The selection of working fluid significantly impacts the geothermal ORC’s Efficiency.Using a mixture as a working fluid is a strategy to improve the output of geothermal ORC.In the current study,modelling and thermod...The selection of working fluid significantly impacts the geothermal ORC’s Efficiency.Using a mixture as a working fluid is a strategy to improve the output of geothermal ORC.In the current study,modelling and thermodynamic analysis of ORC,using geothermal as a heat source,is carried out at fixed operating conditions.The model is simulated in the Engineering Equation Solver(EES).An environment-friendly mixture of fluids,i.e.,R245fa/R600a,with a suitable mole fraction,is used as the operating fluid.The mixture provided the most convenient results compared to the pure working fluid under fixed operating conditions.The impact of varying the evaporator pressure on the performance parameters,including energy efficiency,exergy efficiency and net power output is investigated.The system provided the optimal performance once the evaporator pressure reached the maximum value.The efficiencies:Energy and Exergy,and Net Power output of the system are 16.62%,64.08%and 2199 kW for the basic cycle and 20.72%,67.76%and 2326 kW respectively for the regenerative cycle.展开更多
The dynamic response of the steel lazy wave riser(SLWR)subjected to the internal solitary wave is a key to assessing its application feasibility.The innovation of this paper is to study the dynamic response properties...The dynamic response of the steel lazy wave riser(SLWR)subjected to the internal solitary wave is a key to assessing its application feasibility.The innovation of this paper is to study the dynamic response properties of the SLWR with large deformation characteristics under internal wave excitation.A numerical scheme of the SLWR is constructed using the slender-rod theory,and the internal solitary wave(ISW)with a two-layer seawater model is simulated by the extended Korteweg-deVries equation.The finite element method combined with the Newmark-βmethod is applied to discretize the equations and update the time integration.The ISW excitation combined with vessel motion on the dynamic deformation and stress of the SLWR is investigated,and extensive simulations of the ISW parameters,including the interface depth ratio and density difference,are carried out.Case calculation reveals that the displacement of the riser in the lower interface layer increases significantly under the ISW excitation,and the stresses at a part of both ends grow evidently.Moreover,the mean value of riser responses under a combination of vessel motion and ISW coincides with the ISW-induced ones.Furthermore,the dynamic responses along the whole riser,including the displacement amplitudes,bending moment amplitudes,and stress amplitudes,almost increase with the increase in interface depth ratios and density differences.展开更多
To guarantee the safety of the high speed maglev train system, a novel model based on the winding function theory is proposed for the long-stator linear synchronous motor(LSM), which is suitable for the real-time ca...To guarantee the safety of the high speed maglev train system, a novel model based on the winding function theory is proposed for the long-stator linear synchronous motor(LSM), which is suitable for the real-time calculation of the running state. The accurate coupled mathematical models under different internal fault conditions of the LSM are derived based on the normal model. Then the fault currents and electromagnetic forces are simulated and calculated for the major potential internal faults of the LSM, such as the single-phase short circuit, the phase-phase short circuit and the single-phase open circuit. The characteristic curve between the electromagnetic force and the armature current of the LSM, which is compared with the results from the finite element method, proves the validation of the proposed method. The fault rule is determined and the proposed analytical model also shows its feasibility in the fast fault diagnosis through the comparison of the simulation results of currents and electromagnetic forces under different internal fault types and short circuit ratios.展开更多
European literary criticism was rapidly transformed into literary theory through the United States after Rene Wellek and Austin Warren’s textbook Theory of Literary Theory by Harcourt,Brace and Co.(1949).Within a sho...European literary criticism was rapidly transformed into literary theory through the United States after Rene Wellek and Austin Warren’s textbook Theory of Literary Theory by Harcourt,Brace and Co.(1949).Within a short period of time,American new criticism,European psychoanalysis,semiotics,structuralism,hermeneutics,deconstructivism,and so on,as well as the western Marxism,feminism,new historicism,post-colonial criticism,and cultural studies,all the critical methods little referenced to postwar Western ideology and Soviet Ideology,and are even known for their profound criticism of some problems in capitalist society.These intuitively scientific or neutral literary theories flourished during the Cold War years that contained the Soviet Union.During this period,“political correctness”not only influenced the direction of social development in the West,but also directly influenced the academic pattern and the development trend of universities at that time,so that“literary criticism”,which was originally only based on personal experience,benefited and became“literary theory”in the discipline and curriculum system.As a result,the discipline of literary theory,which benefited from the Cold War pattern,is often in conflict with the specific literary theory that transcends ideology.However,the Cold War ended with the failure of the Soviet Union and its socialist realism theory system,and the western literary theory unexpectedly gained full legitimacy like Fukuyama’s“the end of history”.In the post-Cold War era,Western literary critics reasonably expanded the controversial theories and this has become the most concerned topic for 30 years.Thus,the international politics of the disguised Western literary theory was highlighted.Such Western literary theory has been generalized in China in the last 40 years,because Chinese academic yet has not understood the difference between theory as discipline and theory as doctrine,even anti-western in recent years.展开更多
