利用宇宙成因核素¹⁰Be,²⁶Al估算流域侵蚀速率的原理与应用     

胡二伢  李颍  赵志军 《水土保持通报》2011,31(3):103-107

地表侵蚀是地貌演化的外营力。定量估算地表侵蚀速率,探讨其与构造活动,气候变化的响应和反馈是地学研究的重要课题之一。利用河流阶地沉积物或盆地沉积物宇宙成因核素（10Be and26Al）可获取流域万年尺度平均侵蚀速率时间序列,弥补了热年代学获得的百万年平均剥露速率和水文观测获得的年代级侵蚀速率之间的环节。地表及其附近岩石中的矿物的原子核受到来自外层宇宙空间的高能宇宙射线粒子的轰击,发生核反应而产生放射性核素,然后被快速埋藏,不再接受宇宙射线辐射。总体上,它们在地表的暴露时间短暂,宇生核素含量低,埋藏后宇生放射性核素随时间流逝而衰减。利用10Be和26Al估算流域古侵蚀速率基于此原理,通过测试河流沉积物或盆地沉积物的年代,结合10Be浓度,进而估算流域的平均侵蚀速率。应用宇生核素方法研究流域侵蚀速率,具有采样简便,精确度高,应用范围广等优势,可以反映更大时间尺度和更广空间尺度上的侵蚀速率变化情况,利用10Be和26Al等核素方法对第四纪至全新世的地表演化进行研究正成为一种重要的研究方法。  相似文献   

植酸酶根特异表达载体的构建及大豆转化   总被引：1，自引：0，他引：1  

李桂兰  乔亚科  李明刚  崔姗姗  乔潇  乔坤艳 《核农学报》2011,25(5):892-897

应用PCR方法分别从胡萝卜基因组中扩增出96bp的外展蛋白信号肽编码序列片段,从拟南芥基因组中扩增出1454bp的pyk10启动子片段,用RT-PCR方法从无花果曲霉（Aspergillus ficuum3.4322）中扩增出phyA基因,长1347bp。然后,分别克隆到pMD18-T载体。应用已设计的限制酶切位点,通...  相似文献   

Soil CO₂ efflux vs. soil respiration: Implications for flux models     

M. Maier  H. Schack-KirchnerE.E. Hildebrand  D. Schindler 《Agricultural and Forest Meteorology》2011,151(12):1723-1730

In the long term, all CO₂ produced in the soil must be emitted by the surface and soil CO₂ efflux (FCO₂) must correspond to soil respiration (R_soil). In the short term, however, the efflux can deviate from the instantaneous soil respiration, if the amount of CO₂ stored in the soil pore-space (SCO₂) is changing. We measured FCO₂ continuously for one year using an automated chamber system. Simultaneously, vertical soil profiles of CO₂ concentration, moisture, and temperature were measured in order to assess the changes in the amount of CO₂ stored in the soil. R_soil was calculated as the sum of the rate of change of the CO₂ storage over time and FCO₂. The experiment was split into a warm and a cold season. The dependency of soil respiration and soil efflux on soil temperature and on soil moisture was analyzed separately. Only the moisture-driven model of the warm season was significantly different for FCO₂ and R_soil. At our site, a moisture-driven soil-respiration model derived from CO₂ efflux data would underestimate the importance of soil moisture. This effect can be attributed to a temporary storage of CO₂ in the soil pore-space after rainfalls where up to 40% of the respired CO₂ were stored.  相似文献   

希拉穆仁围封草原土壤呼吸通量研究   总被引：3，自引：2，他引：1  

高天明  张瑞强  梁占岐  刘铁军  郭建英  郝瑞 《草业科学》2011,28(1):33-38

利用ACE土壤呼吸作用自动测定仪对希拉穆仁草原围封6年的克氏针茅(Stipa krylovii)群落从4月末至10月初每隔10 d进行土壤呼吸作用日动态监测,并结合土壤温度和水分状况分析其复合相关关系.结果表明,1)生长季内土壤呼吸日动态均呈单峰曲线,最高值出现在中午12:00-14:00,夜间土壤呼吸速率很低,最低值...  相似文献   

印度芥菜BjJ10-2基因原核表达载体构建及抗盐功能的鉴定     

杨学举  郎明林  郝梦雨 《核农学报》2011,25(2):247-252

利用RT-PCR技术克隆了印度芥菜核糖体相关膜蛋白RAMP4家族成员BjJ10-2基因的开放读码框,成功构建了pET32a-BjJ10-2原核表达栽体,通过热激法将其转化到原核表达菌株BL21(DE3)plysS中,得到重组大肠杆菌BL21(pET32a-BjJ10-2).SDS-PAGE凝胶电泳检测到在IPTG诱导下...  相似文献   

Si4432无线芯片在普适农业系统中的应用     

赵虎  王三根  王纪元 《农机化研究》2011,33(2)

为了解决无线模块发射距离近、穿透能力差的问题,将Si4432模块应用于普适农业系统[1],实现了较大范围农田的温湿度远程监测.该系统由控制中心和传感器节点组成,每个节点包括PIC16F877A单片机、Si4432无线模块和SHT10温湿度传感器,控制中心负责接收、显示、存储和发送温湿度信息.实验证明,该系统可以达到较远的通信距离和较强的穿墙能力,并且通信误码率低,具有很好的推广前景.  相似文献   

