低能离子束的研究进展

低能离子束能精确控制生物体入射深度和部位,与物质作用时不同参数可以根据需要进行组合,可获多种不同需求的新品种。该文简要阐述了离子束在诱变育种、介导转基因、磁性研究以及碳纳米管的除杂方面的研究现状及其发展前景,以为低能离子束的进一步研究和应用提供参考。     

Research Status Quo and Future of Low Temperature Wheat Genotypes

Low temperature wheat genotypes are a group of wheat with a slightly low canopy （plant） temperature, and the research on their biological characters and utilization in wheat breeding has been done at home and abroad for more than 20 years, and has made great progress. The research contents and advances include the following respects： Wheat genotypes with slightly low canopy temperature have been verified to exist in nature; these wheat genotypes, which present cold temperature, are superior to conventional wheat materials in some important biological characters and particularly prominently in metabolic function and cellular structure; when they suffer stresses such as drought, high temperature and overcast and rainy weather, they still retain their superiority in some of their important biological characters and therefore have a wide range of ecological adaptability; slightly low canopy temperatures of these genotypes are closely correlated with low temperatures of their second heat sources and their vigorous plants; since their low canopy temperatures can be inherited, they can exert favorable influence on the temperatures of their offspring while crossing with other wheat materials, and in particular, the discovery of cold-source wheat as a contributor to low temperature, has further formed good conditions for breeding high and stable quality low temperature wheat varieties with a high and stable yield. Thus, low temperature wheat genotypes are of great research importance and have great prospects.     

Hydrogen: Its Future Role in the Nation's Energy Economy

In examining the potential role of hydrogen in the energy economy of the future, we take an optimistic view. All the technology required for implementation is feasible but a great deal of development and refinement is necessary. A pessimistic approach would obviously discourage further thinking about an important and perhaps the most reasonable alternative for the future. We have considered a limited number of alternative energy systems involving hydrogen and have shown that hydrogen could be a viable secondary source of energy derived from nuclear power; for the immediate future, hydrogen could be derived from coal. A hydrogen supply system could have greater flexibility and be competitive with a more conventional all-electric delivery system. Technological improvements could make hydrogen as an energy source an economic reality. The systems examined in this article show how hydrogen can serve as a general-purpose fuel for residential and automotive applications. Aside from being a source of heat and motive power, hydrogen could also supply the electrical needs of the household via fuel cells (19), turbines, or conventional "total energy systems." The total cost of energy to a residence supplied with hydrogen fuel depends on the ratio of the requirements for direct fuel use to the requirements for electrical use. A greater direct use of hydrogen as a fuel without conversion to electricity reduces the overall cost of energy supplied to the household because of the greater expense of electrical transmission and distribution. Hydrogen fuel is especially attractive for use in domestic residential applications where the bulk of the energy requirement is for thermal energy. Although a considerable amount of research is required before any hydrogen energy delivery system can be implemented, the necessary developments are within the capability of present-day technology and the system could be made attractive economically .Techniques for producing hydrogen from water by electrolysis, from coal, and directly from thermal energy could be found that are less expensive than those now available; inexpensive fuel cells could be developed, and high-temperature turbines could be used for the efficient conversion of hydrogen (and oxygen) to electricity. The use of hydrogen as an automotive fuel would be a key factor in the development of a hydrogen energy economy, and safe storage techniques for carrying sufficient quantities of hydrogen in automotive systems can certainly be developed. The use of hydrogen in automobiles would significantly reduce urban pollution because the dispersed fossil fuel emissions would be replaced by radioactive wastes generated at large central stations. The conversion of internal or external combustion engines for combustion of hydrogen fuel would probably have less economic impact on the automotive industry than the mass introduction of electric automobiles. However, this is a subject that requires more detailed study. All of the safety aspects of hydrogen utilization will have to be examined, especially the problems of safety in the domestic use and the long distance transport of hydrogen in pipelines at high pressures. It is our opinion that the various energy planning agencies should now begin to outline the mode of implementing hydrogen energy delivery systems in the energy economy. The initial transition to hydrogen energy derived from available fossil fuels such as coal should be considered together with the long range view of all the hydrogen being derived eventually from nuclear energy. By the year 1985 when petroleum imports may be in excess of the domestic supply, these plans could set the stage for the transition period from fossil to a predominantly nuclear energy economy able to supply abundant synthetic fuels such as hydrogen. Synthetic fuels will obviously be more expensive than fuels now derived from petroleum; however, there may be no other viable choice. Thus, it is essential that the analysis and technological feasibility of a hydrogen energy system be considered now. It is of vital importance to the nation to develop some general-purpose fuel that can be Produced from a variety of domestic energy sources and reduce our dependence on imported oil.     

