emerged as a pivotal factor influencing flooding effectiveness.Furthermore,lower permeability corresponds to lower initial oil production,while higher permeability corresponds to higher initial daily oil production.When reservoir permeability is 1 mD,oil production declines at 1000 days,and at 2 mD,it declines at 700 days.At a surface CO_(2)injection rate of 10,000 m^(3)/d,the daily oil production of a single well is approximately 7.5 m^(3),and this value remains relatively stable over time.The hierarchical order of influence on CO_(2)breakthrough and rapid rise times,from highest to lowest,is permeability,well spacing,CO_(2)injection rate,porosity,and hydraulic fracture conductivity.Similarly,the order of influence on cumulative oil production,from highest to lowest,is well spacing,porosity,permeability,CO_(2)injection rate,and hydraulic fracture conductivity.This paper analyzed the impact of geological and engineering parameters on CO_(2)flooding and oil production and provided insights to optimize CO_(2)injection strategies for enhanced oil recovery.展开更多
The 175,000 cm^(3) Mark III Flex membrane LNG carrier "SEA SPIRIT"built hy Dalian Shipbuilding Intlustry Co.,Ltd.(DLS),a suhsirliary of China State Shipbuilding Corporation(CSSC),and China Shipbuilding Tradi...The 175,000 cm^(3) Mark III Flex membrane LNG carrier "SEA SPIRIT"built hy Dalian Shipbuilding Intlustry Co.,Ltd.(DLS),a suhsirliary of China State Shipbuilding Corporation(CSSC),and China Shipbuilding Trading Co.,Ltd.(CSTC)for China Merchants Energy Shipping and CSTS1 shipbuilding and offshore engineering brokerage joint venture was offirially named and delivered on September 24.marking a new stage of strategic cooperation lietween DLS and China Merchants Shipping in the high-end equipment manufarturing field.展开更多
With the reduction of sequencing costs,optimization of algorithms,and improvement of multi-omics integration capabilities,transcriptomics,as a core technology for analyzing gene expression dynamics and discovering key...With the reduction of sequencing costs,optimization of algorithms,and improvement of multi-omics integration capabilities,transcriptomics,as a core technology for analyzing gene expression dynamics and discovering key functional molecules,has shown great potential in the field of disease prevention and control[1,2].The multi-continental transcriptomics study of tick-borne poxvirus not only provides a new perspective for understanding the evolution and transmission of vector-mediated viruses,but also reflects the trend of transcriptomics research and highlights its key role in disease prevention and control[3].展开更多
Water breakthrough in horizontal wells is now the main factor restricting the stable production of the Tainan Gas Field in the Qaidam Basin.In view of this problem,the distribution characteristics of irreducible water...Water breakthrough in horizontal wells is now the main factor restricting the stable production of the Tainan Gas Field in the Qaidam Basin.In view of this problem,the distribution characteristics of irreducible water saturation were investigated by using the nuclear magnetic resonance logging interpretation technology.And combined with the production situations of the horizontal wells in Tainan Gas Field in the initial stage of their production,the characteristic parameters of the reservoir which produced the intrastratal water as soon as it was put into production were determined.Then,the factors influencing the production of irreducible water were studied by means of gas drive water core experiments,and the factors influencing the sealing ability of the interbeds were researched by conducting mudstone breakdown tests.What's more,the effects on the bottomhole pressure by the length of horizontal section at different daily gas productions were investigated through numerical simulation.Finally,the prevention&control countermeasures for water breakthrough in horizontal wells were proposed.And the following research results were obtained.First,the horizontal well which drills into the reservoir with mobile water saturation higher than 7.2%and gas saturation lower than 63.5%produces formation water in its initial stage of production.Second,the lower the shale content is and the greater the production pressure difference is,the more favorable it is for the production of irreducible water.The production of irreducible water in the reservoirs with stronger areal heterogeneity is a continuous process.Third,the sealing capacity of the interbed increases with the decrease of its vertical permeability and water saturation and with the increase of its shale content and thickness.Fourth,the breakthrough pressure of type I mudstone(shale content>90%)is about 4 MPa,that of type II mudstone(80%<shale content<90%)is about 2 MPa,and that of type III mudstone(60%<shale content<80%)is about 1.5 MPa.In conclusion,the edge water encroachment can be delayed and the water-free gas production period of gas well can be extended by increasing the length of horizontal section and controlling the production pressure difference.It is recommended to carry out balanced gas production in horizontal wells in the initial stage of production,enhance dynamic monitoring in the process of production,and drain the water in time in the case of water breakthrough so as to increase its cumulative gas production.展开更多
AIM: To identify the factors associated with virologic breakthrough and to select a subgroup of patients who respond well to lamivudine without developing virologic breakthrough (VBT). METHODS: Of 79 patients who had ...AIM: To identify the factors associated with virologic breakthrough and to select a subgroup of patients who respond well to lamivudine without developing virologic breakthrough (VBT). METHODS: Of 79 patients who had received lamivudine therapy for 9-57 mo, 34 were HBeAg-positive and 45 were HBeAg-negative, 24 developed virologic breakthrough and 55 did not. Clinical and virologic factors were compared between the two groups. RESULTS: The median duration of therapy was 25 (9-57) mo. Virologic breakthrough was defined as a > 1 log HBV DNA increase following initial suppression. When several factors, including gender, duration of infection, baseline HBV DNA, and baseline ALT in HBeAg-positive chronic hepatitis patients were analyzed by logistic regression, the most important predictor of virologic breakthrough was the baseline HBV DNA (r2 = 0.12, P < 0.05). When HBeAg-postitive chronic hepatitis patients were divided into two groups by a point of 6.6 log HBV DNA, the incidence of virologic breakthough between two groups was significantly different. CONCLUSION: Lamivudine may remain an effective first line therapy for those HBeAg-positive patients with a baseline HBV DNA < 6.6 log10 copies/mL.展开更多
