新疆头屯河流域不良地质现象分布特征及成因分析

 根据实地考察和观测资料,对新疆头屯河流域不良地质现象分布特征进行分析。结果表明:头屯河流域不良地质现象主要发生在流域中游地带,出现时间的分布受降雨条件控制,集中出现在降雨期。不良地质现象受自然环境多因素的影响和制约,是地质、地貌、地表物质组成、地震活动、水文气象、植被条件以及人类活动等诸因素作用的结果。流域不良地质现象的发育,为流域河道来沙提供了大量的物质基础,根据流域自然环境和不良地质现象的活动分布状况,从生物、工程和社会3方面提出了防治措施。     

基于成像高光谱的苹果树叶片病害区域提取方法研究

【目的】对带病斑苹果树叶片的高光谱图像进行病斑提取,为作物病虫害的遥感监测提供支持。【方法】对带有病斑的苹果树叶片成像高光谱图像,从传统基于光谱特征和面向对象特征2个方向入手进行病斑提取。为减少高光谱图像波段之间的冗余,首先对高光谱图像采用PCA变换进行降维处理,利用降维之后的前11个波段,分别采用波谱角分类和面向对象分类的方法提取苹果树叶片病害区域。【结果】由于同物异谱和异物同谱现象的存在,波谱角分类算法在提取病斑时,对叶柄和叶脉产生了错误的分类,而且以像元为分类单位的波谱角分类,在分类结果图中存在椒盐噪声,而面向对象分类则避免了这一现象的发生。【结论】采用面向对象分类方法提取苹果叶片病斑的结果优于基于光谱特征的波谱角分类方法,其总体精度和Kappa系数分别为98.44%和0.97。     

云南蓝果树对种子萌发及幼苗生长的自毒效应

云南蓝果树为中国特有极度濒危一级保护植物,为探讨云南蓝果树濒危机理并进行有效保护,通过野外原位实验和室内受控实验相结合的方法,研究云南蓝果树对种子萌发及幼苗生长是否有自毒效应。结果表明:野外条件下,云南蓝果树的种子萌发受野外枯枝落叶和自身种皮的显著抑制;室内受控实验发现,云南蓝果树的根、茎、叶和种皮浸提液对种子萌发都有不同程度的显著抑制作用,其中,根的抑制作用最强(80.90%),种皮的抑制作用最弱(13.59%),而且云南蓝果树的根、茎、叶浸提液和根际土壤对幼苗生长(株高、叶片数和生物量)也表现出显著的抑制作用。     

改良经皮气管切开术在危重症患者中的应用效果

目的 观察比较改良经皮气管切开术在危重症患者中的应用效果。方法 收集2015年1月至2016年1月期间我院重症监护病房（ICU）行经皮气管切开术的120例患者的临床资料,随机分为Portex法经皮气管切开术组60例和改良经皮气管切开术组60例,对两组患者的性别、年龄、体质量指数（BMI）、APCHEⅡ评分等一般情况和两组患者手术所需时间、手术切口大小、术中出血量、拔除气管套管后切口愈合时间以及手术后并发症的发生率进行比较。结果 Portex法经皮气管切开术组与改良经皮气管切开术组相比较,两组患者在性别、年龄、体重指数（BMI）、APCHEⅡ评分等指标方面差异无统计学意义（P>0.05）;与Portex法经皮气管切开术组相比较,改良经皮气管切开术组手术时间、术中出血量明显减少（P<0.05）,差异有统计学意义,但两组患者的切口大小、切口愈合时间比较差异无统计学意义（P>0.05）;改良经皮气管切开术组与Portex法经皮气管切开术组相比,气管后壁损伤或穿孔的发生率明显减少,差异有统计学意义（P<0.05）。结论 改良经皮气管切开术与Portex法经皮气管切开术相比较,可节约手术时间、减少术中出血量、减少气管后壁损伤或穿孔的发生率,值得临床推广应用。     

