Some studies have confirmed the neuroprotective effect of remote ischemic conditioning against stroke. Although numerous animal researches have shown that the neuroprotective effect of remote ischemic conditioning may...Some studies have confirmed the neuroprotective effect of remote ischemic conditioning against stroke. Although numerous animal researches have shown that the neuroprotective effect of remote ischemic conditioning may be related to neuroinflammation, cellular immunity, apoptosis, and autophagy, the exact underlying molecular mechanisms are unclear. This review summarizes the current status of different types of remote ischemic conditioning methods in animal and clinical studies and analyzes their commonalities and differences in neuroprotective mechanisms and signaling pathways. Remote ischemic conditioning has emerged as a potential therapeutic approach for improving stroke-induced brain injury owing to its simplicity, non-invasiveness, safety, and patient tolerability. Different forms of remote ischemic conditioning exhibit distinct intervention patterns, timing, and application range. Mechanistically, remote ischemic conditioning can exert neuroprotective effects by activating the Notch1/phosphatidylinositol 3-kinase/Akt signaling pathway, improving cerebral perfusion, suppressing neuroinflammation, inhibiting cell apoptosis, activating autophagy, and promoting neural regeneration. While remote ischemic conditioning has shown potential in improving stroke outcomes, its full clinical translation has not yet been achieved.展开更多
Each family has its own specifications and different volume of cultural capital which more or less stimulates the child development. Very specific is the case of book ownership in the family. The paper analyzes materi...Each family has its own specifications and different volume of cultural capital which more or less stimulates the child development. Very specific is the case of book ownership in the family. The paper analyzes material and cultural environment of present-day families in the north-western part of Slovak republic. The author presents the results of observation of some material conditions in Slovak families with primary school children and finds out their impact on the children＇s school success.展开更多
The results of the 2022-2025 study conducted for the vulnerability assessment of pastures and for the development of improvement measures on the degraded land sections in the arid and semi-arid provinces of the Caucas...The results of the 2022-2025 study conducted for the vulnerability assessment of pastures and for the development of improvement measures on the degraded land sections in the arid and semi-arid provinces of the Caucasus under the global climate change conditions are introduced in the current article.The main goal of our scientific work is to study and assess the current ecological and resource state of natural phytocenoses,pastures and hayfields in the arid and semi-arid landscapes under climate change.The paper presents the results of determining the areas and levels of degradation of the natural biogeocenoses and biogeocenoses of the pastures and hayfields in the mountain and highland landscapes.The results were obtained using remote sensing,field and laboratory studies and analyses.The conducted studies have revealed that along 34,174.5 ha pasture and 1342.0 meadows areas of the pastures at the Areni,Yeghegis,Yeghegnadzor and Vayq consolidated administrative territories situated in the arid and semi-arid zones of the Vayots Dzor Region high degradation was recorded in about 6508 hectares of pasture and 407 hectares of meadows areas,which is related to irregular and uncontrolled economic mismanagement of the local population and global climate change.To improve the ecological condition,accessibility and quality of ecosystem services of the pastures,hayfields and natural meadows,comprehensive restoration bioecological and agrotechnical measures have been proposed.They are aimed at improving the air,water and nutrient regimes of soils,at their bioprotection,as well as at the general increase in area and at improving the economic characteristics of the vegetation cover.Such measures on the ecosystem basis are appropriate in the context of enriching the qualitative composition of plants with useful ecological and economic bioecological characteristics,taking into account the characteristics of landscapes,weather and climatic conditions,and agricultural opportunities.展开更多
County economies form a distinctive,integrated regional economic structure.Their growth is shaped by specific social and historical conditions and,in turn,influences many aspects of wider economic and social developme...County economies form a distinctive,integrated regional economic structure.Their growth is shaped by specific social and historical conditions and,in turn,influences many aspects of wider economic and social development.In China's modernization process,they have always played a vital role.The 2024 Central Economic Work Conference placed strong emphasis on vigorously developing county economies.展开更多
Japan’s aging rate (ratio of elderly aged 65 and older to total population) has exceeded 20%. The aim of this study was to clarify the relationships between Health Related Quality of Life, Body Mass Index (BMI), and ...Japan’s aging rate (ratio of elderly aged 65 and older to total population) has exceeded 20%. The aim of this study was to clarify the relationships between Health Related Quality of Life, Body Mass Index (BMI), and sleep quality. Subjects were 51 adults over 55 years old with chronic disease who living in the community. Instruments and structured interviews were used giving due consideration to privacy. Interviews were conducted within 10 - 20 minutes at the out-patient department. The evaluation instruments included bodymass index, Pittsburgh Sleep Quality Index (PSQI), Health Related Quality of Life (HRQOL), and Oral Health Impact Profile (OHIP-14). A significant positive correlation (ρ = 0.321, p < 0.05) between PSQI and QOL (OHIP-14) scores was confirmed with sleep quality being lower with lower QOL scores. A negative correlation (ρ = ?0.339, p < 0.05) between physical health component summary scores (PCS) and mental health component summary scores (MCS) of HRQOL was confirmed, demonstrating that PCS was low, and the level of MCS was high. Sleep quality was found lower among those with lower oral health-related QOL scores. Moreover, in subjects with lower MCS scores, the PCS scores were found to be higher. Accordingly, it was considered appropriate that dental treatment and care, support the maintenance of activities and sleep, and mental health promotion which are likely requisites critical for elderly persons’ maintenance of independent lifestyles in their familiar community.展开更多
