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Transformation of Metallothionein Gene into Mushroom Protoplasts by Application of Electroporation 被引量:7
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作者 张竞 聂思惟 +1 位作者 单龙 茹炳根 《Acta Botanica Sinica》 CSCD 2002年第12期1445-1449,共5页
Metallothionein gene (MT) has been transferred into mushroom protoplasts by electroporation. It is a low molecular weight, cysteine-rich and metal-binding protein. MT can bind metals. Its synthesis is induced by Zn io... Metallothionein gene (MT) has been transferred into mushroom protoplasts by electroporation. It is a low molecular weight, cysteine-rich and metal-binding protein. MT can bind metals. Its synthesis is induced by Zn ion. Thus the expression of MT gene in mushroom can improve the accumulation of Zn in this fungus. This transgenic mushroom, consumed as a kind of vegetable, can supply the necessary Zn to people who are short of the element. When protoplasts were prepared, the concentration (C) of protoplasts is 6.745 x 10(6) /mL. After protoplast electroporation, the transformation rate of protoplasts is 0.01 %. Polymerase chain reaction (PCR) analysis showed that the gene had been integrated into the mushroom chromosome, SDS-PAGE, Western blot analysis indicated that the MT gene had been expressed in the transgenic mushroom. The expressing level, detected by ELISA, is 0.6 % - 0.8 %. Tested for metal resistance, the wild-type mushroom growth was inhibited on die medium containing 1.0 - 1.2 mmoL/L ZnSO4. While the transgenic mushroom was inhibited on the medium containing 1. 5 - 2.0 mmol/L ZnSO4. The mycelium can develop into hymenophore in the medium of rice bran: sawdust = 1: 3, and not in the medium of rice bran: sawdust = 1: 4. 展开更多
关键词 ELECTROPORATION PROTOPLAST transgenic mushroom
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Effect of Phosphorus on the Content of Vitamin E in Different Soybean Cultivars 被引量:3
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作者 接伟光 张勇 +3 位作者 蔡柏岩 白莉 王丽阳 李二平 《Agricultural Science & Technology》 CAS 2011年第12期1881-1884,共4页
[Objective] This study aimed to explore the effects of phosphorus on the contents of vitamin E in different cultivars of soybean grains and find the optimum application amount of phosphorus for different genotypes of ... [Objective] This study aimed to explore the effects of phosphorus on the contents of vitamin E in different cultivars of soybean grains and find the optimum application amount of phosphorus for different genotypes of soybean cultivars,in order to increase the contents of vitamin E in soybean grains and improve the qualities.[Method] Three soybean cultivars were selected as experimental materials,including Heinong 48(high-protein cultivar),Heinong 37(intermediate cultivar) and Heinong 44(high-oil cultivar).The soybeans were planted in pots,with 0.033 g/kg soil of N and K2O,four phosphorus treatments were set,respectively applied with 0(P1),0.033(P2),0.067(P3) and 0.100(P4) g/kg soil of P2O5,and the total contents of vitamin E in different cultivars of soybean grains were determined by high-performance liquid chromatography method.[Result] The total contents of vitamin E in the same cultivar of soybean grains in P3 treatment were significantly higher than that in the other three treatments,the total contents of vitamin E in Heinong 37,Heinong 44 and Heinong 48 in P3 treatment had increased by 11.96%,16.55% and 14.02%,compared with the control;among the three soybean cultivars in P2 treatment,the content of vitamin E in Heinong 37 was the maximum;among the 12 treatment combinations,the total contents of vitamin E in Heinong 44 in P3 treatment was the maximum.The contents of vitamin E in three soybean cultivars significantly varied among the various cultivars and different phosphorus treatments.[Conclusion] Application of phosphorus could affect the contents of vitamin E in three soybean cultivars,appropriate application amount of phosphorus is advantageous to improve the contents of vitamin E in soybean grains. 展开更多
关键词 SOYBEAN Phosphorous level Vitamin E
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Relationship Between Ecophysiological Features and Grain Yield in Different Soybean Varieties 被引量:14
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作者 朱桂杰 蒋高明 +4 位作者 郝乃斌 刘合芹 孔正红 杜维广 满为群 《Acta Botanica Sinica》 CSCD 2002年第6期725-730,共6页