鹌鹑β-防御素10基因的克隆与表达及其体内分布的检测   总被引：1，自引：0，他引：1  

蔺利娟  王瑞琴  韩宗玺  邵昱昊  刘胜旺  程宝晶  孙黎  李子瑞  马得莹 《中国预防兽医学报》2011,33(7)

为测定鹌鹑β-防御素10 (AvBD10)体外抗菌活性及检测其在鹌鹑脏器组织的分布,本研究应用RT-PCR方法从鹌鹑肺脏组织中扩增到鹌鹑AvBD10,经序列同源性分析,鹌鹑AvBD10与鸡AvBD10的氨基酸序列同源性最高(83.8％).将该基因亚克隆到表达载体pGEX-6p-1中进行原核表达,SDS-PAGE电泳表明,鹌鹑AvBD10重组蛋白分子量约为31ku.该重组蛋白经纯化后测定其体外抗菌活性,结果显示,鹌鹑AvBD10重组蛋白具有广谱的抗菌活性.采用定量RT-PCR法检测到AvBD10在鹌鹑脏器组织中广泛表达.  相似文献   

Hydraulic characteristics of composted pig manure,perlite, and mixtures of them,and their impact on cucumber grown on bags     

Ola Al Naddaf  Ioannis Livieratos  Aristides Stamatakis  Ioannis Tsirogiannis  George Gizas  Dimitrios Savvas 《Scientia Horticulturae》2011

Composted pig manure (CPM), unmixed or in mixture with perlite, was evaluated as growing medium based on both physical characteristics and agronomic performance. The physical properties were determined in CPM, perlite (0.5–2.5 mm), and their 75:25, 50:50 and 25:75 mixtures by volume. It was found that unmixed CPM has a higher bulk density (BD) than perlite, a slightly lower air space at a suction of 10 cm, and a markedly higher content in easily available water (EAW), although the water content at a suction of 10 cm is the same in the two media. Mixing CPM with perlite by 50:50 seems to increase the actual water content and decrease the actual air content at container capacity, while the BD and the EAW score intermediate to those in the unmixed constituents. Simulation of the relative hydraulic conductivity (K_r) indicates a sharp decrease in the unsaturated hydraulic conductivity (K) of CPM, perlite and their mixtures as the media suction increases. The differences in the decrease rate of K_r between the tested substrates are rather small, with the most and least steep decrease being observed in perlite and the mixture by 50:50, respectively. The agronomic performance of CPM was assessed by growing greenhouse cucumber in bags filled with perlite up to 20 cm in height, CPM up to 10 or 20 cm in height, and their mixture by 50:50 up to the same heights as CPM. A media height of 10 cm in the bag resulted in appreciably higher yields than a height of 20 cm, regardless of the type of the substrate, while the latter had no significant effect on yield. This effect of media height was ascribed to the steep decrease in K, which was minimized in all media at higher suction levels than 10 cm, thereby severely restricting water availability in their upper layers (10–20 cm) when their height in the bag was 20 cm.  相似文献   

早熟番茄新品种郑番06-10的选育     

应芳卿  黄文  黄晓燕  李武高 《中国蔬菜》2011,1(4):78-80

郑番06-10是以04商引常规-1-混-混为母本,以05早粉父本-混为父本配制的自封顶番茄一代杂种。幼果微具青果肩,成熟果亮粉红色,近圆形,平均单果质量153 g;田间表现对叶霉病、病毒病抗性与中杂9号相当;畸形果和裂果率为2.22 %,抗裂果;果实硬,耐贮运,整齐度高。可溶性固形物含量4.8 %,果肉VC含量294 mg?kg-1,总酸含量0.42 %,可溶性总糖含量2.58 %,品质佳。综合性状表现优良。产量6 400 kg?（667 m2）-1。适合河南、河北、陕西等地早春温室、拱棚、春露地及高山越夏种植。  相似文献   

Plant pararetroviral sequences in wild Dahlia species in their natural habitats in Mexican mountain ranges     

S. Eid  D. E. Saar  K. L. Druffel  H. R. Pappu 《Plant pathology》2011,60(2):378-383

Selected wild Dahlia species in their natural habitats from west‐central Mexico were tested for the presence of three caulimoviruses known to be associated with cultivated dahlia (Dahlia variabilis), viz. Dahlia mosaic virus (DMV), DMV‐D10 and Dahlia common mosaic virus. Virus species‐specific primers and PCR were used followed by cloning and sequencing of the amplicons. Results showed that the wild dahlia species in their natural habitat contained DMV‐D10, which is an endogenous plant pararetrovirus. Viral sequences were found in 91% of the samples (n = 56) representing four different wild species. The gene coding for the movement protein of DMV‐D10 from Dahlia coccinea and all other species was cloned and sequenced. Sequence comparisons showed divergence of this gene when compared to that of DMV‐D10 from cultivated dahlias. The discovery of plant pararetroviruses in wild dahlia species in their natural habitats suggests a possible emergence, co‐existence and co‐evolution of pararetroviruses and their host plants.  相似文献