低功率毫米波辐射对HL60白血病细胞基因表达谱的影响

应用基因芯片技术考察了经频率为41.32GHz的毫米波辐射的HL60白血病细胞和未经毫米波辐射的HL60白血病细胞组的基因表达差异,并用逆转录-聚合酶链式反应(RT-PCR)方法验证了IL-7、EGF和LGALS3基因变化.结果表明,毫米波辐射60 min后.HL60细胞增殖,基因芯片检出基因表达上调18个和下调306个,在下调的基因中,RT-PCR检出IL-7、EGF和LGALS3基因下调的情况与基因芯片结果一致.这说明低功率毫米波可导致HL60细胞的基因表达谱发生变化,这些变化的基因与HL60细胞的增殖功能相关.     

甲乙类电流记忆单元中电荷注入误差的消除

针对电流存储单元电路中存在的电荷注入误差,提出一种新的注入误差消除方法,该方法能够消除由电荷注入效应引起的输入信号相关误差及直流偏置.设计了一种具有极低电荷注入误差的甲乙类开关电流存储单元电路.采用上华半导体有限公司(CSMC)的5 V,0.6 μm双层多晶双层金属互补型金属氧化物半导体(CMOS)工艺对存储单元进行设计.模拟结果表明:改进后的存储单元可工作在2.5～5 V电压条件下;在输入频率为500 kHz,幅度为50 Μa正弦电流,采样信号频率10 MHz条件下,输出电流的误差仅为未采用补偿方案的单元电路误差电流的0.212 %,同常用的伪MOS开关补偿方法相比,误差电流减小了85.5 %.     

A Nonlinear Interval Portfolio Selection Model and Its Application in Banks

In classical Markowitz’s Mean-Variance model, parameters such as the mean and covariance of the underlying assets’ future return are assumed to be known exactly. However, this is not always the case. The parameters often correspond to quantities that fall within a range, or can be known ambiguously at the time when investment decision must be made. In such situations, investors determine returns on investment and risks etc. and make portfolio decisions based on experience and economic wisdom. This paper tries to use the concept of interval numbers in the fuzzy set theory to extend the classical mean-variance portfolio selection model to a mean-downside semi-variance model with consideration of liquidity requirements of a bank. The semi-variance constraint is employed to control the downside risk, filling in the existing interval portfolio optimization model based on the linear semi-absolute deviation to depict the downside risk. Simulation results show that the model behaves robustly for risky assets with highest or lowest mean historical rate of return and the optimal investment proportions have good stability. This suggests that for these kinds of assets the model can reduce the risk of high deviation caused by the deviation in the decision maker’s experience and economic wisdom.     

3个分布区蒜头果叶的解剖特征及其生态适应性

对广西境内的龙虎山、巴马、乐业三个蒜头果（Malania oleifera）自然分布区的蒜头果叶片进行解剖特征研究,探讨不同分布区蒜头果的叶片解剖特征及其表现出的生态适应性。结果表明,3个分布区蒜头果叶片在解剖结构上差异明显,但均表现出早生植物的特征。3个分布区中,巴马样地蒜头果表现出气孔密度较大、气孔较小而数目较多,角质层厚度较大,导管数目较多等特征,说明其具有更明显的生态适应性。     

桩承式路堤承载特性颗粒流细观模拟

采用离散元法软件PFC2D,建立了桩承式路堤承载特性颗粒流试验模型.分析了路堤荷载下填土颗粒间接触力、应力和竖向位移等的分布规律以及桩土应力比的变化规律,并研究了桩间距、桩帽宽度、颗粒间内摩擦角和颗粒形状等因素对桩承式路堤承载特性的影响.结果表明:填土颗粒中土拱结构主要存在于桩顶1倍桩净间距高度范围内;桩帽宽度越大,桩间距越小,桩土应力比越大但土拱结构稳定性越弱;填土颗粒表面越粗糙,内摩擦角越大,桩土应力比越大且土拱结构稳定性越强;随着路堤荷载的增加,填土颗粒中土拱结构呈现出形成-破坏-再形成的变化规律.     