Let the coordinate system xi of flat space-time to absorb a second rank tensor field Φij of the flat space-time deforming into a Riemannian space-time, namely, the tensor field Φuv is regarded as a metric tensor wit...Let the coordinate system xi of flat space-time to absorb a second rank tensor field Φij of the flat space-time deforming into a Riemannian space-time, namely, the tensor field Φuv is regarded as a metric tensor with respect to the coordinate system xu. After done this, xu is not the coordinate system of flat space-time anymore, but is the coordinate system of the new Riemannian space-time. The inverse operation also can be done. According to these notions, the concepts of the absorption operation and the desorption operation are proposed. These notions are actually compatible with Einstein’s equivalence principle. By using these concepts, the relationships of the Riemannian space-time, the de Donder conditions and the gravitational field in flat space-time are analyzed and elaborated. The essential significance of the de Donder conditions (the harmonic conditions or gauge) is to desorb the tensor field of gravitation from the Riemannian space-time to the Minkowski space-time with the Cartesian coordinates. Einstein equations with de Donder conditions can be solved in flat space-time. Base on Fock’s works, the equations of gravitational field in flat space-time are obtained, and the tensor expression of the energy-momentum of gravitational field is found. They all satisfy the global Lorentz covariance.展开更多
The search for the generating compatibility conditions (CC) of a given operator is a very recent problem met in general relativity in order to study the Killing operator for various standard useful metrics. Accordingl...The search for the generating compatibility conditions (CC) of a given operator is a very recent problem met in general relativity in order to study the Killing operator for various standard useful metrics. Accordingly, this paper can be considered as a natural continuation of a previous paper recently published in JMP under the title Minkowski, Schwarschild and Kerr metrics revisited. In particular, we prove that the intrinsic link existing between the lack of formal exactness of an operator sequence on the jet level, the lack of formal exactness of its corresponding symbol sequence and the lack of formal integrability (FI) of the initial operator is of a purely homological nature as it is based on the long exact connecting sequence provided by the so-called snake lemma in homological algebra. It is therefore quite difficult to grasp it in general and even more difficult to use it on explicit examples. It does not seem that any one of the results presented in this paper is known as most of the other authors who studied the above problem of computing the total number of generating CC are confusing this number with the degree of generality introduced by A. Einstein in his 1930 letters to E. Cartan. One of the motivating examples that we provide is so striking that it is even difficult to imagine that such an example could exist. We hope this paper could be used as a source of testing examples for future applications of computer algebra in general relativity and, more generally, in mathematical physics.展开更多
We study the initial-boundary value problem of the Navier-Stokes equations for incompressible fluids in a general domain in R^n with compact and smooth boundary,subject to the kinematic and vorticity boundary conditio...We study the initial-boundary value problem of the Navier-Stokes equations for incompressible fluids in a general domain in R^n with compact and smooth boundary,subject to the kinematic and vorticity boundary conditions on the non-flat boundary.We observe that,under the nonhomogeneous boundary conditions,the pressure p can be still recovered by solving the Neumann problem for the Poisson equation.Then we establish the well-posedness of the unsteady Stokes equations and employ the solution to reduce our initial-boundary value problem into an initial-boundary value problem with absolute boundary conditions.Based on this,we first establish the well-posedness for an appropriate local linearized problem with the absolute boundary conditions and the initial condition(without the incompressibility condition),which establishes a velocity mapping.Then we develop apriori estimates for the velocity mapping,especially involving the Sobolev norm for the time-derivative of the mapping to deal with the complicated boundary conditions,which leads to the existence of the fixed point of the mapping and the existence of solutions to our initial-boundary value problem.Finally,we establish that,when the viscosity coefficient tends zero,the strong solutions of the initial-boundary value problem in R^n(n≥3)with nonhomogeneous vorticity boundary condition converge in L^2 to the corresponding Euler equations satisfying the kinematic condition.展开更多
Natural language processing has got great progress recently. Controlling robots with spoken natural language has become expectable. With the reliability problem of this kind of control in mind a confirmation process o...Natural language processing has got great progress recently. Controlling robots with spoken natural language has become expectable. With the reliability problem of this kind of control in mind a confirmation process of natural language instruction should be included before carried out by the robot autonomously and the prototype dialog system was designed thus the standardization problem was raised for the natural and understandable language interaction. In the application background of remotely navigating a mobile robot inside a building with Chinese natural spoken language considering that as an important navigation element in instructions a place name can be expressed with different lexical terms in spoken language this paper proposes a model for substituting different alternatives of a place name with a standard one (called standardization). First a CRF (Conditional Random Fields) model is trained to label the term required be standardized then a trained word embedding model is to represent lexical terms as digital vectors. In the vector space similarity of lexical terms is defined and used to find out the most similar one to the term picked out to be standardized. Experiments show that the method proposed works well and the dialog system responses to confirm the instructions are natural and understandable.展开更多
