Pinus radiata was introduced to the summer rainfall environments of Sichuan Province, China in the 1990s as a part of an afforestation pmgram for soil and water conservation in the arid and semi-arid river valley area...Pinus radiata was introduced to the summer rainfall environments of Sichuan Province, China in the 1990s as a part of an afforestation pmgram for soil and water conservation in the arid and semi-arid river valley area of Aba Prefecture. Within this region a total area of 26 000 ha have been identified through climate matching as suitable and a further 63 000 ha potentially suitable for environmental plantings of P. radiata. The plantations are being established in widely separated small patches on steep and degraded slopes along the dry river valley The newly introduced P. radiata are exposed to two kinds of forest health risks: they may be attacked by (a) indigenous pathogens and pests against which they may not possess any resistance or (b) by inadvertently introduced foreign pests or pathogens. This paper presents a survey of the potential damaging pests and a preliminary assessment of forest health risks facing the P. radiata plantations over a much longer timeframe than the initial phase of introduction and early plantation establishment. An empirical appmach was adopted to evaluate forest health risks by a combination of literature review, examination of historical records of pest and disease outbreaks in the surrounding conifemus forests, field surveys and inspections, specimen collection and identification, and most importantly, expert analysis of the likelihood of attack by specific pests and pathogens and the subsequent impact of such attacks. The assessment identified some specific forest health risks to the long-term success of P. radiata introduction in this area. These risks are closely associated with the indigenous pests and pathogens of the two native pine species, P. tabulaeformis and P. armondii since these pests and pathogens are considered more likely to establish on P. radiata over time. Exotic pests and pathogens are of a quarantine concern at present. Based on the results of assessment, recommendations are pmvided to improve forest vigour and to reduce the forest health risks posed by indigenous as well as exotic pests and pathogens to the introduced P. radiata. Ways to increase the ability to manage the forest health risks once a particular pest infestation and disease eventuates are also recommended. Although detrimental to the survival and growth of the introduced P. radiata, the impact of identified forest health risks are not considered to be fatal to the long term success ofP. radiata in this area.展开更多
With the research on and development of Genetically Modified Food (GMF), people's attitude toward GMF may fall into two divergent categories, typical- ly represented by the United States(US) and the European Unio...With the research on and development of Genetically Modified Food (GMF), people's attitude toward GMF may fall into two divergent categories, typical- ly represented by the United States(US) and the European Union(EU), respectively. The former follows a "sound science principle" and firmly objects to the precautionary principle, namely a permissive policy of positive support of and voluntary labelling on GMF; while the latter adopts a cautiously precautionary principle, requiring mandatory labelling and traceability. From the standpoint of regulatory principles, together with corresponding supervisory measures and relevant provisions, this paper compared the execution of directives and provisions on GMF from the initial policies enacted by the US and EU to current situation combined with the track and analysis of latest polic ies issued.展开更多
This paper introduces the identification of the defects on the fabric by using two-double neural network and wavelet analysis. The purpose is to fit for the automatic cloth inspection system and to avoid the disadvant...This paper introduces the identification of the defects on the fabric by using two-double neural network and wavelet analysis. The purpose is to fit for the automatic cloth inspection system and to avoid the disadvantages of traditional human inspection. Firstly, training the normal fabric to acquire its characteristics and then using the BP neural network to tell the normal fabric apart from the one with defects. Secondly, doing the two-dimeusional discrete wavelet transformation based on the image of the defects, then wiping off the proper characteristics of the fabric, and identifying the defects utilizing the trained BP neural network. It is proved that this method is of high speed and accuracy. It comes up to the requirement of automatic cloth inspection.展开更多
Condition monitoring is increasingly used to anticipate and detect failures of industrial machines.Failures of machines can cause high maintenance or replacement costs.If neglected,it may result in catastrophic accide...Condition monitoring is increasingly used to anticipate and detect failures of industrial machines.Failures of machines can cause high maintenance or replacement costs.If neglected,it may result in catastrophic accidents leading to production shrinkage.The potential failure would negatively affect the profitability of the company,including production shut down,cost of spare parts,cost of labor,damage of reputation,risk of injury to people and the environment.In recent years,condition-based maintenance( CBM) and prognostic and health management( PHM) are developed and formed a strong connection among science,engineering,computer,reliability,communication,management,etc.Computerized maintenance management systems( CMMS) store a lot of data regarding the fault diagnosis and life prediction of the machinery equipment.It's too necessary to uncover useful knowledge from the huge amount of data.It's vital to find the ways to obtain useful and concise information from these data.This information can be of great influence in the decision making of managers.This article is a review of intelligent approaches in machinery faults diagnosis and prediction based on PHM and CBM.展开更多