Photosynthetic rate ( P n ), transpiration rate ( E ), stomatal conductance ( g s ), water use efficiency ( WUE ), intercellular CO 2( C i ) and leaf water potential ( Ψ ) in varieties of soybean ( G... Photosynthetic rate ( P n ), transpiration rate ( E ), stomatal conductance ( g s ), water use efficiency ( WUE ), intercellular CO 2( C i ) and leaf water potential ( Ψ ) in varieties of soybean ( Glycine max (L.) Merr.) measured in the past three decades (1970s, 1980s and 1990s) and their inter_relationships were analyzed. These parameters of soybean changed with development stages. It is shown that there was a strongly positive relationship between the yield of soybean and its net photosynthetic rate. Soybean varieties with high yield potential had higher P n , g s and Ψ than those with low yield potential. Their values of C i were remarkably lower. Such relationship was especially remarkable at the critical stage of pod_bearing. P n of soybean of high yield was obviously higher than that of low yield. Of the different stages, the highest P n was found in the pod_bearing stage and other values were higher, too. P n and Ψ of modern soybean varieties were higher and such was continuing. Increased partitioning of carbon to seed and the size of sink may also be important for yield formation when P n values were remarkably higher in the pod_bearing stage. 展开更多
关键词 SOYBEAN ecophysiological characteristics photosynthetic rate stomatal conductance water potential
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Evaluation on Service Function of Plain Forest Ecosystem in Northwest China 被引量:5
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作者 岳丹 马青 +2 位作者 法科宇 鲁肃 黄守科 《Agricultural Science & Technology》 CAS 2011年第4期584-587,共4页
[Objective] The paper aimed to evaluate the plain forestry' service function in Northwest China.[Method] Based on general and representative investigations with county used as the minimum unit,evaluation on service f... [Objective] The paper aimed to evaluate the plain forestry' service function in Northwest China.[Method] Based on general and representative investigations with county used as the minimum unit,evaluation on service function of plain forestry ecosystem in Northwest China was carried out by measuring the quality and quantity.[Result] In 2005,the plain forestry in Northwest China plays a profound role in water and soil conversation,carbon sequestration by vegetation and soil,oxygen release by plants,sulfur dioxide absorption and and so on.[Conclusion] This paper laid foundation for research on service function of plain forest ecosystem in Northwest China. 展开更多
关键词 Northwest China Plain forestry Ecosystem services EVALUATION
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Microbial Community Characteristics in the Rhizosphere of Atrazine-contaminated Soil by Dendroremediation of Poplar
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作者 姚斌 刘方 +1 位作者 刘昌勇 韦秀文 《Agricultural Science & Technology》 CAS 2017年第12期2423-2426,2519,共5页
The change of microbial community characteristics in the different rhizo- sphere zones of hybrid poplar (Populusdeltoidsxnigra, DN34) under atrazine stress were investigated by rhizo-boxes and Biolog system in a gre... The change of microbial community characteristics in the different rhizo- sphere zones of hybrid poplar (Populusdeltoidsxnigra, DN34) under atrazine stress were investigated by rhizo-boxes and Biolog system in a greenhouse experiment, with sublimed sulfur and calcium hydroxide as soil pH regulators. Data from the measurement by the Biolog ECO plate demonstrated that the value of average well color development (AWCD) and the carbon source utilization of soil microorganisms in the treatments with pH regulators were promoter than CK during the initial 30 days; while the results from the 90 days indicated that the activity and the carbon source utilization of soil microbes in acid regulator treatment began to fall down, even lower than that of poplar implant treatment, then the alkaline treatment could still stimulate and promote the activity and the carbon source utilization ability of soil microbes. Overall, the activity and community structure of soil microbes in rhizo- sphere zones of atrazine-contaminated soil did not show steady regularity during the phytoremediation process by using hybrid poplars. For the reason that the Biolog E- CO plate, which only had 31 kinds of carbon sources, could not really indicate the detail information about the function diversity of community structure of soil mi- crobes. So it's essential for us to take more sophisticated analysis tools for further study. 展开更多
关键词 POPLAR RHIZOBOX ATRAZINE Microbes Average absorbance Diversity
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The Interplanting Technology of Pleurotus ostreatus and Dendrobium officinale 被引量:1
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作者 莫祺晖 罗先群 +6 位作者 郑元涛 何达崇 李发盛 孙文波 张红岩 莫勇生 蒋永强 《Agricultural Science & Technology》 CAS 2015年第7期1329-1331,共3页