AIM: To identify and understand the regular distribution pattern for Salmonella enteritidis (S. enteritidis) in the internal organs of mice after an oral challenge over a 3 wk period. METHODS: Assays based on the ...AIM: To identify and understand the regular distribution pattern for Salmonella enteritidis (S. enteritidis) in the internal organs of mice after an oral challenge over a 3 wk period. METHODS: Assays based on the serovar-specific DNA sequence of S. enteritidis from GenBank, and a serovar-specific real-time, fluorescence-based quantitative polymerase chain reaction (FQ-PCR) were developed for the detection of S. enteritidis. We used this assay to detect genomic DNA of S. enteritidis in the blood and the internal organs, including heart, liver, spleen, kidney, pancreas, and gallbladder, from mice after oral challenge at different time points respectively.RESULTS: The results showed that the spleen was positive at 12 h post inoculation (PI), and the blood was at 14 h PI. The organism was detected in the liver and heart at 16 h PI, the pancreas was positive at 20 h PI, and the final organs to show positive results were the kidney and gallbladder at 22 h PI. The copy number of S. enteritidis DNA in each tissue reached a peak at 24-36 h PI, with the liver and spleen containing high concentrations of S. enteritidis, whereas the blood, heart, kidney, pancreas, and gallbladder had low concentrations. S. enteritidis populations began to decrease and were not detectable at 3 d PI, but were still present up to 12 d PI in the gallbladder, 2 wk for the liver, and 3 wk for the spleen without causing apparent symptoms.CONCLUSION: The results provided significant data for understanding the life cycle of S. enteritidis in the internal organs, and showed that the liver and spleen may be the primary sites for setting itself up as a commensa over a long time after oral challenge. Interestingly, it may be the first time reported that the gallbladder is a site of carriage for S. enteritidis over a 12 d period. This study will help to understand the mechanisms of action of S. enteriCdis infection in vivo.展开更多
The load and corrosion caused by the harsh marine environment lead to the severe degradation of offshore equipment and to their compromised security and reliability. In the quantitative risk analysis, the failure mode...The load and corrosion caused by the harsh marine environment lead to the severe degradation of offshore equipment and to their compromised security and reliability. In the quantitative risk analysis, the failure models are difficult to establish through traditional statistical methods. Hence, the calculation of the occurrence probability of small sample events is often met with great uncertainty. In this study, the Bayesian statistical method is implemented to analyze the oil and gas leakages of FPSO internal turret, which is a typical small sample risk but could lead to severe losses.According to the corresponding failure mechanism, two Bayesian statistical models using the Weibull distribution and logarithmic normal distribution as the population distribution are established, and the posterior distribution of the corresponding parameters is calculated. The optimal Bayesian statistical model is determined according to the Bayesian information criterion and Akaike criterion. On the basis of the determined optimal model, the corresponding reliability index is solved to provide basic data for the subsequent risk assessments of FPSO systems.展开更多
The internally balanced theory proposed by the Japanese researchers,solved the contradiction between adsorption ability and moving capability of the permanent magnetic adsorption mechanism.However,it still has some pr...The internally balanced theory proposed by the Japanese researchers,solved the contradiction between adsorption ability and moving capability of the permanent magnetic adsorption mechanism.However,it still has some problems when applied to wall climbing robots.This paper analyzes and improves this theory,and the improved internally balanced theory satisfies the requirements of the adsorption mechanism significantly.Finally,a practical prototype is proposed based on this method,and both the analysis using ANSYS and the experiment results justify the design validity.展开更多
BACKGROUND Internal rectal prolapse(IRP)is one of the most common causes of obstructive constipation.The incidence of IRP in women is approximately three times that in men.IRP is mainly treated by surgery,which can be...BACKGROUND Internal rectal prolapse(IRP)is one of the most common causes of obstructive constipation.The incidence of IRP in women is approximately three times that in men.IRP is mainly treated by surgery,which can be divided into two categories:Abdominal procedures and perineal procedures.This study offers a better procedure for the treatment of IRP.AIM To compare the clinical efficacy of laparoscopic integral pelvic floor/ligament repair(IPFLR)combined with a procedure for prolapse and hemorrhoids(PPH)and the laparoscopic IPFLR alone in the treatment of IRP in women.METHODS This study collected the clinical data of 130 female patients with IRP who underwent surgery from January 2012 to October 2014.The patients were divided into groups A and B.Group A had 63 patients who underwent laparoscopic IPFLR alone,and group B had 67 patients who underwent the laparoscopic IPFLR combined with PPH.The degree of internal rectal prolapse(DIRP),Wexner constipation scale(WCS)score,Wexner incontinence scale(WIS)score,and Gastrointestinal Quality of Life Index(GIQLI)score were compared between groups and within groups before surgery and 6 mo and 2 years after surgery.RESULTS All