AIM: To compare the benefi cial effects of early enteral nutrition (EN) with prebiotic fiber supplementation in patients with severe acute pancreatitis (AP).METHODS: Thirty consecutive patients with severe AP, who req...AIM: To compare the benefi cial effects of early enteral nutrition (EN) with prebiotic fiber supplementation in patients with severe acute pancreatitis (AP).METHODS: Thirty consecutive patients with severe AP, who required stoppage of oral feeding for 48 h, were randomly assigned to nasojejunal EN with or without prebiotics. APACHE Ⅱ score, Balthazar’s CT score and CRP were assessed daily during the study period.RESULTS: The median duration of hospital stay was shorter in the study group [10 ± 4 (8-14) d vs 15 ± 6 (7-26) d] (P < 0.05). The median value of days in intensive care unit was also similar in both groups [6 ± 2 (5-8) d vs 6 ± 2 (5-7) d]. The median duration of EN was 8 ± 4 (6-12) d vs 10 ± 4 (6-13) d in the study and control groups, respectively (P > 0.05). Deaths occurred in 6 patients (20%), 2 in the study group and 4 in the control group. The mean duration of APACHE Ⅱ normalization (APACHE Ⅱ score < 8) was shorter in the study group than in the control group (4 ± 2 d vs 6.5 ± 3 d, P < 0.05). The mean duration of CRP normalization was also shorter in the study group than in the control group (7 ± 2 d vs 10 ± 3 d, P < 0.05).CONCLUSION: Nasojejunal EN with prebiotic fiber supplementation in severe AP improves hospital stay, duration nutrition therapy, acute phase response and overall complications compared to standard EN therapy.展开更多
A discrete model is set up for High Resolution Range Profile (HRRP) of an extended target and the model of echo from an extended target for a Stepped Chirp Radar (SCR) is proposed. The effect of target motion on a ran...A discrete model is set up for High Resolution Range Profile (HRRP) of an extended target and the model of echo from an extended target for a Stepped Chirp Radar (SCR) is proposed. The effect of target motion on a range profile is thoroughly analyzed, and based on which precision re- quirement is developed for motion compensation. By studying the time domain correlation and the rule based on the least burst error, a motion compensation algorithm which satisfies the project requirement is presented, and the cyber-emulation confirms the conclusion. At last the processor is designed by using DSP devices to realize motion compensation and target recognition.展开更多
Reactive oxygen species (ROS) attack guanine bases in DNA easily and form 8-hydroxydeoxyguanosine (8-OHdG), which can bind to thymidine rather than cytosine, based on which, the level of 8-OHdG is gen- erally rega...Reactive oxygen species (ROS) attack guanine bases in DNA easily and form 8-hydroxydeoxyguanosine (8-OHdG), which can bind to thymidine rather than cytosine, based on which, the level of 8-OHdG is gen- erally regarded as a biomarker of mutagenesis conse- quent to oxidative stress. For example, higher levels of 8-OHdG are noted in Helicobacter pylori-associated chronic atrophic gastritis as well as gastric cancer. However, we have found that exogenous 8-OHdG can paradoxically reduce ROS production, attenuate the nuclear factor-KB signaling pathway, and ameliorate the expression of proinflammatory mediators such as interleukin (IL)-I, IL-6, cyclo-oxygenase-2, and induc- ible nitric oxide synthase in addition to expression of nicotinamide adenine dinucleotide phosphate oxidase (NOX)-I, NOX organizer-1 and NOX activator-1 in vari- ous conditions of inflammation-based gastrointestinal (GI) diseases including gastritis, inflammatory bowel disease, pancreatitis, and even colitis-associated carci- nogenesis. Our recent finding that exogenous 8-OHdG was very effective in either inflammation-based or oxidative-stress-associated diseases of stress-related mucosal damage has inspired the hope that synthetic 8-OHdG can be a potential candidate for the treatment of inflammation-based GI diseases, as well as the pre- vention of inflammation-associated GI cancer. In this editorial review, the novel fact that exogenous 8-OHdG can be a functional molecule regulating oxidative- stress-induced gastritis through either antagonizing Rac-guanosine triphosphate binding or blocking the signals responsible for gastric inflammatory cascade is introduced.展开更多
