The anatomic research on the mutant clone of Pinus tabulaeformis Carr. in the seed orchard in Xingcheng, Liaoning Province was carried out. The female cone of the mutant clone looked like normal, but its ovules degene...The anatomic research on the mutant clone of Pinus tabulaeformis Carr. in the seed orchard in Xingcheng, Liaoning Province was carried out. The female cone of the mutant clone looked like normal, but its ovules degenerated in the early stage. This paper tries to find out the reason and time of ovule abortion. It seems that the ovule abortion is probably caused by female sterility because the microspores of this mutant clone were normal. Through the serial observations on the one-year-old macrosporangiates and the ovules of two-year-old female cones of mutant and normal clone, it is found that the reason of ovule abortion in mutant clone is the failure of the mitosis of free nuclei in the female gametophyte, and the time is about in the early April.展开更多
To determine the relationship between female sterility of Pinus tabulaeformis Carr. and plant hormones, content changes of several endogenous plant hormones in a female-sterile clone and a normal clone were analyzed d...To determine the relationship between female sterility of Pinus tabulaeformis Carr. and plant hormones, content changes of several endogenous plant hormones in a female-sterile clone and a normal clone were analyzed during the key period of female gametophyte abortion in mutant clones. The change of ABA content showed a similar pattern between normal and mutant clones, but the ABA content of the mutant clone was always much higher than that of the normal clone. In the normal clone, the IAA content decreased significantly at the early stage of the period and reached its minimum during the first ten days of April and stabilized thereafter. The endogenous ZR levels increased sharply at the early stages and reached a maximum in the middle of April, then decreased dramatically. The IAA and ZR contents of the mutant clone did not change perceptively through the entire period. We conclude that the high levels of ABA and the deficit of IAA and ZR may be the reasons of female gametophyte abortion in the female-sterile clones of P. tabulaeformis.展开更多
In order to understand the structural characteristics of lignin in triploid clones ofPopulus tomentosa and its changes in the processes of pulping and bleaching, milled wood lignin （MWL）, lignin carbohydrate complex...In order to understand the structural characteristics of lignin in triploid clones ofPopulus tomentosa and its changes in the processes of pulping and bleaching, milled wood lignin （MWL）, lignin carbohydrate complex （LCC） and the residual lignin from kraft pulp （KP） and sulfite pulp （SP） were isolated and analyzed by Fourier transform infrared （FTIR） spectrum and ^13C nuclear magnetic resonance （NMR）. The most diagnostic peaks were assigned and the differences were discussed. The spectral patterns reveal that triploid P tomentosa shows the specific features of hardwood from temperate areas, but in the spectrum of FTIR, the strength ratio orAl270 cm^-1 to A1226 cm^-1 is 0.88, higher than the average of hardwood from temperate areas, which will make the lignin delignification more difficult during pulping and bleaching. The LCC from triploid P tomentosa is mainly composed of xyloglucan and glucuronic acid, and other glucides have much lower ratio. In LCC FTIR, there are three peaks at 1 427, 1 329 and 1 046 cm^-1, indicating that both semi-cellulose and cellulose could exist in LCC, and that there might be relationships between cellulose and lignin. Compared with the residual lignin from KP and SP, the condensed structure in KP is more than that in SP.展开更多