Focusing on the Yangtze River economic zone,the previous geological researches are systematically summarized,resources and environment conditions and major geological problems which are needing to be concerned in land...Focusing on the Yangtze River economic zone,the previous geological researches are systematically summarized,resources and environment conditions and major geological problems which are needing to be concerned in land planning and construction are studied.The results show that the resource conditions of cultivated land,shale gas,geotherm,lithium and so on are superior in the Yangtze River economic zone,and the resources and environment conditions are conducive to develop the modern agriculture,clean energy industry and strategic emerging industries.3×1013 m^2 farmlands without heavy metal pollution are concentrated;there are three national level shale gas exploration and development bases with explored reserves of 5.441×1011 m^3;geothermal availability is 2.4×109 t of standard coal each year,equivalent to 19% of the amount of coal in 2014;Asia's largest energy lithium metal ore deposit is found.In some parts of Yangtze River economic zone,there are some major geological problems such as active faults,karst collapse,ground subsidence,landslide-collapse-debris flow,affecting the river-crossing channels,high-speed railway,urban agglomeration and green ecological corridor planning and construction.Those problems should be concerned,and the relevant suggestions and countermeasures are put forward.Meanwhile,the ideas to further support the development of the Yangtze River economic zone are put forward.展开更多
Accurate and rapid recognition of weathering degree(WD)and groundwater condition(GC)is essential for evaluating rock mass quality and conducting stability analyses in underground engineering.Conventional WD and GC rec...Accurate and rapid recognition of weathering degree(WD)and groundwater condition(GC)is essential for evaluating rock mass quality and conducting stability analyses in underground engineering.Conventional WD and GC recognition methods often rely on subjective evaluation by field experts,supplemented by field sampling and laboratory testing.These methods are frequently complex and timeconsuming,making it challenging to meet the rapidly evolving demands of underground engineering.Therefore,this study proposes a rock non-geometric parameter classification network(RNPC-net)to rapidly achieve the recognition and mapping ofWD and GC of tunnel faces.The hybrid feature extraction module(HFEM)in RNPC-net can fully extract,fuse,and utilize multi-scale features of images,enhancing the network's classification performance.Moreover,the designed adaptive weighting auxiliary classifier(AC)helps the network learn features more efficiently.Experimental results show that RNPC-net achieved classification accuracies of 0.8756 and 0.8710 for WD and GC,respectively,representing an improvement of approximately 2%e10%compared to other methods.Both quantitative and qualitative experiments confirm the effectiveness and superiority of RNPC-net.Furthermore,for WD and GC mapping,RNPC-net outperformed other methods by achieving the highest mean intersection over union(mIOU)across most tunnel faces.The mapping results closely align with measurements provided by field experts.The application of WD and GC mapping results to the rock mass rating(RMR)system achieved a transition from conventional qualitative to quantitative evaluation.This advancement enables more accurate and reliable rock mass quality evaluations,particularly under critical conditions of RMR.展开更多
It is well recognized that Structural Health Monitoring(SHM)reliability evaluation is a key aspect that needs to be urgently addressed to promote the wide application of SHM methods.However,the existing studies typica...It is well recognized that Structural Health Monitoring(SHM)reliability evaluation is a key aspect that needs to be urgently addressed to promote the wide application of SHM methods.However,the existing studies typically transfer the Non-Destructive Testing/Evaluation(NDT/E)reliability metrics to SHM without a systematic analysis of where these metrics originated.Seldom attentions are paid to the evaluation conditions which are very important to apply these metrics.Aimed at this issue,a new condition control-based Dual-Reliability Evaluation(Dual-RE)method for SHM is proposed.This new method is proposed based on a systematic analysis of the whole framework of reliability evaluation from instrument to NDT,and emphasis is paid to the evaluation condition control.Based on these analyses,considering the special online application scenario of SHM,the proposed Dual-RE method contains two key components:Integrated Sensor-based SHM-RE(IS-SHM-RE)and Critical Service Condition-based SHM-RE(CSC-SHM-RE).ISSHM-RE evaluates the reliability of integrated SHM sensor and system themselves under approximate repeatability conditions,while CSC-SHM-RE assesses SHM reliability under the dominant uncertainties during service,namely intermediate conditions.To demonstrate the Dual-RE,crack monitoring by using the Guided Wave-based-SHM(GW-SHM)on aircraft lug structures is taken as a case study.Both the crack detection and sizing performance are evaluated from accuracy and uncertainty.展开更多
Estuarine and bay ecosystems serve as crucial transitional zones for land-based pollutants entering the ocean.However,there is a critical gap in understanding the behavior of emerging pollutants in the numerous small ...Estuarine and bay ecosystems serve as crucial transitional zones for land-based pollutants entering the ocean.However,there is a critical gap in understanding the behavior of emerging pollutants in the numerous small estuaries and bays located in undeveloped coastal areas.This study provides insights into the fate of antibiotics in these small and scattered estuaries and bays in Shantou's coast,driven by land use types and hydrodynamic conditions.The findings indicated that estuaries were more heavily polluted with antibiotics than the bays(P<0.05),with tetracyclines and fluoroquinolones as the primary antibiotics.Antibiotic pollution levels were more severe in October than in June(P<0.01).Rainfall runoff,aquaculture tailwater,and river discharge were identified as the main sources of antibiotic pollution.Build-up land and aquaculture ponds were the primary land use types contributing to antibiotic pollution.The total antibiotic concentrations in June were positively correlated with the proportion of aquaculture ponds(P<0.05)and negatively correlated with the proportions of cropland and grassland(P<0.05).The concentrations of lomefloxacin and ofloxacin were positively correlated with build-up land.The antibiotic concentrations exhibited strong spatial heterogeneity within both bay and estuarine ecosystems driven by different hydrodynamic conditions.A comparative analysis of global estuaries and bays revealed that specific land-use types and hydrodynamic conditions produced similar trends in antibiotic fate.These insights offered new perspectives to safeguard the health of estuarine and bay ecosystems,such as altering landscape patterns and regulating aquaculture activities.展开更多