低能离子束介导外源基因进入水稻细胞的研究

用离子束介导法将编码β－葡萄糖苷酸酶的ｇｕｅ基因引入受体植物细胞,并实现瞬间表达。水稻悬浮细胞经离子束辐照后,电镜下能观察到细胞表面留下的溅射和刻蚀痕迹,细胞存活率随辐照剂量的增加而显著降低。将离子束（３０ｋｅＶ,２×ｌ０１５Ｎ＋／ｃｍ２）处理后的水稻悬浮细胞,浸入含有ｇｕｓ基因外源ＤＮＡ的ＳＳＣ温育介质,两天后,观察到受离子束直接作用的细胞团的一面有外源ｇｕｓ基因的导入和表达。ｇｕｓ基因瞬间表达的最佳处理剂量悬浮细胞为２×ｌ０１５Ｎ＋／ｃｍ２,成熟胚为２０×ｌ０１５Ｎ＋／ｃｍ２,而且３０ｋｅＶ能量的离子束处理明显较２０ｋｅＶ优越。ＳＳＣ缓冲导入介质最为理想,而添加ＤＭＳＯ（一种细胞促渗透剂）的ＳＳＣ和富含ｃａ２＋的ｋｒｅｎ’ｓＦ溶液（ｃａ２＋对促进质膜稳定性有好处）对离子束介导外源基因进入水稻细胞均不理想。     

低能离子束诱变机理研究进展

自发现离子束生物效应以来,离子注入技术已被应用于生物改良、环境辐射生物学效应等研究领域。其中,在植物遗传育种、创造新种质资源方面的成果非常突出。但是,由于低能离子的能量低,理论射程很短,关于低能离子生物效应和诱变的机理尚不完全清楚。该研究重点综述了离子束生物技术在机理研究方面取得的成果,并对今后的研究趋势进行了展望。     

水稻耐低磷胁迫研究现状及未来发展方向

缺磷是农业生产中限制水稻产量的一个重要因子。通过对磷在土壤中的存在形式及利用效率、水稻品种耐低磷胁迫特性、耐低磷胁迫水稻品种的筛选和鉴定以及耐低磷性状的分子标记、遗传转化、基因克隆等方面进行了综述,并对今后水稻低磷胁迫的研究方向作出预测,为水稻耐低磷及磷高效水稻品种的选育提供一定的理论依据。     

低能离子注入对仙客来幼苗生长发育的影响

以仙客来种子为材料,研究了不同剂量的N＋注入对仙客来种子发芽势、发芽率、成苗率的影响。结果表明：随着N＋注入剂量的增加发芽势和发芽率的变化趋势为先降低后升高再降低,表现为＂马鞍型＂曲线,成苗率在低剂量时与发芽率相接近,在高剂量时成苗率明显降低。     

低能离子束辐照番茄种子的初步研究

研究表明,低能离子束辐照番茄干种子,对番茄农艺学性状有一定影响。在M_0N~+处理发芽率随着剂量升高(能量不变)有所下降,但不明显,出苗时间随剂量增加逐渐推迟1～2d,但Ar~+处理株高多数比对照增高,长势比对照强,果形、果面有变异。不同低能离子束处理得到结果不太一致。M_1叶形、果形有明显变异。     

玉米低能离子束辐照诱变研究

在概述低能离子束辐照诱变研究进展的基础上,提出了低能离子束诱变研究存在的3大困难,着重介绍了玉米作为低能离子束辐照诱变研究材料的优势,报道了玉米花粉离子束辐照诱变的初步研究结果。     

低能离子束生物工程研究现状和展望

低能离子束生物工程在6个方面的研究结果引人瞩目。随着学科的不断发展,迫切需要建立一个更加完善的物理学技术平台,急待形成一个更加完整的研究体系,有必要借助于其他学科的新技术或新工艺形成一个相互补充的技术集成体系,更应该将离子束生物技术的实用性和普遍性的范围不断地拓宽。明确提出了低能离子束生物工程的技术思路,即立足于低能离子束这一物理学技术平台,瞄准学科发展的2个方向,促进研究内容的3个有效转变,分清和综合研究水平的4个层次,注重研究五大生物学特性。     

阻抗匹配平衡变压器低压电能的测量

According to the law for the current and voltage variance of the twophase system of the impedance matching balance transformer''s low equipment,we introduce the measuring method of real and reactive electric energy. A deep analysis for the error arising in     

