The possibility of determining the integrity of a real structure subjected to non-invasive and non-destructive monitoring,such as that carried out by a series of accelerometers placed on the structure,is certainly a g...The possibility of determining the integrity of a real structure subjected to non-invasive and non-destructive monitoring,such as that carried out by a series of accelerometers placed on the structure,is certainly a goal of extreme and current interest.In the present work,the results obtained from the processing of experimental data of a real structure are shown.The analyzed structure is a lattice structure approximately 9 m high,monitored with 18 uniaxial accelerometers positioned in pairs on 9 different levels.The data used refer to continuous monitoring that lasted for a total of 1 year,during which minor damage was caused to the structure by alternatively removing some bracings and repositioning them in the structure.Two methodologies detecting damage based on decomposition techniques of the acquired data were used and tested,as well as a methodology combining the two techniques.The results obtained are extremely interesting,as all the minor damage caused to the structure was identified by the processing methods used,based solely on the monitored data and without any knowledge of the real structure being analyzed.The results use 15 acquisitions in environmental conditions lasting 10 min each,a reasonable amount of time to get immediate feedback on possible damage to the structure.展开更多
BACKGROUND Major hip surgery usually requires neuraxial or general anesthesia with tracheal intubation and may be supplemented with a nerve block to provide intraoperative and postoperative pain relief.CASE SUMMARY Th...BACKGROUND Major hip surgery usually requires neuraxial or general anesthesia with tracheal intubation and may be supplemented with a nerve block to provide intraoperative and postoperative pain relief.CASE SUMMARY This report established that hip surgical procedures can be performed with a fascia iliaca compartment block(FICB)and monitored anesthesia care(MAC)while avoiding neuraxial or general anesthesia.This was a preliminary experience with two geriatric patients with hip fracture,American Society of Anesthesiologists status III,and with many comorbidities.Neither patient could be operated on within 48 h after admission.Both general anesthesia and neuraxial anesthesia were high-risk procedures and had contraindications.Hence,we chose nerve block combined with a small amount of sedation.Intraoperative analgesia was provided by single-injection ultrasound-guided FICB.Light intravenous sedation was added.Surgical exposure was satisfactory,and neither patient complained of any symptoms during the procedure.CONCLUSION This report showed that hip surgery for geriatric patients can be performed with FICB and MAC,although complications and contraindications are common.The anesthetic program was accompanied by stable respiratory and circulatory system responses and satisfactory analgesia while avoiding the adverse effects and problems associated with either neuraxial or general anesthesia.展开更多
Restoration of contaminated soil and groundwater could be divided into two phases. The first phase takes aim at reducing human being's health risks by active remediation, while the second phase aims at eliminating ec...Restoration of contaminated soil and groundwater could be divided into two phases. The first phase takes aim at reducing human being's health risks by active remediation, while the second phase aims at eliminating ecological risks by natural attenuation (NA). Because of cost-effective and sustainable cleanup, monitored natural attenuation (MNA) and enhanced natural attenuation (ENA) have been gaining more attention recently, especially in the respects of ecological risk-oriented contaminated land management and a follow-up measure after active remediation. The uses and procedures of MNA for contaminated site cleanup and remediation in USA and EU were introduced firstly, and then possible applications of MNA in China were suggested. More developments and practices of MNA and ENA for managing contaminated sites in China are expected.展开更多
Clopidogrel Anergy2003 Germany Müller et at 105 patients with stable coronary artery disease using clopidogrel for PCI,about5%of patients showed no response to the drug,which is defined as platelets in the 20μmo...Clopidogrel Anergy2003 Germany Müller et at 105 patients with stable coronary artery disease using clopidogrel for PCI,about5%of patients showed no response to the drug,which is defined as platelets in the 20μmol/L ADP under the action of its aggregation only on the basis of the inhibition rate of 10%or less.These people postoperative thrombosis,showing the drug has resisters,and postoperative thrombosis related.2004 SchrPat the current展开更多
Rat Liver Cd5Zn2-metallothionein isoforms were titrated with cuprous ion and monitored by 1H NMR Initial replacement occurred in β-domain followed by α-domain.MT exhibited well-defined structure under 10 mole equiva...Rat Liver Cd5Zn2-metallothionein isoforms were titrated with cuprous ion and monitored by 1H NMR Initial replacement occurred in β-domain followed by α-domain.MT exhibited well-defined structure under 10 mole equivalents cuprous ion.展开更多
Objective To summarize the clinical features of intracranial aneurysms of posterior cerebral artery (PCA) ,and the surgical approaches and operative skills to treat them . Methods The aneurysms arose from the P1 segme...Objective To summarize the clinical features of intracranial aneurysms of posterior cerebral artery (PCA) ,and the surgical approaches and operative skills to treat them . Methods The aneurysms arose from the P1 segment in 3 patients,the P2 segment in 5 patients and the P3 segment in 2 patients.展开更多