Scaled physical model tests for steam breakthrough were conducted based on the analysis of mechanisms and influence factors of steam breakthrough. Physical simulation results showed that at the initial steam breakthro...Scaled physical model tests for steam breakthrough were conducted based on the analysis of mechanisms and influence factors of steam breakthrough. Physical simulation results showed that at the initial steam breakthrough, preferential flow channels were formed in narrow sand packs and most residual oil left in these channels was immobile. This shortened the steam breakthrough time of follow-up steam flooding and decreased the increment of oil recovery efficiency. Steam breakthrough occurred easily for a smaller producer-injector spacing, and a bigger difference in physical properties between fluids and rock. Steam breakthrough is more likely to occur at a larger formation permeability （k）, greater steam displacement velocity （u） and smaller producer-injector spacing （L）. Steam breakthrough time is a function of the parameter group （uk/L）, i.e. tb=3.2151 （uk/L）^-0.5142. A non piston-like displacement model was built based on steam breakthrough observation for a steam stimulated well in the Jinglou Oilfield, Henan Oilfield Company. The steam volume swept in different directions could be obtained from inter-well permeability capacity and breakthrough angle, and the steam swept pore volume （SSPV） was also determined. Numerical simulation showed that steam sweep efficiency reached its peak value when a slug of profile control agent （slug size 10%-15% SSPV） was set at one half of the inter-well spacing. Field test with 12.5% SSPV of profile control agents in the Jinglou Oilfield achieved success in sealing breakthrough channels and good production performance of adjacent producers.展开更多
Cerebral arteriovenous malformations(AVMs) have abnormally enlarged arteries and veins prone to spontaneous hemorrhage.Immediately following surgical excision of a cerebral AVM,even normal brain tissue surrounding the...Cerebral arteriovenous malformations(AVMs) have abnormally enlarged arteries and veins prone to spontaneous hemorrhage.Immediately following surgical excision of a cerebral AVM,even normal brain tissue surrounding the lesion is subject to hemorrhage,a phenomenon termed normal perfusion pressure breakthrough(NPPB) syndrome.According to this theory,arteries supplying cerebral AVMs become dilated and lose their capacity to dilate or constrict to autoregulate pressure.Acutely after removal of a cerebral AVM,excessive blood pressure in these arterial feeders can cause normal brain tissue to bleed.However,this theory remains controversial.We present a patient with a cerebral AVM that demonstrated cerebrovascular reactivity and argues against an assumption underlying the theory of NPPB syndrome.展开更多
Based on exploration and development results and evaluation of marine shale gas in South China in the past ten years, in view of the features of "high maturity, strong tectonic reformation and high shear stress&q...Based on exploration and development results and evaluation of marine shale gas in South China in the past ten years, in view of the features of "high maturity, strong tectonic reformation and high shear stress" of the shale in Zhaotong exploration zone in the Yunnan and Guizhou Plateau, as well as the key issues of long time diffusion and leakage of shallow shale gas, and the preservation conditions, the factors controlling shallow shale gas sweet spot and key zone selection evaluation technology of shale gas are investigated. From 2017 to 2018, the first significant exploration breakthrough was made in the Taiyang anticline at a buried depth of 700 to 2 000 m, discovering large-scale proved geological reserves of shallow shale gas. By examining the accumulation conditions and sweet spot control factors of the shallow shale gas in this area, it is found that the accumulation and productivity potential of shale gas in the mountainous area with complex structure outside basin are controlled by five factors:(1) The gas-rich area has weak tectonic reformation and good preservation conditions on the whole, taking on typical anticline trap occurrence mode.(2) The gas-rich area is in over-pressure state and high in shale gas content.(3) The gas-rich area has high quality shale and thus superior source rock condition.(4) The gas-rich area has high quality reservoirs dominated by class I.(5) The shale gas reservoir in the gas-rich area has high content of brittle minerals and small difference between maximum and minimum horizontal stresses which are conducive to hydraulic fracturing. The innovative practice and core technologies formed during the exploration and production capacity construction of shallow shale gas in the Zhaotong demonstration zone have great reference significance for shallow shale gas exploration and development in other areas.展开更多
It is well known that the complicated channeling of fluid flow and heat transfer is strongly related with the intricate natural fracture system.However,it is still challenging to set up the fracture network model whic...It is well known that the complicated channeling of fluid flow and heat transfer is strongly related with the intricate natural fracture system.However,it is still challenging to set up the fracture network model which is strong heterogeneous.Compared with other methods(e.g.equivalent continuum model(ECM),discrete fracture model(DFM),and ECM-DFM),the fracture flow module in the COMSOL Multiphysics simulator is powerful in definition of fractures as the inner flow boundary existing in the porous media.Thus it is selected to simulate the fluid flow and heat transfer in the geothermal-developed fractured granite of Sanguliu area located at Liaodong Peninsula,Eastern China.The natural faults/fractures based on field investigation combined with the discrete fracture network(DFN)generated by the MATLAB are used to represent the two-dimensional geological model.Numerical results show that early thermal breakthrough occurs at the production well caused by quick flow of cold water along the highly connected fractures.Suitable hydraulic fracturing treatments with proper injection rates,locations,etc.can efficiently hinder the thermal breakthrough time in the natural fracture system.Large well spacing helps the long-term operation of geothermal production,but it is highly dependent on the geometrical morphology of the fracture network.The enhancement of reservoir properties at the near-well regions can also increase the geothermal production efficiency.The results in this study can provide references to achieve a sustainable geothermal exploitation in fractured granitic geothermal reservoirs or hot dry rocks at depth.展开更多
