珍稀濒危植物膝柄木种子催芽研究

以采自越南广宁省海河县的膝柄木种子为试材,研究了不同药剂和浓度对种子发芽率和芽苗主根生长的影响。结果表明:与水浸相比,艾比蒂生根剂1号和双吉尔氨基酸肥料6号0.5~15.0mg/L浸种1h,对膝柄木种子发芽均没有促进作用,可见水浸即可有效促进膝柄木种子发芽;艾比蒂生根剂1号0.5mg/L和双吉尔氨基酸肥料6号0.5~10.0mg/L对膝柄木芽苗主根生长有很好的促进作用。     

国内外致泻大肠埃希氏菌O157:H7的检测标准比较及建议

致泻大肠埃希氏菌O157:H7（STEC O157:H7）是大肠埃希氏菌中致病性最严重的一种食源性致病菌,主要存在于牛肉、牛奶、水果及其制品中,对身体健康造成很大危害,甚至引发死亡。食品中STEC O157:H7检测尤为重要。本文对国内外STEC O157:H7的检测标准进行比较,提出我国标准在样品前处理、快速筛选方法的应用等方面需要加强,以便为该菌快速准确检测提供帮助,实现与国际标准化体系建设接轨,满足实验室检测需要。     

右美托咪定抑制NOX4缓解急性应激致大鼠肾损伤

本研究拟探索右美托咪定（dexmedetomidine,DEX）对大鼠急性应激致肾损伤的保护作用,并从氧化应激的角度探索DEX对大鼠肾的保护通路。本研究使用了急性束缚应激模型,其中,大鼠被迫游泳15 min,并束缚3 h。本试验采用生化检测、组织病理学切片观察以评估肾功能,然后测定了氧化应激以及氧化应激的相关通路蛋白。旷场试验证实成功建立了急性应激模型。急性应激引起的肾损伤增加了NOX4,降低了Nrf2/HO-1/NQO1表达水平。DEX可降低NOX4表达,同时升高Nrf2/HO-1/NQO1的表达水平。DEX治疗组与急性应激组相比的肾生化结果明显恢复正常,病理切片观察损伤显著降低。试验结果表明,DEX治疗急性应激可影响NOX4/Nrf2/HO-1/NQO1信号通路,并抑制氧化应激。因此,DEX对急性应激引起的肾损伤具有保护作用,并在应激综合征中具有潜在的临床应用。     

The Biological Effects of Low Frequency Electromagnetic Fields on Cells

The biological effects of ELFMES including proliferation and apoptosis of cells as well as the damage of DNA are initially evaluated with the treatment of plant cells and human pulmonary fibroblasts in low frequency magnetic fields with certain intensity and different time intervals in vitro. Cell culture, counting in vitro, fluorescent dyeing analysis and single cell gel electrophoresis are adopted. The results demonstrate that the electromagnetic field with the intensity of 3mT can affect the proliferation and apoptosis of cells significantly.     

Experimental Research on High-strength Inorganic Anchoring Material

A new type of inorganic anchoring material is developed as a substitution for anchoring adhesive to overcome some imperfections in the process of planting reinforcing steel bar.The mix proportion of the anchoring material is determined by experiments.The compressive strength,adhesive force to concrete,volume stability and anchoring force with steel bar are studied.The early strength of the anchoring inorganic material is quite high: for 1d up to 38.5MPa and 3d up to 60MPa.It is a good adhesive to concrete and the adhesive strength of 28d is about 2MPa.The anchoring material will have tiny volume expansion with the age,which is beneficial to enhancing the anchoring force.The essential component of the inorganic anchoring material is cement-based material,so some defects of the organic macromolecular material can be avoided,such as poor stability and requirement for vigorous construction conditions.Its characteristics in early strength,adhesive force to concrete and volume expansion can satisfy the requirement of the construction to the planting reinforcing steel bar and the loading force,thus it can be used as a substituting material for anchoring adhesive.     