Most existing network representation learning algorithms focus on network structures for learning.However,network structure is only one kind of view and feature for various networks,and it cannot fully reflect all cha...Most existing network representation learning algorithms focus on network structures for learning.However,network structure is only one kind of view and feature for various networks,and it cannot fully reflect all characteristics of networks.In fact,network vertices usually contain rich text information,which can be well utilized to learn text-enhanced network representations.Meanwhile,Matrix-Forest Index(MFI)has shown its high effectiveness and stability in link prediction tasks compared with other algorithms of link prediction.Both MFI and Inductive Matrix Completion(IMC)are not well applied with algorithmic frameworks of typical representation learning methods.Therefore,we proposed a novel semi-supervised algorithm,tri-party deep network representation learning using inductive matrix completion(TDNR).Based on inductive matrix completion algorithm,TDNR incorporates text features,the link certainty degrees of existing edges and the future link probabilities of non-existing edges into network representations.The experimental results demonstrated that TFNR outperforms other baselines on three real-world datasets.The visualizations of TDNR show that proposed algorithm is more discriminative than other unsupervised approaches.展开更多
According to news from the website of National Health and Family Planning Commission(NHFPC)on April 17,Ministry of Finance and NHFPC recently issued Opinions on Further Improving the Input Mechanism in Family Planning,
Discourse markers(DMs) are characterized by multifunctionality in different contexts.This study addressed the use of the Chinese DM,na(那),as a solution to topical divergence,during clinical interactions with right-he...Discourse markers(DMs) are characterized by multifunctionality in different contexts.This study addressed the use of the Chinese DM,na(那),as a solution to topical divergence,during clinical interactions with right-hemisphere-damaged(RHD) patients.Drawing on data collected from clinical interviews between psychotherapists and RHD patients,this study examined the functions of na in response to RHD topical divergence,focusing on the topic and attitudinal aspects.It was found that na was mainly employed by psychotherapists to mark a reproffer of interview topics(i.e.,an attempt to return to earlier topics),and a display of disalignment and disaffiliation with RHD topical divergence.These functions of na reflect the psychotherapists’ attempts to overcome communicative problems arising from RHD topical divergence,so as to ensure the achievement of the communicative goal.Thus,na can be interpreted as a compensatory strategy for dealing with RHD topical divergence on an interpersonal level.These findings not only expand our knowledge about the function spectrum of na,but also offer insights for RHD patients’ interlocutors to enhance conversational communication with RHD patients via the compensatory strategy.展开更多
A real extended scene and moving targets multi-channel Synthetic Aperture Radar(SAR) raw signal simulator accounting for Inertial Navigation System(INS) errors and antenna patterns is presented in this paper. INS erro...A real extended scene and moving targets multi-channel Synthetic Aperture Radar(SAR) raw signal simulator accounting for Inertial Navigation System(INS) errors and antenna patterns is presented in this paper. INS errors are obtained by solving INS error differential equations with Runge-Kutta method. A high resolution SAR image is used to estimate the complex reflectance of real extended scene. Extended scene and moving target are simulated separately and then are superposed in time domain. The simulated multi-channel SAR data can be used for development of multi-channel SAR Ground Moving Target Indication(SAR-GMTI) and also can be used for development of SAR motion compensation.展开更多
Three dispersion compensation schemes of an optical label switching transmission system were investigated, which employs 40 Gbit/s return zero differential phase-shift keying(RZ-DPSK) payload labeled with 2.5 Gbit/s...Three dispersion compensation schemes of an optical label switching transmission system were investigated, which employs 40 Gbit/s return zero differential phase-shift keying(RZ-DPSK) payload labeled with 2.5 Gbit/s on-off keying(OOK) signal based on the optical carrier suppression and separation(OCSS) techniq ue, In the system, proposed are the receiver sensi ti vity oS payload and label, achieving -- 32. 4 dBm and --38.5 dBm, respectively. Using the optimal dispersion compensation scheme, after transmitted over 160 km and 320 km SMF respectively, the label can be recovered without power penalty, while the payload can be recovered with less than 2 dB and 5 dB penalty, respectively.展开更多
The recent financial crisis has led to a vigorous debate about the pros and cons of fair-value accounting (FVA). This debate presents a major challenge for FVA going forward and standard setters' push to extend FVA...The recent financial crisis has led to a vigorous debate about the pros and cons of fair-value accounting (FVA). This debate presents a major challenge for FVA going forward and standard setters' push to extend FVA into other areas. In this article, we highlight three important issues as an attempt to make sense of the debate. First, much of the controversy results from confusion about what is new and different about FVA. Second, while there are legitimate concerns about marking to market (or pure FVA) in times of financial crisis, it is less clear that these problems apply to FVA as stipulated by the accounting standards, be it IFRS or U.S. GAAP. Third, historical cost accounting (HCA) is unlikely to be the remedy. There are a number of concerns about HCA as well and these problems could be larger than those with FVA.展开更多