laparoscopic surgeries were successful.The general information,number of bowel movements before surgery,DIRP,GIQLI score,WIS score,and WCS score before surgery were not significantly different between the two groups(all P>0.05).The WCS score,WIS score,GIQLI score,and DIRP in each group 6 mo,and 2 years after surgery were significantly better than before surgery(P<0.001).In group A,the DIRP and WCS score gradually improved from 6 mo to 2 years after surgery(P<0.001),and the GIQLI score progressively improved from 6 mo to 2 years after surgery(P<0.05).In group B,the DIRP,WCS score and WIS score significantly improved from 6 mo to 2 years after surgery(P<0.05),and the GIQLI score 2 years after surgery was significantly higher than that 6 mo after surgery(P<0.05).The WCS score,WIS score,GIQLI score,and DIRP of group B were significantly better than those of group A 6 mo and 2 years after surgery(all P<0.001,Bonferroni)except DIRP at 2 years after surgery.There was a significant difference in the recurrence rate of IRP between the two groups 6 mo after surgery(P=0.011).There was no significant difference in postoperative grade I-III complications between the two groups(P=0.822).CONCLUSION Integral theory–guided laparoscopic IPFLR combined with PPH has a higher cure rate and a better clinical efficacy than laparoscopic IPFLR alone.展开更多
A microstructural constitutive theory of ER suspensions was formulated in this investigation. The framework was based on the internal variable theory and the mechanism analysis. The ER suspension consists of fine part...A microstructural constitutive theory of ER suspensions was formulated in this investigation. The framework was based on the internal variable theory and the mechanism analysis. The ER suspension consists of fine particles with high dielectric constant and the supporting fluid. Under the action of the electric field, the polarized particles will aggregate together to form the chain-like structures along the direction of the electric field. As the size and orientation of the particle aggregates are volatile, and they adjust according to the applied electric field and strain rate, the energy conservation equation and the force equilibrium equation were thus established to determine the orientation and size of the aggregates. Following that, a three-dimensional, explicit form of the constitutive equation was derived based on the interaction energy and the dissipation function of the system. The response of the system under the action of a simple shearing load was considered and discussed in detail. It is found that the shear-thinning viscosity of an ER suspension is wed approximated by the power-law proportional to (Mn)(-D.82).展开更多
This paper from the unified visual angle of philosophy and economics has observed Marx's theory of ecological economics, clarified the misunderstanding on Marx's theory of nature and ecological environmental t...This paper from the unified visual angle of philosophy and economics has observed Marx's theory of ecological economics, clarified the misunderstanding on Marx's theory of nature and ecological environmental thought at home and abroad for a long time, studied systematically and deeply the Marx's thought that natural and ecological environment is external condition and internal elements of human social economic growth, confirmed firstly Marx is the forerunner who established the theory of internal cause of natural ecological environment. It is of far-reaching academic and practical significance.展开更多
Based on density functional theory (DFT) calculations, we investigate the spin-related properties of spinless-hole injected organic molecule pentacene (Pc). DFT calculations reveal that there is spontaneous spin p...Based on density functional theory (DFT) calculations, we investigate the spin-related properties of spinless-hole injected organic molecule pentacene (Pc). DFT calculations reveal that there is spontaneous spin polarization in Pc when spinless-hole is injected. The chargeinduced magnetic moment of Pc increases linearly with the increasing of the extra hole charge amount and its maximum can be up to 1 μB per injected spinless-hole per Pc molecule. The magnetic moment is expected due to the injected unpaired charge. The injected hole will preferably ll the spin-splitted carbon pz orbitals, which makes the Pc molecule spin polarize.展开更多
The initiating condition for the accelerated creep of rocks has caused difficulty in analyzing the whole creep process.Moreover,the existing Nishihara model has evident shortcomings in describing the accelerated creep...The initiating condition for the accelerated creep of rocks has caused difficulty in analyzing the whole creep process.Moreover,the existing Nishihara model has evident shortcomings in describing the accelerated creep characteristics of the viscoplastic stage from the perspective of internal energy to analyze the mechanism of rock creep failure and determine the threshold of accelerated creep initiation.Based on the kinetic energy theorem,Perzyna viscoplastic theory,and the Nishihara model,a unified creep constitutive model that can describe the whole process of decaying creep,stable creep,and accelerated creep is established.Results reveal that the energy consumption and creep damage in the process of creep loading mainly come from the internal energy changes of geotechnical materials.The established creep model can not only describe the viscoelasticeplastic creep characteristics of rock,but also reflect the relationship between rock energy and creep deformation change.In addition,the research results provide a new method for determining the critical point of creep deformation and a new idea for studying the creep model and creep mechanical properties.展开更多