In summer, Cha No. 39 of 292 bags and 205 of 244 bags were inter- planted with Dendrobium officinale on cultivation bed, respectively, whose yields and biological efficiencies reached 102.46 kg and 103.98%, and 96.77 ... In summer, Cha No. 39 of 292 bags and 205 of 244 bags were inter- planted with Dendrobium officinale on cultivation bed, respectively, whose yields and biological efficiencies reached 102.46 kg and 103.98%, and 96.77 kg and 113.32%, accordingly. The seedlings of Dendrobium officinale interplanted with Pleurotus os- treatus grew by 2.78 cm during 10 weeks on cultivation beds, and the seedlings grew by 2.68 cm in the cultivation beds without interplanting arrangement. These demonstrated that the interplanting of Dendrobium officinale and Pleurotus ostreatus has none adverse effects on growth of Dendrobium officinale. 展开更多
关键词 Dendrobium officinale Pleurotus ostreatus INTERPLANTING Biological effi- ciency
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Driving Analysis on Ecological Security in Vulnerable Transition Areas of Mountain and Plain 被引量:1
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作者 刘欣 赵艳霞 +2 位作者 秦彦杰 张金英 武爱彬 《Agricultural Science & Technology》 CAS 2013年第3期433-435,共3页
[Objective] This study aimed to investigate the driving mechanism of eco- logical security in vulnerable areas in mountain and plain. [Method] The ecological security evaluation index system of Lincheng County was est... [Objective] This study aimed to investigate the driving mechanism of eco- logical security in vulnerable areas in mountain and plain. [Method] The ecological security evaluation index system of Lincheng County was established using PSR model. Driving mechanism was analyzed in total system and subsystems respectively by the principal components. The ecological safety driving factor was calculated through the total system and subsystem respectively. And the intersection was adopt- ed as dominant driving factor. [Result] A total of 10 indices including density index of rivers, land degradation index, farmland drought and flood insurance yield, human in- terference index, population density, the natural population growth rate, per capita GDP, the R&D funds spending accounts for the proportion of GDP, laborer by edu- cation degree and three industry accounted for the proportion of GDP, are the domi- nant driving factors of the regional ecological security. [Conclusion] This study will pro- vide reasonable and feasible advice for the benign development of the area. 展开更多
关键词 Ecological security Driving force Transition areas of mountains and plains
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颠簸状态下制冷系统气液分离器性能的影响研究 被引量:3
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作者 陈光明 张荣涛 +3 位作者 杨申音 郝新月 周秋丽 高能 《流体机械》 CSCD 北大核心 2018年第2期54-59,共6页
主要针对混合工质两级喷射制冷系统在船舶出海条件下的运行稳定性进行了分析研究。气液分离器是喷射式制冷系统中一个较为重要的设备部件。内部液体的波动与飞溅,容易使得气液分离器出现出气带液的现象,而高压级喷射器引射的出气带液量... 主要针对混合工质两级喷射制冷系统在船舶出海条件下的运行稳定性进行了分析研究。气液分离器是喷射式制冷系统中一个较为重要的设备部件。内部液体的波动与飞溅,容易使得气液分离器出现出气带液的现象,而高压级喷射器引射的出气带液量对整个系统的工作性能会有一定的影响。本文通过数值模拟与试验研究的方法对系统中的气液分离器进行了研究,结果表明,25cm为内部最大安全液位。当分离器内部液位高于25 cm时,气液分离器的出气带液量会随着内部液面高度的上升而增加。另外,在分离器中增设挡板对内部液体的波动与飞溅有明显的抑制作用。 展开更多
关键词 渔船废热 喷射制冷系统 颠簸状态 稳定性 气液分离器 出气带液量
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Functional Equilibrium Between Photosynthetic and Above-ground Nonphotosynthetic Structures of Plants: Evidence from a Pruning Experiment with Three Subtropical Tree Species 被引量:4
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作者 曾波 《Acta Botanica Sinica》 CSCD 2003年第2期152-157,共6页
It is well known that plants have functional equilibrium between their above-ground parts (shoots) and below-ground parts (roots), but whether the above-ground parts of plants have functional equilibrium between their... It is well known that plants have functional equilibrium between their above-ground parts (shoots) and below-ground parts (roots), but whether the above-ground parts of plants have functional equilibrium between their photosynthetic structures (leaves) and non-photosynthetic structures (branches and stem) is unknown. The purpose of this study is to test the hypotheses that: (1) the above-ground parts of plants have functional equilibriums between their photosynthetic structures and non-photosynthetic structures; (2) the maintenance of the equilibriums is guaranteed by the alteration of biomass partitioning to photosynthetic and non-photosynthetic structures. To test these hypotheses, a pruning experiment with four pruning intensities (0%, 20%, 50%, and 70%) were carried out with three subtropical Chinese tree species ( Ficus microcarpa, Ficus virens, Cinnamomum camphora). Pruning treatments were conducted in two successive years. The results were in conformity with the hypothesis, i.e. above-ground