AC / DC converter is a kind of devices applicable to reactive power compensation. Three parameters including losses, Total Harmonic Distortion (THD) and compensation capacity have important role in designing procedu...AC / DC converter is a kind of devices applicable to reactive power compensation. Three parameters including losses, Total Harmonic Distortion (THD) and compensation capacity have important role in designing procedure that these parameters are affected by the firing angle. Consideration trade of between these parameters can cause be selected suitable firing angle for optimal working of the compensator. In this paper is defined an objective function which includes the above parameters. This objective function is optimized through appropriate weighting factor for any parameters and the optimal firing angle will be obtained. So, the mention parameters can be selected optimally.展开更多
In visual measurement,high-precision camera calibration often employs circular targets.To address issues in mainstream methods,such as the eccentricity error of the circle from using the circle’s center for calibrati...In visual measurement,high-precision camera calibration often employs circular targets.To address issues in mainstream methods,such as the eccentricity error of the circle from using the circle’s center for calibration,overfitting or local minimum from fullparameter optimization,and calibration errors due to neglecting the center of distortion,a stepwise camera calibration method incorporating compensation for eccentricity error was proposed to enhance monocular camera calibration precision.Initially,the multiimage distortion correction method calculated the common center of distortion and coefficients,improving precision,stability,and efficiency compared to single-image distortion correction methods.Subsequently,the projection point of the circle’s center was compared with the center of the contour’s projection to iteratively correct the eccentricity error,leading to more precise and stable calibration.Finally,nonlinear optimization refined the calibration parameters to minimize reprojection error and boosts precision.These processes achieved stepwise camera calibration,which enhanced robustness.In addition,the module comparison experiment showed that both the eccentricity error compensation and the camera parameter optimization could improve the calibration precision,but the latter had a greater impact.The combined use of the two methods further improved the precision and stability.Simulations and experiments confirmed that the proposed method achieved high precision,stability,and robustness,suitable for high-precision visual measurements.展开更多
Kuancheng Traditional Chestnut Cultivation System is located in the Beijing-Tianjin-Hebei Water Containment Function Area.The Traditional Chestnut Cultivation System is characterized by agroforestry compound,and some ...Kuancheng Traditional Chestnut Cultivation System is located in the Beijing-Tianjin-Hebei Water Containment Function Area.The Traditional Chestnut Cultivation System is characterized by agroforestry compound,and some studies have shown that the compound planting of chestnut has better ecological benefits than the single chestnut planting mode.However,most of the local farmers in Kuancheng are mainly engaged in single chestnut cultivation.Through ecological compensation,farmers are being encouraged to change their chestnut planting mode,which can achieve the purpose of inheriting China’s important agricultural heritage and improving the ecological benefits.This paper introduces preference coefficients to correct for opportunity costs,and through interviews and questionnaires,we obtained the input and output of the single chestnut cultivation,chestnut-maitake,chestnut-millet,and chestnut-chicken and the income of laborers working outside the home in the Kuancheng area.Through analysis and calculation,we obtained the following results:(1)Although the net income of the three chestnut composite modes is higher,their economic input is higher than that of a single chestnut planting mode,and the return on unit investment is lower.(2)The average income of young and middle-aged workers who work outside is higher than that of the local farming industry,so the local chestnut agroforestry plantation has a higher opportunity cost.(3)The final calculation shows that the chestnut-chicken agroforestry operation mode needs no compensation,the chestnut-maitake plantation mode is compensated at least 1608.5 USD ha^(-1) yr^(-1),and the minimum compensation for the chestnut-millet plantation mode is 198.3 USD ha^(-1) yr^(-1),which can guarantee that farmers receive the full value of their creations.Ultimately,farmers are incentivized to revive the traditional agroforestry production mode to achieve both economic and ecological benefits while inheriting agricultural heritage.展开更多