A comprehensive monitoring program was conducted to measure the rock mass displacements, support response, and stress changes at a longwall tailgate entry in West Virginia.Monitoring was initiated a few days after dev...A comprehensive monitoring program was conducted to measure the rock mass displacements, support response, and stress changes at a longwall tailgate entry in West Virginia.Monitoring was initiated a few days after development of the gateroad entries and continued during passage of the longwall panels on both sides of the entry.Monitoring included overcore stress measurements of the initial stress within the rock mass, changes in cable bolt loading, standing support pressure, roof deformation, rib deformation,stress changes in the coal pillar, and changes in the full three-dimensional stress tensor within the rock mass at six locations around the monitoring site.During the passage of the first longwall, stress measurements in the rock and coal detected minor changes in loading while minor changes were detected in roof deformation.As a result of the relatively favorable stress and geological conditions, the support systems did not experience severe loading or rock deformation until the second panel approached within 10–15 m of the instrumented locations.After reaching the peak loading at about 50–75 mm of roof sag, the cable bolts started to unload, and load was transferred to the standing supports.The standing support system was able to maintain an adequate opening inby the shields to provide ventilation to the first crosscut inby the face, as designed.The results were used to calibrate modeled cable bolt response to field data, and to validate numerical modeling procedures that have been developed to evaluate entry support systems.It is concluded that the support system was more than adequate to control the roof of the tailgate up to the longwall face location.The monitoring results have provided valuable data for the development and validation of support design strategies for longwall tailgate entries.展开更多
This paper analyses the five years’ monitored strains collected from a long-term health monitoring system installed on a bridge with wavelet transform.In the analysis,the monitored strains are pre-processed,features ...This paper analyses the five years’ monitored strains collected from a long-term health monitoring system installed on a bridge with wavelet transform.In the analysis,the monitored strains are pre-processed,features of the monitored data are summarized briefly.The influences of the base functions on the results of wavelet analysis are studied simultaneously.The results show that the db wavelet is a good mother wavelet function in the analysis,and the order N should be larger than 20,but less than 46 in decomposing the monitored strains of the bridge.According to the strain variation features of concrete bridge,the proper decomposition level is 4 in the wavelet multi-resolution analysis.With the present method,the strains caused by random loads and daily sunlight can be accurately extracted from the monitored strains.The decomposed components of the monitored strains show that the amplitudes of the strains caused by random loads,daily sunlight,and annual temperature effect,are about 5 με,25 με,and 50 με respectively.The structural response under random load is smaller than the other parts.展开更多
The status of woody plants in dry-land systems is a fundamental determinant of key ecosystem processes. Monitoring of this status plays an important role in understanding the dynamics of woody plants in arid and semi-...The status of woody plants in dry-land systems is a fundamental determinant of key ecosystem processes. Monitoring of this status plays an important role in understanding the dynamics of woody plants in arid and semi-arid ecosystems. The present study determined the dynamism of the Zagros forests in Iran using Remote Sensing and Geographic Information System techniques and statistical science. The results show that the density of trees varied from 10 to 53 % according to the physio- graphic and climatic conditions of semi-arid regions. The best and lowest correlation between vegetation indices and forest density were obtained for the global environmental monitoring index (GEMI; R2 = 0.94) and soil adjust vegetation index (R2 = 0.81), respectively. GEMI is used to monitor land use changes over a 10-year period. Results show that 2720 ha2 of forest have been destroyed by human interference and tillage on steep slopes during this period which also resulted in the loss of the fertile soil layer. GEMI determined the areas with a biomass of trees and could normally separate border regions with low bio- mass density of trees from regions without canopy cover. The results revealed that assessment of forest and vegetation cover in arid and semi-arid arduous forest regions using satellite digital numbers and ordinary sampling is subject to uncertainty. A stratified grouping procedure should be established to increase the accuracy of assessment.展开更多
This study includes some aspects of the shift in the Dutch attitude in relation to water during the past millennia from defense to attack to keeping the balance(“co-evolution'). It has a special focus on the fres...This study includes some aspects of the shift in the Dutch attitude in relation to water during the past millennia from defense to attack to keeping the balance(“co-evolution'). It has a special focus on the freshwater tidal part, which embraces the largest seaport of the world: Rotterdam, as well as the largest national park of the Netherlands. It reports especially about a young mans endeavor in half a century real time monitoring of some land(scape) units with simple means.展开更多