AIM: Predictive value of serum b2-microglobulin (b2m)levels for virological breakthrough (VB) in HBeAg-negative chronic hepatitis B (CHB) patients under long-term treatment schedules including lamivudine (LAM).METHODS...AIM: Predictive value of serum b2-microglobulin (b2m)levels for virological breakthrough (VB) in HBeAg-negative chronic hepatitis B (CHB) patients under long-term treatment schedules including lamivudine (LAM).METHODS: Serum b2m levels were calculated during treatment in 25 CHB patients under long-term LAM monotherapy (group A) and 12 patients under initial interferon plus LAM treatment followed by LAM monotherapy (group B), using the MEIA technology. We used Cox proportional hazard models in order to investigate the association between serum b2m levels and VB.RESULTS: Seven of 25 patients (28%), 9/25 (36%) and 14/25 (56%) from group A and 0/12, 2/12 (16.6%) and 3/12 (25%) from group B exhibited VB at months 12, 24 and 36 of treatment, respectively. All patients, from both groups, who did not show VB exhibited b2m elevation in mo 3. The duration of b2m elevation was significantly longer in the virological responder's subgroup from group A than the non-responder's one (7.3±2.6 vs 3.8±3.4 mo,P = 0.02). In comparison to group A patients whose b2m levels were increased at 3 mo, patients whose b2m levels were decreased had 4.6 times higher risk of experiencing VB (RR = 4.6, P = 0.024). When baseline variables were simultaneously included in the same Cox model, decreased b2m status was still associated with increased risk of VB (RR = 12.2, P = 0.03).CONCLUSION: In HBeAg-negative CHB patients under either long-term LAM monotherapy or initial combination treatment, serum b2m levels at 3 mo of treatment,compared to baseline ones, might be a predictor of risk for VB.展开更多
The liver is the largest solid organ,and it is involved in multiple biological processes,including energy metabolism,protein synthesis,and detoxification1.Under physiological or pathological conditions,the liver can r...The liver is the largest solid organ,and it is involved in multiple biological processes,including energy metabolism,protein synthesis,and detoxification1.Under physiological or pathological conditions,the liver can regrow to normal size even after resection of 90%of the liver volume because of its strong regeneration ability2.Changes in diet,viral infection(HBV and/or HCV)。展开更多
Breakthrough innovation is seen as a leading technology and industrial development direction, by which enterprises obtain the key for winning sustainable competitive advantage. In this paper, a chaos model is develope...Breakthrough innovation is seen as a leading technology and industrial development direction, by which enterprises obtain the key for winning sustainable competitive advantage. In this paper, a chaos model is developed to examine how the breakthrough innovation evolves with the changed external environment ability and internal power. Numerical simulations based on chaos theory illustrate that the breakthrough innovation leads to chaos through the period-doubling bifurcation, and the chaos is the result of nonlinear interaction which is a qualitative change in the process between internal dynamics and external factors. The general conditions in which the breakthrough innovation comes to chaos instead of being in good order are gotten. The results show that the breakthrough innovation has chaotic characteristics and has a very sensitive dependence on the initial conditions in the process of running. The chaotic evolution can reflect the nonlinear character of the breakthrough innovation development and it can provide theoretical guidance for the application of chaos and chaotic control of innovation management.展开更多
Dimensional analysis and numerical simulations were carried out to research prediction method of breakthrough time of horizontal wells in bottom water reservoir. Four dimensionless independent variables and dimensionl...Dimensional analysis and numerical simulations were carried out to research prediction method of breakthrough time of horizontal wells in bottom water reservoir. Four dimensionless independent variables and dimensionless time were derived from 10 influencing factors of the problem by using dimensional analysis. Simulations of horizontal well in reservoir with bottom water were run to find the prediction correlation. A general and concise functional relationship for predicting breakthrough time was established based on simulation results and theoretical analysis. The breakthrough time of one conceptual model predicted by the correlation is very close to the result by Eclipse with less than 2% error. The practical breakthrough time of one well in Helder oilfield is 10 d, and the predicted results by the method is 11.2 d, which is more accurate than the analytical result. Case study indicates that the method could predict breakthrough time of horizontal well under different reservoir conditions accurately. For its university and ease of use, the method is suitable for quick prediction of breakthrough time.展开更多
Gas breakthrough pressure is a key parameter to evaluate the sealing capacity of caprock,and it also plays important roles in safety and capacity of CO_(2)geological storage.Based on the published experimental results...Gas breakthrough pressure is a key parameter to evaluate the sealing capacity of caprock,and it also plays important roles in safety and capacity of CO_(2)geological storage.Based on the published experimental results,we present numerical simulations on CO_(2)breakthrough pressure in unsaturated low-permeability rock under 9 multiple P-T conditions(which can keep CO_(2)in gaseous,liquid and supercritical states)and thus,a numerical method which can be used to accurately predict CO_(2)breakthrough pressure on rock-core scale is proposed.The simulation results show that CO_(2)breakthrough pressure and breakthrough time are exponential correlated with P-T conditions.Meanwhile,pressure has stronger effects on experimental results than that of temperature.Moreover,we performed sensitivity studies on the pore distribution indexλ(0.6,0.7,0.8,and 0.9)in van Genuchten-Muale model.Results show that with the increase ofλ,CO_(2)breakthrough pressure and breakthrough time both show decreasing trends.In other words,the larger the value ofλis,the better the permeability of the caprock is,and the worse the CO_(2)sealing capacity is.The numerical method established in this study can provide an important reference for the prediction of gas breakthrough pressure on rock-core scale and for related numerical studies.展开更多
