BACKGROUND Blood glucose and serum albumin have been associated with cardiovascular disease prognosis,but the impact of admission-blood-glucose-to-albumin ratio(AAR)on adverse outcomes in critical ill coronary artery ...BACKGROUND Blood glucose and serum albumin have been associated with cardiovascular disease prognosis,but the impact of admission-blood-glucose-to-albumin ratio(AAR)on adverse outcomes in critical ill coronary artery disease(CAD)patients was not investigated.METHODS Patients diagnosed with CAD were non-consecutively selected from the MIMIC-IV database and categorized into quartiles based on their AAR.The primary outcome was 1-year mortality,and secondary endpoints were in-hospital mortality,acute kidney injury(AKI),and renal replacement therapy(RRT).A restricted cubic splines model and Cox proportional hazard models assessed the association between AAR and adverse outcomes in CAD patients.Kaplan-Meier survival analysis determined differences in endpoints across subgroups.RESULTS A total of 8360 patients were included.There were 726 patients(8.7%)died in the hospital and 1944 patients(23%)died at 1 year.The incidence of AKI and RRT was 63%and 4.3%,respectively.High AAR was markedly associated with in-hospital mortality(HR=1.587,P=0.003),1-year mortality(HR=1.502,P<0.001),AKI incidence(HR=1.579,P<0.001),and RRT(HR=1.640,P<0.016)in CAD patients in the completely adjusted Cox proportional hazard model.Kaplan-Meier survival analysis noted substantial differences in all endpoints based on AAR quartiles.Stratified analysis and interaction test demonstrated stable correlations between AAR and outcomes.CONCLUSIONS The results highlight that AAR may be a potential indicator for assessing in-hospital mortality,1-year mortality,and adverse renal prognosis in critical CAD patients.展开更多
Damage to electrical equipment in an earthquake can lead to power outage of power systems.Seismic fragility analysis is a common method to assess the seismic reliability of electrical equipment.To further guarantee th...Damage to electrical equipment in an earthquake can lead to power outage of power systems.Seismic fragility analysis is a common method to assess the seismic reliability of electrical equipment.To further guarantee the efficiency of analysis,multi-source uncertainties including the structure itself and seismic excitation need to be considered.A method for seismic fragility analysis that reflects structural and seismic parameter uncertainty was developed in this study.The proposed method used a random sampling method based on Latin hypercube sampling(LHS)to account for the structure parameter uncertainty and the group structure characteristics of electrical equipment.Then,logistic Lasso regression(LLR)was used to find the seismic fragility surface based on double ground motion intensity measures(IM).The seismic fragility based on the finite element model of an±1000 kV main transformer(UHVMT)was analyzed using the proposed method.The results show that the seismic fragility function obtained by this method can be used to construct the relationship between the uncertainty parameters and the failure probability.The seismic fragility surface did not only provide the probabilities of seismic damage states under different IMs,but also had better stability than the fragility curve.Furthermore,the sensitivity analysis of the structural parameters revealed that the elastic module of the bushing and the height of the high-voltage bushing may have a greater influence.展开更多
<strong>Objective:</strong> To observe the changes of fetal umbilical vein (UV) Doppler parameters in pregnant women with preeclampsia (PE) and analyze their predictive values for maternal PE. <strong&g...<strong>Objective:</strong> To observe the changes of fetal umbilical vein (UV) Doppler parameters in pregnant women with preeclampsia (PE) and analyze their predictive values for maternal PE. <strong>Methods:</strong> Forty-six patients with PE who underwent systematic ultrasound examination in our hospital from December 2017 to May 2021 were included as the subjects, which were divided into two groups according to the severity of the disease (23 cases in each group). And 120 normal pregnant women who underwent health examination in our hospital during the same period were enrolled as the control group. Color Doppler ultrasonography was used to monitor the umbilical vein flow (QUV), left portal vein flow (QLPV), venous catheter flow (QDV), left portal vein (LPV) shunt rate and venous catheter (DV) shunt rate. And the sensitivity and specificity of the related indexes were calculated and analyzed according to the gold standard for clinical diagnosis of PE. <strong>Results:</strong> As the severity of PE increased, the fetal QUV, QLPV and LPV shunt rates decreased, and the QDV and DV shunt rates increased, with statistically significant differences compared with the control group (P < 0.05). The specificity and sensitivity of the combination of fetal QUV, QLPV, QDV, LPV shunt rate and DV shunt rate in predicting PE were higher than those of the indexes used alone (P < 0.05). <strong>Conclusion:</strong> The fetal umbilical vein Doppler parameters QUV, QLPV, QDV, LPV shunt rate, and DV shunt rate have some value in predicting PE, but their combination showed greater value, as well as higher diagnostic and clinical significance.展开更多