In general,the material properties,loads,resistance of the prestressed concrete continuous rigid frame bridge in different construction stages are time-varying.So,it is essential to monitor the internal force state wh...In general,the material properties,loads,resistance of the prestressed concrete continuous rigid frame bridge in different construction stages are time-varying.So,it is essential to monitor the internal force state when the bridge is in construction.Among them,how to assess the safety is one of the challenges.As the continuous monitoring over a long-term period can increase the reliability of the assessment,so,based on a large number of monitored strain data collected from the structural health monitoring system(SHMS)during construction,a calculation method of the punctiform time-varying reliability is proposed in this paper to evaluate the stress state of this type bridge in cantilever construction stage by using the basic reliability theory.At the same time,the optimal stress distribution function in the bridge mid-span base plate is determined when the bridge is closed.This method can provide basis and direction for the internal force control of this type bridge in construction process.So,it can reduce the bridge safety and quality accidents in construction stages.展开更多
With the development of the monitoring technology,it is more and more common that the system is continuously monitored.Therefore,the research on the maintenance optimization of the continuously monitored deterioration...With the development of the monitoring technology,it is more and more common that the system is continuously monitored.Therefore,the research on the maintenance optimization of the continuously monitored deterioration system is important.The deterioration process of the discussed system is described by a Gamma process.The predictive maintenance is considered to be imperfect and formulated.The expected interval of two continuous preventive maintenances is derived.Then,the maintenance optimization model of the continuously monitored deterioration system is presented.In the model,the minimization of the expected operational cost per unit time and the maximization of the system availability are the optimization objectives.The improved ideal point method with the normalized objective functions is employed to solve the proposed model.The validity and sensitivity of the proposed multiobjective maintenance optimization model are analyzed by a numerical example.展开更多
When the bridge components needing maintenance are the world problem at present,and the health monitoring system is considered to be a very helpful tool for solving this problem.In this paper,a large number of s...When the bridge components needing maintenance are the world problem at present,and the health monitoring system is considered to be a very helpful tool for solving this problem.In this paper,a large number of strain data acquired from the structural health monitoring system(SHMS)installed on a continuous rigid frame bridge are adopted to do reliability assessment.Firstly,a calculation method of punctiform time-dependent reliability is proposed based on the basic reliability theory,and introduced how to calculate reliability of the bridge by using the stress data transformed from the strain data.Secondly,combined with“Three Sigma”principle and the basic pressure safety reserve requirement,the critical load effects distribution function of the bridge is defined,and then the maintenance reliability threshold for controlling the unfavorable load state which appears in the early operation stage of this type bridge is suggested,and then the combination of bridge maintenance management and health monitoring system is realized.Finally,the transformed stress distribution certifies that the load effects of concrete bridges practically have a normal distribution;as for the concrete continuous rigid frame bridge with C50 strength grade concrete,the retrofit reliability threshold should be valued at 6.13.The methodology suggested in this article can help bridge engineers do effective maintenance of bridges,which can effectively extend the service life of the bridge and bring better economic and social benefits.展开更多
Epilepsy is a severe,relapsing,and multifactorial neurological disorder.Studies regarding the accurate diagnosis,prognosis,and in-depth pathogenesis are crucial for the precise and effective treatment of epilepsy.The ...Epilepsy is a severe,relapsing,and multifactorial neurological disorder.Studies regarding the accurate diagnosis,prognosis,and in-depth pathogenesis are crucial for the precise and effective treatment of epilepsy.The pathogenesis of epilepsy is complex and involves alterations in variables such as gene expression,protein expression,ion channel activity,energy metabolites,and gut microbiota composition.Satisfactory results are lacking for conventional treatments for epilepsy.Surgical resection of lesions,drug therapy,and non-drug interventions are mainly used in clinical practice to treat pain associated with epilepsy.Non-pharmacological treatments,such as a ketogenic diet,gene therapy for nerve regeneration,and neural regulation,are currently areas of research focus.This review provides a comprehensive overview of the pathogenesis,diagnostic methods,and treatments of epilepsy.It also elaborates on the theoretical basis,treatment modes,and effects of invasive nerve stimulation in neurotherapy,including percutaneous vagus nerve stimulation,deep brain electrical stimulation,repetitive nerve electrical stimulation,in addition to non-invasive transcranial magnetic stimulation and transcranial direct current stimulation.Numerous studies have shown that electromagnetic stimulation-mediated neuromodulation therapy can markedly improve neurological function and reduce the frequency of epileptic seizures.Additionally,many new technologies for the diagnosis and treatment of epilepsy are being explored.However,current research is mainly focused on analyzing patients’clinical manifestations and exploring relevant diagnostic and treatment methods to study the pathogenesis at a molecular level,which has led to a lack of consensus regarding the mechanisms related to the disease.展开更多