The regeneration of a spent packing is crucial with respect to the development of circular economy and abstemious society.Thus,the effects of regeneration temperature,resistant time,heating rate,and regeneration cycle...The regeneration of a spent packing is crucial with respect to the development of circular economy and abstemious society.Thus,the effects of regeneration temperature,resistant time,heating rate,and regeneration cycle on the breakthrough performance of methylene blue(MB)dye⁃exhausted ceramsite in a two⁃stage fixed⁃bed column were studied in this work.Results illustrate that the ceramsite exhibited excellent potential regeneration properties under the following optimal regeneration conditions:treatment temperature was 600°C,resistant time was 15 min,heating rate was 20℃/min,regeneration cycle was over 9 cycles,and the breakthrough time,saturation time,regeneration efficiency(RE),and regeneration loss rate(RLR)were 540 min,1020 min,64.61%,and 17.73%,respectively.The RE declined by 35.14%in over 1 cycle,while the RLR increased by 3.15 times in over 9 cycles.Besides,Thomas model was suitable to describe the two⁃stage fixed⁃bed column adsorption and thermal regeneration process with R2=0.978.In conclusion,a thorough understanding of the regeneration behavior of the two⁃stage fixed⁃bed column packed with ceramsite provides reference to obtain an effective and feasible regeneration approach,and it is beneficial for further application in water treatment.展开更多
Fractures play a pivotal role in carbonate thermal storage systems,serving as primary hydraulic conductivity channels that significantly influence thermal breakthrough times and heat extraction efficiency in geotherma...Fractures play a pivotal role in carbonate thermal storage systems,serving as primary hydraulic conductivity channels that significantly influence thermal breakthrough times and heat extraction efficiency in geothermal-to-well systems.Their impact is critical for well placement and system life prediction.This paper focuses on a geothermal-to-well system within the carbonate reservoir of the Wumishan formation in the Rongcheng geothermal field,Xiong'an new area.It employs a combination of field tests and numerical simulations to determine the permeability of the reservoir and the evolution of fractures between wells.It also examines the influence of fracture width and roughness coefficient on the seepage and temperature fields under various injection scenarios and predicts thermal breakthrough times for production wells.The results show:Higher permeability is observed near well D16 compared to well D22 within the studied geothermal-to-well systems.Wider fractures between wells result in faster temperature decline in production wells.Lower injection flow rates lead to slower temperature reduction in injection wells.The use of roughness coefficients minimizes temperature variations in production wells.This study not only offers guidance for the development and utilization of the geothermal well system,but also contributes to a deeper understanding of the groundwater seepage and heat transfer process influenced by fractures.展开更多
文摘Water oxidation-a critical yet sluggish step in green hydrogen production-is a major bottleneck for electrolysis efficiency.Traditional catalysts often degrade quickly under the high current densities needed for industrial scale.
文摘With the continuous deepening of vocational education reform,core literacy,as an important concept of educational reform,has gradually been introduced into English teaching.The cultivation of core literacy requires students not only to master basic language knowledge but also to flexibly use cross-cultural communication skills,innovative thinking,and professional literacy to solve problems in actual work situations.In this context,constructing a vocational English evaluation system based on core literacy has become an urgent need to improve the quality of vocational English teaching and cultivate high-quality applied talents.Therefore,the following will focus on exploring the relevant content of the vocational English evaluation system in order to provide some help.
基金supported by grants from the Science Fund for Creative Research Groups of the National Natural Science Founda-tion of China(81521091 and 82073031)the National Natural Sci-ence Foundation of China(92269204)Clinical Research Plan of SHDC(SHDC2020CR5007 and SHDC22020213)。
文摘Background:Currently,there is a deficiency in a strong risk prediction framework for precisely evaluating the likelihood of severe postoperative complications in patients undergoing elective hepato-pancreatobiliary surgery subsequent to experiencing breakthrough infection of coronavirus disease 2019(COVID-19).This study aimed to find factors predicting postoperative complications and construct an innovative nomogram to pinpoint patients who were susceptible to developing severe complications following breakthrough infection of COVID-19 after undergoing elective hepato-pancreato-biliary surgery.Methods:This multicenter retrospective cohort study included consecutive patients who underwent elective hepato-pancreato-biliary surgeries between January 3 and April 1,2023 from four hospitals in China.All of these patients had experienced breakthrough infection of COVID-19 prior to their surgeries.Additionally,two groups of patients without preoperative COVID-19 infection were included as comparative controls.Surgical complications were meticulously documented and evaluated using the comprehensive complication index(CCI),which ranged from 0(uneventful course)to 100(death).A CCI value of 20.9 was identified as the threshold for defining severe complications.Results:Among 2636 patients who were included in this study,873 were included in the reference group I,941 in the reference group II,389 in the internal cohort,and 433 in the external validation cohort.Multivariate logistic regression analysis revealed that completing a full course of COVID-19 vaccination>6 months before surgery,undergoing surgery within 4 weeks of diagnosis of COVID-19 breakthrough infection,operation duration of 4 h or longer,cancer-related surgery,and major surgical procedures were significantly linked to a CCI>20.9.A nomogram model was constructed utilizing CCI>20.9 in the training cohort[area under the curve(AUC):0.919,95%confidence interval(CI):0.881–0.957],the internal validation cohort(AUC:0.910,95%CI:0.847–0.973),and the external validation cohort(AUC:0.841,95%CI:0.799–0.883).The calibration curve for the probability of CCI>20.9 demonstrated good agreement between the predictions made by the nomogram and the actual observations.Conclusions:The developed model holds significant potential in aiding clinicians with clinical decisionmaking and risk stratification for patients who have experienced breakthrough infection of COVID-19 prior to undergoing elective hepato-pancreato-biliary surgery.