Pig (Sus scrofa) fat accumulation can be reduced by feeding with high dosages of clenbuterol, but the molecular mechanism has not yet been explained. In our study, a porcine cDNA microarray representing 3 358 pig ge...Pig (Sus scrofa) fat accumulation can be reduced by feeding with high dosages of clenbuterol, but the molecular mechanism has not yet been explained. In our study, a porcine cDNA microarray representing 3 358 pig genes was successfully developed. This microarray is the first porcine DNA microarray in China and its false positive rate is 0.98%, which means the microarray platform is reliable. The microarray can be used to study gene expression profiles in multiple pig tissues because the present genes percentage of adipose, skeletal muscle, heart, liver, lung, kidney, and spleen were all more than 60%. This microarray was used to identify the genes responding to clenbuterol stimulation in pig internal organs, including heart, liver, lung, spleen, and kidney. Many genes were identified including enzymes involved in lipids metabolism (lipoprotein lipase up-regulated in liver, heart and lung, ATP-citrate lyase and carnitine palmitoyltransferase II precursor up-regulated in liver, succinyl-CoA up-regulated in lung, mitochondrial malate dehydrogenase down-regulated in spleen), and signaling pathway genes (cAMP-protein kinase A signaling pathway was found up-regulated in liver, heart, lung, and kidney as reported previously, while transforming growth factor was found down-regulated in heart and lung). However, no common gene responding to clenbuterol administration was found in all tissues. The expression levels of 14 genes were analyzed using real-time PCR with 82.1% of them induced to express similar magnitudes as in the microarray analyses. This work offers some understanding of how clenbuterol so effectively reduces pig adipose accumulation on the molecular level.展开更多
The objective of this study was to investigate the effects of phytase supplementation on growth performance, slaughter performance, growth of internal organs and small intestine, and serum biochemical indices of broil...The objective of this study was to investigate the effects of phytase supplementation on growth performance, slaughter performance, growth of internal organs and small intestine, and serum biochemical indices of broilers. A total of 360 1-day-old Ross 308 broilers were randomly divided into 4 groups with 3 replicates and 30 broilers per replicate (15 male, 15 female). The treatments were fed with basal diet supplemented with 0%, 0.01%, 0.02% and 0.03% phytase. The results showed that: 1) Phytase supplementation increased the body weight gain and the body weight of Ross 308 broilers (P serum calcium (Ca) consistency was 0.02%. According to the above analysis, the feasible supplementation of phytase (enzyme activity for 5000 u/g) in broiler dietary was 0.02%.展开更多
Conformational elasticity theory recently developed has been used to explore the internal energy contribution to the elastic force f(e)/f as a function of strain for poly(cis-1,4-isoprene) and poly(trans-1,4-isoprene)...Conformational elasticity theory recently developed has been used to explore the internal energy contribution to the elastic force f(e)/f as a function of strain for poly(cis-1,4-isoprene) and poly(trans-1,4-isoprene). Calculated f(e)/f values are in good agreement with those obtained experimentally. Results show that behavior of f(e)/f is mainly contributed by chemical structure, or intramolecular interaction, supporting the experimental observations, and that the internal energy contribution is strain dependent.展开更多
Technical Barriers to Trade (TBT) have become an important obstacle to the export of Chinese agricultural products. The paper analyzes the connotation and the development trend of TBT, then analyzes the birth of TBT...Technical Barriers to Trade (TBT) have become an important obstacle to the export of Chinese agricultural products. The paper analyzes the connotation and the development trend of TBT, then analyzes the birth of TBT through using Game theory and explains the motives of the countries setting up TBT. Finally, the paper proposes countermeasures from two aspects of government and enterprises in China.展开更多
We investigate the thermal characteristics of standard organic light-emitting diodes (OLEDs) using a simple and clear 1D thermal model based on the basic heat transfer theory. The thermal model can accurately estima...We investigate the thermal characteristics of standard organic light-emitting diodes (OLEDs) using a simple and clear 1D thermal model based on the basic heat transfer theory. The thermal model can accurately estimate the device temperature, which is linearly with electrical input power. The simulation results show that there is almost no temperature gradient within the OLED device working under steady state conditions. Furthermore, thermal analysis simulation results show that the surface properties (convective heat transfer coetficient and surface emissivity) of the substrate or cathode can significantly affect the temperature distribution of the OLED.展开更多
The term “globalization” designates the rapidly advancing international economic integration through substantial growth in trade of goods and services as well as surging cross-border factor mobility from the early 1...The term “globalization” designates the rapidly advancing international economic integration through substantial growth in trade of goods and services as well as surging cross-border factor mobility from the early 1990s onwards. This acceleration in the liberalization of world trade and capital movements is largely attributable to technological progress which significantly curtailed the expenses for transport as well as communication. In conjunction with the progressing opening of major newly industrializing economies endowed with abundant and cheap labor forces, it has reinforced a geographical fragmentation of production processes according to cost considerations. This phenomenon termed as “vertical specialization”, “outsourcing” or also “slicing the value chain” in turn has translated into a hike in FDI and international trade of intermediate products. The main objective of this paper is to identify adequate trade models for assessing the corresponding effects of those developments. In this context, textbook trade theories spanning from comparative advantage à la Ricardo to the new-new trade theory are examined. Subsequently, we expand on globalization-induced new forms of trade (intra-firm trade, trade within the value chain) and finally conclude with our findings to properly account for those trends.展开更多