The atmospheric corrosion monitoring(ACM)technique has been widely employed to track the real-time corrosion behavior of metal materials.However,limited studies have applied ACM to the corrosion protection properties ...The atmospheric corrosion monitoring(ACM)technique has been widely employed to track the real-time corrosion behavior of metal materials.However,limited studies have applied ACM to the corrosion protection properties of organic coatings.This study compared a bare epoxy coating with one containing zinc phosphate corrosion inhibitors,both applied on ACM sensors,to observe their corrosion protection properties over time.Coatings with artificial damage via scratches were exposed to immersion and alternating dry and wet environments,which allowed for monitoring galvanic corrosion currents in real-time.Throughout the corrosion tests,the ACM currents of the zinc phosphate/epoxy coating were considerably lower than those of the blank epoxy coating.The trend in ACM current variations closely matched the results obtained from regular electrochemical tests and surface analysis.This alignment highlights the potential of the ACM technique in evaluating the corrosion protection capabilities of organic coatings.Compared with the blank epoxy coating,the zinc phosphate/epoxy coating showed much-decreased ACM current values that confirmed the effective inhibition of zinc phosphate against steel corrosion beneath the damaged coating.展开更多
Background:Awake craniotomy(AC)has become gold standard in surgical resection of gliomas located in eloquent areas.The conscious sedation techniques in AC include both monitored anesthesia care(MAC)and asleep-awake-as...Background:Awake craniotomy(AC)has become gold standard in surgical resection of gliomas located in eloquent areas.The conscious sedation techniques in AC include both monitored anesthesia care(MAC)and asleep-awake-asleep(AAA).The choice of optimal anesthetic method depends on the preferences of the surgical team(mainly anesthesiologist and neurosurgeon).The aim of this study was to compare the difference in physiological and blood gas data,dosage of different drugs,the probability of switching to endotracheal intubation,and extent of tumor resection and dysfunction after operation between AAA and MAC anesthetic management for resection of gliomas in eloquent brain areas.Methods:Two-hundred and twenty-five patients with super-tentorial tumor located in eloquent areas underwent AC from 2009 to 2021 in Xijing Hospital.Forty-one patients underwent AAA technique,and the rest one-hundred eighty-four patients underwent MAC technique.Anesthetic management,dosage of different drugs,intraoperative complications,postoperative outcomes,adverse events,extent of resection and motor,and sensory and language dysfunction after operation were compared between MAC and AAA.Result:There was no significant difference in gender,KPS score,MMSE score,glioma grade,type,and growth site between the patients in the two groups,except the older age of patients in MAC group than that in AAA group.During the whole process of operation,there were greater pulse pressure difference(P=0.046),shorter operation time(P=0.039),less dosage of remifentanil(P=0.000),more dosage of dexmedetomidine(P=0.013),more use of antiemetics(81%,P=0.0067),lower use of vasoactive agent(45.1%,P=0.010),and lower probability of conversion to general anesthesia(GA,P=0.027)in MAC group than that in AAA group.Blood gas analysis showed that PetCO2(P=0.000),Glu concentration(P=0.000),and PaCO2(P=0.000)were higher,but SPO2(P=0.002)and PaO2(P=0.000)were lower in MAC group than that in AAA group.In the postoperative recovery stage,compared with that of AAA group,the probability of dysfunction in MAC group at 1,3,5,and 7 days after operation was lower,which were 27.8%vs 53.6%(P=0.003),31%vs 68.3%(P=0.000),28.8%vs 63.4%(P=0.000),and 25.6%vs 58.5%(P=0.000),respectively.Conclusion:Compared with AAA,it seems that MAC has more advantages in the management for resection of gliomas in eloquent brain areas,and MAC combined with multiple monitoring such as cerebral cortical mapping,neuronavigation,and ultrasonic detection is worthy of popularization for the resection of gliomas in eloquent brain areas.展开更多
The stochastic alpha beta rho(SABR)model introduced by Hagan et al.(2002)is widely used in both fixed income and the foreign exchange(FX)markets.Continuously monitored barrier option contracts are among the most popul...The stochastic alpha beta rho(SABR)model introduced by Hagan et al.(2002)is widely used in both fixed income and the foreign exchange(FX)markets.Continuously monitored barrier option contracts are among the most popular derivative contracts in the FX markets.In this paper,we develop closed-form formulas to approximate various types of barrier option prices(down-and-out/in,up-and-out/in)under the SABR model.We first derive an approximate formula for the survival density.The barrier option price is the one-dimensional integral of its payoff function and the survival density,which can be easily implemented and quickly evaluated.The approximation error of the survival density is also analyzed.To the best of our knowledge,it is the first time that analytical(approximate)formulas for the survival density and the barrier option prices for the SABR model are derived.Numerical experiments demonstrate the validity and efficiency of these formulas.展开更多
: To measure and monitor the crustal motion in China, a GPS network has been established with an average side length of 1 000 km and with more than 20 points on the margins of each major tectonic block and fault zone ...: To measure and monitor the crustal motion in China, a GPS network has been established with an average side length of 1 000 km and with more than 20 points on the margins of each major tectonic block and fault zone in China. Three campaigns were carried out in 1992,1994 and 1996, respectively by this network. Here we present, for the first time, the horizontal displacement rates of 22 GPS monitoring stations distributed over the whole China and global IGS stations surrounding China, based on these GPS repeated measurements. From these results by GPS, we have obtained the sketch of crustal motion in China.展开更多
基金The author N.I.Giannoccaro received funds from the Department of Innovation Engineering,University of Salento,for acquiring the tool Structural Health Monitoring.