The real-time and accurate calculation of electricity indirect carbon emissions is not only the critical component for quantifying the carbon emission levels of the power system but also an effective mean to guide ele...The real-time and accurate calculation of electricity indirect carbon emissions is not only the critical component for quantifying the carbon emission levels of the power system but also an effective mean to guide electricity users in carbon reduction and promote power industry low-carbon transformation.Fundamentally,calculating indirect carbon emissions involves allocating direct carbon emission data from the power source side,indicating that accurate indirect emission results rely on the precise measurement of power source emissions.However,existing research on indirect carbon emissions in large-scale power systems rarely accounts for variations in carbon emission characteristics under different operating conditions of power sources,such as rated/non-rated operating conditions and ramping up/down conditions,making it difficult to reflect source-side and load-side carbon emission information variation during providing ancillary services.Quadratic and exponential functions are proposed to characterize the energy consumption profiles of coal-fired and gas-fired power generation,respectively,to construct a refined carbon emission model for power sources.By leveraging the theory of power system carbon flow,we analyze how variable operating conditions of power sources impact indirect carbon emissions.Case studies demonstrate that changes in power source emissions under variable conditions have a significant effect on the indirect carbon emissions of power grids.展开更多
Increase in requirement of hydrosulphuric water for improvement of the population set the task of identification of places of their possible congestion for hydrogeological service. Earlier detection of such congestion...Increase in requirement of hydrosulphuric water for improvement of the population set the task of identification of places of their possible congestion for hydrogeological service. Earlier detection of such congestions was accidental at well-drilling of different function. Therefore, development of new methodical approaches of search and allocation of perspective zones of their formation was required. It was for this purpose necessary to study in what conditions and what factors have an impact on formation of underground hydrosulphuric water. So far, definition of communication attempts only with separate geochemical signs was known. Results of studying of influence on formations of hydrosulphuric water of such factors as lithologic and facial in combination with oil-and-gas content, the geological and structural and hydrodynamic mode are given in this work. It is established that the main sign for formation of hydrosulphuric water is existence of evaporite thickness and hydrocarbon congestions. Besides, it is shown that small depth (up to 2 km) of their bedding has to be an indispensable condition and existence of explosive violation on which there has to be a water infiltration (a geological and structural factor). In the Surkhandarya region, the hydrodynamic mode caused by inclined bedding of aquifers was also one of essential factors. Active water is an exchange process with washing away (oxidation) sulfate of the containing thicknesses and subsequently, its restoration in interaction with hydrocarbons with formation of hydrosulphuric water is described. The technique is developed and the expected card of perspective zones of formation of hydrosulphuric water is constructed.展开更多
The stable operation of the central air conditioning water system always is a major difficulty for the control profession. Paper focus on the water system with multi variable, strong coupling, nonlinear, large time de...The stable operation of the central air conditioning water system always is a major difficulty for the control profession. Paper focus on the water system with multi variable, strong coupling, nonlinear, large time delay characteristics, presented use feed forward coupling compensation method, to eliminate the coupling effect between temperature and pressure. In this paper, the Elman neural network controller is designed for the first time, and the simulation results show that the response time of Elman neural network controller is shorter, the system is more stable and the overshoot is small.展开更多
The alternating method based on the fundamental solutions of the infinite domain containing a crack,namely Muskhelishvili’s solutions,divides the complex structure with a crack into a simple model without crack which...The alternating method based on the fundamental solutions of the infinite domain containing a crack,namely Muskhelishvili’s solutions,divides the complex structure with a crack into a simple model without crack which can be solved by traditional numerical methods and an infinite domain with a crack which can be solved by Muskhelishvili’s solutions.However,this alternating method cannot be directly applied to the edge crack problems since partial crack surface of Muskhelishvili’s solutions is located outside the computational domain.In this paper,an improved alternating method,the spline fictitious boundary element alternating method(SFBEAM),based on infinite domain with the combination of spline fictitious boundary element method(SFBEM)and Muskhelishvili’s solutions is proposed to solve the edge crack problems.Since the SFBEM and Muskhelishvili’s solutions are obtained in the framework of infinite domain,no special treatment is needed for solving the problem of edge cracks.Different mixed boundary conditions edge crack problems with varies of computational parameters are given to certify the high precision,efficiency and applicability of the proposed method compared with other alternating methods and extend finite element method.展开更多
Novel exact solutions of one-dimensional transient dynamic piezoelectric problems for thickness polarized layers and disks, or length polarized rods, are obtained. The solutions are derived using a time-domain Green’...Novel exact solutions of one-dimensional transient dynamic piezoelectric problems for thickness polarized layers and disks, or length polarized rods, are obtained. The solutions are derived using a time-domain Green’s function method that leads to an exact analytical recursive procedure which is applicable for a wide variety of boundary conditions including nonlinear cases. A nonlinear damper boundary condition is considered in more detail. The corresponding nonlinear relationship between stresses and velocities at a current time moment is used in the recursive procedure. In addition to the exact recursive procedure that is effective for calculations, some new practically important explicit exact solutions are presented. Several examples of the time behavior of the output electric potential difference are given to illustrate the effectiveness of the proposed exact approach.展开更多
