In order to provide directionally genetically improved breeding materials of poplar by exploring the phenological traits genetic variation level and its develop- ment potential of Populus deltoides and the resource ev...In order to provide directionally genetically improved breeding materials of poplar by exploring the phenological traits genetic variation level and its develop- ment potential of Populus deltoides and the resource evaluation was carried out; 8 phenological phases in seedling period were observed and analyzed of 60 Populus deltoids clones introduced from America. The results showed that: (1) there was obvious difference in phonological character among clones, especially in leaf-spread- ing peak stage and the end term of leaf-falling stage, with the largest variation co- efficient of 14.97% and the minimum of 3.83% respectively. (2) Leaf-spreading peak stage scattered but the end term of leaf-falling stage concentrated the most. The phonological character in early stage of seedling growth was the main factor influ- encing the length of growing season. (3) By principal component analysis, pheno- logical phases were classified into 3 typical periods, including germination stage, leaf-spreading peak stage and leaf-falling stage. (4) Totaling 60 clones were classi- fied into 4 types by using clustering analysis in phenological time variables of clones.展开更多
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
Major consideration dimensions for the physical layer design of wireless sensor network (WSN) nodes is analyzed by comparing different wireless communication approaches, diverse mature standards, important radio fre...Major consideration dimensions for the physical layer design of wireless sensor network (WSN) nodes is analyzed by comparing different wireless communication approaches, diverse mature standards, important radio frequency (RF) parameters and various microcontroller unit (MCU) solutions. An implementation of the WSN node is presented with experimental results and a novel "one processor working at two frequencies" energy saving strategy. The lifetime estimation issue is analyzed with consideration to the periodical listen required by common WSN media access control (MAC) algorithms. It can be concluded that the startup time of the RF which determines the best sleep time ratio and the shortest backoff slot time of MAC, the RF frequency and modulation methods which determinate the RX and TX current, and the overall energy consumption of the dual frequency MCU SOC ( system on chip) are the most essential factors for the WSN node physical layer design.展开更多
[Objective]The research aimed to study the biomass structure of the functional modules of clonal population of Puccinellia tenuifora on Songnen Plain and its relationship with the functional modules quantitatively.[Me...[Objective]The research aimed to study the biomass structure of the functional modules of clonal population of Puccinellia tenuifora on Songnen Plain and its relationship with the functional modules quantitatively.[Method]Using the sample method of digging up the whole tiller tuft randomly at flowering stage,the relationships between the biomass of functional modules and turf size,biomass of different modules and the clone production,reproductive tillers of clones and the biomass of component modules of Puccinellia tenuifora clones on Songnen Plain were quantitatively analyzed.[Result]The biomass of sexual reproductive module,photosynthesis module and supporting module showed a linear increase with the increasing of turf size(P 〈0.05),while the linear relationship between the biomass of vegetative reproductive module and turf size did not reach the significant level(P 〉0.05).The restriction degree of turf size on the biomass of functional modules was supporting module sexual reproductive module photosynthesis module vegetative reproductive module.Biomass of reproductive tillers and vegetative tillers showed a linear increase as the biomass of total modules increased(P〈 0.05),while the linear correlation between the biomass of tillering seedlings and biomass of total modules did not reach the significant level(P 〉0.05).Biomass of stem,spike and leaf of reproductive plants showed a linear functional increase as reproductive tiller increased(P 〈0.05),and the ratio of accumulation of biomass of stem,spike and leaf was 7:2:1.[Conclusion]The research laid the theoretical foundation for the further research on the ecology of clustered clone plants.展开更多