文摘The possibility of determining the integrity of a real structure subjected to non-invasive and non-destructive monitoring,such as that carried out by a series of accelerometers placed on the structure,is certainly a goal of extreme and current interest.In the present work,the results obtained from the processing of experimental data of a real structure are shown.The analyzed structure is a lattice structure approximately 9 m high,monitored with 18 uniaxial accelerometers positioned in pairs on 9 different levels.The data used refer to continuous monitoring that lasted for a total of 1 year,during which minor damage was caused to the structure by alternatively removing some bracings and repositioning them in the structure.Two methodologies detecting damage based on decomposition techniques of the acquired data were used and tested,as well as a methodology combining the two techniques.The results obtained are extremely interesting,as all the minor damage caused to the structure was identified by the processing methods used,based solely on the monitored data and without any knowledge of the real structure being analyzed.The results use 15 acquisitions in environmental conditions lasting 10 min each,a reasonable amount of time to get immediate feedback on possible damage to the structure.
文摘BACKGROUND Major hip surgery usually requires neuraxial or general anesthesia with tracheal intubation and may be supplemented with a nerve block to provide intraoperative and postoperative pain relief.CASE SUMMARY This report established that hip surgical procedures can be performed with a fascia iliaca compartment block(FICB)and monitored anesthesia care(MAC)while avoiding neuraxial or general anesthesia.This was a preliminary experience with two geriatric patients with hip fracture,American Society of Anesthesiologists status III,and with many comorbidities.Neither patient could be operated on within 48 h after admission.Both general anesthesia and neuraxial anesthesia were high-risk procedures and had contraindications.Hence,we chose nerve block combined with a small amount of sedation.Intraoperative analgesia was provided by single-injection ultrasound-guided FICB.Light intravenous sedation was added.Surgical exposure was satisfactory,and neither patient complained of any symptoms during the procedure.CONCLUSION This report showed that hip surgery for geriatric patients can be performed with FICB and MAC,although complications and contraindications are common.The anesthetic program was accompanied by stable respiratory and circulatory system responses and satisfactory analgesia while avoiding the adverse effects and problems associated with either neuraxial or general anesthesia.
文摘Restoration of contaminated soil and groundwater could be divided into two phases. The first phase takes aim at reducing human being's health risks by active remediation, while the second phase aims at eliminating ecological risks by natural attenuation (NA). Because of cost-effective and sustainable cleanup, monitored natural attenuation (MNA) and enhanced natural attenuation (ENA) have been gaining more attention recently, especially in the respects of ecological risk-oriented contaminated land management and a follow-up measure after active remediation. The uses and procedures of MNA for contaminated site cleanup and remediation in USA and EU were introduced firstly, and then possible applications of MNA in China were suggested. More developments and practices of MNA and ENA for managing contaminated sites in China are expected.
文摘Clopidogrel Anergy2003 Germany Müller et at 105 patients with stable coronary artery disease using clopidogrel for PCI,about5%of patients showed no response to the drug,which is defined as platelets in the 20μmol/L ADP under the action of its aggregation only on the basis of the inhibition rate of 10%or less.These people postoperative thrombosis,showing the drug has resisters,and postoperative thrombosis related.2004 SchrPat the current
文摘Rat Liver Cd5Zn2-metallothionein isoforms were titrated with cuprous ion and monitored by 1H NMR Initial replacement occurred in β-domain followed by α-domain.MT exhibited well-defined structure under 10 mole equivalents cuprous ion.