Determination to Weighting Coefficient of Combination Forecast Based on Rough Set Theory

The problem of determination to weighting coefficient is a key and difficulty for combination forecast. A method of determining weighting coefficient based on rough set theory is showed in this paper. Determining weighting coefficient is translated into estimating significance of attributes among rough set. A relation data model about combination forecast is established. Knowledge systems are built through making attribute value into eigenvalue. Under data moving, the weighting coefficients of a combination forecast model are computed by analyzing the dependence and significance of forecasting method for the predicted object. The proposed approach overcomes the subjectivity of traditional determination to weighting coefficient, avoids computing linear or nonlinear extremum problem and makes combination forecast more objective. The validity of the proposed approach is verified with a case.     

Influence of MUD on the System Capability of CDMA

In CDMA communication system, the relativities between users result in Multiple Access Interference (MAI). With the increase of users, MAI becomes the main jam of broadband CDMA communication system. Multi-User Detection (MUD) is the most important technology of anti-jamming in the broadband CDMA communication system, which can eliminates MAI effectively by using the information of all user signals to detection single. This paper analyze the expression of system capability without MUD and with MUD, and puts forward the way to increase system capability by using MUD. Then the influence of MUD on CDMA system capability is discussed by MATLAB emulation. Basing analysis and emulation, the conclusion is got: the higher the MUD efficiency, the better the improvement of CDMA system capability; under the same MUD efficiency, the lower data rate, the smaller inter-cell interference, the lower the ratio of bit energy to power spectrum, the better the improvement of CDMA system capability.     

沼液与化肥和有机肥配施对桃产量和品质的效应

采用田间试验研究了沼液在不同施肥处理中对桃产量和品质的影响。结果表明,与常规施肥相比,仅在常规施肥基础上增施沼液(T2处理)不能提高桃产量,沼液仅与钾肥配施(T3处理)还会降低桃产量,沼液配施磷钾(T4处理)或配施油饼(T5处理)能提高桃产量,且配施油饼的增产效果最显著,增产幅度最大。T4和T5处理均能增加桃果实中的Vc含量。各处理与常规施肥相比,桃果实中的还原糖含量均有所降低,以T5处理中还原糖的含量最低,仅为常规处理的48.48%。除T5处理中桃果实的有机酸含量略有增加外(1.77%),其他处理的有机酸含量都有所降低(5.42%～9.22%)。各处理的糖/酸与常规施肥相比均大幅度下降,降幅为21.42%～53.36%。     

民勤荒漠区无霜期及春季低温变化特征分析

以甘肃民勤治沙综合试验站数十年气象定点观测资料为基础,统计、分析了民勤荒漠区无霜期、春季低温、冻土层的变化特征。结果显示:该地区平均终霜期为5月10日,初霜期为9月28日,50 a来终霜期有逐渐提前、初霜期有逐渐推后的趋势,但不同年份变异幅度增大;3-5月份地表平均最低温度、气温逐渐上升,≤0℃出现比率下降,但4月下旬至5月上旬大强度的降温天气时有发生;3月份冻土层的变化与气温变化趋势相近。30 a以来地表平均日最低温度和气温亦有所提高。     

入侵植物黄花草木樨的生殖构件性状及种子萌发特性研究

黄花草木樨是广泛分布于我国的一种外来入侵植物,对被入侵地的生物多样性造成严重威胁。通过样方调查和种子萌发实验,对黄花草木樨的生殖构件特性和种子休眠萌发特性进行研究,并探讨其繁殖能力。结果表明,密度对黄花草木樨各生殖构件性状影响各不相同,单枝种子量、总种子量和百粒重与密度成反比,而分枝数在中密度下达到最大,高密度和低密度的株高和分枝数均比中密度下的小;在生殖构件性状相关性方面,总种子量与单枝种子量(r=0.946)呈极显著正相关,百粒重与单枝种子量(r=0.178)呈显著正相关;在萌发特性方面,冷藏对黄花草木樨种子的萌发有促进作用,萌发率提高了约10%,而冷冻对黄花草木樨种子的萌发有抑制作用,萌发率降低约30%;在常温条件下,黄花草木樨种子休眠特性表现为前7个月波动变化很大,7～20个月之间变化基本平稳,萌发率保持80%左右,之后开始逐渐下降,5年后下降至10%以下。研究表明,黄花草木樨具有较高的种子产量和持久的高萌发率,有利于其种群的扩散和定殖。