Homogenization theory provides a rigorous framework for calculating the effective diffusivity of a decaying passive scalar field in a turbulent or complex flow.The authors extend this framework to the case where the p...Homogenization theory provides a rigorous framework for calculating the effective diffusivity of a decaying passive scalar field in a turbulent or complex flow.The authors extend this framework to the case where the passive scalar fluctuations are continuously replenished by a source (and/or sink).The basic structure of the homogenized equations carries over,but in some cases the homogenized source can involve a non-trivial coupling of the velocity field and the source.The authors derive expressions for the homogenized source term for various multiscale source structures and interpret them physically.展开更多
文摘AIM: To compare the benefi cial effects of early enteral nutrition (EN) with prebiotic fiber supplementation in patients with severe acute pancreatitis (AP).METHODS: Thirty consecutive patients with severe AP, who required stoppage of oral feeding for 48 h, were randomly assigned to nasojejunal EN with or without prebiotics. APACHE Ⅱ score, Balthazar’s CT score and CRP were assessed daily during the study period.RESULTS: The median duration of hospital stay was shorter in the study group [10 ± 4 (8-14) d vs 15 ± 6 (7-26) d] (P < 0.05). The median value of days in intensive care unit was also similar in both groups [6 ± 2 (5-8) d vs 6 ± 2 (5-7) d]. The median duration of EN was 8 ± 4 (6-12) d vs 10 ± 4 (6-13) d in the study and control groups, respectively (P > 0.05). Deaths occurred in 6 patients (20%), 2 in the study group and 4 in the control group. The mean duration of APACHE Ⅱ normalization (APACHE Ⅱ score < 8) was shorter in the study group than in the control group (4 ± 2 d vs 6.5 ± 3 d, P < 0.05). The mean duration of CRP normalization was also shorter in the study group than in the control group (7 ± 2 d vs 10 ± 3 d, P < 0.05).CONCLUSION: Nasojejunal EN with prebiotic fiber supplementation in severe AP improves hospital stay, duration nutrition therapy, acute phase response and overall complications compared to standard EN therapy.
基金Supported by National Natural Science Foundation of China (No.60402032).
文摘A discrete model is set up for High Resolution Range Profile (HRRP) of an extended target and the model of echo from an extended target for a Stepped Chirp Radar (SCR) is proposed. The effect of target motion on a range profile is thoroughly analyzed, and based on which precision re- quirement is developed for motion compensation. By studying the time domain correlation and the rule based on the least burst error, a motion compensation algorithm which satisfies the project requirement is presented, and the cyber-emulation confirms the conclusion. At last the processor is designed by using DSP devices to realize motion compensation and target recognition.
基金Supported by A grant from the Ministry of Education and Science Technology,South Korea,No.2010-0002052
文摘Reactive oxygen species (ROS) attack guanine bases in DNA easily and form 8-hydroxydeoxyguanosine (8-OHdG), which can bind to thymidine rather than cytosine, based on which, the level of 8-OHdG is gen- erally regarded as a biomarker of mutagenesis conse- quent to oxidative stress. For example, higher levels of 8-OHdG are noted in Helicobacter pylori-associated chronic atrophic gastritis as well as gastric cancer. However, we have found that exogenous 8-OHdG can paradoxically reduce ROS production, attenuate the nuclear factor-KB signaling pathway, and ameliorate the expression of proinflammatory mediators such as interleukin (IL)-I, IL-6, cyclo-oxygenase-2, and induc- ible nitric oxide synthase in addition to expression of nicotinamide adenine dinucleotide phosphate oxidase (NOX)-I, NOX organizer-1 and NOX activator-1 in vari- ous conditions of inflammation-based gastrointestinal (GI) diseases including gastritis, inflammatory bowel disease, pancreatitis, and even colitis-associated carci- nogenesis. Our recent finding that exogenous 8-OHdG was very effective in either inflammation-based or oxidative-stress-associated diseases of stress-related mucosal damage has inspired the hope that synthetic 8-OHdG can be a potential candidate for the treatment of inflammation-based GI diseases, as well as the pre- vention of inflammation-associated GI cancer. In this editorial review, the novel fact that exogenous 8-OHdG can be a functional molecule regulating oxidative- stress-induced gastritis through either antagonizing Rac-guanosine triphosphate binding or blocking the signals responsible for gastric inflammatory cascade is introduced.