AIM To investigate the performance of transient elastography(TE) for diagnosis of fibrosis in patients with autoimmune hepatitis-primary biliary cholangitis(AIHPBC) overlap syndrome.METHODS A total of 70 patients with...AIM To investigate the performance of transient elastography(TE) for diagnosis of fibrosis in patients with autoimmune hepatitis-primary biliary cholangitis(AIHPBC) overlap syndrome.METHODS A total of 70 patients with biopsy-proven AIH-PBC overlap syndrome were included. Spearman correlation test was used to analyze the correlation of liver stiffness measurement(LSM) and fibrosis stage. Independent samples Student's t-test or one-way analysis of variance was used to compare quantitative variables. Receiver operating characteristics(ROC) curve was used to calculate the optimal cut-off values of LSM for predicting individual fibrosis stages. A comparison on the diagnostic accuracy for severe fibrosis was made between LSM and other serological scores.RESULTS Patients with AIH-PBC overlap syndrome had higher median LSM than healthy controls(11.3 ± 6.4 k Pa vs 4.3 ± 1.4 k Pa, P < 0.01). LSM was significantly correlated with fibrosis stage(r = 0.756, P < 0.01). LSM values increased gradually with an increased fibrosis stage. The areas under the ROC curves of LSM for stages F ≥ 2, F ≥ 3, and F4 were 0.837(95%CI: 0.729-0.914), 0.910(0.817-0.965), and 0.966(0.893-0.995), respectively. The optimal cut-off values of LSM for fibrosis stages F ≥ 2, F ≥ 3, and F4 were 6.55, 10.50, and 14.45 k Pa, respectively. LSM was significantly superior to fibrosis-4, glutaglumyl-transferase/platelet ratio, and aspartate aminotransferase-to-platelet ratio index scores in detecting severe fibrosis(F ≥ 3)(0.910 vs 0.715, P < 0.01; 0.910 vs 0.649, P < 0.01; 0.910 vs 0.616, P < 0.01, respectively).CONCLUSION TE can accurately detect hepatic fibrosis as a noninvasive method in patients with AIH-PBC overlap syndrome.展开更多
Sand fences made of punched steel plate(PSP)have recently been applied to control wind-blown sand in desertified and Gobi areas due to their strong wind resistance and convenient in situ construction.However,few studi...Sand fences made of punched steel plate(PSP)have recently been applied to control wind-blown sand in desertified and Gobi areas due to their strong wind resistance and convenient in situ construction.However,few studies have assessed the protective effect of PSP sand fences,especially through field observations.This study analyzes the effects of double-row PSP sand fences on wind and sand resistance using field observations and a computational fluid dynamics(CFD)numerical simulation.The results of field observations showed that the average windproof efficiencies of the first-row and second-row sand fences were 79.8%and 70.8%,respectively.Moreover,the average windproof efficiencies of the numerical simulation behind the first-row and second-row sand fences were 89.8%and 81.1%,respectively.The sand-resistance efficiency of the double-row PSP sand fences was 65.4%.Sand deposition occurred close to the first-row sand fence;however,there was relatively little sand on the leeward side of the second-row sand fence.The length of sand accumulation near PSP sand fences obtained by numerical simulation was basically consistent with that through field observations,indicating that field observations combined with numerical simulation can provide insight into the complex wind-blown sand field over PSP sand fences.This study indicates that the protection efficiency of the double-row PSP sand fences is sufficient for effective control of sand hazards associated with extremely strong wind in the Gobi areas.The output of this work is expected to improve the future application of PSP sand fences.展开更多
With the increasing intelligence and integration,a great number of two-valued variables(generally stored in the form of 0 or 1)often exist in large-scale industrial processes.However,these variables cannot be effectiv...With the increasing intelligence and integration,a great number of two-valued variables(generally stored in the form of 0 or 1)often exist in large-scale industrial processes.However,these variables cannot be effectively handled by traditional monitoring methods such as linear discriminant analysis(LDA),principal component analysis(PCA)and partial least square(PLS)analysis.Recently,a mixed hidden naive Bayesian model(MHNBM)is developed for the first time to utilize both two-valued and continuous variables for abnormality monitoring.Although the MHNBM is effective,it still has some shortcomings that need to be improved.For the MHNBM,the variables with greater correlation to other variables have greater weights,which can not guarantee greater weights are assigned to the more discriminating variables.In addition,the conditional P(x j|x j′,y=k)probability must be computed based on historical data.When the training data is scarce,the conditional probability between continuous variables tends to be uniformly distributed,which affects the performance of MHNBM.Here a novel feature weighted mixed naive Bayes model(FWMNBM)is developed to overcome the above shortcomings.For the FWMNBM,the variables that are more correlated to the class have greater weights,which makes the more discriminating variables contribute more to the model.At the same time,FWMNBM does not have to calculate the conditional probability between variables,thus it is less restricted by the number of training data samples.Compared with the MHNBM,the FWMNBM has better performance,and its effectiveness is validated through numerical cases of a simulation example and a practical case of the Zhoushan thermal power plant(ZTPP),China.展开更多