Eleven tertiarv alkaloids were isolated from Corvdalis decumbens rhizome Their structures were identified as protopine(Ⅶ),allocryptopine(Ⅷ),cryptopine (Ⅸ),muramine(ⅩⅦ);(+)-tetrahydropalmatine(Ⅲ),(+)-kikemanine (...Eleven tertiarv alkaloids were isolated from Corvdalis decumbens rhizome Their structures were identified as protopine(Ⅶ),allocryptopine(Ⅷ),cryptopine (Ⅸ),muramine(ⅩⅦ);(+)-tetrahydropalmatine(Ⅲ),(+)-kikemanine (Ⅳ),(一)-scoulerine (ⅩⅧ),(十)-bulbo- capnine (ⅩⅨ),and(一)一capnoidine(Ⅰ),(一)一bicuculline(Ⅴ),(+) coriumidine(ⅩⅣ), respecti vely。 Among these,cryptopine,muramine,(+)-kikemanine,(-)-scoulerine,(一)capnoidine,(一)一bicuculline were isolated for the first time from this plant展开更多
[Objective] This study aimed to investigate the effects of drought stress on osmotic regulation substances of Catalpa bungei clones. [Method] Potting experimental was carried out with plastic film sealing method, to d...[Objective] This study aimed to investigate the effects of drought stress on osmotic regulation substances of Catalpa bungei clones. [Method] Potting experimental was carried out with plastic film sealing method, to differentiate the degrees of drought stress based on changes in soil water content and leaf water potential and investigate variations in contents of osmotic regulation substances(free proline,soluble sugar and soluble protein) in leaves of five Catalpa bungei clones under different degrees of drought stresses. [Result] According to changes in soil water content and leaf water potential, the whole process of drought stress was divided into normal level(CK, with soil water content of 97.49% and leaf water potential of-0.54MPa), light drought(LD with soil water content of 59.96% and leaf water potential of-1.28 MPa), mediate drought(MD with soil water content of 34.19% and leaf water potential of-2.32 MPa) and severe drought(SD with soil water content of 14.52%and leaf water potential of-2.99 MPa). The soil water content and leaf water potential of five Catalpa bungei clones reached the highest correlation in exponential fitting, with an average R2of 0.989 3(P0.001). The free proline content in leaves of five Catalpa bungei clones increased rapidly with the increasing degree of drought stress(P 0.001). To be specific, free proline contents of Catalpa bungei clones015-1 and 7080 were 34.39 and 33.41 times of the normal level under severe drought conditions, which reached an extremely significant level(P0.001); the free proline content of Catalpa bungei clone 1-3 rapidly increased to(855.46±227.52) μg/g Fw under light drought conditions. The soluble protein content in leaves showed different variation trends. To be specific, the soluble protein content of Catalpa bungei clone 7080 was the lowest at various drought stages and reached(1.644 ±0.137)mg/g Fw under normal conditions; the soluble protein content of Catalpa bungei clone 1-3 was relatively high under normal conditions and was reduced rapidly under light drought conditions, showing different response patterns. [Conclusion] Osmotic regulation substances in leaves of five Catalpa bungei clones all have certain response to drought stress. Free proline is the most important osmotic regulation substance, followed by soluble protein, while soluble sugar makes no significant contribution. According to changes in content of osmotic regulation substances, Catalpa bungei clone 7080 has relatively high capacity and good drought resistance, while Catalpa bungei clone 1-3 has the rapidest response to drought stress.展开更多
The exotic Sonneratia apetala in Leizhou Peninsula, has shown outstanding fast-growing ability in restored mangrove forests, at the middle and high tide intertidal zone, with year-round fresh water input from drainage...The exotic Sonneratia apetala in Leizhou Peninsula, has shown outstanding fast-growing ability in restored mangrove forests, at the middle and high tide intertidal zone, with year-round fresh water input from drainage. By setting plot and selecting standard tree, investigation and measurement on height growth, diameter growth, biomass, productivity, and so on, were made in a S. apetala plantation at age of six at Lanbei, Fucheng, Leizhou Peninsula in May 2001. The investigating results showed that the mean annual height growth of plantation was 2.03 m and mean annual growth of diameter at breast height (DBH) was 2.35 cm. There exists a significant correlation between the diameter at ground surface (DGS) and DBH. The average biomass of a single standard tree in dry weight was 95.647 kg/m2. A ratio of above-ground biomass to under-ground biomass was 1.60. The stand biomass of unit area was 22.955 kg/m2, singletree wood volume was 88.23 dm3, and the annual wood volume productivity (PA) of the same year was 0.407. The forest energy accumulation was 424.851 MJ/m2, with annual solar energy fixing rate of 40.68 ×10-7%. It is concluded that S. apetala species had characteristics of outstanding high biomass accumulation and could be used as coastal planting tree species in southern China.展开更多