Tractor hydraulic fluids are tested to maximize their performance levels and to ensure manufacturer′s standards are met.Common tractor hydraulic fluid tests include: Gear Wear Protection,Brake Chatter Reduction,Wet-C...Tractor hydraulic fluids are tested to maximize their performance levels and to ensure manufacturer′s standards are met.Common tractor hydraulic fluid tests include: Gear Wear Protection,Brake Chatter Reduction,Wet-Clutch Capacity,and Pump Performance tests.These tests are run by Southwest Research Institute,in the U.S.A.,for tractors built by John Deere and Case-New Holland.This paper details current methods for evaluating tractor hydraulic fluids.The tests that are described utilize full size equipment and were developed by the tractor′s original equipment manufacturers(OEMs).展开更多
基金supported partly by the National Natural Science Foundation of China,No.82071332the Chongqing Natural Science Foundation Joint Fund for Innovation and Development,No.CSTB2023NSCQ-LZX0041 (both to ZG)。
文摘Some studies have confirmed the neuroprotective effect of remote ischemic conditioning against stroke. Although numerous animal researches have shown that the neuroprotective effect of remote ischemic conditioning may be related to neuroinflammation, cellular immunity, apoptosis, and autophagy, the exact underlying molecular mechanisms are unclear. This review summarizes the current status of different types of remote ischemic conditioning methods in animal and clinical studies and analyzes their commonalities and differences in neuroprotective mechanisms and signaling pathways. Remote ischemic conditioning has emerged as a potential therapeutic approach for improving stroke-induced brain injury owing to its simplicity, non-invasiveness, safety, and patient tolerability. Different forms of remote ischemic conditioning exhibit distinct intervention patterns, timing, and application range. Mechanistically, remote ischemic conditioning can exert neuroprotective effects by activating the Notch1/phosphatidylinositol 3-kinase/Akt signaling pathway, improving cerebral perfusion, suppressing neuroinflammation, inhibiting cell apoptosis, activating autophagy, and promoting neural regeneration. While remote ischemic conditioning has shown potential in improving stroke outcomes, its full clinical translation has not yet been achieved.
文摘Each family has its own specifications and different volume of cultural capital which more or less stimulates the child development. Very specific is the case of book ownership in the family. The paper analyzes material and cultural environment of present-day families in the north-western part of Slovak republic. The author presents the results of observation of some material conditions in Slovak families with primary school children and finds out their impact on the children＇s school success.
基金the framework of the Project 21T-4C045 of the Higher Education and Science Committee(RA)。
文摘The results of the 2022-2025 study conducted for the vulnerability assessment of pastures and for the development of improvement measures on the degraded land sections in the arid and semi-arid provinces of the Caucasus under the global climate change conditions are introduced in the current article.The main goal of our scientific work is to study and assess the current ecological and resource state of natural phytocenoses,pastures and hayfields in the arid and semi-arid landscapes under climate change.The paper presents the results of determining the areas and levels of degradation of the natural biogeocenoses and biogeocenoses of the pastures and hayfields in the mountain and highland landscapes.The results were obtained using remote sensing,field and laboratory studies and analyses.The conducted studies have revealed that along 34,174.5 ha pasture and 1342.0 meadows areas of the pastures at the Areni,Yeghegis,Yeghegnadzor and Vayq consolidated administrative territories situated in the arid and semi-arid zones of the Vayots Dzor Region high degradation was recorded in about 6508 hectares of pasture and 407 hectares of meadows areas,which is related to irregular and uncontrolled economic mismanagement of the local population and global climate change.To improve the ecological condition,accessibility and quality of ecosystem services of the pastures,hayfields and natural meadows,comprehensive restoration bioecological and agrotechnical measures have been proposed.They are aimed at improving the air,water and nutrient regimes of soils,at their bioprotection,as well as at the general increase in area and at improving the economic characteristics of the vegetation cover.Such measures on the ecosystem basis are appropriate in the context of enriching the qualitative composition of plants with useful ecological and economic bioecological characteristics,taking into account the characteristics of landscapes,weather and climatic conditions,and agricultural opportunities.
文摘County economies form a distinctive,integrated regional economic structure.Their growth is shaped by specific social and historical conditions and,in turn,influences many aspects of wider economic and social development.In China's modernization process,they have always played a vital role.The 2024 Central Economic Work Conference placed strong emphasis on vigorously developing county economies.
文摘Japan’s aging rate (ratio of elderly aged 65 and older to total population) has exceeded 20%. The aim of this study was to clarify the relationships between Health Related Quality of Life, Body Mass Index (BMI), and sleep quality. Subjects were 51 adults over 55 years old with chronic disease who living in the community. Instruments and structured interviews were used giving due consideration to privacy. Interviews were conducted within 10 - 20 minutes at the out-patient department. The evaluation instruments included bodymass index, Pittsburgh Sleep Quality Index (PSQI), Health Related Quality of Life (HRQOL), and Oral Health Impact Profile (OHIP-14). A significant positive correlation (ρ = 0.321, p < 0.05) between PSQI and QOL (OHIP-14) scores was confirmed with sleep quality being lower with lower QOL scores. A negative correlation (ρ = ?0.339, p < 0.05) between physical health component summary scores (PCS) and mental health component summary scores (MCS) of HRQOL was confirmed, demonstrating that PCS was low, and the level of MCS was high. Sleep quality was found lower among those with lower oral health-related QOL scores. Moreover, in subjects with lower MCS scores, the PCS scores were found to be higher. Accordingly, it was considered appropriate that dental treatment and care, support the maintenance of activities and sleep, and mental health promotion which are likely requisites critical for elderly persons’ maintenance of independent lifestyles in their familiar community.