During the last decade,the rapid development of lithium-ion battery(LIB)energy storage systems has provided significant support for the efficient operation of renewable energy stations.In the coming years,the service ...During the last decade,the rapid development of lithium-ion battery(LIB)energy storage systems has provided significant support for the efficient operation of renewable energy stations.In the coming years,the service life demand of energy storage systems will be further increased to 30 years from the current 20 years on the basis of the equivalent service life of renewable energy stations.However,the life of the present LIB is far from meeting such high demand.Therefore,research on the next-generation LIB with ultra-long service life is imminent.Prelithiation technology has been widely studied as an important means to compensate for the initial coulombic efficiency loss and improve the service life of LIBs.This review systematically summarized the different prelithiation methods from anode and cathode electrodes.Moreover,the large-scale industrialization challenge and the possibility of the existing prelithiation technology are analyzed,based on three key parameters:industry compatibility,prelithiation efficiency,and energy density.Finally,the future trends of improvement in LIB performance by other overlithiated cathode materials are presented,which gives a reference for subsequent research.展开更多
The lithium dendrite and parasitic reactions are two major challenges for lithium(Li)metal anode—the most promising anode materials for high-energy-density batteries.In this work,both the dendrite and parasitic react...The lithium dendrite and parasitic reactions are two major challenges for lithium(Li)metal anode—the most promising anode materials for high-energy-density batteries.In this work,both the dendrite and parasitic reactions that occurred between the liquid electrolyte and Li-metal anode could be largely inhibited by regulating the Li+-solvation structure.The saturated Li+-solvation species exist in commonly used LiPF 6 liquid electrolyte that needs extra energy to desolvation during Li-electrodeposition.Partial solvation induced high-energy state Li-ions would be more energy favorable during the electron-reduction process,dominating the competition with solvent reduction reactions.The Li-symmetric cells that are cycling at higher temperatures show better performance;the cycled lithium metal anode with metallic lustre and the dendrite-free surface is observed.Theoretical calculation and experimental measurements reveal the existence of high-energy state Li+-solvates species,and their concentration increases with temperature.This study provides insight into the Li+-solvation structure and its electrodeposition characteristics.展开更多
BACKGROUND Lipid metabolism disorder and inflammatory-immune activation are vital triggers in the pathogenesis of nonalcoholic fatty liver disease(NAFLD).Various studies have shown that PPAR-γexerts potent anti-infla...BACKGROUND Lipid metabolism disorder and inflammatory-immune activation are vital triggers in the pathogenesis of nonalcoholic fatty liver disease(NAFLD).Various studies have shown that PPAR-γexerts potent anti-inflammatory and immunomodulatory properties.However,little is known about the regulation of PPAR-γactivity in modulating cell crosstalk in NAFLD.AIM To investigate whether the regulation of PPAR-γactivity in lipid-laden hepatocytes affects macrophage polarization and inflammation.METHODS Primary hepatocytes were isolated from wild-type C57BL6/J mice or hepatocytespecific PPAR-γknockout mice and incubated with free fatty acids(FFAs).Macrophages were incubated with conditioned medium(CM)from lipid-laden hepatocytes with or without a PPAR-γagonist.Wild-type C57BL/6J mice were fed a high-fat(HF)diet and administered rosiglitazone.RESULTS Primary hepatocytes exhibited significant lipid deposition and increased ROS production after incubation with FFAs.CM from lipid-laden hepatocytes promoted macrophage polarization to the M1 type and activation of the TLR4/NF-κB pathway.A PPAR-γagonist ameliorated oxidative stress and NLRP3 inflammasome activation in lipid-laden hepatocytes and subsequently prevented M1 macrophage polarization.Hepatocyte-specific PPAR-γdeficiency aggravated oxidative stress and NLRP3 inflammasome activation in lipid-laden hepatocytes,which further promoted M1 macrophage polarization.Rosiglitazone administration improved oxidative stress and NLRP3 inflammasome activation in HF diet-induced NAFLD mice in vivo.CONCLUSION Upregulation of PPAR-γactivity in hepatocytes alleviated NAFLD by modulating the crosstalk between hepatocytes and macrophages via the reactive oxygen species-NLRP3-IL-1βpathway.展开更多