文摘The selection of working fluid significantly impacts the geothermal ORC’s Efficiency.Using a mixture as a working fluid is a strategy to improve the output of geothermal ORC.In the current study,modelling and thermodynamic analysis of ORC,using geothermal as a heat source,is carried out at fixed operating conditions.The model is simulated in the Engineering Equation Solver(EES).An environment-friendly mixture of fluids,i.e.,R245fa/R600a,with a suitable mole fraction,is used as the operating fluid.The mixture provided the most convenient results compared to the pure working fluid under fixed operating conditions.The impact of varying the evaporator pressure on the performance parameters,including energy efficiency,exergy efficiency and net power output is investigated.The system provided the optimal performance once the evaporator pressure reached the maximum value.The efficiencies:Energy and Exergy,and Net Power output of the system are 16.62%,64.08%and 2199 kW for the basic cycle and 20.72%,67.76%and 2326 kW respectively for the regenerative cycle.
基金This work was supported by the National Natural Science Foundation of China(Nos.U2006226,51979257)the Shandong Provincial Natural Science Foundation,China(Nos.ZR2020ME261,ZR2019MEE032).
文摘The dynamic response of the steel lazy wave riser(SLWR)subjected to the internal solitary wave is a key to assessing its application feasibility.The innovation of this paper is to study the dynamic response properties of the SLWR with large deformation characteristics under internal wave excitation.A numerical scheme of the SLWR is constructed using the slender-rod theory,and the internal solitary wave(ISW)with a two-layer seawater model is simulated by the extended Korteweg-deVries equation.The finite element method combined with the Newmark-βmethod is applied to discretize the equations and update the time integration.The ISW excitation combined with vessel motion on the dynamic deformation and stress of the SLWR is investigated,and extensive simulations of the ISW parameters,including the interface depth ratio and density difference,are carried out.Case calculation reveals that the displacement of the riser in the lower interface layer increases significantly under the ISW excitation,and the stresses at a part of both ends grow evidently.Moreover,the mean value of riser responses under a combination of vessel motion and ISW coincides with the ISW-induced ones.Furthermore,the dynamic responses along the whole riser,including the displacement amplitudes,bending moment amplitudes,and stress amplitudes,almost increase with the increase in interface depth ratios and density differences.
文摘To guarantee the safety of the high speed maglev train system, a novel model based on the winding function theory is proposed for the long-stator linear synchronous motor(LSM), which is suitable for the real-time calculation of the running state. The accurate coupled mathematical models under different internal fault conditions of the LSM are derived based on the normal model. Then the fault currents and electromagnetic forces are simulated and calculated for the major potential internal faults of the LSM, such as the single-phase short circuit, the phase-phase short circuit and the single-phase open circuit. The characteristic curve between the electromagnetic force and the armature current of the LSM, which is compared with the results from the finite element method, proves the validation of the proposed method. The fault rule is determined and the proposed analytical model also shows its feasibility in the fast fault diagnosis through the comparison of the simulation results of currents and electromagnetic forces under different internal fault types and short circuit ratios.
文摘European literary criticism was rapidly transformed into literary theory through the United States after Rene Wellek and Austin Warren’s textbook Theory of Literary Theory by Harcourt,Brace and Co.(1949).Within a short period of time,American new criticism,European psychoanalysis,semiotics,structuralism,hermeneutics,deconstructivism,and so on,as well as the western Marxism,feminism,new historicism,post-colonial criticism,and cultural studies,all the critical methods little referenced to postwar Western ideology and Soviet Ideology,and are even known for their profound criticism of some problems in capitalist society.These intuitively scientific or neutral literary theories flourished during the Cold War years that contained the Soviet Union.During this period,“political correctness”not only influenced the direction of social development in the West,but also directly influenced the academic pattern and the development trend of universities at that time,so that“literary criticism”,which was originally only based on personal experience,benefited and became“literary theory”in the discipline and curriculum system.As a result,the discipline of literary theory,which benefited from the Cold War pattern,is often in conflict with the specific literary theory that transcends ideology.However,the Cold War ended with the failure of the Soviet Union and its socialist realism theory system,and the western literary theory unexpectedly gained full legitimacy like Fukuyama’s“the end of history”.In the post-Cold War era,Western literary critics reasonably expanded the controversial theories and this has become the most concerned topic for 30 years.Thus,the international politics of the disguised Western literary theory was highlighted.Such Western literary theory has been generalized in China in the last 40 years,because Chinese academic yet has not understood the difference between theory as discipline and theory as doctrine,even anti-western in recent years.