parts of trees had functional equilibriums between photosynthetic and non-photosynthetic structures. Pruning decreased instantaneously the mass ratios of photosynthetic structures to non-photosynthetic structures (P/NP) of all three tree species, the reduction in P/NP was strengthened with pruning intensity. However, one year after pruning, the P/NP of all pruned trees increased and were not smaller than those of unpruned trees. In agreement with the expectation, the biomass partitioning of pruned trees was altered, more newly produced above-ground biomass was partitioned to leaf growth and less to branch and stem growth, thus enabled the damaged trees to restore their functional equilibrium between photosynthetic and non-photosynthetic structures. It is clear that the maintenance of functional equilibrium between photosynthetic and non-photosynthetic structures guaranteed by the alteration of biomass partitioning provides plants a good strategy to resist external disturbance and damage. 展开更多
关键词 biomass partitioning functional equilibrium non-photosynthetic structures photosynthetic structures tree
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Effects of Interaction between Density and Nitrogen Rate on Growth and Yield of No-tilling and Direct Sowing Rapeseed in Chengdu Plain 被引量:2
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作者 陈红琳 陈尚洪 +2 位作者 乔善宝 蒋梁材 刘定辉 《Agricultural Science & Technology》 CAS 2012年第9期1924-1928,1970,共6页
[Objective] The aim was to explore the optimal density and nitrogen rate of no-tilling and direct sowing rapeseeds in Chengdu plain. [Methods] Effects of in- teraction between density and nitrogen rate on the growth a... [Objective] The aim was to explore the optimal density and nitrogen rate of no-tilling and direct sowing rapeseeds in Chengdu plain. [Methods] Effects of in- teraction between density and nitrogen rate on the growth and yield of direct sowing rapeseed under no-tillage condition were investigated with Chuanyou 58 as materials and a split-plot experiment adopted. [Results] In Chengdu Plain, the yields of rape- seed changed from increasing to decreasing with increase of density and nitrogen rate. Both of density and nitrogen rate had significant effects on growth and yield of rapeseed and the latter overweighed in the effect. In addition, interaction of the two had negative effects on rapeseed yield. The yield of rapeseeds achieved the highest at 3 395.25 kg/hm^2 with interaction of density at 30.00×10^4 plant/hm^2 and nitrogen rate at 180.00 kg/hm^2; the theoretical maximal yield was 3 403.41 kg/hm^2 with interaction of density at 40.80×10^4 plants/hm^2 and nitrogen rate at 198.90 kg/hm^2. [Conclusion] In Chengdu Plain, the optimal density and nitrogen rate are 30.00×10^4-45.00×10^4 plant/hm^2 and 180.00-198.90 kg/hm^2, respectively. 展开更多
关键词 Tillage-free and direct sowing rapeseed DENSITY Nitrogen rate YIELD Chengdu Plain
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Study on the Occurrence and Epidemic Regularity and Region Division of Rice Blast in Nanchong City 被引量:1
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作者 彭昌家 白体坤 +2 位作者 丁攀 冯礼斌 杨宇衡 《Agricultural Science & Technology》 CAS 2016年第4期927-937,共11页
With the aim to improve the level of monitoring and warning as well as the comprehensive control of rice blast disease, and to feasibly reduce the disease threat in Nanchong City, the methods of GPS and GIS, systemati... With the aim to improve the level of monitoring and warning as well as the comprehensive control of rice blast disease, and to feasibly reduce the disease threat in Nanchong City, the methods of GPS and GIS, systematical monitoring and field survey, rice blast resistance identification, physiologic races of rice blast monitoring, and meteorological data analysis were performed to study the occurrence and epidemic region division, precise demarcation and occurrence and epidemic regularity of rice blast in Nanchong City. This study first completed the epidemic region division and precise demarcation; first clarified the initial affection(beginning period) locations, occurrence characteristics, epidemic trends and characteristics; explicated the existence of four epidemic peak periods of rice blast in the field, where the damage areas of first peak period played a decisive role during the blast epidemic years; in late May, the cumulative occurrence areas and annual occurrence areas presented higher positive correlation with the correlation coefficient of 0.817;and established a prediction model of occurrence areas per year based on the disease field rate at the end of boot stages and the diseased plant rate at dough stages. The results of investigation on the