基金the National Natural Science Foundationof China (Grant No. 42030714).
文摘Predicting the gas breakthrough pressure of saturated compacted bentonite is crucial for ensuring the long-term safe operation of deep geological repositories for the disposal of high-level radioactive nuclear wastes.In this work,the swelling pressure,water injection,gas injection and mercury intrusion porosimetry(MIP)tests on saturated compacted Gaomiaozi(GMZ)bentonite specimens with a dry density of 1.3 Mg/m^(3),1.4 Mg/m^(3),1.5 Mg/m^(3),1.6 Mg/m^(3) and 1.7 Mg/m^(3) were conducted.Subsequently,the relationships between the swelling pressure and average inter-particle distance,as well as between the gas entry pressure and the maximum effective pore size were analyzed and established.Considering that gas migration and breakthrough are all closely related to the pore structures of the tested geomaterials,a novel gas breakthrough pressure prediction model based on the pore size distribution(PSD)curve was constructed using an existing prediction model based on gas entry pressure and swelling pressure.Finally,based on the test results of the specimens 1.5 Mg/m^(3),1.6 Mg/m^(3) and 1.7 Mg/m^(3),gas breakthrough pressures of the specimens with dry densities of 1.3 Mg/m^(3) and 1.4 Mg/m^(3) were predicted.The results show that the calculated gas breakthrough pressures of 0.76 MPa and 1.28 MPa are very close to the measured values of 0.80 MPa and 1.30 MPa,validating the accuracy of the proposed model.
基金supported by the China Postdoctoral Science Foundation(No.2024M752803)the National Natural Science Foundation of China(No.52179112)+1 种基金the Open Fund of National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,China(No.PLN2023-02)the Open Fund of Key Laboratory of Deep Geothermal Resources,Ministry of Natural Resources of the People's Republic of China(No.KLDGR2024B01).
文摘Comprehensive studies on CO_(2)breakthrough times and flooding effects are crucial for optimizing CO_(2)flooding strategies.This study utilized numerical simulations to investigate the effects of hydraulic fractures,permeability,and CO_(2)injection rates on CO_(2)breakthrough times and cumulative oil production.Nonlinear relationships among the respective variables were established,with Sobol method analysis delineating the dominant control factors.The key findings indicate that although hydraulic fracturing shortens CO_(2)breakthrough time,it concurrently enhances cumulative oil production.The orientation of hydraulic fractures emerged as a pivotal factor influencing flooding effectiveness.Furthermore,lower permeability corresponds to lower initial oil production,while higher permeability corresponds to higher initial daily oil production.When reservoir permeability is 1 mD,oil production declines at 1000 days,and at 2 mD,it declines at 700 days.At a surface CO_(2)injection rate of 10,000 m^(3)/d,the daily oil production of a single well is approximately 7.5 m^(3),and this value remains relatively stable over time.The hierarchical order of influence on CO_(2)breakthrough and rapid rise times,from highest to lowest,is permeability,well spacing,CO_(2)injection rate,porosity,and hydraulic fracture conductivity.Similarly,the order of influence on cumulative oil production,from highest to lowest,is well spacing,porosity,permeability,CO_(2)injection rate,and hydraulic fracture conductivity.This paper analyzed the impact of geological and engineering parameters on CO_(2)flooding and oil production and provided insights to optimize CO_(2)injection strategies for enhanced oil recovery.
文摘The 175,000 cm^(3) Mark III Flex membrane LNG carrier "SEA SPIRIT"built hy Dalian Shipbuilding Intlustry Co.,Ltd.(DLS),a suhsirliary of China State Shipbuilding Corporation(CSSC),and China Shipbuilding Trading Co.,Ltd.(CSTC)for China Merchants Energy Shipping and CSTS1 shipbuilding and offshore engineering brokerage joint venture was offirially named and delivered on September 24.marking a new stage of strategic cooperation lietween DLS and China Merchants Shipping in the high-end equipment manufarturing field.
文摘With the reduction of sequencing costs,optimization of algorithms,and improvement of multi-omics integration capabilities,transcriptomics,as a core technology for analyzing gene expression dynamics and discovering key functional molecules,has shown great potential in the field of disease prevention and control[1,2].The multi-continental transcriptomics study of tick-borne poxvirus not only provides a new perspective for understanding the evolution and transmission of vector-mediated viruses,but also reflects the trend of transcriptomics research and highlights its key role in disease prevention and control[3].
基金supported by the National Major Science and Technology Project“Technologies for maintain stable production of unconsolidated gas reservoir”(No.:2016ZX05015-004)PetroChina Major Science and Technology Project“Technologies for water control&gas stabilization in mature blocks and efficient development of new gas bocks in the Qaidam Basin”(No.:2016E-0106GE).