文摘Let the coordinate system xi of flat space-time to absorb a second rank tensor field Φij of the flat space-time deforming into a Riemannian space-time, namely, the tensor field Φuv is regarded as a metric tensor with respect to the coordinate system xu. After done this, xu is not the coordinate system of flat space-time anymore, but is the coordinate system of the new Riemannian space-time. The inverse operation also can be done. According to these notions, the concepts of the absorption operation and the desorption operation are proposed. These notions are actually compatible with Einstein’s equivalence principle. By using these concepts, the relationships of the Riemannian space-time, the de Donder conditions and the gravitational field in flat space-time are analyzed and elaborated. The essential significance of the de Donder conditions (the harmonic conditions or gauge) is to desorb the tensor field of gravitation from the Riemannian space-time to the Minkowski space-time with the Cartesian coordinates. Einstein equations with de Donder conditions can be solved in flat space-time. Base on Fock’s works, the equations of gravitational field in flat space-time are obtained, and the tensor expression of the energy-momentum of gravitational field is found. They all satisfy the global Lorentz covariance.
文摘The search for the generating compatibility conditions (CC) of a given operator is a very recent problem met in general relativity in order to study the Killing operator for various standard useful metrics. Accordingly, this paper can be considered as a natural continuation of a previous paper recently published in JMP under the title Minkowski, Schwarschild and Kerr metrics revisited. In particular, we prove that the intrinsic link existing between the lack of formal exactness of an operator sequence on the jet level, the lack of formal exactness of its corresponding symbol sequence and the lack of formal integrability (FI) of the initial operator is of a purely homological nature as it is based on the long exact connecting sequence provided by the so-called snake lemma in homological algebra. It is therefore quite difficult to grasp it in general and even more difficult to use it on explicit examples. It does not seem that any one of the results presented in this paper is known as most of the other authors who studied the above problem of computing the total number of generating CC are confusing this number with the degree of generality introduced by A. Einstein in his 1930 letters to E. Cartan. One of the motivating examples that we provide is so striking that it is even difficult to imagine that such an example could exist. We hope this paper could be used as a source of testing examples for future applications of computer algebra in general relativity and, more generally, in mathematical physics.
基金supported in part by the National Science Foundation under Grants DMS-0807551,DMS-0720925,and DMS-0505473the Natural Science Foundationof China(10728101)supported in part by EPSRC grant EP/F029578/1
文摘We study the initial-boundary value problem of the Navier-Stokes equations for incompressible fluids in a general domain in R^n with compact and smooth boundary,subject to the kinematic and vorticity boundary conditions on the non-flat boundary.We observe that,under the nonhomogeneous boundary conditions,the pressure p can be still recovered by solving the Neumann problem for the Poisson equation.Then we establish the well-posedness of the unsteady Stokes equations and employ the solution to reduce our initial-boundary value problem into an initial-boundary value problem with absolute boundary conditions.Based on this,we first establish the well-posedness for an appropriate local linearized problem with the absolute boundary conditions and the initial condition(without the incompressibility condition),which establishes a velocity mapping.Then we develop apriori estimates for the velocity mapping,especially involving the Sobolev norm for the time-derivative of the mapping to deal with the complicated boundary conditions,which leads to the existence of the fixed point of the mapping and the existence of solutions to our initial-boundary value problem.Finally,we establish that,when the viscosity coefficient tends zero,the strong solutions of the initial-boundary value problem in R^n(n≥3)with nonhomogeneous vorticity boundary condition converge in L^2 to the corresponding Euler equations satisfying the kinematic condition.
基金Sponsored by the Basic Research Development Program of China ( Grant No. 2013CB03554)the Fundamental Research Funds for Universities, Central South University (Grant No. 2017zzts394).
文摘Natural language processing has got great progress recently. Controlling robots with spoken natural language has become expectable. With the reliability problem of this kind of control in mind a confirmation process of natural language instruction should be included before carried out by the robot autonomously and the prototype dialog system was designed thus the standardization problem was raised for the natural and understandable language interaction. In the application background of remotely navigating a mobile robot inside a building with Chinese natural spoken language considering that as an important navigation element in instructions a place name can be expressed with different lexical terms in spoken language this paper proposes a model for substituting different alternatives of a place name with a standard one (called standardization). First a CRF (Conditional Random Fields) model is trained to label the term required be standardized then a trained word embedding model is to represent lexical terms as digital vectors. In the vector space similarity of lexical terms is defined and used to find out the most similar one to the term picked out to be standardized. Experiments show that the method proposed works well and the dialog system responses to confirm the instructions are natural and understandable.
文摘Focusing on the Yangtze River economic zone,the previous geological researches are systematically summarized,resources and environment conditions and major geological problems which are needing to be concerned in land planning and construction are studied.The results show that the resource conditions of cultivated land,shale gas,geotherm,lithium and so on are superior in the Yangtze River economic zone,and the resources and environment conditions are conducive to develop the modern agriculture,clean energy industry and strategic emerging industries.3×1013 m^2 farmlands without heavy metal pollution are concentrated;there are three national level shale gas exploration and development bases with explored reserves of 5.441×1011 m^3;geothermal availability is 2.4×109 t of standard coal each year,equivalent to 19% of the amount of coal in 2014;Asia's largest energy lithium metal ore deposit is found.In some parts of Yangtze River economic zone,there are some major geological problems such as active faults,karst collapse,ground subsidence,landslide-collapse-debris flow,affecting the river-crossing channels,high-speed railway,urban agglomeration and green ecological corridor planning and construction.Those problems should be concerned,and the relevant suggestions and countermeasures are put forward.Meanwhile,the ideas to further support the development of the Yangtze River economic zone are put forward.