impact factors investigation of blast disease in Nanchong in recent years suggested that the internal causes were the decrease or loss of blast resistance of the rice cultivars, as well as the increase of physiological races with strong resistance to rice blast and the emergence of new virulent physiologic varieties; the external causes were suitable temperature, too much rainy, and sunlight shortage. Between 2010 and 2015, the short-term forecast accuracy for rice blast in Nanchong was up to 100%, and medium-and long-term forecast accuracy was also up to 98% and 95%, respectively, which increased by 5-15% than that before 1997, thereby making the control effect of rice blast in Nanchong increased by 15-30%. 展开更多
关键词 Rice Rice blast Region division Occurrence characteristics Epidemic regularity Early warning level
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Study on Epidemic Characteristics and Its Causes of Wheat Stripe Rust in Nanchong City 被引量:1
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作者 彭昌家 丁攀 +7 位作者 白体坤 冯礼斌 陈如胜 王婉秋 尹怀中 龙维国 肖立 文旭 《Agricultural Science & Technology》 CAS 2015年第2期292-297,共6页
On basis of the research result of stripe rust for 16 years since 1999,the epidemic characteristics and trend of stripe rust in the city were determined.Namely,the earlier the initial stage appeared,the heavier the di... On basis of the research result of stripe rust for 16 years since 1999,the epidemic characteristics and trend of stripe rust in the city were determined.Namely,the earlier the initial stage appeared,the heavier the disease would be.Furthermore,stripe rust has two introduction infection peaks,of which the first peak plays a key role.In farmlands,there are one to three epidemic peaks,and the infection area of the first peak plays the key role on the epidemic area of that year.In addition,the accumulated areas of late January was in significantly positive correlation with annually total area,with a correlation coefficient of 0.769 2.In recent 16 years,the frequency of severe stripe rust was as high as 81.25% which was 50% higher than that before 1995.The slight stripe rust became just in 2013,with a frequency of 6.3%,which indicated that the city has become a region hit by severe stripe rust.The internal reason is the reduction or loss of wheat variety's resistance to tripe rust for a new physiological race of rust is becoming pathogenic stronger and be the major race.Big fluctuation of temperatures in warm winter and spring,foggy and dew days slants much would be the external reason. 展开更多
关键词 WHEAT Stripe rust Occurrence characteristics Epidemic rule WARNING Improvement
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Study on High-yield Potential for Maize Varieties in Mountain Area of Yunnan-Guizhou Plateau
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作者 管俊娇 张鹏 +5 位作者 黄清梅 张惠 张运锋 王彦林 王宝书 张建华 《Agricultural Science & Technology》 CAS 2015年第11期2467-2470,共4页
By field experiments with Uniform Design, the effects of planting density and nitrogen rate on three varieties (Yunrui No.8, Yunrui No.6 and Yunrui No.88) grain yield under different ecological conditions were studi... By field experiments with Uniform Design, the effects of planting density and nitrogen rate on three varieties (Yunrui No.8, Yunrui No.6 and Yunrui No.88) grain yield under different ecological conditions were studied in Yunnan Province. The results showed that the grain yields were different among the five experiment locations, when increasing of planting density, it did not affected the plant height, ear height and ear factor, with the planting density increased, stem diameter, leaf width, ear length, number of grains per row and 1 000-grain weight decreased sig- nificantly, but the grain yield of the third varieties increased. High planting density had a negative impact on ear traits, but the grain yield increased by high-density compensate for the adverse effects.Control space and time of fertilizer application can reach the highest yield under less Nitrogen fertilizer Yunrui 88 had the charec- teristics of wide range of adaptability and the density-tolerance, high-yielding poten- tial, which was favorable in planting on large areas. 展开更多
关键词 MAIZE Ecological conditions Planting density Nitrogen application rate
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Sea level change and forecast in the future — climate of the past,today and the future 被引量:1
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作者 岳军 DONG yue +3 位作者 陈满春 韩芳 段焕春 王国明 《Marine Science Bulletin》 CAS 2011年第2期33-50,共18页