文摘Water breakthrough in horizontal wells is now the main factor restricting the stable production of the Tainan Gas Field in the Qaidam Basin.In view of this problem,the distribution characteristics of irreducible water saturation were investigated by using the nuclear magnetic resonance logging interpretation technology.And combined with the production situations of the horizontal wells in Tainan Gas Field in the initial stage of their production,the characteristic parameters of the reservoir which produced the intrastratal water as soon as it was put into production were determined.Then,the factors influencing the production of irreducible water were studied by means of gas drive water core experiments,and the factors influencing the sealing ability of the interbeds were researched by conducting mudstone breakdown tests.What's more,the effects on the bottomhole pressure by the length of horizontal section at different daily gas productions were investigated through numerical simulation.Finally,the prevention&control countermeasures for water breakthrough in horizontal wells were proposed.And the following research results were obtained.First,the horizontal well which drills into the reservoir with mobile water saturation higher than 7.2%and gas saturation lower than 63.5%produces formation water in its initial stage of production.Second,the lower the shale content is and the greater the production pressure difference is,the more favorable it is for the production of irreducible water.The production of irreducible water in the reservoirs with stronger areal heterogeneity is a continuous process.Third,the sealing capacity of the interbed increases with the decrease of its vertical permeability and water saturation and with the increase of its shale content and thickness.Fourth,the breakthrough pressure of type I mudstone(shale content>90%)is about 4 MPa,that of type II mudstone(80%<shale content<90%)is about 2 MPa,and that of type III mudstone(60%<shale content<80%)is about 1.5 MPa.In conclusion,the edge water encroachment can be delayed and the water-free gas production period of gas well can be extended by increasing the length of horizontal section and controlling the production pressure difference.It is recommended to carry out balanced gas production in horizontal wells in the initial stage of production,enhance dynamic monitoring in the process of production,and drain the water in time in the case of water breakthrough so as to increase its cumulative gas production.
基金Supported by the research grant of the Chungbuk National University in 2004
文摘AIM: To identify the factors associated with virologic breakthrough and to select a subgroup of patients who respond well to lamivudine without developing virologic breakthrough (VBT). METHODS: Of 79 patients who had received lamivudine therapy for 9-57 mo, 34 were HBeAg-positive and 45 were HBeAg-negative, 24 developed virologic breakthrough and 55 did not. Clinical and virologic factors were compared between the two groups. RESULTS: The median duration of therapy was 25 (9-57) mo. Virologic breakthrough was defined as a > 1 log HBV DNA increase following initial suppression. When several factors, including gender, duration of infection, baseline HBV DNA, and baseline ALT in HBeAg-positive chronic hepatitis patients were analyzed by logistic regression, the most important predictor of virologic breakthrough was the baseline HBV DNA (r2 = 0.12, P < 0.05). When HBeAg-postitive chronic hepatitis patients were divided into two groups by a point of 6.6 log HBV DNA, the incidence of virologic breakthough between two groups was significantly different. CONCLUSION: Lamivudine may remain an effective first line therapy for those HBeAg-positive patients with a baseline HBV DNA < 6.6 log10 copies/mL.
文摘Scaled physical model tests for steam breakthrough were conducted based on the analysis of mechanisms and influence factors of steam breakthrough. Physical simulation results showed that at the initial steam breakthrough, preferential flow channels were formed in narrow sand packs and most residual oil left in these channels was immobile. This shortened the steam breakthrough time of follow-up steam flooding and decreased the increment of oil recovery efficiency. Steam breakthrough occurred easily for a smaller producer-injector spacing, and a bigger difference in physical properties between fluids and rock. Steam breakthrough is more likely to occur at a larger formation permeability （k）, greater steam displacement velocity （u） and smaller producer-injector spacing （L）. Steam breakthrough time is a function of the parameter group （uk/L）, i.e. tb=3.2151 （uk/L）^-0.5142. A non piston-like displacement model was built based on steam breakthrough observation for a steam stimulated well in the Jinglou Oilfield, Henan Oilfield Company. The steam volume swept in different directions could be obtained from inter-well permeability capacity and breakthrough angle, and the steam swept pore volume （SSPV） was also determined. Numerical simulation showed that steam sweep efficiency reached its peak value when a slug of profile control agent （slug size 10%-15% SSPV） was set at one half of the inter-well spacing. Field test with 12.5% SSPV of profile control agents in the Jinglou Oilfield achieved success in sealing breakthrough channels and good production performance of adjacent producers.
文摘Cerebral arteriovenous malformations(AVMs) have abnormally enlarged arteries and veins prone to spontaneous hemorrhage.Immediately following surgical excision of a cerebral AVM,even normal brain tissue surrounding the lesion is subject to hemorrhage,a phenomenon termed normal perfusion pressure breakthrough(NPPB) syndrome.According to this theory,arteries supplying cerebral AVMs become dilated and lose their capacity to dilate or constrict to autoregulate pressure.Acutely after removal of a cerebral AVM,excessive blood pressure in these arterial feeders can cause normal brain tissue to bleed.However,this theory remains controversial.We present a patient with a cerebral AVM that demonstrated cerebrovascular reactivity and argues against an assumption underlying the theory of NPPB syndrome.
基金Supported by the China National Science and Technology Major Project(2017ZX05063).