To ensure the long-term safety and stability of bridge pile foundations in permafrost regions,it is necessary to investigate the rheological effects on the pile tip and pile side bearing capacities.The creep character...To ensure the long-term safety and stability of bridge pile foundations in permafrost regions,it is necessary to investigate the rheological effects on the pile tip and pile side bearing capacities.The creep characteristics of the pile-frozen soil interface are critical for determining the long-term stability of permafrost pile foundations.This study utilized a self-developed large stress-controlled shear apparatus to investigate the shear creep characteristics of the frozen silt-concrete interface,and examined the influence of freezing temperatures(−1,−2,and−5°C),contact surface roughness(0,0.60,0.75,and 1.15 mm),normal stress(50,100,and 150 kPa),and shear stress on the creep characteristics of the contact surface.By incorporating the contact surface’s creep behavior and development trends,we established a creep constitutive model for the frozen silt-concrete interface based on the Nishihara model,introducing nonlinear elements and a damage factor.The results revealed significant creep effects on the frozen silt-concrete interface under constant load,with creep displacement at approximately 2-15 times the instantaneous displacement and a failure creep displacement ranging from 6 to 8 mm.Under different experimental conditions,the creep characteristics of the frozen silt-concrete interface varied.A larger roughness,lower freezing temperatures,and higher normal stresses resulted in a longer sample attenuation creep time,a lower steady-state creep rate,higher long-term creep strength,and stronger creep stability.Building upon the Nishihara model,we considered the influence of shear stress and time on the viscoelastic viscosity coefficient and introduced a damage factor to the viscoplasticity.The improved model effectively described the entire creep process of the frozen silt-concrete interface.The results provide theoretical support for the interaction between pile and soil in permafrost regions.展开更多
BACKGROUND Hepatic steatosis commonly occurs in some chronic liver diseases and may affect disease progression.AIM To investigate the performance of controlled attenuation parameter(CAP)for the diagnosis of hepatic st...BACKGROUND Hepatic steatosis commonly occurs in some chronic liver diseases and may affect disease progression.AIM To investigate the performance of controlled attenuation parameter(CAP)for the diagnosis of hepatic steatosis in patients with autoimmune liver diseases(AILDs).METHODS Patients who were suspected of having AILDs and underwent liver biopsy were consistently enrolled.Liver stiffness measurement(LSM)and CAP were performed by transient elastography.The area under the receiver operating characteristic(AUROC)curve was used to evaluate the performance of CAP for diagnosing hepatic steatosis compared with biopsy.RESULTS Among 190 patients with biopsy-proven hepatic steatosis,69 were diagnosed with autoimmune hepatitis(AIH),18 with primary biliary cholangitis(PBC),and 27 with AIH-PBC overlap syndrome.The AUROCs of CAP for the diagnosis of steatosis in AILDS were 0.878(0.791-0.965)for S1,0.764(0.676-0.853)for S2,and 0.821(0.716-0.926)for S3.The CAP value was significantly related to hepatic steatosis grade(P<0.001).Among 69 patients with AIH,the median CAP score was 205.63±47.36 dB/m for S0,258.41±42.83 dB/m for S1,293.00±37.18 dB/m for S2,and 313.60±27.89 dB/m for S3.Compared with patients with nonalcoholic fatty liver disease(NAFLD)presenting with autoimmune markers,patients with AIH concomitant with NAFLD were much older and had higher serum IgG levels and LSM values.CONCLUSION CAP can be used as a noninvasive diagnostic method to evaluate hepatic steatosis in patients with AILDs.Determination of LSM combined with CAP may help to identify patients with AIH concomitant with NAFLD from those with NAFLD with autoimmune phenomena.展开更多
As a key material for lithium metal batteries(LMBs),lithium metal is one of the most promising anode materials to break the bottleneck of battery energy density and a commonly used active material for reference electr...As a key material for lithium metal batteries(LMBs),lithium metal is one of the most promising anode materials to break the bottleneck of battery energy density and a commonly used active material for reference electrodes.Although lithium anodes are regarded as the holy grail of lithium batteries,decades of exploration have not led to the successful commercialization of LMBs,due mainly to the challenges related to the inherent properties of lithium metal.To pave the way for further investigation,herein,a comprehensive review focusing on the fundamental science of lithium are provided.Firstly,the natures of lithium atoms and their isotopes,lithium clusters and lithium crystals are revisited,especially their structural and energetic properties.Subsequently,the electrochemical properties of lithium metal are reviewed.Numerous important concepts and scientific questions,including the electronic structure of lithium,influence of high pressure and low temperature on the properties of lithium,factors influencing lithium deposition,generation of lithium dendrites,and electrode potential of lithium in different electrolytes,are explained and analyzed in detail.Approaches to improve the performance of lithium anodes and thoughtfulness about the electrode potential in lithium battery research are proposed.展开更多
基金supported by the National Nature Science Foundation of China(No.82370336&No.82330014)the Key Research and Development Plan of Heilongjiang Province(2022ZX06C23&JD2023SJ44)the Research Project of the First Affiliated Hospital of Harbin Medical University(No.2021M19).