基金The National Key Technology R&D Program of China, No. 2004BA901A03National Scientific and Technical Support Program, No. 2007Z06-017+3 种基金The Cultivation Fund of the Key Scientific and Technical Innovation Project & Ministry of Education of China, No. 706050Program for New Century Excellent Talents in University, No. NCET-04-0906/NCET-06-0818Sichuan Province Basic Research Program, No. 04JY0290061/07JY029-017Program for Key DisciplinesConstruction of Sichuan Province No. SZD0418
文摘AIM: To identify and understand the regular distribution pattern for Salmonella enteritidis (S. enteritidis) in the internal organs of mice after an oral challenge over a 3 wk period. METHODS: Assays based on the serovar-specific DNA sequence of S. enteritidis from GenBank, and a serovar-specific real-time, fluorescence-based quantitative polymerase chain reaction (FQ-PCR) were developed for the detection of S. enteritidis. We used this assay to detect genomic DNA of S. enteritidis in the blood and the internal organs, including heart, liver, spleen, kidney, pancreas, and gallbladder, from mice after oral challenge at different time points respectively.RESULTS: The results showed that the spleen was positive at 12 h post inoculation (PI), and the blood was at 14 h PI. The organism was detected in the liver and heart at 16 h PI, the pancreas was positive at 20 h PI, and the final organs to show positive results were the kidney and gallbladder at 22 h PI. The copy number of S. enteritidis DNA in each tissue reached a peak at 24-36 h PI, with the liver and spleen containing high concentrations of S. enteritidis, whereas the blood, heart, kidney, pancreas, and gallbladder had low concentrations. S. enteritidis populations began to decrease and were not detectable at 3 d PI, but were still present up to 12 d PI in the gallbladder, 2 wk for the liver, and 3 wk for the spleen without causing apparent symptoms.CONCLUSION: The results provided significant data for understanding the life cycle of S. enteritidis in the internal organs, and showed that the liver and spleen may be the primary sites for setting itself up as a commensa over a long time after oral challenge. Interestingly, it may be the first time reported that the gallbladder is a site of carriage for S. enteritidis over a 12 d period. This study will help to understand the mechanisms of action of S. enteriCdis infection in vivo.
基金financially supported by the National International Science and Technology Cooperation Specific Projectthe Development of Risk Assessment Software for Floating Offshore Wind Turbine(Grant No.2013DFE73060)the Development of Failure Database and Risk Assessment System for FPSO(Grant No.G014614002)
文摘The load and corrosion caused by the harsh marine environment lead to the severe degradation of offshore equipment and to their compromised security and reliability. In the quantitative risk analysis, the failure models are difficult to establish through traditional statistical methods. Hence, the calculation of the occurrence probability of small sample events is often met with great uncertainty. In this study, the Bayesian statistical method is implemented to analyze the oil and gas leakages of FPSO internal turret, which is a typical small sample risk but could lead to severe losses.According to the corresponding failure mechanism, two Bayesian statistical models using the Weibull distribution and logarithmic normal distribution as the population distribution are established, and the posterior distribution of the corresponding parameters is calculated. The optimal Bayesian statistical model is determined according to the Bayesian information criterion and Akaike criterion. On the basis of the determined optimal model, the corresponding reliability index is solved to provide basic data for the subsequent risk assessments of FPSO systems.
文摘The internally balanced theory proposed by the Japanese researchers,solved the contradiction between adsorption ability and moving capability of the permanent magnetic adsorption mechanism.However,it still has some problems when applied to wall climbing robots.This paper analyzes and improves this theory,and the improved internally balanced theory satisfies the requirements of the adsorption mechanism significantly.Finally,a practical prototype is proposed based on this method,and both the analysis using ANSYS and the experiment results justify the design validity.
基金Supported by Medical Science and Technology Project of Henan Province,China,No.2011030031.