[Objective] The aim of this study was to explore the effects of substrates before and after fermenting treatment on the growth,development and cut flower quality of lily.[Method] Oriental lily cultivar 'Siberia' was...[Objective] The aim of this study was to explore the effects of substrates before and after fermenting treatment on the growth,development and cut flower quality of lily.[Method] Oriental lily cultivar 'Siberia' was taken as material to study the effect of using fermentative and unfermented agricultural waste as substrates on the growth,development and cut flower quality of lily.And the physical and chemical properties of substrates before and after fermenting treatment were studied.[Result] The full decomposition of agricultural waste would greatly improve the physical and chemical properties of substrates,such as the fermentative substrates changed to stabilization,the ratio of carbon nitrogen had dropped drastically,the total porosity was increase,the ratio of gas and water was better,and the nutrition elements was increased.Moreover,it could significantly increased the plant height,stem diameter,leaf number,leaf area,leaf fresh weight and so on,as well as expanded the lily roots and significantly improved the rate of cut flower and cut flower quality.[Conclusion] This study had provided theoretically basis for the cultivation of cut lily.展开更多
The quality of straw affects N release after straw retention. As straw with high C: N ratio could result in N immobilization, additional N is needed to compensate N demand of crops. However, more and more N fertilize...The quality of straw affects N release after straw retention. As straw with high C: N ratio could result in N immobilization, additional N is needed to compensate N demand of crops. However, more and more N fertilizers have been applied to the soil to improve crop yields in China, which not only increases production cost but also reduces soil quality. Therefore, reasonable application of N fertilizer becomes a key problem after straw retention. This study aimed to assess the effects of applying maize straw with high quality alfalfa straw on mineral N content, microbial biomass and enzyme activity under controlled conditions. The effect of applying maize straw with alfalfa straw was compared with that of maize straw in combination with N fertilizer under the same C: N ratio (25:1). The laboratory incubation experiment consisted of four treatments: (1) soil with no addition (CK); (2) soil amended with maize straw (M); (3) soil amended with alfalfa straw and maize straw with an adjusted C: N ratio of 25:1 (MM); (4) soil amended with inorganic nitrogen fertilizer and maize straw with an adjusted C:N ratio of 25:1 (MF). The results showed that application of maize straw leaded to an N immobilization during the 270 d of incubation. Combined application of alfalfa and maize straw and or mineral N fertilizer alleviates the N immobilization and increase soil mineral N content. Compared to MF treatment, MM treatment prolonged N availability during the incubation. MM and MF treatments increased the soil microbial biomass carbon and nitrogen contents, and soil invertase and β-glycosidase activities. There was no difference between MM and M treatment in soil urease activity. MF treatment had significantly negative influence on soil urease activity compared with M treatment. The amount of added N significantly affected mineral N content, soil microbial biomass and enzyme activity. The mixture of alfalfa straw and maize straw sustains higher level of mineral N content, microbial biomass and enzyme activity as it had high N input compared to maize straw in combination with N fertilizer. It is concluded that alfalfa straw may be a better N source than N fertilizer in alleviating N immobilization caused by maize straw retention.展开更多