The sea-level change is resulted from superposition of sun, moon and other planeries, and earth itself, biological process, atmosphere and oceanography, as well as artificial actions. As a result, the sea level change... The sea-level change is resulted from superposition of sun, moon and other planeries, and earth itself, biological process, atmosphere and oceanography, as well as artificial actions. As a result, the sea level change is really a sensitive integral variation value of many variations, or a combined function of coupling effects of various big systems. Therefore the above mentioned superposed action of different systems and the coupling effect of sun earth and biological aspects may be called as sun earth biological coupling effect system. Based on this hypothesis, the corresponding sun dynamic, air dynamic, water dynamic and earth dynamic conceptional models are established in order to research the multiple coupling effects and feedback machsnism between these big systems. In order to determine the relations, effectness and coherent relation of different variations, the quantity, analysis is conducted through collective variation and stage division. The quantity analysis indicates that the earths spindle rotation speed is the dynamic mechanism controlling the sea level change of fluctuation. The change rate of sea level in the world is +1.32 + 0.22 mm/a, while the sea level change rate in China is only+1.39 + 0.26 mm/a in average. If take the CO2 content as the climate marker, eight cold stages (periods) are grouped out since two hundreds years AC. The extreme cold of the eighth cold stage started approximately at 1850 years AC. and if the stage from the extreme cold to extreme warm is determined as long as 200 years, the present ongoing warm stage will end at about 2050 years, there after the temperature will begin to tower. If the stage between cold and warm extremes lasts for 250 years, then the temperature will become lower at about 2100 year. Until to that time, the sea-level is estimated to raise +7 - +11 + 3.5 cm again, and there after, the sea level will begin the new lowering trend. In the same time, the climate will enter into next new cold stage subsequently. 展开更多
关键词 Sun earth biological coupling effect system sea-level change mechanism change rate of the sea-level climate cold stage forecast of the sea-level changes in the future
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Change of Cultivated Land and Its Implications on Food Security in China 被引量:22
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作者 YU Bohua LU Changhe 《Chinese Geographical Science》 SCIE CSCD 2006年第4期299-305,共7页
The population growth and demand for high living standard not only increase food demand but also cause more loss of the limited cultivated land resources. Cultivated land loss caused by disasters and the implementatio... The population growth and demand for high living standard not only increase food demand but also cause more loss of the limited cultivated land resources. Cultivated land loss caused by disasters and the implementation of the "Conversion of Cropland to Forest or Grassland" project make this situation even worse in China. Thus, there is a problem to be solved imminently that to what extent the cultivated land can guarantee food security of China. Based on time-series data on food production and cultivated land area from 1989 to 2003 and other research results, this paper constructs quality index of cultivated land according to different land quality. Regression models are adopted to predicate changes of main factors from 2004 to 2030, which have great effect on cultivated land area or grain productivity, and verify accuracy with coc^cient of determination (R2). Nine results were got according to three scenarios of decreasing rate of population growth rate and three cases of urban and rural built-up area per capita. There results show that China's food supply can only be maintained at a low to middle level of 370-410kg per capita, that is, China has enough land productivity to meet primary demand of food independently. However, it cannot reach the safe target of 500kg per capita if there is no breakthrough in breeding or no remarkable improvement of irrigation works, when the grain self-sufficiency maintains no less than 80%. To breed productive crops and to improve land productivity by mefiorating low quality cultivated land are appropriate measures to shrink the gap between food demand and supply. The results may offer helpful information for the formulation of policies on population growth, land use, protection of cultivated land. 展开更多
关键词 population growth cultivated land available food per capita food security China
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Uniformity Investigation in 3C-SiC Epitaxial Layers Grown on Si Substrates by Horizontal Hot-Wall CVD