基于CASA模型的皖江城市带植被净初级生产力时空变化特征研究

运用GIS和RS技术,利用植被、气候和辐射等地面空间数据,基于CASA模型估算2001-2010年之间皖江城市带植被净初级生产力(NPP),并分析其时空变化特征.结果表明:10年之间皖江城市带植被净初级生产力呈减少趋势,其中NPPMAX年均减少速度5.3gC/m2·a,NPPMEAN年均减少率0.513%;10年NPPMAX均值为805.09gC/m2·a,NPPMEAN均值为463.26gC/m2·a;净初级生产力年累计量变化幅度较大,约在30.052-43.483TgC/a之间;年际变化十分明显,最大值出现在2008年,为43.483TgC,最小值在2006年,为30.052TgC,年均减少率0.51%.植被净初级生产力空间格局表现出较大的不均匀性,整体分布状况是以长江为界,长江以南植被净初级生产力较大,但有逐渐变小趋势;长江以北植被净初级生产力较小,却表现出逐渐增加的趋势.     

平原水库运行条件下的土工膜气胀试验研究

为研究土工膜气胀及其与地下水位上升、水库蓄水及库水位骤降等影响因素的关系,研制了土工膜气胀模型试验装置,并对不同模拟工况下的土工膜位移、膜下气压、吸力、孔隙水压力以及竖向土压力的变化规律进行了试验研究。结果表明:膜下气压和孔隙水压力均随地下水位上升而增大,其大小由地下水位上升幅度决定;当地下水位与土工膜之间的非饱和区域较小时,膜下孔隙压力受库水荷载作用增加显著,在蓄水初期极易引发土工膜气胀变形,建议在膜上设置一定压重防止土工膜被顶起;膜下孔隙压力变化滞后于膜上荷载,库水位骤降时,膜下气压将大于膜上荷载,从而引起土工膜气胀破坏。     

Angular-based spatially resolved laser-induced breakdown spectroscopy: a new technique for the effective enhancement of signals without an external time delay system

In this study, we developed a novel angularbased spatially resolved laser-induced breakdown spectroscopy(ABSR-LIBS) technique. This new method allows the spatially resolved spectroscopic properties of laserinduced plasma to be investigated using different angles and polar distances with a spatially adjustable fiber optics probe. The experimental evaluations suggested that the intensity of the Al signal distributions in the ‘‘side-view'depended greatly on the angle of the collection probe. The location of a collection probe at 50° would facilitate efficient spectral collection and minimize the disturbance of the plasma plume. The spectral signals in the plasma emissions had different distribution at various polar distances using the same collection angle, and the highest signal intensity was observed between 15 and 35 mm polar distances. This ABSR-LIBS technique improved both the LIBS signal and the maximum emission intensity of Al atoms by several times at the best spatial position in our experimental conditions. Furthermore, we successfully obtained well-resolved line emission spectroscopy signals without any external time delay using a nongated spectrometer based on the ABSR-LIBS system. We consider that the ABSR-LIBS technique has great potential for obtaining new insights with laser-induced plasma instruments and it could facilitate the development of a low-cost instrument.     

地方高校转型契机下的制药工程专业应用型人才培养的探索

“应用型”大学首先是对经济社会发展对人才需求的一种积极回应，是一种以满足经济社会发展需求，以应用型人才为主要培养目标，其培养的学生，动手能力强于研究型，理论基础和专业能力又强于高职院校，这就构成了“应用型”大学的内涵和要求。通过探讨转型背景下地方高校制药工程专业人才培养方案，从专业方向的转型，培养模式和教学内容的转型，教师队伍的转型和实践教学的更新和发展几个方面来构建地方高校制药工程专业应用型人才培养模式，以期培养出适应社会需求的高层次人才。     

The Clinical Application of Endoscopic Ultrasound

超声内镜是一种集超声与内镜检查为一体的医疗设备,文章就超声内镜在人体管腔疾病的诊治应用中作一概述.