基金supported by the National Natural Science Foundation of China(Grant Nos.42077242 and 42171407)the Graduate Innovation Fund of Jilin University.
文摘Accurate and rapid recognition of weathering degree(WD)and groundwater condition(GC)is essential for evaluating rock mass quality and conducting stability analyses in underground engineering.Conventional WD and GC recognition methods often rely on subjective evaluation by field experts,supplemented by field sampling and laboratory testing.These methods are frequently complex and timeconsuming,making it challenging to meet the rapidly evolving demands of underground engineering.Therefore,this study proposes a rock non-geometric parameter classification network(RNPC-net)to rapidly achieve the recognition and mapping ofWD and GC of tunnel faces.The hybrid feature extraction module(HFEM)in RNPC-net can fully extract,fuse,and utilize multi-scale features of images,enhancing the network's classification performance.Moreover,the designed adaptive weighting auxiliary classifier(AC)helps the network learn features more efficiently.Experimental results show that RNPC-net achieved classification accuracies of 0.8756 and 0.8710 for WD and GC,respectively,representing an improvement of approximately 2%e10%compared to other methods.Both quantitative and qualitative experiments confirm the effectiveness and superiority of RNPC-net.Furthermore,for WD and GC mapping,RNPC-net outperformed other methods by achieving the highest mean intersection over union(mIOU)across most tunnel faces.The mapping results closely align with measurements provided by field experts.The application of WD and GC mapping results to the rock mass rating(RMR)system achieved a transition from conventional qualitative to quantitative evaluation.This advancement enables more accurate and reliable rock mass quality evaluations,particularly under critical conditions of RMR.
基金the support from National Natural Science Foundation of China(No.52275153)the Frontier Technologies R&D Program of Jiangsu,China(No.BF2024068)+1 种基金The Fund of Prospective Layout of Scientific Research for Nanjing University of Aeronautics and Astronautics,ChinaResearch Fund of State Key Laboratory of Mechanics and Control for Aerospace Structures(Nanjing University of Aeronautics and Astronautics),China(Nos.MCAS-I-0425K01,MCAS-I-0423G01)。
文摘It is well recognized that Structural Health Monitoring(SHM)reliability evaluation is a key aspect that needs to be urgently addressed to promote the wide application of SHM methods.However,the existing studies typically transfer the Non-Destructive Testing/Evaluation(NDT/E)reliability metrics to SHM without a systematic analysis of where these metrics originated.Seldom attentions are paid to the evaluation conditions which are very important to apply these metrics.Aimed at this issue,a new condition control-based Dual-Reliability Evaluation(Dual-RE)method for SHM is proposed.This new method is proposed based on a systematic analysis of the whole framework of reliability evaluation from instrument to NDT,and emphasis is paid to the evaluation condition control.Based on these analyses,considering the special online application scenario of SHM,the proposed Dual-RE method contains two key components:Integrated Sensor-based SHM-RE(IS-SHM-RE)and Critical Service Condition-based SHM-RE(CSC-SHM-RE).ISSHM-RE evaluates the reliability of integrated SHM sensor and system themselves under approximate repeatability conditions,while CSC-SHM-RE assesses SHM reliability under the dominant uncertainties during service,namely intermediate conditions.To demonstrate the Dual-RE,crack monitoring by using the Guided Wave-based-SHM(GW-SHM)on aircraft lug structures is taken as a case study.Both the crack detection and sizing performance are evaluated from accuracy and uncertainty.
基金supported by the National Key Research and Development Program of China(Nos.2022YFF0801104 and 2021YFD1700600)the National Natural Science Foundation of China(No.51809177)the Science Foundation of Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences(No.NIGLAS2022GS08).
文摘Estuarine and bay ecosystems serve as crucial transitional zones for land-based pollutants entering the ocean.However,there is a critical gap in understanding the behavior of emerging pollutants in the numerous small estuaries and bays located in undeveloped coastal areas.This study provides insights into the fate of antibiotics in these small and scattered estuaries and bays in Shantou's coast,driven by land use types and hydrodynamic conditions.The findings indicated that estuaries were more heavily polluted with antibiotics than the bays(P<0.05),with tetracyclines and fluoroquinolones as the primary antibiotics.Antibiotic pollution levels were more severe in October than in June(P<0.01).Rainfall runoff,aquaculture tailwater,and river discharge were identified as the main sources of antibiotic pollution.Build-up land and aquaculture ponds were the primary land use types contributing to antibiotic pollution.The total antibiotic concentrations in June were positively correlated with the proportion of aquaculture ponds(P<0.05)and negatively correlated with the proportions of cropland and grassland(P<0.05).The concentrations of lomefloxacin and ofloxacin were positively correlated with build-up land.The antibiotic concentrations exhibited strong spatial heterogeneity within both bay and estuarine ecosystems driven by different hydrodynamic conditions.A comparative analysis of global estuaries and bays revealed that specific land-use types and hydrodynamic conditions produced similar trends in antibiotic fate.These insights offered new perspectives to safeguard the health of estuarine and bay ecosystems,such as altering landscape patterns and regulating aquaculture activities.