文摘BACKGROUND Internal rectal prolapse(IRP)is one of the most common causes of obstructive constipation.The incidence of IRP in women is approximately three times that in men.IRP is mainly treated by surgery,which can be divided into two categories:Abdominal procedures and perineal procedures.This study offers a better procedure for the treatment of IRP.AIM To compare the clinical efficacy of laparoscopic integral pelvic floor/ligament repair(IPFLR)combined with a procedure for prolapse and hemorrhoids(PPH)and the laparoscopic IPFLR alone in the treatment of IRP in women.METHODS This study collected the clinical data of 130 female patients with IRP who underwent surgery from January 2012 to October 2014.The patients were divided into groups A and B.Group A had 63 patients who underwent laparoscopic IPFLR alone,and group B had 67 patients who underwent the laparoscopic IPFLR combined with PPH.The degree of internal rectal prolapse(DIRP),Wexner constipation scale(WCS)score,Wexner incontinence scale(WIS)score,and Gastrointestinal Quality of Life Index(GIQLI)score were compared between groups and within groups before surgery and 6 mo and 2 years after surgery.RESULTS All laparoscopic surgeries were successful.The general information,number of bowel movements before surgery,DIRP,GIQLI score,WIS score,and WCS score before surgery were not significantly different between the two groups(all P>0.05).The WCS score,WIS score,GIQLI score,and DIRP in each group 6 mo,and 2 years after surgery were significantly better than before surgery(P<0.001).In group A,the DIRP and WCS score gradually improved from 6 mo to 2 years after surgery(P<0.001),and the GIQLI score progressively improved from 6 mo to 2 years after surgery(P<0.05).In group B,the DIRP,WCS score and WIS score significantly improved from 6 mo to 2 years after surgery(P<0.05),and the GIQLI score 2 years after surgery was significantly higher than that 6 mo after surgery(P<0.05).The WCS score,WIS score,GIQLI score,and DIRP of group B were significantly better than those of group A 6 mo and 2 years after surgery(all P<0.001,Bonferroni)except DIRP at 2 years after surgery.There was a significant difference in the recurrence rate of IRP between the two groups 6 mo after surgery(P=0.011).There was no significant difference in postoperative grade I-III complications between the two groups(P=0.822).CONCLUSION Integral theory–guided laparoscopic IPFLR combined with PPH has a higher cure rate and a better clinical efficacy than laparoscopic IPFLR alone.
文摘A microstructural constitutive theory of ER suspensions was formulated in this investigation. The framework was based on the internal variable theory and the mechanism analysis. The ER suspension consists of fine particles with high dielectric constant and the supporting fluid. Under the action of the electric field, the polarized particles will aggregate together to form the chain-like structures along the direction of the electric field. As the size and orientation of the particle aggregates are volatile, and they adjust according to the applied electric field and strain rate, the energy conservation equation and the force equilibrium equation were thus established to determine the orientation and size of the aggregates. Following that, a three-dimensional, explicit form of the constitutive equation was derived based on the interaction energy and the dissipation function of the system. The response of the system under the action of a simple shearing load was considered and discussed in detail. It is found that the shear-thinning viscosity of an ER suspension is wed approximated by the power-law proportional to (Mn)(-D.82).
文摘This paper from the unified visual angle of philosophy and economics has observed Marx's theory of ecological economics, clarified the misunderstanding on Marx's theory of nature and ecological environmental thought at home and abroad for a long time, studied systematically and deeply the Marx's thought that natural and ecological environment is external condition and internal elements of human social economic growth, confirmed firstly Marx is the forerunner who established the theory of internal cause of natural ecological environment. It is of far-reaching academic and practical significance.
文摘Based on density functional theory (DFT) calculations, we investigate the spin-related properties of spinless-hole injected organic molecule pentacene (Pc). DFT calculations reveal that there is spontaneous spin polarization in Pc when spinless-hole is injected. The chargeinduced magnetic moment of Pc increases linearly with the increasing of the extra hole charge amount and its maximum can be up to 1 μB per injected spinless-hole per Pc molecule. The magnetic moment is expected due to the injected unpaired charge. The injected hole will preferably ll the spin-splitted carbon pz orbitals, which makes the Pc molecule spin polarize.
基金This work was supported by the National Natural Science Foundation of China(Grant No.41941018)the Science and Tech-nology Service Network Initiative of the Chinese Academy of Sci-ences(Grant No.KFJSTS-QYZD-174),and the Guangxi Natural Science Foundation(Grant No.2020GXNSFAA159125).
文摘The initiating condition for the accelerated creep of rocks has caused difficulty in analyzing the whole creep process.Moreover,the existing Nishihara model has evident shortcomings in describing the accelerated creep characteristics of the viscoplastic stage from the perspective of internal energy to analyze the mechanism of rock creep failure and determine the threshold of accelerated creep initiation.Based on the kinetic energy theorem,Perzyna viscoplastic theory,and the Nishihara model,a unified creep constitutive model that can describe the whole process of decaying creep,stable creep,and accelerated creep is established.Results reveal that the energy consumption and creep damage in the process of creep loading mainly come from the internal energy changes of geotechnical materials.The established creep model can not only describe the viscoelasticeplastic creep characteristics of rock,but also reflect the relationship between rock energy and creep deformation change.In addition,the research results provide a new method for determining the critical point of creep deformation and a new idea for studying the creep model and creep mechanical properties.
