The possible response of life zones in China under global climate change

The response of natural vegetation to climate change is of global concern. In this research, an aggregated Holdridge Life Zone System was used to study the possible response of life zones in China under doubled atmospheric CO₂ concentration with the input climatic parameters at 0.5×0.5° resolution of longitude and latitude from NCAR regional climate model 2 (RegCM2) coupled with the CSIRO global climate model. The results indicate that the latitudinal distribution of life zones would become irregular because of the complicated climate change. In particular, new life zones, such as subtropical desert (SD), tropical desert (TDE) and tropical thorn woodland (TTW), would appear. Subtropical evergreen broadleaved forest (SEBF), tropical rainforest and monsoon forest (TRF), SD, TDE and TTW zones would appear in the northeastern China. Cool-temperate mixed coniferous and broadleaved forest (CMC) and warm-temperate deciduous broadleaved forest (WDBF) zones would appear at latitudes 25–35°N. The temperate desert (TD) in the western China would become Tibetan high-cold plateau (THP), SEBF, WDBF and temperate steppe (TS), and a large part of THP would be replaced by TRF, TDE, SEBF, TS and TTW. The relative area (distribution area/total terrestrial area) of CMC, TRF, TDE and TTW zone would increase about 3%, 21%, 3% and 6%, respectively. However, the relative area of SEBF, TS, TD and THP would decrease about 5%, 3%, 19% and 4%, respectively. In all, the relative area of forests (CCF, CMC, WDBF, SEBF, TRF) would increase about 15%, but the relative area of desert (TD, SD, TDE, and TTW) and THP would decrease about 9% and 4%, respectively. Therefore, responses of different life zones in China to climate change would be dramatic, and nationwide corridors should be considered for the conservation of migrating species under climate change.     

Expression of the Phycoerythrin Gene of Gracilaria lemaneiformis (Rhodophyta) in E. coli and Evaluation of the Bioactivity of Recombinant PE

Phycoerythrin (PE) is one of the most important proteins involved in light capturing during photosynthesis in red algae. Its potential biological activities had gained wide concerns. In the present study, tumor cytotoxic and hydroxyl radical assay were preformed to detect the bioactivity of recombinant PE. Recombinant plasmids pGEX-PE and pBGL were transformed into E.coli BL21 to make two recombinant strains BEX (pGEX-PE) and BGL (pBGL). PE expressing in BEX (pGEX-PE) was validated by SDS-PAGE and Western blotting analysis. SDS-PAGE analysis indicated that the PE-GST fusion protein was mostly inclusion bod- ies. Specific expression of PE was confirmed by Western blotting analysis. The recombinant E. coli BEX (pGEX-PE) cells were col- lected and sonicated. The supernatants were reserved for the tumor cytotoxic experiments. The result of tumor cytotoxic assay indi- cated that the supernatants containing PE had the activity of inhibiting the growth of Hela cells and with the increase of protein con- centration, the inhibiting rate increased from 37.31% to 63.26%, which showed significant difference from the control. Hydroxyl radical scavenging effect was tested with supernatants of BEX (pGEX-PE) and BGL (pBGL) cell lysates treated with sonication and heating. For the sonication samples, the scavenging rates of the supernatants of BEX (pGEX-PE) and BGL (pBGL) cell lysates were significantly higher than the negative control BL21(pGEX-4T) (P<0.02), and the scavenging rates increased slowly following the increase of the protein content. For the heating samples, except for the 0.2 mg mL-1 BGL (pBGL) products, the scavenging effects of the supernatants of BEX (pGEX-PE) and BGL (pBGL) cell lysates were stronger than that of negative control BL21(pGEX-4T). However, the effect intensity was not positively correlated with the increase of the protein concentration. Though a partially de- creased hydroxyl radical scavenging activity was led by heating, the biological activity was still retained and conspicuous. This re- search showed that phycoerythrin protein expressing in E. coli has the potential medical and sanitarian value.     

不同培养方式及换水频率对坛紫菜(Porphyra haitanensis)自由丝状体生长及藻胆蛋白含量的影响

本实验以坛紫菜自由丝状体为材料,研究不同培养方式(静置、摇床、通气)和换水频率(5d、7d、10d、20d)对丝状体生长及藻胆蛋白(PE、PC)含量变化的影响。研究结果表明:坛紫菜自由丝状体在摇床培养条件下生长较好,特定生长速率可达10.832 7%~10.891 5%;摇床培养下的丝状体PE含量相对静置培养的较高一些,通气培养的相对较低,最高为36.816 8mg/g;静置条件下培养的丝状体PC含量最高,摇床培养次之,通气培养最低,最低为1.082 4mg/g。相同培养方式下,换水频率对丝状体特定生长速率影响不大;除通气培养外,换水频率20d其PE、PC含量较高。方差分析结果表明:实验范围内的培养方式及换水频率对丝状体特定生长速率大小、PE和PC含量不存在交互作用。本文实验结果对坛紫菜自由丝状体产业化应用于食品加工、色素提取等产业提供了实验理论和依据。     

近40年甘南草原生命地带偏移趋势及干湿变化

利用Holdridge生命地带系统对1971—2010年甘南草原的Holdridge生命地带偏移趋势及干湿变化进行分析,发现甘南草原目前仍属于青藏高原高寒植被地区的亚高山高寒草甸生命地带,但由于甘南草原生物温度明显升高,甘南草原南部和北部降水量呈现不同的变化趋势,位于青藏高原边坡地带的甘南草原的Holdridge生命地带距平均中心的偏移趋势逐年增大,甘南草原生态系统的稳定性在减弱;甘南草原潜在蒸散率以0.02/10 a~0.03/10 a趋势上升,其中以玛曲上升最明显,达0.03/10 a;20世纪90年代后,甘南草原呈明显的暖干化趋势,其中以位于南部的碌曲、玛曲变化最为明显,碌曲已由极湿润区转变为湿润区;玛曲有从极湿润区向湿润区过渡的趋势。影响甘南草原潜在蒸散率上升的主要气候因子是温度,其次为降水和空气湿度,温度上升是甘南草原暖干化的主要原因。     