基金supported by the Science and Technology Project of China Southern Power Grid Co.,Ltd.(ZBKTM20232244)the Project of National Natural of Science Foundation of China(52477103).
文摘The real-time and accurate calculation of electricity indirect carbon emissions is not only the critical component for quantifying the carbon emission levels of the power system but also an effective mean to guide electricity users in carbon reduction and promote power industry low-carbon transformation.Fundamentally,calculating indirect carbon emissions involves allocating direct carbon emission data from the power source side,indicating that accurate indirect emission results rely on the precise measurement of power source emissions.However,existing research on indirect carbon emissions in large-scale power systems rarely accounts for variations in carbon emission characteristics under different operating conditions of power sources,such as rated/non-rated operating conditions and ramping up/down conditions,making it difficult to reflect source-side and load-side carbon emission information variation during providing ancillary services.Quadratic and exponential functions are proposed to characterize the energy consumption profiles of coal-fired and gas-fired power generation,respectively,to construct a refined carbon emission model for power sources.By leveraging the theory of power system carbon flow,we analyze how variable operating conditions of power sources impact indirect carbon emissions.Case studies demonstrate that changes in power source emissions under variable conditions have a significant effect on the indirect carbon emissions of power grids.
文摘Increase in requirement of hydrosulphuric water for improvement of the population set the task of identification of places of their possible congestion for hydrogeological service. Earlier detection of such congestions was accidental at well-drilling of different function. Therefore, development of new methodical approaches of search and allocation of perspective zones of their formation was required. It was for this purpose necessary to study in what conditions and what factors have an impact on formation of underground hydrosulphuric water. So far, definition of communication attempts only with separate geochemical signs was known. Results of studying of influence on formations of hydrosulphuric water of such factors as lithologic and facial in combination with oil-and-gas content, the geological and structural and hydrodynamic mode are given in this work. It is established that the main sign for formation of hydrosulphuric water is existence of evaporite thickness and hydrocarbon congestions. Besides, it is shown that small depth (up to 2 km) of their bedding has to be an indispensable condition and existence of explosive violation on which there has to be a water infiltration (a geological and structural factor). In the Surkhandarya region, the hydrodynamic mode caused by inclined bedding of aquifers was also one of essential factors. Active water is an exchange process with washing away (oxidation) sulfate of the containing thicknesses and subsequently, its restoration in interaction with hydrocarbons with formation of hydrosulphuric water is described. The technique is developed and the expected card of perspective zones of formation of hydrosulphuric water is constructed.
文摘The stable operation of the central air conditioning water system always is a major difficulty for the control profession. Paper focus on the water system with multi variable, strong coupling, nonlinear, large time delay characteristics, presented use feed forward coupling compensation method, to eliminate the coupling effect between temperature and pressure. In this paper, the Elman neural network controller is designed for the first time, and the simulation results show that the response time of Elman neural network controller is shorter, the system is more stable and the overshoot is small.
基金supported by the National Natural Science Foundation of China(51078150)the National Natural Science Foundation of China(11602087)+1 种基金the State Key Laboratory of Subtropical Building Science,South China University of Technology(2017ZB32)National Undergraduate Innovative and Entrepreneurial Training Program(201810561180).
文摘The alternating method based on the fundamental solutions of the infinite domain containing a crack,namely Muskhelishvili’s solutions,divides the complex structure with a crack into a simple model without crack which can be solved by traditional numerical methods and an infinite domain with a crack which can be solved by Muskhelishvili’s solutions.However,this alternating method cannot be directly applied to the edge crack problems since partial crack surface of Muskhelishvili’s solutions is located outside the computational domain.In this paper,an improved alternating method,the spline fictitious boundary element alternating method(SFBEAM),based on infinite domain with the combination of spline fictitious boundary element method(SFBEM)and Muskhelishvili’s solutions is proposed to solve the edge crack problems.Since the SFBEM and Muskhelishvili’s solutions are obtained in the framework of infinite domain,no special treatment is needed for solving the problem of edge cracks.Different mixed boundary conditions edge crack problems with varies of computational parameters are given to certify the high precision,efficiency and applicability of the proposed method compared with other alternating methods and extend finite element method.
文摘Novel exact solutions of one-dimensional transient dynamic piezoelectric problems for thickness polarized layers and disks, or length polarized rods, are obtained. The solutions are derived using a time-domain Green’s function method that leads to an exact analytical recursive procedure which is applicable for a wide variety of boundary conditions including nonlinear cases. A nonlinear damper boundary condition is considered in more detail. The corresponding nonlinear relationship between stresses and velocities at a current time moment is used in the recursive procedure. In addition to the exact recursive procedure that is effective for calculations, some new practically important explicit exact solutions are presented. Several examples of the time behavior of the output electric potential difference are given to illustrate the effectiveness of the proposed exact approach.
文摘Tractor hydraulic fluids are tested to maximize their performance levels and to ensure manufacturer′s standards are met.Common tractor hydraulic fluid tests include: Gear Wear Protection,Brake Chatter Reduction,Wet-Clutch Capacity,and Pump Performance tests.These tests are run by Southwest Research Institute,in the U.S.A.,for tractors built by John Deere and Case-New Holland.This paper details current methods for evaluating tractor hydraulic fluids.The tests that are described utilize full size equipment and were developed by the tractor′s original equipment manufacturers(OEMs).