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作者 李家业 赵永梅 +6 位作者 刘兴昉 孙国胜 罗木昌 王雷 赵万顺 曾一平 李晋闽 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2007年第1期1-4,共4页
50mm 3C-SiC epilayers are grown on (100) and (111) Si substrates in a newly developed horizontal lowpressure hot-wall CVD reactor under different growth pressures and flow rates of H2 carrier gas. The structure,el... 50mm 3C-SiC epilayers are grown on (100) and (111) Si substrates in a newly developed horizontal lowpressure hot-wall CVD reactor under different growth pressures and flow rates of H2 carrier gas. The structure,electrical properties, and thickness uniformity of the 3C-SiC epilayers are investigated by X-ray diffraction (XRD) ,sheet resistance measurement, and spectroscopic ellipsometry. XRD patterns show that the 3C-SiC films have excellent crystallinity. The narrowest full widths at half maximum of the SIC(200) and (111) peaks are 0.41° and 0.21°, respectively. The best electrical uniformity of the 50mm 3C-SiC films obtained by sheet resistance measurement is 2.15%. A σ/mean value of ± 5.7% in thickness uniformity is obtained. 展开更多
关键词 3C-SIC heteroepitaxial growth horizontal hot-wall CVD UNIFORMITY
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Relationship between Rice Planthopper Occurrence Area in China and Atmospheric Circulation Indices 被引量:3
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作者 季璐 朱敏 《Agricultural Science & Technology》 CAS 2012年第9期2006-2011,共6页
[Objective] This study aimed to establish models based on atmospheric cir- culation indices for forecasting the area attacked by rice planthopper every year, and to provide guide for preventing and controlling plantho... [Objective] This study aimed to establish models based on atmospheric cir- culation indices for forecasting the area attacked by rice planthopper every year, and to provide guide for preventing and controlling planthopper damage. [Method] The data related to rice planthopper occurrence and atmospheric circulation were collected and analyzed with the method of stepwise regression to establish the prediction models. [Result] The factors significantly related to the area attacked by rice plan-thopper were selected. Two types of prediction models were established. One was for Sogatella furcifera (Horvath), based on Atlantic-Europe circulation pattern W in October in that year, Pacific polar vortex area index in October in that year, North America subtropical high index in August in that year, Atlantic-Europe circulation pattern W in June in that year, northern boundary of North America subtropical high in February in that year, Atlantic-Europe polar vortex intensity index in October in that year and Asia polar vortex intensity index in November in the last year; the other type of prediction models were for Nilaparvata lugens (Stal), based on the Eastern Pacific subtropical high intensity index in July in that year, northern hemi- sphere polar vortex area index in October in the last year, Asia polar vortex strength index in November in the last year, north boundary of North America-At- lantic subtropical high in September in that year, north boundary of North Africa-At- lantic-North America subtropical high in January in that year, sunspot in September of the last year and eastern Pacific subtropical high area index in September in that year. [Conclusion] With the stepwise regression, the forecasting equations of the rice planthopper occurrence established based on the atmospheric circulation indices could be used for actual forecast. 展开更多
关键词 Rice planthopper Atmospheric circulation Prediction models
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Species-diversified plant cover enhances orchard ecosystem resistance to climatic stress and soil erosion in subtropical hillside 被引量:9
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作者 陈欣 杨一松 唐建军 《Journal of Zhejiang University Science》 EI CSCD 2004年第10期1191-1198,共8页
Naturally occurring plants in agroecosystem evidently play an important role in ecosystem stability. Field studies on the ecological effects of native plants conserved in orchard and their resistance to adverse climat... Naturally occurring plants in agroecosystem evidently play an important role in ecosystem stability. Field studies on the ecological effects of native plants conserved in orchard and their resistance to adverse climatic stress, and soil erosion were conducted from 1998 to 2001 in a newly developed Changshan-huyou (Citrus changshan-huyou Y.B. Chang) orchard. The experimental area covered 150 ha in typical red soil hilly region in southeastern China. The experimental design was a randomized complete block with six combinations of twelve plant