双源CT诊断兔急性肺栓塞实验研究

目的:应用双源CT探讨新西兰兔耳缘静脉注入明胶海绵制造急性肺动脉栓塞(PE)模型的可行性。方法:新西兰兔24只随机分为实验组(n=22只,按栓塞后检查时间分为2h、1d、3d和7d组)与对照组(n=2只)。实验组22只采用经耳缘静脉快速注射明胶海绵栓子制成急性PE模型,栓塞前后均行CTPA及肺灌注检查,检查结束后全部处死。对照组2只新西兰兔经耳缘静脉注入等渗盐水后立即处死。全部行病理检查。结果:22只实验组新西兰兔制模成功20只,其中有2只分别因为栓塞过量和麻醉过量而未取得数据,模型制备成功率为90%。以肺叶为单位,在CT图像上分析100个肺叶影像表现,可见栓塞后2h组对应的肺叶纹理稀疏12叶;1d及3d组对应肺叶呈磨玻璃改变22叶;7d组对应肺叶实变3叶。DEPI均呈现低灌注。病理检查发现:2h组相应肺组织呈鲜红色,未见结构破坏及肺泡渗出;1d组对应肺组织呈水肿、淤血、出血及炎细胞浸润改变;3d组部分肺组织轻度梗死,对应肺组织呈深红色,肺泡间隔增宽,大量炎细胞浸润;7d组肺泡腔被渗出物填充,对应肺组织呈暗红色,实变坏死。实验组共发现3只新西兰兔肺动脉管腔内含明胶海绵。结论:经新西兰兔耳缘静脉注射明胶海绵制作急性肺栓塞动物模型操作简单,成本低廉,成功率较高,是肺栓塞影像学研究较容易制作的实验模型。      

内蒙古扎鲁特旗伊和布拉格多金属矿地球物理、地球化学特征及找矿预测

内蒙古自治区扎鲁特旗伊和布拉格多金属矿位于额济纳旗-大兴安岭成矿区之突泉-林西华力西燕山期铁（锡）铜、铅、锌、银、铌（钽）成矿带。区内共发现7条矿化蚀变带,土壤地球化学测量圈定了元素组合异常4个。矿化蚀变带受NE-SW向断裂构造控制,其中Ⅲ号矿化蚀变带、Ⅴ号矿化蚀变带位于该区近东西向和近南北向断裂带的交汇处。矿化蚀变主要产于下二叠统或上侏罗统,成矿作用与燕山中晚期岩浆侵入活动相关。矿化蚀变带与地球化学异常及低电阻率,高极化激电异常均相关性,其中Ⅲ号蚀变带深部已见多层银铅锌矿体。从地质、物化探资料分析并与有关同类型的矿床类比,区内多条矿化蚀变带均具有寻找中-大型银铅锌多金属矿潜力。     

圆形网箱框架用PE管材的弯曲疲劳试验

网箱框架在风、浪、流单一载荷或其复合载荷的作用下,始终处于动态变化中,在这样的工况条件下,很容易发生疲劳破坏。本文通过对网箱框架工况条件的分析,认为网箱框架在沿直径方向的弯曲疲劳为主要因素,且在弯曲过程中周长保持不变。以圆形框架在直径方向产生20%的压缩变形为极端条件,通过几点假设,将工况条件向试验条件进行转化,提出1种圆形网箱框架用PE管材的弯曲疲劳试验方法。采用此方法对3种改性配方的聚乙烯管材样品进行了弯曲疲劳试验。结果表明,经10万次弯曲试验,3种配方的试样表面均无开裂等破坏现象,各配方的最大应力水平分别下降了14.3%,9.4%和16.9%。     

低压供电系统接地制式的分类

我国制定的建筑物内电气装置安全性能标准已经与国际电工委员会(1EC)制定的标准相一致，简要介绍了IEC标准中关于供电系统的接地形式和分类。正确理解低压供电系统接地形式的分类和规定的相关术语，对山西省以后大规模的防雷检测和防雷工程施工有极大的帮助。     

树木年轮研究的扫描图像分析方法及其在环境演变中的应用

本文主要探讨用普通扫描仪作为获取树轮信息手段的有效途径,以及研究将图像分析和数字处理技术应用于树木年轮学的方法。通过对树轮图像的分布特征和噪声变化规律的统计分析,本文设计出一套图像分割、信息提取算法和相应的处理程序。从实际的应用效果以及与其它树轮研究方法所作的对比分析结果表明,这种扫描图像处理方法不仅可行,而且高效、准确,拓宽了树木年轮学方法在环境演变研究中的应用途径。     

中尺度涡影响下目的层地震成像的畸变与影响因素分析

将PE方法与地震数值模拟方法相结合研究了中尺度涡影响下目标地层成像的畸变.模拟了不同声源频率、不同水深条件下的地震波场.计算结果发现,中尺度涡的存在使得真实地形结构无法在地震成像中反映,而且地震成像畸变随着海水深度、震源频率的增加而增大.机理分析表明,中尺度涡所带来的水体温度梯度变化是产生地震成像畸变的主要因素.为了便于工程应用,本文还推导了有效涡强度、温度差与地形畸变率的关系式.本文的研究结果将对提高深海地震成像精度有一定的指导意义.