基金supported by the National Natural Science Foundation of China (30800778 and 31072004)the Hebei Natural Science Foundation (C2009000871)+2 种基金the Hebei Educational Foundation,China (2009119)the Hebei Excellent Expert for Overseas Advanced Training Program (2009)Scientific Research Innovation Team Funds of Hebei Normal University of Sci & Tech,China
文摘Pig (Sus scrofa) fat accumulation can be reduced by feeding with high dosages of clenbuterol, but the molecular mechanism has not yet been explained. In our study, a porcine cDNA microarray representing 3 358 pig genes was successfully developed. This microarray is the first porcine DNA microarray in China and its false positive rate is 0.98%, which means the microarray platform is reliable. The microarray can be used to study gene expression profiles in multiple pig tissues because the present genes percentage of adipose, skeletal muscle, heart, liver, lung, kidney, and spleen were all more than 60%. This microarray was used to identify the genes responding to clenbuterol stimulation in pig internal organs, including heart, liver, lung, spleen, and kidney. Many genes were identified including enzymes involved in lipids metabolism (lipoprotein lipase up-regulated in liver, heart and lung, ATP-citrate lyase and carnitine palmitoyltransferase II precursor up-regulated in liver, succinyl-CoA up-regulated in lung, mitochondrial malate dehydrogenase down-regulated in spleen), and signaling pathway genes (cAMP-protein kinase A signaling pathway was found up-regulated in liver, heart, lung, and kidney as reported previously, while transforming growth factor was found down-regulated in heart and lung). However, no common gene responding to clenbuterol administration was found in all tissues. The expression levels of 14 genes were analyzed using real-time PCR with 82.1% of them induced to express similar magnitudes as in the microarray analyses. This work offers some understanding of how clenbuterol so effectively reduces pig adipose accumulation on the molecular level.
文摘The objective of this study was to investigate the effects of phytase supplementation on growth performance, slaughter performance, growth of internal organs and small intestine, and serum biochemical indices of broilers. A total of 360 1-day-old Ross 308 broilers were randomly divided into 4 groups with 3 replicates and 30 broilers per replicate (15 male, 15 female). The treatments were fed with basal diet supplemented with 0%, 0.01%, 0.02% and 0.03% phytase. The results showed that: 1) Phytase supplementation increased the body weight gain and the body weight of Ross 308 broilers (P serum calcium (Ca) consistency was 0.02%. According to the above analysis, the feasible supplementation of phytase (enzyme activity for 5000 u/g) in broiler dietary was 0.02%.
基金This project has been supported by the National Natural Science Foundation of China, 863 High Technology Project, Special Funds for Major State Basic Research Project (G1999064800).
文摘Conformational elasticity theory recently developed has been used to explore the internal energy contribution to the elastic force f(e)/f as a function of strain for poly(cis-1,4-isoprene) and poly(trans-1,4-isoprene). Calculated f(e)/f values are in good agreement with those obtained experimentally. Results show that behavior of f(e)/f is mainly contributed by chemical structure, or intramolecular interaction, supporting the experimental observations, and that the internal energy contribution is strain dependent.
文摘Technical Barriers to Trade (TBT) have become an important obstacle to the export of Chinese agricultural products. The paper analyzes the connotation and the development trend of TBT, then analyzes the birth of TBT through using Game theory and explains the motives of the countries setting up TBT. Finally, the paper proposes countermeasures from two aspects of government and enterprises in China.
基金Supported by the National Natural Science Foundation of China under Grant No 11304247the Shaanxi Provincial Research Plan for Young Scientific and Technological New Stars(No 2015KJXX-40)the Youth Foundation of Xi’an University of Post&Telecommunication under Grant Nos 1011215 and 1010473
文摘We investigate the thermal characteristics of standard organic light-emitting diodes (OLEDs) using a simple and clear 1D thermal model based on the basic heat transfer theory. The thermal model can accurately estimate the device temperature, which is linearly with electrical input power. The simulation results show that there is almost no temperature gradient within the OLED device working under steady state conditions. Furthermore, thermal analysis simulation results show that the surface properties (convective heat transfer coetficient and surface emissivity) of the substrate or cathode can significantly affect the temperature distribution of the OLED.
文摘The term “globalization” designates the rapidly advancing international economic integration through substantial growth in trade of goods and services as well as surging cross-border factor mobility from the early 1990s onwards. This acceleration in the liberalization of world trade and capital movements is largely attributable to technological progress which significantly curtailed the expenses for transport as well as communication. In conjunction with the progressing opening of major newly industrializing economies endowed with abundant and cheap labor forces, it has reinforced a geographical fragmentation of production processes according to cost considerations. This phenomenon termed as “vertical specialization”, “outsourcing” or also “slicing the value chain” in turn has translated into a hike in FDI and international trade of intermediate products. The main objective of this paper is to identify adequate trade models for assessing the corresponding effects of those developments. In this context, textbook trade theories spanning from comparative advantage à la Ricardo to the new-new trade theory are examined. Subsequently, we expand on globalization-induced new forms of trade (intra-firm trade, trade within the value chain) and finally conclude with our findings to properly account for those trends.