We calculate the Langevin noise sources of self-pulsation laser diodes,analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation,and propos...We calculate the Langevin noise sources of self-pulsation laser diodes,analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation,and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system,the results indicate that the effects of noise in absorption region can be ignored;that with the increase of DC injecting current,the noise effects enhance power jitter,and nevertheless,the period jitter is decreased;and that with external sinusoidal current modulating the self-pulsation laser diode,the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.展开更多
The quantitative trait loci (QTLs) for cold tolerance relative characters were identified with microsatellite markers.Ten QTLs located on chromosome 1, 3, 4, 5, 6, 8, 9, 11(two)and 12 were detected for seedling height...The quantitative trait loci (QTLs) for cold tolerance relative characters were identified with microsatellite markers.Ten QTLs located on chromosome 1, 3, 4, 5, 6, 8, 9, 11(two)and 12 were detected for seedling height at different low temperature. Only 2 of these were detected at the same locus at four environments, 1 was significant at three environments, 6 were significant at two environments and 1 was significant at one environment. Seven QTLs located on chromosome 1(two), 2(two),5,6,8 were found for low temperature chlorosis resistance and five QTLs located on chromosome 3, 4, 7, 8, 11 resistant to chilling injury. The amount of variation explained by individual QTL ranged from 4.85%to 49.34%. There was no linkage relationship among the three characters, which indicates seedling cold tolerance is a complex character and is controlled by different QTLs.展开更多
At present, China's equity crowd-funding platform development like a raging fire, its business model is financing online for small and medium-sized enterprises, many investors to participate in the same project, whil...At present, China's equity crowd-funding platform development like a raging fire, its business model is financing online for small and medium-sized enterprises, many investors to participate in the same project, while equity in return for a platform to receive a certain percentage of service charge. However, no related domestic regulatory measures, divorced from a legal gray zone, improper operation may become a pool of funds to engage in illegal fund-raising, illegal securities activities. Therefore, this article is based on two domestic representative platform-"Angercrunch"and "Dajiatou" to raise public equity, the comparative study of the problem currently facing a series of recommendations, including the introduction of regulation, improve the legal system, conduct investor risk education and self-education, etc.展开更多
文摘Pinus radiata was introduced to the summer rainfall environments of Sichuan Province, China in the 1990s as a part of an afforestation pmgram for soil and water conservation in the arid and semi-arid river valley area of Aba Prefecture. Within this region a total area of 26 000 ha have been identified through climate matching as suitable and a further 63 000 ha potentially suitable for environmental plantings of P. radiata. The plantations are being established in widely separated small patches on steep and degraded slopes along the dry river valley The newly introduced P. radiata are exposed to two kinds of forest health risks: they may be attacked by (a) indigenous pathogens and pests against which they may not possess any resistance or (b) by inadvertently introduced foreign pests or pathogens. This paper presents a survey of the potential damaging pests and a preliminary assessment of forest health risks facing the P. radiata plantations over a much longer timeframe than the initial phase of introduction and early plantation establishment. An empirical appmach was adopted to evaluate forest health risks by a combination of literature review, examination of historical records of pest and disease outbreaks in the surrounding conifemus forests, field surveys and inspections, specimen collection and identification, and most importantly, expert analysis of the likelihood of attack by specific pests and pathogens and the subsequent impact of such attacks. The assessment identified some specific forest health risks to the long-term success of P. radiata introduction in this area. These risks are closely associated with the indigenous pests and pathogens of the two native pine species, P. tabulaeformis and P. armondii since these pests and pathogens are considered more likely to establish on P. radiata over time. Exotic pests and pathogens are of a quarantine concern at present. Based on the results of assessment, recommendations are pmvided to improve forest vigour and to reduce the forest health risks posed by indigenous as well as exotic pests and pathogens to the introduced P. radiata. Ways to increase the ability to manage the forest health risks once a particular pest infestation and disease eventuates are also recommended. Although detrimental to the survival and growth of the introduced P. radiata, the impact of identified forest health risks are not considered to be fatal to the long term success ofP. radiata in this area.