This paper summarizes a nontoxic Anti-fouling coating utilizing capsaicin as an anti-fouling agent. The capsaicin constituent used in the coating has a rating from about 100 000 to about 1 500 000 Scoville Heat Units....This paper summarizes a nontoxic Anti-fouling coating utilizing capsaicin as an anti-fouling agent. The capsaicin constituent used in the coating has a rating from about 100 000 to about 1 500 000 Scoville Heat Units. The capsaicin is mixed with a silicon dioxide and then solubilized into a free-flowing homogeneous liquid oleoresin composition by adding a solvent to increase solubility and facilitate mixing. The oleoresin capsaicin liquid solution is mixed with a suitable corrosion resistant epoxy resin, which is then mixed with a hardening catalyst and applied to the surface to be treated.展开更多
[Objective] The aim of the study was to establish the effective and accurate formulas for estimating the digestible energy (DE) values of plant protein supplement in pig. [Method] By difference method with different...[Objective] The aim of the study was to establish the effective and accurate formulas for estimating the digestible energy (DE) values of plant protein supplement in pig. [Method] By difference method with different amount of alternative feeds (20% -50%), two4 x4 Latin- square-designed trials were taken on eight castrated male pigs [ Yorkshire x Landrace x Neijiang pig, initial body-weight: (46 ±2) kg ] to deter- mine the apparent digestible energy (ADE) of the eight kinds of plant protein supplement commonly used in China, that is, corn gluten meal (sol.), soybean meal ( sol. ), fababean, pea, rapeseed meal ( sol. ), sesame meal ( sol. ), rapeseed meal ( exp. ) and cotton seed meal (sol.). [Resultl (1) Fiber was the most important factor to estimate the ADE of plant protein supplement in pigs, and ADF was the best one. (2) The most effective equations were as below: ( 1 ) OE (kJ/kg DM) = 14 741.86 - 185.01ADF+54.01SCHO+22.45CP ( R =0.988,RSD= 67.9,P〈0.01 ) ; (2) DE (kJ/kg DM) =22 223.26 -209.58ADF+26.79SCHO-1.09GE ( Ff =0.989,RSD=66.9, P〈0.01 ) . [Conclusion] The accurate, practical and specific regression equations were established for DE prediction of plant protein supplement in pig.展开更多
[Objective] This study was to design an intelligent greenhouse real-time monitoring system based on the core technology of Internet of Things in order to meet the needs of agricultural informatization and intellectual...[Objective] This study was to design an intelligent greenhouse real-time monitoring system based on the core technology of Internet of Things in order to meet the needs of agricultural informatization and intellectualization. [Method] Based on the application characteristics of Wireless Sensor Network (WSN), the intelligent greenhouse monitoring system was designed. And for the incompleteness strategy of load balancing in the Low-Energy Adaptive Clustering Hierarchy (LEACH), a Real- time Threshold Routing Algorithm (RTRA) was proposed. [Result] The performance of network lifetime and network delay of RTRA were tested in MATLAB and found that, within the same testing environment, RTRA can save nodes energy consumption, prolong network lifetime, and had better real-time performance than LEACH. The al- gorithm satisfies the crops' requirements on real-time and energy efficiency in the greenhouse system. [Conclusion] For the good performance on real-time, the de- signed intelligent greenhouse real-time monitoring system laid the foundation for the research and development of agricultural informatization and intellectualization.展开更多
The role of forest litter as an acid-base buffering system was assessed by litter from plantation and natural forests in South China. Samples were either extracted with acid solutions or titrated with acid or base sol...The role of forest litter as an acid-base buffering system was assessed by litter from plantation and natural forests in South China. Samples were either extracted with acid solutions or titrated with acid or base solutions. Litter was found to be a strong acid-base buffering system. Two legume species, Acacia mangium Willd and A. auriculaiformis A. Cunn, had very high litter pH values of around 6, which was 2 pH units higher than that of the soil where they grew. Litter of all other plantation species had litter pH of around 4, similar to that of the soil. Both legume species have high potential to neutralize soil acidity and the litter layer could act to shield soil against acid rain. The current stand of two legume species was estimated to be able to raise rain acidity by 0.1 to 0.4 pH units. Inorganic ions did not fully explain the pH pattern of different litter extracts, but high sodium and low nitrate partly accounted for the high pH of the two legume species. Some natural forest species had extremely low pH. As a whole, the litter of the natural climax forest was the driving force of soil acidification. Although plant residues are strong acid-base buffering system and able to adjust acidity of environment, only a few species can be expected to make soil more acid or alkaline through this mechanism since most species have litter pH values similar to those of soil where they grow.展开更多