世界极度濒危物种崖柏研究进展

崖柏(Thuja sutchuenensis)为柏科(Cupressaceae)崖柏属常绿乔木, 属我国特有、世界极危物种(CR), 具有重要的学术研究价值和广阔的开发利用前景。1892年4月在重庆市城口县首次发现, 此后"绝迹"了100多年。世界自然保护联盟(IUCN)曾将其定为野外已灭绝物种。1999年10月重新发现。在崖柏"绝迹"期间, 由于研究材料缺乏, 对崖柏的研究几近空白; 重新发现之后, 有关研究才相继展开。近十几年来, 广大科研工作者围绕崖柏的生物学特性、地理分布、群落组成与结构、种群结构与动态、遗传多样性、生态适应性、苗木繁育等开展了广泛研究, 并取得了丰硕成果。文中综述了崖柏的研究现状, 并探讨了未来的研究方向, 以期为崖柏的深入研究和拯救繁育提供参考。     

稻曲病危害损失率测定

本试验选用豫南稻区三个重感稻曲病品种桂朝二号、特青二号和吨稻,按单穗病粒数1粒为一级分级,每级取50穗,与健穗进行比较,计算秕粒率,百穗重损失率和千粒重损失率。经相关分析表明,各品种的秕粒率,百穗重损失率和千粒重损失率都与单穗病粒数有极显著的正相关,而百穗重和千粒重则与其有极显著的负相关。回归分析结果:平均每粒加1个病粒,桂朝二号、特青二号和吨稻的千粒重损失率分别上升0.59％,0.68％,0.82％。桂朝二号、特青一号的单穗病粒数与秕粒率的二条回归直线可以用一个回归系数即2.248。     

Abnormalities of Serum Magnesium in Critically III Dogs: Incidence and Implications

Serum magnesium (Mg) is an infrequnetly measured electrolyte in small animal patients. Currently, little is known about the prevalence and significance of abnormalities in serum Mg in animals. Therefore, a prospective study was performed to examine the incidence and clinical implications of abnormalities in serum Mg levels in critically ill dogs.
Serum Mg and other electrolytes were measured in 93 normal dogs housed at the Purina Pet Care Center and in 48 ill dogs admitted to a small animal critical care unit. The normal reference range for canine serum Mg was determined to be 1.89 – 2.51 mg/dl. Based on this range, 54% of the critically ill dogs were hypomagnesemic (< 1.89 mg/dl) and 13% were hypermagnesemic (> 2.51 mg/dl). Of the electrolytes measured in these patients, serum Mg had the highest prevalence of abnormal values. Hypomagnesemic patients had a significantly higher incidence of concurrent hypokalemia and hyponatremia (p < 0.05), as well as a longer length of hospitalization (p < 0.05) than their normomagnesemic counterparts. Hypermagnesemic patients were 2.6 times more likely not to survive their illness when compared to patients with normal serum Mg levels.
Abnormalities in serum Mg appear to be common in critically ill dogs. These patients commonly have other concurrent electrolyte abnormalities. Since serum Mg is not routinely measured, the presence of hypokalemia or hyponatremia should alert the clinician to the possibility of coexisting hypomagnesemia. The clinical implications of hypomagnesemia and hypermagnesemia in ill dogs appear to involve prolonged hospitalization and increased mortality, respectively: however, the exact etiology remains undetermined.     

Multiple Load Flow Solutions in Electric Power Systems Based on Genetic Algorithm

Methods for satisfying the power balance requirement and the voltage magnitude costraint are developed and incorporated into the genetic algorithm method to form a constrained genetic algorithm for solving the load flow problem.The robustness of the load flow algorithm is enhanced by the dynamic population.the technique for accelerating the convergence of the optimisation process and the network node sequencing procedure described in the paper.The efficiency and feasibility of the developed CGALF algorithm have been tested using KK 11 node system under light load and heavy load conditions.