文摘Objective To summarize the clinical features of intracranial aneurysms of posterior cerebral artery (PCA) ,and the surgical approaches and operative skills to treat them . Methods The aneurysms arose from the P1 segment in 3 patients,the P2 segment in 5 patients and the P3 segment in 2 patients.
文摘A comprehensive monitoring program was conducted to measure the rock mass displacements, support response, and stress changes at a longwall tailgate entry in West Virginia.Monitoring was initiated a few days after development of the gateroad entries and continued during passage of the longwall panels on both sides of the entry.Monitoring included overcore stress measurements of the initial stress within the rock mass, changes in cable bolt loading, standing support pressure, roof deformation, rib deformation,stress changes in the coal pillar, and changes in the full three-dimensional stress tensor within the rock mass at six locations around the monitoring site.During the passage of the first longwall, stress measurements in the rock and coal detected minor changes in loading while minor changes were detected in roof deformation.As a result of the relatively favorable stress and geological conditions, the support systems did not experience severe loading or rock deformation until the second panel approached within 10–15 m of the instrumented locations.After reaching the peak loading at about 50–75 mm of roof sag, the cable bolts started to unload, and load was transferred to the standing supports.The standing support system was able to maintain an adequate opening inby the shields to provide ventilation to the first crosscut inby the face, as designed.The results were used to calibrate modeled cable bolt response to field data, and to validate numerical modeling procedures that have been developed to evaluate entry support systems.It is concluded that the support system was more than adequate to control the roof of the tailgate up to the longwall face location.The monitoring results have provided valuable data for the development and validation of support design strategies for longwall tailgate entries.
文摘This paper analyses the five years’ monitored strains collected from a long-term health monitoring system installed on a bridge with wavelet transform.In the analysis,the monitored strains are pre-processed,features of the monitored data are summarized briefly.The influences of the base functions on the results of wavelet analysis are studied simultaneously.The results show that the db wavelet is a good mother wavelet function in the analysis,and the order N should be larger than 20,but less than 46 in decomposing the monitored strains of the bridge.According to the strain variation features of concrete bridge,the proper decomposition level is 4 in the wavelet multi-resolution analysis.With the present method,the strains caused by random loads and daily sunlight can be accurately extracted from the monitored strains.The decomposed components of the monitored strains show that the amplitudes of the strains caused by random loads,daily sunlight,and annual temperature effect,are about 5 με,25 με,and 50 με respectively.The structural response under random load is smaller than the other parts.
文摘The status of woody plants in dry-land systems is a fundamental determinant of key ecosystem processes. Monitoring of this status plays an important role in understanding the dynamics of woody plants in arid and semi-arid ecosystems. The present study determined the dynamism of the Zagros forests in Iran using Remote Sensing and Geographic Information System techniques and statistical science. The results show that the density of trees varied from 10 to 53 % according to the physio- graphic and climatic conditions of semi-arid regions. The best and lowest correlation between vegetation indices and forest density were obtained for the global environmental monitoring index (GEMI; R2 = 0.94) and soil adjust vegetation index (R2 = 0.81), respectively. GEMI is used to monitor land use changes over a 10-year period. Results show that 2720 ha2 of forest have been destroyed by human interference and tillage on steep slopes during this period which also resulted in the loss of the fertile soil layer. GEMI determined the areas with a biomass of trees and could normally separate border regions with low bio- mass density of trees from regions without canopy cover. The results revealed that assessment of forest and vegetation cover in arid and semi-arid arduous forest regions using satellite digital numbers and ordinary sampling is subject to uncertainty. A stratified grouping procedure should be established to increase the accuracy of assessment.
文摘This study includes some aspects of the shift in the Dutch attitude in relation to water during the past millennia from defense to attack to keeping the balance(“co-evolution'). It has a special focus on the freshwater tidal part, which embraces the largest seaport of the world: Rotterdam, as well as the largest national park of the Netherlands. It reports especially about a young mans endeavor in half a century real time monitoring of some land(scape) units with simple means.
文摘In general,the material properties,loads,resistance of the prestressed concrete continuous rigid frame bridge in different construction stages are time-varying.So,it is essential to monitor the internal force state when the bridge is in construction.Among them,how to assess the safety is one of the challenges.As the continuous monitoring over a long-term period can increase the reliability of the assessment,so,based on a large number of monitored strain data collected from the structural health monitoring system(SHMS)during construction,a calculation method of the punctiform time-varying reliability is proposed in this paper to evaluate the stress state of this type bridge in cantilever construction stage by using the basic reliability theory.At the same time,the optimal stress distribution function in the bridge mid-span base plate is determined when the bridge is closed.This method can provide basis and direction for the internal force control of this type bridge in construction process.So,it can reduce the bridge safety and quality accidents in construction stages.