文摘BACKGROUND Blood glucose and serum albumin have been associated with cardiovascular disease prognosis,but the impact of admission-blood-glucose-to-albumin ratio(AAR)on adverse outcomes in critical ill coronary artery disease(CAD)patients was not investigated.METHODS Patients diagnosed with CAD were non-consecutively selected from the MIMIC-IV database and categorized into quartiles based on their AAR.The primary outcome was 1-year mortality,and secondary endpoints were in-hospital mortality,acute kidney injury(AKI),and renal replacement therapy(RRT).A restricted cubic splines model and Cox proportional hazard models assessed the association between AAR and adverse outcomes in CAD patients.Kaplan-Meier survival analysis determined differences in endpoints across subgroups.RESULTS A total of 8360 patients were included.There were 726 patients(8.7%)died in the hospital and 1944 patients(23%)died at 1 year.The incidence of AKI and RRT was 63%and 4.3%,respectively.High AAR was markedly associated with in-hospital mortality(HR=1.587,P=0.003),1-year mortality(HR=1.502,P<0.001),AKI incidence(HR=1.579,P<0.001),and RRT(HR=1.640,P<0.016)in CAD patients in the completely adjusted Cox proportional hazard model.Kaplan-Meier survival analysis noted substantial differences in all endpoints based on AAR quartiles.Stratified analysis and interaction test demonstrated stable correlations between AAR and outcomes.CONCLUSIONS The results highlight that AAR may be a potential indicator for assessing in-hospital mortality,1-year mortality,and adverse renal prognosis in critical CAD patients.
基金National Key R&D Program of China under Grant Nos.2018YFC1504504 and 2018YFC0809404。
文摘Damage to electrical equipment in an earthquake can lead to power outage of power systems.Seismic fragility analysis is a common method to assess the seismic reliability of electrical equipment.To further guarantee the efficiency of analysis,multi-source uncertainties including the structure itself and seismic excitation need to be considered.A method for seismic fragility analysis that reflects structural and seismic parameter uncertainty was developed in this study.The proposed method used a random sampling method based on Latin hypercube sampling(LHS)to account for the structure parameter uncertainty and the group structure characteristics of electrical equipment.Then,logistic Lasso regression(LLR)was used to find the seismic fragility surface based on double ground motion intensity measures(IM).The seismic fragility based on the finite element model of an±1000 kV main transformer(UHVMT)was analyzed using the proposed method.The results show that the seismic fragility function obtained by this method can be used to construct the relationship between the uncertainty parameters and the failure probability.The seismic fragility surface did not only provide the probabilities of seismic damage states under different IMs,but also had better stability than the fragility curve.Furthermore,the sensitivity analysis of the structural parameters revealed that the elastic module of the bushing and the height of the high-voltage bushing may have a greater influence.
文摘<strong>Objective:</strong> To observe the changes of fetal umbilical vein (UV) Doppler parameters in pregnant women with preeclampsia (PE) and analyze their predictive values for maternal PE. <strong>Methods:</strong> Forty-six patients with PE who underwent systematic ultrasound examination in our hospital from December 2017 to May 2021 were included as the subjects, which were divided into two groups according to the severity of the disease (23 cases in each group). And 120 normal pregnant women who underwent health examination in our hospital during the same period were enrolled as the control group. Color Doppler ultrasonography was used to monitor the umbilical vein flow (QUV), left portal vein flow (QLPV), venous catheter flow (QDV), left portal vein (LPV) shunt rate and venous catheter (DV) shunt rate. And the sensitivity and specificity of the related indexes were calculated and analyzed according to the gold standard for clinical diagnosis of PE. <strong>Results:</strong> As the severity of PE increased, the fetal QUV, QLPV and LPV shunt rates decreased, and the QDV and DV shunt rates increased, with statistically significant differences compared with the control group (P < 0.05). The specificity and sensitivity of the combination of fetal QUV, QLPV, QDV, LPV shunt rate and DV shunt rate in predicting PE were higher than those of the indexes used alone (P < 0.05). <strong>Conclusion:</strong> The fetal umbilical vein Doppler parameters QUV, QLPV, QDV, LPV shunt rate, and DV shunt rate have some value in predicting PE, but their combination showed greater value, as well as higher diagnostic and clinical significance.