The fiber morphology variation of triploid clone of Populus tomentosa Carr. and the supposed harvesting age for the paper industry were investigated in this paper. The results shows that in the first few years, 2-4 ye...The fiber morphology variation of triploid clone of Populus tomentosa Carr. and the supposed harvesting age for the paper industry were investigated in this paper. The results shows that in the first few years, 2-4 years for example, the fiber length at breast high grows faster than it does in the later years. But the standard deviation of distribution in fiber length at breast high in mature wood is larger than in the young tree. The technologically harvestable age of triploid clone of Populus tomentosa Carr., BL304 could be 4-7 year old to meet the requirement for paper industry. The distribution of fiber length become concentrated within an annual ring as the tree grows. The test results also show that the cloned poplar has a small Runkel ratio value (less than 0.4, generally about 0.3), and this ratio increases slightly with the tree grows.展开更多
针对中国先进研究堆(CARR)的具体结构和运行特点,利用Fortran程序设计语言开发了CARR热工水力安全分析程序TSACC(Thermal-hydraulic and Safety Analysis Code for CARR)。TSACC完全采用模块化结构设计,便于二次开发,可应用于多种事故...针对中国先进研究堆(CARR)的具体结构和运行特点,利用Fortran程序设计语言开发了CARR热工水力安全分析程序TSACC(Thermal-hydraulic and Safety Analysis Code for CARR)。TSACC完全采用模块化结构设计,便于二次开发,可应用于多种事故工况及其他堆型的分析计算。基于程序验证的基本思想,分别利用TSACC和商用程序RELAP5/Mod3对CARR丧失厂外电源事故工况进行了计算。得到了堆芯平均通道以及最热通道内冷却剂流量、温度和最小偏离泡核沸腾比(MDNBR)等参数的瞬态响应。将TSACC计算结果与RELAP5/Mod3计算结果进行比较、分析后发现:除冷却剂发生倒流前后二者计算结果相差较大外,总体吻合较好。局部值差别较大的主要原因是两个程序在低流速区域选用的换热公式不同。程序验证结果表明了TSACC的准确性和适用性。展开更多
中子散射技术利用中子不带电、穿透力极强、能直接鉴别核素、较之 X 射线对轻元素灵敏、具有磁矩和粒子、波动二重性等特点,使之成为一种独特的、从原子和分子尺度上研究各种物质结构和微观世界运动规律的高新技术。中国先进研究堆 (CA...中子散射技术利用中子不带电、穿透力极强、能直接鉴别核素、较之 X 射线对轻元素灵敏、具有磁矩和粒子、波动二重性等特点,使之成为一种独特的、从原子和分子尺度上研究各种物质结构和微观世界运动规律的高新技术。中国先进研究堆 (CARR)上的中子散射工程将充分利用中国先进研究堆为中子散射工程提供的高通量、具有冷中子源、切向水平孔道等有利条件,建造三台新谱仪,更新原有的五台谱仪,瞄准世界先进水平,建立起研究手段基本配套、基本上覆盖中子散射研究的主要领域、强调应用又具备必要的基础研究能力的中子散射设备,为生命科学、材料科学、物理、化学、地矿、环境等各种学科及工程技术方面的研究,为国防工业和国民经济的应用提供先进的中子散射技术。其最终目标是建立起符合我国国情、其综合研究能力与世界先进水平接轨的中子散射国家重点实验室,使之成为我国二十一世纪中子散射研究和应用的中心及人才培养基地。展开更多
基金National Natural Science Foundation of China(Grant No.39970602)
文摘The anatomic research on the mutant clone of Pinus tabulaeformis Carr. in the seed orchard in Xingcheng, Liaoning Province was carried out. The female cone of the mutant clone looked like normal, but its ovules degenerated in the early stage. This paper tries to find out the reason and time of ovule abortion. It seems that the ovule abortion is probably caused by female sterility because the microspores of this mutant clone were normal. Through the serial observations on the one-year-old macrosporangiates and the ovules of two-year-old female cones of mutant and normal clone, it is found that the reason of ovule abortion in mutant clone is the failure of the mitosis of free nuclei in the female gametophyte, and the time is about in the early April.
基金Supported by the National Natural Science Foundation of China (Grant No. 30371144) and Postgraduate Foundation of Beijing Forestry University
文摘To determine the relationship between female sterility of Pinus tabulaeformis Carr. and plant hormones, content changes of several endogenous plant hormones in a female-sterile clone and a normal clone were analyzed during the key period of female gametophyte abortion in mutant clones. The change of ABA content showed a similar pattern between normal and mutant clones, but the ABA content of the mutant clone was always much higher than that of the normal clone. In the normal clone, the IAA content decreased significantly at the early stage of the period and reached its minimum during the first ten days of April and stabilized thereafter. The endogenous ZR levels increased sharply at the early stages and reached a maximum in the middle of April, then decreased dramatically. The IAA and ZR contents of the mutant clone did not change perceptively through the entire period. We conclude that the high levels of ABA and the deficit of IAA and ZR may be the reasons of female gametophyte abortion in the female-sterile clones of P. tabulaeformis.