基金supported by the Fundamental Research Funds for the Central Universities (N090303005)Key National Science and Technology Special Project (2010ZX04014-014)
文摘With the development of the monitoring technology,it is more and more common that the system is continuously monitored.Therefore,the research on the maintenance optimization of the continuously monitored deterioration system is important.The deterioration process of the discussed system is described by a Gamma process.The predictive maintenance is considered to be imperfect and formulated.The expected interval of two continuous preventive maintenances is derived.Then,the maintenance optimization model of the continuously monitored deterioration system is presented.In the model,the minimization of the expected operational cost per unit time and the maximization of the system availability are the optimization objectives.The improved ideal point method with the normalized objective functions is employed to solve the proposed model.The validity and sensitivity of the proposed multiobjective maintenance optimization model are analyzed by a numerical example.
文摘When the bridge components needing maintenance are the world problem at present,and the health monitoring system is considered to be a very helpful tool for solving this problem.In this paper,a large number of strain data acquired from the structural health monitoring system(SHMS)installed on a continuous rigid frame bridge are adopted to do reliability assessment.Firstly,a calculation method of punctiform time-dependent reliability is proposed based on the basic reliability theory,and introduced how to calculate reliability of the bridge by using the stress data transformed from the strain data.Secondly,combined with“Three Sigma”principle and the basic pressure safety reserve requirement,the critical load effects distribution function of the bridge is defined,and then the maintenance reliability threshold for controlling the unfavorable load state which appears in the early operation stage of this type bridge is suggested,and then the combination of bridge maintenance management and health monitoring system is realized.Finally,the transformed stress distribution certifies that the load effects of concrete bridges practically have a normal distribution;as for the concrete continuous rigid frame bridge with C50 strength grade concrete,the retrofit reliability threshold should be valued at 6.13.The methodology suggested in this article can help bridge engineers do effective maintenance of bridges,which can effectively extend the service life of the bridge and bring better economic and social benefits.
基金supported by the National Natural Science Foundation of China,No.32130060(to XG).
文摘Epilepsy is a severe,relapsing,and multifactorial neurological disorder.Studies regarding the accurate diagnosis,prognosis,and in-depth pathogenesis are crucial for the precise and effective treatment of epilepsy.The pathogenesis of epilepsy is complex and involves alterations in variables such as gene expression,protein expression,ion channel activity,energy metabolites,and gut microbiota composition.Satisfactory results are lacking for conventional treatments for epilepsy.Surgical resection of lesions,drug therapy,and non-drug interventions are mainly used in clinical practice to treat pain associated with epilepsy.Non-pharmacological treatments,such as a ketogenic diet,gene therapy for nerve regeneration,and neural regulation,are currently areas of research focus.This review provides a comprehensive overview of the pathogenesis,diagnostic methods,and treatments of epilepsy.It also elaborates on the theoretical basis,treatment modes,and effects of invasive nerve stimulation in neurotherapy,including percutaneous vagus nerve stimulation,deep brain electrical stimulation,repetitive nerve electrical stimulation,in addition to non-invasive transcranial magnetic stimulation and transcranial direct current stimulation.Numerous studies have shown that electromagnetic stimulation-mediated neuromodulation therapy can markedly improve neurological function and reduce the frequency of epileptic seizures.Additionally,many new technologies for the diagnosis and treatment of epilepsy are being explored.However,current research is mainly focused on analyzing patients’clinical manifestations and exploring relevant diagnostic and treatment methods to study the pathogenesis at a molecular level,which has led to a lack of consensus regarding the mechanisms related to the disease.
基金financially supported by the National Natural Science Foundation of China(No.52371049)the Young Elite Scientists Sponsorship Program by the China Association for Science and Technology(YESS,No.2020QNRC001)the National Science and Technology Resources Investigation Program of China(Nos.2021FY100603 and 2019FY101404)。
文摘The atmospheric corrosion monitoring(ACM)technique has been widely employed to track the real-time corrosion behavior of metal materials.However,limited studies have applied ACM to the corrosion protection properties of organic coatings.This study compared a bare epoxy coating with one containing zinc phosphate corrosion inhibitors,both applied on ACM sensors,to observe their corrosion protection properties over time.Coatings with artificial damage via scratches were exposed to immersion and alternating dry and wet environments,which allowed for monitoring galvanic corrosion currents in real-time.Throughout the corrosion tests,the ACM currents of the zinc phosphate/epoxy coating were considerably lower than those of the blank epoxy coating.The trend in ACM current variations closely matched the results obtained from regular electrochemical tests and surface analysis.This alignment highlights the potential of the ACM technique in evaluating the corrosion protection capabilities of organic coatings.Compared with the blank epoxy coating,the zinc phosphate/epoxy coating showed much-decreased ACM current values that confirmed the effective inhibition of zinc phosphate against steel corrosion beneath the damaged coating.