文摘Based on exploration and development results and evaluation of marine shale gas in South China in the past ten years, in view of the features of "high maturity, strong tectonic reformation and high shear stress" of the shale in Zhaotong exploration zone in the Yunnan and Guizhou Plateau, as well as the key issues of long time diffusion and leakage of shallow shale gas, and the preservation conditions, the factors controlling shallow shale gas sweet spot and key zone selection evaluation technology of shale gas are investigated. From 2017 to 2018, the first significant exploration breakthrough was made in the Taiyang anticline at a buried depth of 700 to 2 000 m, discovering large-scale proved geological reserves of shallow shale gas. By examining the accumulation conditions and sweet spot control factors of the shallow shale gas in this area, it is found that the accumulation and productivity potential of shale gas in the mountainous area with complex structure outside basin are controlled by five factors:(1) The gas-rich area has weak tectonic reformation and good preservation conditions on the whole, taking on typical anticline trap occurrence mode.(2) The gas-rich area is in over-pressure state and high in shale gas content.(3) The gas-rich area has high quality shale and thus superior source rock condition.(4) The gas-rich area has high quality reservoirs dominated by class I.(5) The shale gas reservoir in the gas-rich area has high content of brittle minerals and small difference between maximum and minimum horizontal stresses which are conducive to hydraulic fracturing. The innovative practice and core technologies formed during the exploration and production capacity construction of shallow shale gas in the Zhaotong demonstration zone have great reference significance for shallow shale gas exploration and development in other areas.
基金financial support from the projects of the National Natural Science Foundation of China(NSFC)(Grant Nos.51809259,51774056,and 51774095)the CAS Pioneer Hundred Talents Program in China。
文摘It is well known that the complicated channeling of fluid flow and heat transfer is strongly related with the intricate natural fracture system.However,it is still challenging to set up the fracture network model which is strong heterogeneous.Compared with other methods(e.g.equivalent continuum model(ECM),discrete fracture model(DFM),and ECM-DFM),the fracture flow module in the COMSOL Multiphysics simulator is powerful in definition of fractures as the inner flow boundary existing in the porous media.Thus it is selected to simulate the fluid flow and heat transfer in the geothermal-developed fractured granite of Sanguliu area located at Liaodong Peninsula,Eastern China.The natural faults/fractures based on field investigation combined with the discrete fracture network(DFN)generated by the MATLAB are used to represent the two-dimensional geological model.Numerical results show that early thermal breakthrough occurs at the production well caused by quick flow of cold water along the highly connected fractures.Suitable hydraulic fracturing treatments with proper injection rates,locations,etc.can efficiently hinder the thermal breakthrough time in the natural fracture system.Large well spacing helps the long-term operation of geothermal production,but it is highly dependent on the geometrical morphology of the fracture network.The enhancement of reservoir properties at the near-well regions can also increase the geothermal production efficiency.The results in this study can provide references to achieve a sustainable geothermal exploitation in fractured granitic geothermal reservoirs or hot dry rocks at depth.
文摘AIM: Predictive value of serum b2-microglobulin (b2m)levels for virological breakthrough (VB) in HBeAg-negative chronic hepatitis B (CHB) patients under long-term treatment schedules including lamivudine (LAM).METHODS: Serum b2m levels were calculated during treatment in 25 CHB patients under long-term LAM monotherapy (group A) and 12 patients under initial interferon plus LAM treatment followed by LAM monotherapy (group B), using the MEIA technology. We used Cox proportional hazard models in order to investigate the association between serum b2m levels and VB.RESULTS: Seven of 25 patients (28%), 9/25 (36%) and 14/25 (56%) from group A and 0/12, 2/12 (16.6%) and 3/12 (25%) from group B exhibited VB at months 12, 24 and 36 of treatment, respectively. All patients, from both groups, who did not show VB exhibited b2m elevation in mo 3. The duration of b2m elevation was significantly longer in the virological responder's subgroup from group A than the non-responder's one (7.3±2.6 vs 3.8±3.4 mo,P = 0.02). In comparison to group A patients whose b2m levels were increased at 3 mo, patients whose b2m levels were decreased had 4.6 times higher risk of experiencing VB (RR = 4.6, P = 0.024). When baseline variables were simultaneously included in the same Cox model, decreased b2m status was still associated with increased risk of VB (RR = 12.2, P = 0.03).CONCLUSION: In HBeAg-negative CHB patients under either long-term LAM monotherapy or initial combination treatment, serum b2m levels at 3 mo of treatment,compared to baseline ones, might be a predictor of risk for VB.
基金supported by grants from the National Natural Science Foundation of China(Grant No.81970459)。
文摘The liver is the largest solid organ,and it is involved in multiple biological processes,including energy metabolism,protein synthesis,and detoxification1.Under physiological or pathological conditions,the liver can regrow to normal size even after resection of 90%of the liver volume because of its strong regeneration ability2.Changes in diet,viral infection(HBV and/or HCV)。
基金Supported by the National Natural Science Foundation of China(71572028,71872027)the Research Funds of Civil Aviation Flight University of China(XM3882).
文摘Breakthrough innovation is seen as a leading technology and industrial development direction, by which enterprises obtain the key for winning sustainable competitive advantage. In this paper, a chaos model is developed to examine how the breakthrough innovation evolves with the changed external environment ability and internal power. Numerical simulations based on chaos theory illustrate that the breakthrough innovation leads to chaos through the period-doubling bifurcation, and the chaos is the result of nonlinear interaction which is a qualitative change in the process between internal dynamics and external factors. The general conditions in which the breakthrough innovation comes to chaos instead of being in good order are gotten. The results show that the breakthrough innovation has chaotic characteristics and has a very sensitive dependence on the initial conditions in the process of running. The chaotic evolution can reflect the nonlinear character of the breakthrough innovation development and it can provide theoretical guidance for the application of chaos and chaotic control of innovation management.