基金Supported by National Special Funds for Forest Research in the Public Interest(201004004)~~
文摘In order to provide directionally genetically improved breeding materials of poplar by exploring the phenological traits genetic variation level and its develop- ment potential of Populus deltoides and the resource evaluation was carried out; 8 phenological phases in seedling period were observed and analyzed of 60 Populus deltoids clones introduced from America. The results showed that: (1) there was obvious difference in phonological character among clones, especially in leaf-spread- ing peak stage and the end term of leaf-falling stage, with the largest variation co- efficient of 14.97% and the minimum of 3.83% respectively. (2) Leaf-spreading peak stage scattered but the end term of leaf-falling stage concentrated the most. The phonological character in early stage of seedling growth was the main factor influ- encing the length of growing season. (3) By principal component analysis, pheno- logical phases were classified into 3 typical periods, including germination stage, leaf-spreading peak stage and leaf-falling stage. (4) Totaling 60 clones were classi- fied into 4 types by using clustering analysis in phenological time variables of clones.
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.
基金The National High Technology Research and Deve-lopment Program of China (863Program) (No.2003AA143040).
文摘Major consideration dimensions for the physical layer design of wireless sensor network (WSN) nodes is analyzed by comparing different wireless communication approaches, diverse mature standards, important radio frequency (RF) parameters and various microcontroller unit (MCU) solutions. An implementation of the WSN node is presented with experimental results and a novel "one processor working at two frequencies" energy saving strategy. The lifetime estimation issue is analyzed with consideration to the periodical listen required by common WSN media access control (MAC) algorithms. It can be concluded that the startup time of the RF which determines the best sleep time ratio and the shortest backoff slot time of MAC, the RF frequency and modulation methods which determinate the RX and TX current, and the overall energy consumption of the dual frequency MCU SOC ( system on chip) are the most essential factors for the WSN node physical layer design.
基金Suppported by National High Technology Research and Development Program of China (2008AA10Z224)National Natural Science Foundation of China(30960261,30700055)Ph. D. Programs Foundation of Ministry of Education of China(20070200005)~~
文摘[Objective]The research aimed to study the biomass structure of the functional modules of clonal population of Puccinellia tenuifora on Songnen Plain and its relationship with the functional modules quantitatively.[Method]Using the sample method of digging up the whole tiller tuft randomly at flowering stage,the relationships between the biomass of functional modules and turf size,biomass of different modules and the clone production,reproductive tillers of clones and the biomass of component modules of Puccinellia tenuifora clones on Songnen Plain were quantitatively analyzed.[Result]The biomass of sexual reproductive module,photosynthesis module and supporting module showed a linear increase with the increasing of turf size(P 〈0.05),while the linear relationship between the biomass of vegetative reproductive module and turf size did not reach the significant level(P 〉0.05).The restriction degree of turf size on the biomass of functional modules was supporting module sexual reproductive module photosynthesis module vegetative reproductive module.Biomass of reproductive tillers and vegetative tillers showed a linear increase as the biomass of total modules increased(P〈 0.05),while the linear correlation between the biomass of tillering seedlings and biomass of total modules did not reach the significant level(P 〉0.05).Biomass of stem,spike and leaf of reproductive plants showed a linear functional increase as reproductive tiller increased(P 〈0.05),and the ratio of accumulation of biomass of stem,spike and leaf was 7:2:1.[Conclusion]The research laid the theoretical foundation for the further research on the ecology of clustered clone plants.