基金funded by multidisciplinary MDT diagnosis and treatment fund for glioma and academic discipline boosting of Xijing Hospital.
文摘Background:Awake craniotomy(AC)has become gold standard in surgical resection of gliomas located in eloquent areas.The conscious sedation techniques in AC include both monitored anesthesia care(MAC)and asleep-awake-asleep(AAA).The choice of optimal anesthetic method depends on the preferences of the surgical team(mainly anesthesiologist and neurosurgeon).The aim of this study was to compare the difference in physiological and blood gas data,dosage of different drugs,the probability of switching to endotracheal intubation,and extent of tumor resection and dysfunction after operation between AAA and MAC anesthetic management for resection of gliomas in eloquent brain areas.Methods:Two-hundred and twenty-five patients with super-tentorial tumor located in eloquent areas underwent AC from 2009 to 2021 in Xijing Hospital.Forty-one patients underwent AAA technique,and the rest one-hundred eighty-four patients underwent MAC technique.Anesthetic management,dosage of different drugs,intraoperative complications,postoperative outcomes,adverse events,extent of resection and motor,and sensory and language dysfunction after operation were compared between MAC and AAA.Result:There was no significant difference in gender,KPS score,MMSE score,glioma grade,type,and growth site between the patients in the two groups,except the older age of patients in MAC group than that in AAA group.During the whole process of operation,there were greater pulse pressure difference(P=0.046),shorter operation time(P=0.039),less dosage of remifentanil(P=0.000),more dosage of dexmedetomidine(P=0.013),more use of antiemetics(81%,P=0.0067),lower use of vasoactive agent(45.1%,P=0.010),and lower probability of conversion to general anesthesia(GA,P=0.027)in MAC group than that in AAA group.Blood gas analysis showed that PetCO2(P=0.000),Glu concentration(P=0.000),and PaCO2(P=0.000)were higher,but SPO2(P=0.002)and PaO2(P=0.000)were lower in MAC group than that in AAA group.In the postoperative recovery stage,compared with that of AAA group,the probability of dysfunction in MAC group at 1,3,5,and 7 days after operation was lower,which were 27.8%vs 53.6%(P=0.003),31%vs 68.3%(P=0.000),28.8%vs 63.4%(P=0.000),and 25.6%vs 58.5%(P=0.000),respectively.Conclusion:Compared with AAA,it seems that MAC has more advantages in the management for resection of gliomas in eloquent brain areas,and MAC combined with multiple monitoring such as cerebral cortical mapping,neuronavigation,and ultrasonic detection is worthy of popularization for the resection of gliomas in eloquent brain areas.
基金support of the China National Social Science Fund under Grant No.15BJL093Yanchu Liu is partially supported by the National Natural Science Foundation of China under Grant No.71501196,No.71231008,No.71721001+4 种基金the China National Social Science Fund under Grant No.17ZDA073the Natural Science Foundation of Guangdong Province of China under Grant No.2014A030312003the Innovative Research Team Project of Guangdong Province of China under Grant No.2016WCXTD001the Fundamental Research Funds for the Central Universities under Grant No.14wkpy63research grants from Lingnan(University)College and Advanced Research Institute of Finance at Sun Yat-sen University.
文摘The stochastic alpha beta rho(SABR)model introduced by Hagan et al.(2002)is widely used in both fixed income and the foreign exchange(FX)markets.Continuously monitored barrier option contracts are among the most popular derivative contracts in the FX markets.In this paper,we develop closed-form formulas to approximate various types of barrier option prices(down-and-out/in,up-and-out/in)under the SABR model.We first derive an approximate formula for the survival density.The barrier option price is the one-dimensional integral of its payoff function and the survival density,which can be easily implemented and quickly evaluated.The approximation error of the survival density is also analyzed.To the best of our knowledge,it is the first time that analytical(approximate)formulas for the survival density and the barrier option prices for the SABR model are derived.Numerical experiments demonstrate the validity and efficiency of these formulas.
文摘: To measure and monitor the crustal motion in China, a GPS network has been established with an average side length of 1 000 km and with more than 20 points on the margins of each major tectonic block and fault zone in China. Three campaigns were carried out in 1992,1994 and 1996, respectively by this network. Here we present, for the first time, the horizontal displacement rates of 22 GPS monitoring stations distributed over the whole China and global IGS stations surrounding China, based on these GPS repeated measurements. From these results by GPS, we have obtained the sketch of crustal motion in China.