基金Projects(11661069,61763041) supported by the National Natural Science Foundation of ChinaProject(IRT_15R40) supported by Changjiang Scholars and Innovative Research Team in University,ChinaProject(2017TS045) supported by the Fundamental Research Funds for the Central Universities,China
文摘Most existing network representation learning algorithms focus on network structures for learning.However,network structure is only one kind of view and feature for various networks,and it cannot fully reflect all characteristics of networks.In fact,network vertices usually contain rich text information,which can be well utilized to learn text-enhanced network representations.Meanwhile,Matrix-Forest Index(MFI)has shown its high effectiveness and stability in link prediction tasks compared with other algorithms of link prediction.Both MFI and Inductive Matrix Completion(IMC)are not well applied with algorithmic frameworks of typical representation learning methods.Therefore,we proposed a novel semi-supervised algorithm,tri-party deep network representation learning using inductive matrix completion(TDNR).Based on inductive matrix completion algorithm,TDNR incorporates text features,the link certainty degrees of existing edges and the future link probabilities of non-existing edges into network representations.The experimental results demonstrated that TFNR outperforms other baselines on three real-world datasets.The visualizations of TDNR show that proposed algorithm is more discriminative than other unsupervised approaches.
文摘According to news from the website of National Health and Family Planning Commission(NHFPC)on April 17,Ministry of Finance and NHFPC recently issued Opinions on Further Improving the Input Mechanism in Family Planning,
基金This study is supported by the following projects:the Chinese Ministry of Education(MOE)Humanities and Social Science Research Funding(18YJC740042)the Research Project of Guangdong Planning Office of Philosophy and Social Science(GD16CWW05)+1 种基金the MOE Key Research Project of Humanities and Social Science(16JJD740006)conducted by the Center for Linguistics and Applied Linguistics(CLAL),Guangdong University of Foreign Studies(GDUFS)supported by both the Department of Education of Guangdong Province and the Center for Linguistics and Applied Linguistics at Guangdong University of Foreign Studies,P.R.China for the frontier research and its theoretical innovations in interpersonal pragmatics(“人际语用学前沿研究与理论创新”项目)(2018WZDXM006).
文摘Discourse markers(DMs) are characterized by multifunctionality in different contexts.This study addressed the use of the Chinese DM,na(那),as a solution to topical divergence,during clinical interactions with right-hemisphere-damaged(RHD) patients.Drawing on data collected from clinical interviews between psychotherapists and RHD patients,this study examined the functions of na in response to RHD topical divergence,focusing on the topic and attitudinal aspects.It was found that na was mainly employed by psychotherapists to mark a reproffer of interview topics(i.e.,an attempt to return to earlier topics),and a display of disalignment and disaffiliation with RHD topical divergence.These functions of na reflect the psychotherapists’ attempts to overcome communicative problems arising from RHD topical divergence,so as to ensure the achievement of the communicative goal.Thus,na can be interpreted as a compensatory strategy for dealing with RHD topical divergence on an interpersonal level.These findings not only expand our knowledge about the function spectrum of na,but also offer insights for RHD patients’ interlocutors to enhance conversational communication with RHD patients via the compensatory strategy.
文摘A real extended scene and moving targets multi-channel Synthetic Aperture Radar(SAR) raw signal simulator accounting for Inertial Navigation System(INS) errors and antenna patterns is presented in this paper. INS errors are obtained by solving INS error differential equations with Runge-Kutta method. A high resolution SAR image is used to estimate the complex reflectance of real extended scene. Extended scene and moving target are simulated separately and then are superposed in time domain. The simulated multi-channel SAR data can be used for development of multi-channel SAR Ground Moving Target Indication(SAR-GMTI) and also can be used for development of SAR motion compensation.
基金National Natural Science Foundation of China(60677004)National High Technology"863"Research and Development Program of China(2007AA01Z260)+4 种基金Key Project of Chinese Ministry of Education(107011)Key Laboratory of Broadband Optical Fiber Transmission and Communication Networks(Ministry of Education)Teaching and Scientific Research Foundation for the Returned Overseas Chinese Scholars(State Education Ministry)the Corporative Building Project of Beijing Educational Committee(XK100130737)Program for New Century Excellent Talents in University of China( NECT-07-0111)
文摘Three dispersion compensation schemes of an optical label switching transmission system were investigated, which employs 40 Gbit/s return zero differential phase-shift keying(RZ-DPSK) payload labeled with 2.5 Gbit/s on-off keying(OOK) signal based on the optical carrier suppression and separation(OCSS) techniq ue, In the system, proposed are the receiver sensi ti vity oS payload and label, achieving -- 32. 4 dBm and --38.5 dBm, respectively. Using the optimal dispersion compensation scheme, after transmitted over 160 km and 320 km SMF respectively, the label can be recovered without power penalty, while the payload can be recovered with less than 2 dB and 5 dB penalty, respectively.