文摘Eleven tertiarv alkaloids were isolated from Corvdalis decumbens rhizome Their structures were identified as protopine(Ⅶ),allocryptopine(Ⅷ),cryptopine (Ⅸ),muramine(ⅩⅦ);(+)-tetrahydropalmatine(Ⅲ),(+)-kikemanine (Ⅳ),(一)-scoulerine (ⅩⅧ),(十)-bulbo- capnine (ⅩⅨ),and(一)一capnoidine(Ⅰ),(一)一bicuculline(Ⅴ),(+) coriumidine(ⅩⅣ), respecti vely。 Among these,cryptopine,muramine,(+)-kikemanine,(-)-scoulerine,(一)capnoidine,(一)一bicuculline were isolated for the first time from this plant
基金Supported by National Scientific and Technological Project in Rural Areas in the "Twelfth Five Year" Plan(2012BAD21B03,2012BAD21B0304)~~
文摘[Objective] This study aimed to investigate the effects of drought stress on osmotic regulation substances of Catalpa bungei clones. [Method] Potting experimental was carried out with plastic film sealing method, to differentiate the degrees of drought stress based on changes in soil water content and leaf water potential and investigate variations in contents of osmotic regulation substances(free proline,soluble sugar and soluble protein) in leaves of five Catalpa bungei clones under different degrees of drought stresses. [Result] According to changes in soil water content and leaf water potential, the whole process of drought stress was divided into normal level(CK, with soil water content of 97.49% and leaf water potential of-0.54MPa), light drought(LD with soil water content of 59.96% and leaf water potential of-1.28 MPa), mediate drought(MD with soil water content of 34.19% and leaf water potential of-2.32 MPa) and severe drought(SD with soil water content of 14.52%and leaf water potential of-2.99 MPa). The soil water content and leaf water potential of five Catalpa bungei clones reached the highest correlation in exponential fitting, with an average R2of 0.989 3(P0.001). The free proline content in leaves of five Catalpa bungei clones increased rapidly with the increasing degree of drought stress(P 0.001). To be specific, free proline contents of Catalpa bungei clones015-1 and 7080 were 34.39 and 33.41 times of the normal level under severe drought conditions, which reached an extremely significant level(P0.001); the free proline content of Catalpa bungei clone 1-3 rapidly increased to(855.46±227.52) μg/g Fw under light drought conditions. The soluble protein content in leaves showed different variation trends. To be specific, the soluble protein content of Catalpa bungei clone 7080 was the lowest at various drought stages and reached(1.644 ±0.137)mg/g Fw under normal conditions; the soluble protein content of Catalpa bungei clone 1-3 was relatively high under normal conditions and was reduced rapidly under light drought conditions, showing different response patterns. [Conclusion] Osmotic regulation substances in leaves of five Catalpa bungei clones all have certain response to drought stress. Free proline is the most important osmotic regulation substance, followed by soluble protein, while soluble sugar makes no significant contribution. According to changes in content of osmotic regulation substances, Catalpa bungei clone 7080 has relatively high capacity and good drought resistance, while Catalpa bungei clone 1-3 has the rapidest response to drought stress.
基金The paper was supported by the project of integrated mangrove management and coastal protection(IMMCP) in Leizhou Peninsula Guangdong Province.