基金Supported by the National Natural Science Foundation of China,No.81470842 and No.81770572 to Hua J
文摘AIM To investigate the performance of transient elastography(TE) for diagnosis of fibrosis in patients with autoimmune hepatitis-primary biliary cholangitis(AIHPBC) overlap syndrome.METHODS A total of 70 patients with biopsy-proven AIH-PBC overlap syndrome were included. Spearman correlation test was used to analyze the correlation of liver stiffness measurement(LSM) and fibrosis stage. Independent samples Student's t-test or one-way analysis of variance was used to compare quantitative variables. Receiver operating characteristics(ROC) curve was used to calculate the optimal cut-off values of LSM for predicting individual fibrosis stages. A comparison on the diagnostic accuracy for severe fibrosis was made between LSM and other serological scores.RESULTS Patients with AIH-PBC overlap syndrome had higher median LSM than healthy controls(11.3 ± 6.4 k Pa vs 4.3 ± 1.4 k Pa, P < 0.01). LSM was significantly correlated with fibrosis stage(r = 0.756, P < 0.01). LSM values increased gradually with an increased fibrosis stage. The areas under the ROC curves of LSM for stages F ≥ 2, F ≥ 3, and F4 were 0.837(95%CI: 0.729-0.914), 0.910(0.817-0.965), and 0.966(0.893-0.995), respectively. The optimal cut-off values of LSM for fibrosis stages F ≥ 2, F ≥ 3, and F4 were 6.55, 10.50, and 14.45 k Pa, respectively. LSM was significantly superior to fibrosis-4, glutaglumyl-transferase/platelet ratio, and aspartate aminotransferase-to-platelet ratio index scores in detecting severe fibrosis(F ≥ 3)(0.910 vs 0.715, P < 0.01; 0.910 vs 0.649, P < 0.01; 0.910 vs 0.616, P < 0.01, respectively).CONCLUSION TE can accurately detect hepatic fibrosis as a noninvasive method in patients with AIH-PBC overlap syndrome.
基金This research was funded by the Fellowship of the China Postdoctoral Science Foundation(2021M703466)the Basic Research Innovation Group Project of Gansu Province,China(21JR7RA347)the Natural Science Foundation of Gansu Province,China(20JR10RA231).
文摘Sand fences made of punched steel plate(PSP)have recently been applied to control wind-blown sand in desertified and Gobi areas due to their strong wind resistance and convenient in situ construction.However,few studies have assessed the protective effect of PSP sand fences,especially through field observations.This study analyzes the effects of double-row PSP sand fences on wind and sand resistance using field observations and a computational fluid dynamics(CFD)numerical simulation.The results of field observations showed that the average windproof efficiencies of the first-row and second-row sand fences were 79.8%and 70.8%,respectively.Moreover,the average windproof efficiencies of the numerical simulation behind the first-row and second-row sand fences were 89.8%and 81.1%,respectively.The sand-resistance efficiency of the double-row PSP sand fences was 65.4%.Sand deposition occurred close to the first-row sand fence;however,there was relatively little sand on the leeward side of the second-row sand fence.The length of sand accumulation near PSP sand fences obtained by numerical simulation was basically consistent with that through field observations,indicating that field observations combined with numerical simulation can provide insight into the complex wind-blown sand field over PSP sand fences.This study indicates that the protection efficiency of the double-row PSP sand fences is sufficient for effective control of sand hazards associated with extremely strong wind in the Gobi areas.The output of this work is expected to improve the future application of PSP sand fences.
基金supported by the National Natural Science Foundation of China(62033008,61873143)。
文摘With the increasing intelligence and integration,a great number of two-valued variables(generally stored in the form of 0 or 1)often exist in large-scale industrial processes.However,these variables cannot be effectively handled by traditional monitoring methods such as linear discriminant analysis(LDA),principal component analysis(PCA)and partial least square(PLS)analysis.Recently,a mixed hidden naive Bayesian model(MHNBM)is developed for the first time to utilize both two-valued and continuous variables for abnormality monitoring.Although the MHNBM is effective,it still has some shortcomings that need to be improved.For the MHNBM,the variables with greater correlation to other variables have greater weights,which can not guarantee greater weights are assigned to the more discriminating variables.In addition,the conditional P(x j|x j′,y=k)probability must be computed based on historical data.When the training data is scarce,the conditional probability between continuous variables tends to be uniformly distributed,which affects the performance of MHNBM.Here a novel feature weighted mixed naive Bayes model(FWMNBM)is developed to overcome the above shortcomings.For the FWMNBM,the variables that are more correlated to the class have greater weights,which makes the more discriminating variables contribute more to the model.At the same time,FWMNBM does not have to calculate the conditional probability between variables,thus it is less restricted by the number of training data samples.Compared with the MHNBM,the FWMNBM has better performance,and its effectiveness is validated through numerical cases of a simulation example and a practical case of the Zhoushan thermal power plant(ZTPP),China.