小麦种子注入低能氮离子束的诱变效应

为促进优质小麦育种技术体系建设,提升小麦品质,应用低能氮离子束注入技术,对小麦种子注入剂量为3×1017N+/cm2的氮离子,研究注入氮离子束对小麦种子活力、幼苗POD和CAT活性以及植株农艺形状的影响。结果表明：与未注入氮离子束处理相比,注入氮离子束的小麦种子发芽势和出苗率显著降低（P＜0.05）,发芽率、幼苗鲜重和苗长降低,幼苗POD、CAT活性增大;注入氮离子束的小麦植株形态变化明显,顶一叶长度突变,株高变矮,麦穗从有芒变为部分缺芒和无芒,千粒重增加。低能氮离子束注入小麦种子对小麦幼苗、植株及穗粒形态有明显的生物学效应,对小麦种质材料的改良具有一定作用。     

低能离子束注入在小麦育种中的应用探析

常规育种在近年来取得了很大的成果,但同时也使小麦品种出现一定的同质化现象。离子束注入生物体后能够打破基因连锁,从而使小麦育种材料的遗传背景多样化。本文概括了离子束诱变育种方法及在小麦育种上的应用研究进展,并对存在的问题及应用前景进行阐述。     

基于能源消费的湖南省低碳经济发展研究

运用碳排放公式估算2008～2010年湖南省煤、石油、电能三种主要能源的碳排放量,根据估算结果对湖南省能源消费状况和产业结构进行分析,将其与中部五省GDP能耗相比较,得出湖南省GDP能耗偏高的结果。依据湖南省低碳经济发展的基础,从优化能源结构和产业体系两个方面来研究湖南省低碳经济的发展。     

太阳能低温相变蓄热装置的设计与应用

太阳能采暖具有间歇性,易受天气等影响,是制约其普及的一个重要因素。将太阳能与低温相变蓄热装置相结合,在日光充足时利用太阳能采暖并蓄热,在夜间或光照不足时释放热量供给温室采暖,有助于提高系统的稳定性和太阳能的利用率,并提高太阳能采暖系统的灵活性,为冬季温室采暖节省成本。结合试验温室基本情况,经过初步计算,设计出适合的太阳能集热系统及与其联用的低温相变蓄热装置,以期为冬季温室采暖提供新思路,降低农户运行费用,为温室的管理及植物的生长提供必要的条件,同时减少环境污染,为太阳能集热系统相变蓄热装置的设计优化及应用提供参考。     

水稻miRNA应答低能N^＋束辐照的基因芯片分析

[目的]探讨水稻应答N^＋束辐照机制中相关miRNA的表达差异。[方法]各选取3组N^＋束辐照处理水稻种子和未处理的水稻种子,提取其在30℃发芽96h幼苗总RNA,采用Agilent单通道水稻基因表达谱芯片筛选2组水稻幼苗差异表达基因。芯片中含有miRNA探针510个,分析其在样品间表达差异2倍左右作为域值范围。[结果]辐照组与对照组相比表达差异显著的miRNA分子有14个,且均为下调。[结论]水稻N^＋束辐照组和对照组中存在差异表达的miRNA分子,可能调控某些基因的表达来应答离子辐照,从而表现出与对照不一样的生理生化和表型差异。     

水稻miRNA应答低能N+束辐照的基因芯片分析

[目的]探讨水稻应答N＋束辐照机制中相关miRNA的表达差异。[方法]各选取3组N＋束辐照处理水稻种子和未处理的水稻种子,提取其在30℃发芽96 h幼苗总RNA,采用Agilent单通道水稻基因表达谱芯片筛选2组水稻幼苗差异表达基因。芯片中含有miRNA探针510个,分析其在样品间表达差异2倍左右作为域值范围。[结果]辐照组与对照组相比表达差异显著的miRNA分子有14个,且均为下调。[结论]水稻N＋束辐照组和对照组中存在差异表达的miRNA分子,可能调控某些基因的表达来应答离子辐照,从而表现出与对照不一样的生理生化和表型差异。     

低能离子注入诱变选育盐霉素高产菌株

[目的]研究N+离子注入对白色链霉菌的诱变效应,同时筛选高产盐霉素的变异菌株。[方法]利用不同剂量的氮离子对白色链霉菌S-11-04菌株进行诱变处理,研究低能氮离子注入对其存活率、菌落形状及产盐霉素能力的影响。[结果]低能氮离子注入对白色链霉菌的诱变效应显著,试验得到了13株盐霉素产量较高的突变菌株,其中N3-6菌株经连续传代4次,遗传稳定性较好,其摇瓶发酵水平较对照提高了41%,发酵生产后平均发酵水平提高了20.5%。[结论]离子注入诱变是获得高产盐霉素突变菌株的有效方法。