species with four replications. All species used were native in the orchard. Plots were 15×8m^2 and separated by 2m buffer strips. Precipitation, soil erosion in rainstorm days and aboveground biomass of plant community when rainstorm days ended, soil temperature and moisture under various plant covers during seasonal megathermal drought period, antiscourability of soil with different root density under various simulated rainfalls were measured. Plant cover significantly decreased the daily highest and mean soil temperature and its daily variation in hot-drought season, but there was no significant difference of the alleviation among various plant covers. Plant covers significantly increased the soil moisture in seasonal megathermal drought period. Better moisture maintenance and soil erosion reduction was found when the plant species numbers in cover plant communities increased from one to eight. Higher root density in plant communities with higher species richness increased significantly the antiscourability of the soil. It was suggested that conserving plant communities with diversified native species could produce the best positive ecological effects on citrus orchard ecosystem stability. 展开更多
关键词 Diversified cover plant Soil erosion Antiscourability Stress alleviation Subtropical area
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The Neglected Significance of Glomerular Density as a 5-year Progression Indicator for IgA Nephropathy 被引量:4
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作者 陈振杰 李航 +8 位作者 蔡建芳 张鑫 李超 邹佩美 李明喜 陈丽萌 李雪梅 李学旺 文煜冰 《Chinese Medical Sciences Journal》 CAS CSCD 2017年第3期145-151,共7页
Objective To investigate whether glomerular density (GD) could be an independent prognostic factor for patients of IgA nephropathy with estimated glomerular filtration rate (eGFR) of 30 to 60 ml/min per 1.73 m2, ... Objective To investigate whether glomerular density (GD) could be an independent prognostic factor for patients of IgA nephropathy with estimated glomerular filtration rate (eGFR) of 30 to 60 ml/min per 1.73 m2, or for patients with time-average proteinuria 〈 0.5 g/d. Methods A total of 173 patients with biopsy-confirmed IgA nephropathy diagnosed from January 2000 to December 2010 were included. All of these patients were followed up for more than 5 years. The endpoint was a 〉 30% of decline in eGFR from baseline after 5-year follow-up. The optimal cut-off value of GD was calculated by ROC curve. Kaplan-Meier method and Cox regression analysis was used for survival analysis. Results A 30% of decline in eGFR occurred in 14.5% of all patients. The optimal diagnostic cut-off value of GD was 1.99/mm2 (AUC = 0.90, sensitivity = 84.0%, specificity = 81.8%) determined by ROC curve. The low GD group (GD 〈 1.99 per mm2) experienced a significant increase in renal endpoint for patients with eGFR of 30 to 60 ml/min per 1.73 m2 (six patients in lower GD group, while one patient in the other group). For patients with time-average proteinuria 〈 0.5 g/d, the lower GD group showed a higher eGFR decline from baseline (4.5±16.7 ml/min per 1.73 m2 vs. –8.1±21.4 ml/min per 1.73 m2, P = 0.038); two patients in this group reached the endpoint, while no patients in the higher GD group did. Conclusion GD could be an independent prognostic factor for patients of IgA nephropathy with eGFR at 30 to 60 ml/min per 1.73 m2 of body surface, particularly for those with time-averaged amount of urine protein less than 0.5 g per day. 展开更多
关键词 glomerular density IgA nephropathy renal progression
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Assessment of South Pacific Albacore Stock (Thunnus alalunga) by Improved Schaefer Model 被引量:12
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作者 Wang Chien-Hsiung Wang Shyh-Bin 《Journal of Ocean University of China》 SCIE CAS 2006年第2期106-114,共9页
Based on catch and effort data of tuna longline fishery operating in the South Pacific Ocean, the South Pacific albacore stock was assessed by an improved Schaefer model. The results revealed that the intrinsic growth... Based on catch and effort data of tuna longline fishery operating in the South Pacific Ocean, the South Pacific albacore stock was assessed by an improved Schaefer model. The results revealed that the intrinsic growth rate was about 1.283 74 and carrying capacities vareied in the range from 73 734 to 266 732 metric tons. The growth ability of this species is remarkable. Stock dynamics mainly depends on environmental conditions. The stock is still in good condition. However, the continuous decreasing of biomass in recent years should be noticed. 展开更多
关键词 improved Schaefer model stock dynamics ALBACORE
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