基金Project(2011ZX05009-004)supported by the National Science and Technology Major Projects of China
文摘Dimensional analysis and numerical simulations were carried out to research prediction method of breakthrough time of horizontal wells in bottom water reservoir. Four dimensionless independent variables and dimensionless time were derived from 10 influencing factors of the problem by using dimensional analysis. Simulations of horizontal well in reservoir with bottom water were run to find the prediction correlation. A general and concise functional relationship for predicting breakthrough time was established based on simulation results and theoretical analysis. The breakthrough time of one conceptual model predicted by the correlation is very close to the result by Eclipse with less than 2% error. The practical breakthrough time of one well in Helder oilfield is 10 d, and the predicted results by the method is 11.2 d, which is more accurate than the analytical result. Case study indicates that the method could predict breakthrough time of horizontal well under different reservoir conditions accurately. For its university and ease of use, the method is suitable for quick prediction of breakthrough time.
基金supported by Open Research Fund of State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences(Grant No.SKLGME021010)funded by the National Natural Science Foundation of China(Grant No.41702251 and 42141010)the MOE Key Laboratory of Groundwater Circulation and Environmental Evolution。
文摘Gas breakthrough pressure is a key parameter to evaluate the sealing capacity of caprock,and it also plays important roles in safety and capacity of CO_(2)geological storage.Based on the published experimental results,we present numerical simulations on CO_(2)breakthrough pressure in unsaturated low-permeability rock under 9 multiple P-T conditions(which can keep CO_(2)in gaseous,liquid and supercritical states)and thus,a numerical method which can be used to accurately predict CO_(2)breakthrough pressure on rock-core scale is proposed.The simulation results show that CO_(2)breakthrough pressure and breakthrough time are exponential correlated with P-T conditions.Meanwhile,pressure has stronger effects on experimental results than that of temperature.Moreover,we performed sensitivity studies on the pore distribution indexλ(0.6,0.7,0.8,and 0.9)in van Genuchten-Muale model.Results show that with the increase ofλ,CO_(2)breakthrough pressure and breakthrough time both show decreasing trends.In other words,the larger the value ofλis,the better the permeability of the caprock is,and the worse the CO_(2)sealing capacity is.The numerical method established in this study can provide an important reference for the prediction of gas breakthrough pressure on rock-core scale and for related numerical studies.
基金the Natural Science Foundation Training Project of Shandong Province,China(Grant No.ZR2018PEE026)the Science and Technology Planning Project of Zaozhuang City,Shandong Province,China(Grant No.2018GX12)+1 种基金the Project of Science Research Foundation of Zaozhuang University,China(Grant No.2017ZX16)the Doctoral Scientific Research Foundation of Zaozhuang University,China(Grant No.2017BS01).
文摘The regeneration of a spent packing is crucial with respect to the development of circular economy and abstemious society.Thus,the effects of regeneration temperature,resistant time,heating rate,and regeneration cycle on the breakthrough performance of methylene blue(MB)dye⁃exhausted ceramsite in a two⁃stage fixed⁃bed column were studied in this work.Results illustrate that the ceramsite exhibited excellent potential regeneration properties under the following optimal regeneration conditions:treatment temperature was 600°C,resistant time was 15 min,heating rate was 20℃/min,regeneration cycle was over 9 cycles,and the breakthrough time,saturation time,regeneration efficiency(RE),and regeneration loss rate(RLR)were 540 min,1020 min,64.61%,and 17.73%,respectively.The RE declined by 35.14%in over 1 cycle,while the RLR increased by 3.15 times in over 9 cycles.Besides,Thomas model was suitable to describe the two⁃stage fixed⁃bed column adsorption and thermal regeneration process with R2=0.978.In conclusion,a thorough understanding of the regeneration behavior of the two⁃stage fixed⁃bed column packed with ceramsite provides reference to obtain an effective and feasible regeneration approach,and it is beneficial for further application in water treatment.
基金supported by basic research project of Chinese Academy of Geological Sciences(No.YK202309).Special thanks are due to the reviewers and editors of this journal for their valuable suggestions and revisions of the manuscript.
文摘Fractures play a pivotal role in carbonate thermal storage systems,serving as primary hydraulic conductivity channels that significantly influence thermal breakthrough times and heat extraction efficiency in geothermal-to-well systems.Their impact is critical for well placement and system life prediction.This paper focuses on a geothermal-to-well system within the carbonate reservoir of the Wumishan formation in the Rongcheng geothermal field,Xiong'an new area.It employs a combination of field tests and numerical simulations to determine the permeability of the reservoir and the evolution of fractures between wells.It also examines the influence of fracture width and roughness coefficient on the seepage and temperature fields under various injection scenarios and predicts thermal breakthrough times for production wells.The results show:Higher permeability is observed near well D16 compared to well D22 within the studied geothermal-to-well systems.Wider fractures between wells result in faster temperature decline in production wells.Lower injection flow rates lead to slower temperature reduction in injection wells.The use of roughness coefficients minimizes temperature variations in production wells.This study not only offers guidance for the development and utilization of the geothermal well system,but also contributes to a deeper understanding of the groundwater seepage and heat transfer process influenced by fractures.