文摘The exotic Sonneratia apetala in Leizhou Peninsula, has shown outstanding fast-growing ability in restored mangrove forests, at the middle and high tide intertidal zone, with year-round fresh water input from drainage. By setting plot and selecting standard tree, investigation and measurement on height growth, diameter growth, biomass, productivity, and so on, were made in a S. apetala plantation at age of six at Lanbei, Fucheng, Leizhou Peninsula in May 2001. The investigating results showed that the mean annual height growth of plantation was 2.03 m and mean annual growth of diameter at breast height (DBH) was 2.35 cm. There exists a significant correlation between the diameter at ground surface (DGS) and DBH. The average biomass of a single standard tree in dry weight was 95.647 kg/m2. A ratio of above-ground biomass to under-ground biomass was 1.60. The stand biomass of unit area was 22.955 kg/m2, singletree wood volume was 88.23 dm3, and the annual wood volume productivity (PA) of the same year was 0.407. The forest energy accumulation was 424.851 MJ/m2, with annual solar energy fixing rate of 40.68 ×10-7%. It is concluded that S. apetala species had characteristics of outstanding high biomass accumulation and could be used as coastal planting tree species in southern China.
基金Supported by "12th Five-Year" National Science and Technology Suppot Project(2011BAD12B02)Beijing Finance Bureau Support Project~~
文摘[Objective] The aim of this study was to explore the effects of substrates before and after fermenting treatment on the growth,development and cut flower quality of lily.[Method] Oriental lily cultivar 'Siberia' was taken as material to study the effect of using fermentative and unfermented agricultural waste as substrates on the growth,development and cut flower quality of lily.And the physical and chemical properties of substrates before and after fermenting treatment were studied.[Result] The full decomposition of agricultural waste would greatly improve the physical and chemical properties of substrates,such as the fermentative substrates changed to stabilization,the ratio of carbon nitrogen had dropped drastically,the total porosity was increase,the ratio of gas and water was better,and the nutrition elements was increased.Moreover,it could significantly increased the plant height,stem diameter,leaf number,leaf area,leaf fresh weight and so on,as well as expanded the lily roots and significantly improved the rate of cut flower and cut flower quality.[Conclusion] This study had provided theoretically basis for the cultivation of cut lily.
文摘The quality of straw affects N release after straw retention. As straw with high C: N ratio could result in N immobilization, additional N is needed to compensate N demand of crops. However, more and more N fertilizers have been applied to the soil to improve crop yields in China, which not only increases production cost but also reduces soil quality. Therefore, reasonable application of N fertilizer becomes a key problem after straw retention. This study aimed to assess the effects of applying maize straw with high quality alfalfa straw on mineral N content, microbial biomass and enzyme activity under controlled conditions. The effect of applying maize straw with alfalfa straw was compared with that of maize straw in combination with N fertilizer under the same C: N ratio (25:1). The laboratory incubation experiment consisted of four treatments: (1) soil with no addition (CK); (2) soil amended with maize straw (M); (3) soil amended with alfalfa straw and maize straw with an adjusted C: N ratio of 25:1 (MM); (4) soil amended with inorganic nitrogen fertilizer and maize straw with an adjusted C:N ratio of 25:1 (MF). The results showed that application of maize straw leaded to an N immobilization during the 270 d of incubation. Combined application of alfalfa and maize straw and or mineral N fertilizer alleviates the N immobilization and increase soil mineral N content. Compared to MF treatment, MM treatment prolonged N availability during the incubation. MM and MF treatments increased the soil microbial biomass carbon and nitrogen contents, and soil invertase and β-glycosidase activities. There was no difference between MM and M treatment in soil urease activity. MF treatment had significantly negative influence on soil urease activity compared with M treatment. The amount of added N significantly affected mineral N content, soil microbial biomass and enzyme activity. The mixture of alfalfa straw and maize straw sustains higher level of mineral N content, microbial biomass and enzyme activity as it had high N input compared to maize straw in combination with N fertilizer. It is concluded that alfalfa straw may be a better N source than N fertilizer in alleviating N immobilization caused by maize straw retention.