文摘The recent financial crisis has led to a vigorous debate about the pros and cons of fair-value accounting (FVA). This debate presents a major challenge for FVA going forward and standard setters' push to extend FVA into other areas. In this article, we highlight three important issues as an attempt to make sense of the debate. First, much of the controversy results from confusion about what is new and different about FVA. Second, while there are legitimate concerns about marking to market (or pure FVA) in times of financial crisis, it is less clear that these problems apply to FVA as stipulated by the accounting standards, be it IFRS or U.S. GAAP. Third, historical cost accounting (HCA) is unlikely to be the remedy. There are a number of concerns about HCA as well and these problems could be larger than those with FVA.
文摘AC / DC converter is a kind of devices applicable to reactive power compensation. Three parameters including losses, Total Harmonic Distortion (THD) and compensation capacity have important role in designing procedure that these parameters are affected by the firing angle. Consideration trade of between these parameters can cause be selected suitable firing angle for optimal working of the compensator. In this paper is defined an objective function which includes the above parameters. This objective function is optimized through appropriate weighting factor for any parameters and the optimal firing angle will be obtained. So, the mention parameters can be selected optimally.
文摘In visual measurement,high-precision camera calibration often employs circular targets.To address issues in mainstream methods,such as the eccentricity error of the circle from using the circle’s center for calibration,overfitting or local minimum from fullparameter optimization,and calibration errors due to neglecting the center of distortion,a stepwise camera calibration method incorporating compensation for eccentricity error was proposed to enhance monocular camera calibration precision.Initially,the multiimage distortion correction method calculated the common center of distortion and coefficients,improving precision,stability,and efficiency compared to single-image distortion correction methods.Subsequently,the projection point of the circle’s center was compared with the center of the contour’s projection to iteratively correct the eccentricity error,leading to more precise and stable calibration.Finally,nonlinear optimization refined the calibration parameters to minimize reprojection error and boosts precision.These processes achieved stepwise camera calibration,which enhanced robustness.In addition,the module comparison experiment showed that both the eccentricity error compensation and the camera parameter optimization could improve the calibration precision,but the latter had a greater impact.The combined use of the two methods further improved the precision and stability.Simulations and experiments confirmed that the proposed method achieved high precision,stability,and robustness,suitable for high-precision visual measurements.
基金The Mobility Programme DFG-NSFC (M-0342)Ecology Young Talents Support Project of the Chinese Society of Ecology (STQT2020B03)The National Natural Science Foundation of China (41801204)。
文摘Kuancheng Traditional Chestnut Cultivation System is located in the Beijing-Tianjin-Hebei Water Containment Function Area.The Traditional Chestnut Cultivation System is characterized by agroforestry compound,and some studies have shown that the compound planting of chestnut has better ecological benefits than the single chestnut planting mode.However,most of the local farmers in Kuancheng are mainly engaged in single chestnut cultivation.Through ecological compensation,farmers are being encouraged to change their chestnut planting mode,which can achieve the purpose of inheriting China’s important agricultural heritage and improving the ecological benefits.This paper introduces preference coefficients to correct for opportunity costs,and through interviews and questionnaires,we obtained the input and output of the single chestnut cultivation,chestnut-maitake,chestnut-millet,and chestnut-chicken and the income of laborers working outside the home in the Kuancheng area.Through analysis and calculation,we obtained the following results:(1)Although the net income of the three chestnut composite modes is higher,their economic input is higher than that of a single chestnut planting mode,and the return on unit investment is lower.(2)The average income of young and middle-aged workers who work outside is higher than that of the local farming industry,so the local chestnut agroforestry plantation has a higher opportunity cost.(3)The final calculation shows that the chestnut-chicken agroforestry operation mode needs no compensation,the chestnut-maitake plantation mode is compensated at least 1608.5 USD ha^(-1) yr^(-1),and the minimum compensation for the chestnut-millet plantation mode is 198.3 USD ha^(-1) yr^(-1),which can guarantee that farmers receive the full value of their creations.Ultimately,farmers are incentivized to revive the traditional agroforestry production mode to achieve both economic and ecological benefits while inheriting agricultural heritage.
基金Project supported by the National Science Foundation "Collaborations in Mathematical Geosciences"(No.OCE-0620956)
文摘Homogenization theory provides a rigorous framework for calculating the effective diffusivity of a decaying passive scalar field in a turbulent or complex flow.The authors extend this framework to the case where the passive scalar fluctuations are continuously replenished by a source (and/or sink).The basic structure of the homogenized equations carries over,but in some cases the homogenized source can involve a non-trivial coupling of the velocity field and the source.The authors derive expressions for the homogenized source term for various multiscale source structures and interpret them physically.