基金funded by the National Natural Science Foundation of China(No.U21A20170(X.He))the Ministry of Science and Technology of China(No.2019YFE0100200(X.He)and 2019YFA0705703(L.Wang))the Tsinghua University Initiative Scientific Research Program(No.2019Z02UTY06(X.He)and 2019THFS0132(L.Wang)).The authors also thank Joint Work Plan for Research Projects under the Clean Vehicles Consortium at U.S.and China-Clean Energy Research Center(CERC-CVC2.0,2016-2020)
文摘During the last decade,the rapid development of lithium-ion battery(LIB)energy storage systems has provided significant support for the efficient operation of renewable energy stations.In the coming years,the service life demand of energy storage systems will be further increased to 30 years from the current 20 years on the basis of the equivalent service life of renewable energy stations.However,the life of the present LIB is far from meeting such high demand.Therefore,research on the next-generation LIB with ultra-long service life is imminent.Prelithiation technology has been widely studied as an important means to compensate for the initial coulombic efficiency loss and improve the service life of LIBs.This review systematically summarized the different prelithiation methods from anode and cathode electrodes.Moreover,the large-scale industrialization challenge and the possibility of the existing prelithiation technology are analyzed,based on three key parameters:industry compatibility,prelithiation efficiency,and energy density.Finally,the future trends of improvement in LIB performance by other overlithiated cathode materials are presented,which gives a reference for subsequent research.
基金This work was funded by the National Natural Science Foundation of China (52073161 and U1564205)the Ministry of Science and Technology of China (No.2019YFE0100200 and 2019YFA0705703)+1 种基金The authors also thank Joint Work Plan for Research Projects under the Clean Vehicles Consortium at U.S.and China-Clean Energy Research Center (CERC-CVC2.0,2016-2020)thank Tsinghua University-Zhangjiagang Joint Institute for Hydrogen Energy and Lithium Ion Battery Technology.
文摘The lithium dendrite and parasitic reactions are two major challenges for lithium(Li)metal anode—the most promising anode materials for high-energy-density batteries.In this work,both the dendrite and parasitic reactions that occurred between the liquid electrolyte and Li-metal anode could be largely inhibited by regulating the Li+-solvation structure.The saturated Li+-solvation species exist in commonly used LiPF 6 liquid electrolyte that needs extra energy to desolvation during Li-electrodeposition.Partial solvation induced high-energy state Li-ions would be more energy favorable during the electron-reduction process,dominating the competition with solvent reduction reactions.The Li-symmetric cells that are cycling at higher temperatures show better performance;the cycled lithium metal anode with metallic lustre and the dendrite-free surface is observed.Theoretical calculation and experimental measurements reveal the existence of high-energy state Li+-solvates species,and their concentration increases with temperature.This study provides insight into the Li+-solvation structure and its electrodeposition characteristics.
基金the National Natural Science Foundation of China,No.81770572.
文摘BACKGROUND Lipid metabolism disorder and inflammatory-immune activation are vital triggers in the pathogenesis of nonalcoholic fatty liver disease(NAFLD).Various studies have shown that PPAR-γexerts potent anti-inflammatory and immunomodulatory properties.However,little is known about the regulation of PPAR-γactivity in modulating cell crosstalk in NAFLD.AIM To investigate whether the regulation of PPAR-γactivity in lipid-laden hepatocytes affects macrophage polarization and inflammation.METHODS Primary hepatocytes were isolated from wild-type C57BL6/J mice or hepatocytespecific PPAR-γknockout mice and incubated with free fatty acids(FFAs).Macrophages were incubated with conditioned medium(CM)from lipid-laden hepatocytes with or without a PPAR-γagonist.Wild-type C57BL/6J mice were fed a high-fat(HF)diet and administered rosiglitazone.RESULTS Primary hepatocytes exhibited significant lipid deposition and increased ROS production after incubation with FFAs.CM from lipid-laden hepatocytes promoted macrophage polarization to the M1 type and activation of the TLR4/NF-κB pathway.A PPAR-γagonist ameliorated oxidative stress and NLRP3 inflammasome activation in lipid-laden hepatocytes and subsequently prevented M1 macrophage polarization.Hepatocyte-specific PPAR-γdeficiency aggravated oxidative stress and NLRP3 inflammasome activation in lipid-laden hepatocytes,which further promoted M1 macrophage polarization.Rosiglitazone administration improved oxidative stress and NLRP3 inflammasome activation in HF diet-induced NAFLD mice in vivo.CONCLUSION Upregulation of PPAR-γactivity in hepatocytes alleviated NAFLD by modulating the crosstalk between hepatocytes and macrophages via the reactive oxygen species-NLRP3-IL-1βpathway.
基金financial support from the National Natural Science Foundation of China(41902272)Gansu Province Basic Research Innovation Group Project(21JR7RA347).