文摘With the research on and development of Genetically Modified Food (GMF), people's attitude toward GMF may fall into two divergent categories, typical- ly represented by the United States(US) and the European Union(EU), respectively. The former follows a "sound science principle" and firmly objects to the precautionary principle, namely a permissive policy of positive support of and voluntary labelling on GMF; while the latter adopts a cautiously precautionary principle, requiring mandatory labelling and traceability. From the standpoint of regulatory principles, together with corresponding supervisory measures and relevant provisions, this paper compared the execution of directives and provisions on GMF from the initial policies enacted by the US and EU to current situation combined with the track and analysis of latest polic ies issued.
文摘This paper introduces the identification of the defects on the fabric by using two-double neural network and wavelet analysis. The purpose is to fit for the automatic cloth inspection system and to avoid the disadvantages of traditional human inspection. Firstly, training the normal fabric to acquire its characteristics and then using the BP neural network to tell the normal fabric apart from the one with defects. Secondly, doing the two-dimeusional discrete wavelet transformation based on the image of the defects, then wiping off the proper characteristics of the fabric, and identifying the defects utilizing the trained BP neural network. It is proved that this method is of high speed and accuracy. It comes up to the requirement of automatic cloth inspection.
基金Fundamental Research Funds for the Central Universities,China(No.DUT17GF214)
文摘Condition monitoring is increasingly used to anticipate and detect failures of industrial machines.Failures of machines can cause high maintenance or replacement costs.If neglected,it may result in catastrophic accidents leading to production shrinkage.The potential failure would negatively affect the profitability of the company,including production shut down,cost of spare parts,cost of labor,damage of reputation,risk of injury to people and the environment.In recent years,condition-based maintenance( CBM) and prognostic and health management( PHM) are developed and formed a strong connection among science,engineering,computer,reliability,communication,management,etc.Computerized maintenance management systems( CMMS) store a lot of data regarding the fault diagnosis and life prediction of the machinery equipment.It's too necessary to uncover useful knowledge from the huge amount of data.It's vital to find the ways to obtain useful and concise information from these data.This information can be of great influence in the decision making of managers.This article is a review of intelligent approaches in machinery faults diagnosis and prediction based on PHM and CBM.
基金the National Natural Science Foundation of China ( Grant No 10174057 and 90201011)the Key Project of Chinese Ministry of Education ( Grant No. 105148)
文摘We calculate the Langevin noise sources of self-pulsation laser diodes,analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation,and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system,the results indicate that the effects of noise in absorption region can be ignored;that with the increase of DC injecting current,the noise effects enhance power jitter,and nevertheless,the period jitter is decreased;and that with external sinusoidal current modulating the self-pulsation laser diode,the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.
文摘The quantitative trait loci (QTLs) for cold tolerance relative characters were identified with microsatellite markers.Ten QTLs located on chromosome 1, 3, 4, 5, 6, 8, 9, 11(two)and 12 were detected for seedling height at different low temperature. Only 2 of these were detected at the same locus at four environments, 1 was significant at three environments, 6 were significant at two environments and 1 was significant at one environment. Seven QTLs located on chromosome 1(two), 2(two),5,6,8 were found for low temperature chlorosis resistance and five QTLs located on chromosome 3, 4, 7, 8, 11 resistant to chilling injury. The amount of variation explained by individual QTL ranged from 4.85%to 49.34%. There was no linkage relationship among the three characters, which indicates seedling cold tolerance is a complex character and is controlled by different QTLs.
文摘At present, China's equity crowd-funding platform development like a raging fire, its business model is financing online for small and medium-sized enterprises, many investors to participate in the same project, while equity in return for a platform to receive a certain percentage of service charge. However, no related domestic regulatory measures, divorced from a legal gray zone, improper operation may become a pool of funds to engage in illegal fund-raising, illegal securities activities. Therefore, this article is based on two domestic representative platform-"Angercrunch"and "Dajiatou" to raise public equity, the comparative study of the problem currently facing a series of recommendations, including the introduction of regulation, improve the legal system, conduct investor risk education and self-education, etc.