文摘This paper summarizes a nontoxic Anti-fouling coating utilizing capsaicin as an anti-fouling agent. The capsaicin constituent used in the coating has a rating from about 100 000 to about 1 500 000 Scoville Heat Units. The capsaicin is mixed with a silicon dioxide and then solubilized into a free-flowing homogeneous liquid oleoresin composition by adding a solvent to increase solubility and facilitate mixing. The oleoresin capsaicin liquid solution is mixed with a suitable corrosion resistant epoxy resin, which is then mixed with a hardening catalyst and applied to the surface to be treated.
文摘[Objective] The aim of the study was to establish the effective and accurate formulas for estimating the digestible energy (DE) values of plant protein supplement in pig. [Method] By difference method with different amount of alternative feeds (20% -50%), two4 x4 Latin- square-designed trials were taken on eight castrated male pigs [ Yorkshire x Landrace x Neijiang pig, initial body-weight: (46 ±2) kg ] to deter- mine the apparent digestible energy (ADE) of the eight kinds of plant protein supplement commonly used in China, that is, corn gluten meal (sol.), soybean meal ( sol. ), fababean, pea, rapeseed meal ( sol. ), sesame meal ( sol. ), rapeseed meal ( exp. ) and cotton seed meal (sol.). [Resultl (1) Fiber was the most important factor to estimate the ADE of plant protein supplement in pigs, and ADF was the best one. (2) The most effective equations were as below: ( 1 ) OE (kJ/kg DM) = 14 741.86 - 185.01ADF+54.01SCHO+22.45CP ( R =0.988,RSD= 67.9,P〈0.01 ) ; (2) DE (kJ/kg DM) =22 223.26 -209.58ADF+26.79SCHO-1.09GE ( Ff =0.989,RSD=66.9, P〈0.01 ) . [Conclusion] The accurate, practical and specific regression equations were established for DE prediction of plant protein supplement in pig.
基金Supported by the Science and Technology Surface Project of Yunnan Province(2010ZC142)the Doctoral Foundation of Dali University(KYBS201015),the Scientific Research Program for College Students of Dali University~~
文摘[Objective] This study was to design an intelligent greenhouse real-time monitoring system based on the core technology of Internet of Things in order to meet the needs of agricultural informatization and intellectualization. [Method] Based on the application characteristics of Wireless Sensor Network (WSN), the intelligent greenhouse monitoring system was designed. And for the incompleteness strategy of load balancing in the Low-Energy Adaptive Clustering Hierarchy (LEACH), a Real- time Threshold Routing Algorithm (RTRA) was proposed. [Result] The performance of network lifetime and network delay of RTRA were tested in MATLAB and found that, within the same testing environment, RTRA can save nodes energy consumption, prolong network lifetime, and had better real-time performance than LEACH. The al- gorithm satisfies the crops' requirements on real-time and energy efficiency in the greenhouse system. [Conclusion] For the good performance on real-time, the de- signed intelligent greenhouse real-time monitoring system laid the foundation for the research and development of agricultural informatization and intellectualization.
文摘The role of forest litter as an acid-base buffering system was assessed by litter from plantation and natural forests in South China. Samples were either extracted with acid solutions or titrated with acid or base solutions. Litter was found to be a strong acid-base buffering system. Two legume species, Acacia mangium Willd and A. auriculaiformis A. Cunn, had very high litter pH values of around 6, which was 2 pH units higher than that of the soil where they grew. Litter of all other plantation species had litter pH of around 4, similar to that of the soil. Both legume species have high potential to neutralize soil acidity and the litter layer could act to shield soil against acid rain. The current stand of two legume species was estimated to be able to raise rain acidity by 0.1 to 0.4 pH units. Inorganic ions did not fully explain the pH pattern of different litter extracts, but high sodium and low nitrate partly accounted for the high pH of the two legume species. Some natural forest species had extremely low pH. As a whole, the litter of the natural climax forest was the driving force of soil acidification. Although plant residues are strong acid-base buffering system and able to adjust acidity of environment, only a few species can be expected to make soil more acid or alkaline through this mechanism since most species have litter pH values similar to those of soil where they grow.