文摘In order to understand the structural characteristics of lignin in triploid clones ofPopulus tomentosa and its changes in the processes of pulping and bleaching, milled wood lignin （MWL）, lignin carbohydrate complex （LCC） and the residual lignin from kraft pulp （KP） and sulfite pulp （SP） were isolated and analyzed by Fourier transform infrared （FTIR） spectrum and ^13C nuclear magnetic resonance （NMR）. The most diagnostic peaks were assigned and the differences were discussed. The spectral patterns reveal that triploid P tomentosa shows the specific features of hardwood from temperate areas, but in the spectrum of FTIR, the strength ratio orAl270 cm^-1 to A1226 cm^-1 is 0.88, higher than the average of hardwood from temperate areas, which will make the lignin delignification more difficult during pulping and bleaching. The LCC from triploid P tomentosa is mainly composed of xyloglucan and glucuronic acid, and other glucides have much lower ratio. In LCC FTIR, there are three peaks at 1 427, 1 329 and 1 046 cm^-1, indicating that both semi-cellulose and cellulose could exist in LCC, and that there might be relationships between cellulose and lignin. Compared with the residual lignin from KP and SP, the condensed structure in KP is more than that in SP.
文摘The fiber morphology variation of triploid clone of Populus tomentosa Carr. and the supposed harvesting age for the paper industry were investigated in this paper. The results shows that in the first few years, 2-4 years for example, the fiber length at breast high grows faster than it does in the later years. But the standard deviation of distribution in fiber length at breast high in mature wood is larger than in the young tree. The technologically harvestable age of triploid clone of Populus tomentosa Carr., BL304 could be 4-7 year old to meet the requirement for paper industry. The distribution of fiber length become concentrated within an annual ring as the tree grows. The test results also show that the cloned poplar has a small Runkel ratio value (less than 0.4, generally about 0.3), and this ratio increases slightly with the tree grows.
文摘针对中国先进研究堆(CARR)的具体结构和运行特点,利用Fortran程序设计语言开发了CARR热工水力安全分析程序TSACC(Thermal-hydraulic and Safety Analysis Code for CARR)。TSACC完全采用模块化结构设计,便于二次开发,可应用于多种事故工况及其他堆型的分析计算。基于程序验证的基本思想,分别利用TSACC和商用程序RELAP5/Mod3对CARR丧失厂外电源事故工况进行了计算。得到了堆芯平均通道以及最热通道内冷却剂流量、温度和最小偏离泡核沸腾比(MDNBR)等参数的瞬态响应。将TSACC计算结果与RELAP5/Mod3计算结果进行比较、分析后发现:除冷却剂发生倒流前后二者计算结果相差较大外,总体吻合较好。局部值差别较大的主要原因是两个程序在低流速区域选用的换热公式不同。程序验证结果表明了TSACC的准确性和适用性。
文摘中子散射技术利用中子不带电、穿透力极强、能直接鉴别核素、较之 X 射线对轻元素灵敏、具有磁矩和粒子、波动二重性等特点,使之成为一种独特的、从原子和分子尺度上研究各种物质结构和微观世界运动规律的高新技术。中国先进研究堆 (CARR)上的中子散射工程将充分利用中国先进研究堆为中子散射工程提供的高通量、具有冷中子源、切向水平孔道等有利条件,建造三台新谱仪,更新原有的五台谱仪,瞄准世界先进水平,建立起研究手段基本配套、基本上覆盖中子散射研究的主要领域、强调应用又具备必要的基础研究能力的中子散射设备,为生命科学、材料科学、物理、化学、地矿、环境等各种学科及工程技术方面的研究,为国防工业和国民经济的应用提供先进的中子散射技术。其最终目标是建立起符合我国国情、其综合研究能力与世界先进水平接轨的中子散射国家重点实验室,使之成为我国二十一世纪中子散射研究和应用的中心及人才培养基地。