文摘To ensure the long-term safety and stability of bridge pile foundations in permafrost regions,it is necessary to investigate the rheological effects on the pile tip and pile side bearing capacities.The creep characteristics of the pile-frozen soil interface are critical for determining the long-term stability of permafrost pile foundations.This study utilized a self-developed large stress-controlled shear apparatus to investigate the shear creep characteristics of the frozen silt-concrete interface,and examined the influence of freezing temperatures(−1,−2,and−5°C),contact surface roughness(0,0.60,0.75,and 1.15 mm),normal stress(50,100,and 150 kPa),and shear stress on the creep characteristics of the contact surface.By incorporating the contact surface’s creep behavior and development trends,we established a creep constitutive model for the frozen silt-concrete interface based on the Nishihara model,introducing nonlinear elements and a damage factor.The results revealed significant creep effects on the frozen silt-concrete interface under constant load,with creep displacement at approximately 2-15 times the instantaneous displacement and a failure creep displacement ranging from 6 to 8 mm.Under different experimental conditions,the creep characteristics of the frozen silt-concrete interface varied.A larger roughness,lower freezing temperatures,and higher normal stresses resulted in a longer sample attenuation creep time,a lower steady-state creep rate,higher long-term creep strength,and stronger creep stability.Building upon the Nishihara model,we considered the influence of shear stress and time on the viscoelastic viscosity coefficient and introduced a damage factor to the viscoplasticity.The improved model effectively described the entire creep process of the frozen silt-concrete interface.The results provide theoretical support for the interaction between pile and soil in permafrost regions.
基金Supported by National Natural Science Foundation of China,No.81470842 and No.81770572.
文摘BACKGROUND Hepatic steatosis commonly occurs in some chronic liver diseases and may affect disease progression.AIM To investigate the performance of controlled attenuation parameter(CAP)for the diagnosis of hepatic steatosis in patients with autoimmune liver diseases(AILDs).METHODS Patients who were suspected of having AILDs and underwent liver biopsy were consistently enrolled.Liver stiffness measurement(LSM)and CAP were performed by transient elastography.The area under the receiver operating characteristic(AUROC)curve was used to evaluate the performance of CAP for diagnosing hepatic steatosis compared with biopsy.RESULTS Among 190 patients with biopsy-proven hepatic steatosis,69 were diagnosed with autoimmune hepatitis(AIH),18 with primary biliary cholangitis(PBC),and 27 with AIH-PBC overlap syndrome.The AUROCs of CAP for the diagnosis of steatosis in AILDS were 0.878(0.791-0.965)for S1,0.764(0.676-0.853)for S2,and 0.821(0.716-0.926)for S3.The CAP value was significantly related to hepatic steatosis grade(P<0.001).Among 69 patients with AIH,the median CAP score was 205.63±47.36 dB/m for S0,258.41±42.83 dB/m for S1,293.00±37.18 dB/m for S2,and 313.60±27.89 dB/m for S3.Compared with patients with nonalcoholic fatty liver disease(NAFLD)presenting with autoimmune markers,patients with AIH concomitant with NAFLD were much older and had higher serum IgG levels and LSM values.CONCLUSION CAP can be used as a noninvasive diagnostic method to evaluate hepatic steatosis in patients with AILDs.Determination of LSM combined with CAP may help to identify patients with AIH concomitant with NAFLD from those with NAFLD with autoimmune phenomena.
基金gratitude to the National Natural Science Foundation of China(No.22279070,U21A20170,22279071 and 52206263)the Ministry of Science and Technology of China(No.2019YFA0705703 and 2019YFE0100200)The authors thank Joint Work Plan for Research Projects under the Clean Vehicles Consortium at U.S.and China-Clean Energy Research Center(CERCCVC2.0,2016-2020)。
文摘As a key material for lithium metal batteries(LMBs),lithium metal is one of the most promising anode materials to break the bottleneck of battery energy density and a commonly used active material for reference electrodes.Although lithium anodes are regarded as the holy grail of lithium batteries,decades of exploration have not led to the successful commercialization of LMBs,due mainly to the challenges related to the inherent properties of lithium metal.To pave the way for further investigation,herein,a comprehensive review focusing on the fundamental science of lithium are provided.Firstly,the natures of lithium atoms and their isotopes,lithium clusters and lithium crystals are revisited,especially their structural and energetic properties.Subsequently,the electrochemical properties of lithium metal are reviewed.Numerous important concepts and scientific questions,including the electronic structure of lithium,influence of high pressure and low temperature on the properties of lithium,factors influencing lithium deposition,generation of lithium dendrites,and electrode potential of lithium in different electrolytes,are explained and analyzed in detail.Approaches to improve the performance of lithium anodes and thoughtfulness about the electrode potential in lithium battery research are proposed.
