基于主成分分析南京空气污染各成分的关系

根据从南京9个空气环境监测站所得到的空气污染物数据,在空气各成分的相关性指标中,运用主成分分析法,对各个监测样本各个特征性指标进行了分类分析,结果表明：占总方差的79．038％的3个因子来反映空气污染的总体程度,这3个因子归类分别为：①NO2、03、032和SO2,②AQI和03,③PM10和CO。有主成分分析法可以准确地探讨出空气各污染指数准确的内在关系,为当下的环境治理提供一些参考和帮助。     

基于代码生成的电控空气悬架系统电子控制单元

为提高某型SUV车辆的行驶平顺性、通过性等,对其进行空气悬架改装,并设计了由最小系统、车速信号调理模块、电动气泵控制模块、组合电磁阀控制模块、车身高度检测模块、CAN总线模块、车身加速度测量模块等组成的以Freescale XDP512为核心芯片的电控空气悬架系统电子控制单元,利用Real-Time Workshop(RTW)代码生成技术将所制定电控空气悬架系统控制策略转化为ANSI C代码并下载至电子控制单元,然后对安装电控空气悬架系统的试验车辆进行了车身高度与车速耦合试验、转向试验、急加速试验、急减速试验、平顺性试验,结果表明所设计的电控空气悬架系统控制单元能够实现车速信号调理、车身高度与车速耦合、电动气泵控制及组合阀控制等功能。     

Recent developments and improvements in ornamental fish packaging systems for air transport

Current ornamental fish packaging systems are characterized by very high fish loading densities and high metabolic wastes in the transport water after shipment. They focus mainly on management of the quality of transport water. Recent studies using the guppy as a model fish showed that post‐shipment mortality could be reduced through enhancement of the stress resistance of the fish, and hence emphases should also be placed on the preparation of the fish for transport and recovery of the fish after shipment. Farmers can contribute significantly by applying nutritional prophylaxis before harvesting. Exporters may use the salinity stress test to identify fish lots of good quality for transport, apply health prophylaxis to eradicate parasites and optimize other techniques such as starvation of the fish or addition of salt to the transport water to enhance the stress resistance of the fish. Importers may adopt proper acclimation procedure and allow fish to recover in low salinity water to reduce post‐shipment mortality. As the main bulk of post‐shipment mortality is stress‐mediated and occurs during the 1‐week recovery period, the industry should consider revising the basis of the current warranty system for their customers, from death on arrival to cumulative mortality at 7 days post shipment (or death after 7 days, DA7), in order to cut down fish losses after shipment.     

高级别动物生物安全实验室气密性的探讨

高级别动物生物安全实验室气密性是保证实验室空气洁净度、室内实验人员和室外环境安全的重要手段。我国现行规范对高级别动物生物实验室各区域气密性有严格的规定。从实验室装修、围护结构设备安装以及气密性检测方面对实验室气密性进行了讨论,以期为我国高级别动物生物安全实验室的建设提供参考。     

浙北黑木耳大棚栽培与露地栽培对比分析

大棚栽培桑木耳试验成果显示,在大棚中排场,可有效提高产量和效益,12月5日大棚内排场产量极显著高于11月5日露地排场和12月5日露地排场的,拉长了桑木耳制棒时间,有利于规模化、合作社化生产。     

The effect of acid water on oxygen consumption,circulating catecholamines and blood ionic and acid-base status in rainbow trout (Salmo gairdneri,Richardson)

Chronically cannulated rainbow trout were exposed in acid water (pH 4.0) for 72h. The gill potential was strongly dependent on water pH, being blood side negative in neutral water, but positive in acid water. Catecholamine levels increased irregularly during acid exposure, and the Bohr and Root effects were not completely erased by the effect of catecholamines during acid exposure. Long term exposure to low water pH, although causing an acidosis in the fish, did not suppress resting oxygen consumption. Prolonged exposure to acid conditions, however, resulted in an increase in ammonia excretion. Changes in plasma sodium and chloride were similar to that reported previously for trout exposed to low calcium, acid water. We conclude that exposure of trout to pH 4 soft water, although impairing oxygen transport, does not limit resting oxygen consumption but does reduce the scope for activity. More extreme acid conditions do impair resting oxygen uptake.     

Effects of mechanical stress in under-sized clams, Tapes philippinarum: a laboratory approach

The present study is a first attempt at evaluating the effects of repeated disturbance, such as that caused by mechanical fishing systems, on the target species, Tapes philippinarum, intensively exploited in the Lagoon of Venice (North-East Italy). In particular, in free-access fishing grounds, detrimental effects of dredging may be suffered by under-sized clams, which are disturbed by fishing tools many times throughout their lives before they are collected. Similar mechanical stress conditions are experienced by T. philippinarum in licensed areas, where they are farmed in aquaculture conditions and undergo the harmful impact of hydraulic dredging. To evaluate the effects of short-term mechanical stress, under-sized clams were subjected to experimental shaking in the laboratory, and detrimental effects on their well-being were investigated by applying the biomarker approach. Changes in physiological, biochemical and behavioural responses were evaluated by determining scope for growth, adenylate energy charge, survival in air time, reburrowing time, and shell damage level. Responses highlighted general worsening in clam condition as mechanical stress increased. Among the various measurements, survival in air and reburrowing time appeared particularly suitable as indices, their responsiveness and applicability suggesting their use in assessing mechanical stress due to dredging in field conditions.     

Gastric dilation and air sacculitis in farmed chinook salmon, Oncorhynchus tshawytscha (Walbaum)

A syndrome affecting cultured chinook salmon, Oncorhynchus tshawytscha (Walbaum), characterized by distended abdomens, gastric dilation, air sacculitis (GDAS), increased feed conversion rates and increased mortality has been recognized in New Zealand. Affected fish were most obvious in sea cages but were also present in fresh water. Mortality rates associated with this condition were highest in late summer and approached 6% per month. A dilated and flaccid stomach, without visible rugal folds containing copious oil, watery fluid or undigested feed was typical. Gastric mucosal ulceration or inflammation were not present. The air sacculitis consisted of a thickened, dilated bladder with a mixed mucosal inflammatory infiltrate and a luminal exudate associated with large numbers of morphologically diverse bacteria. Gastric dilation or air sacculitis occurred alone or together in the same fish. In a group of 20 subclinically affected fish with or without gastric dilation, there were no significant differences in weight, length, serum osmolality, sodium, total protein or packed cell volume. Twenty-three severely affected fish had significantly ( P  < 0.05) higher serum osmolality but similar sodium and total protein to that of clinically normal fish.     

胶州市小麦禾谷孢囊线虫群体动态的年度间差异

为明确山东胶州市禾谷孢囊线虫(Heterodera avenae,CCN)的田间发生状况及其年度间的差异,于2011-2012和2012-2013年两个小麦生长季在该地区麦田进行定点定期取样、土壤中线虫分离和根组织内线虫染色后镜检,以确定各虫态的季节和年度间群体动态变化。结果表明,与2011-2012年相比,2012-2013年春季CCN 2龄幼虫(J2)孵出较早,但对根系侵入较晚;土壤中J2群体密度较高,根组织中反而较低;根内幼虫发育不良,表现为3龄和4龄幼虫发生较晚且持续时间较短,没有明显发生高峰,群体密度持续低下;小麦收获后土壤中孢囊密度减少85.9%。2012-2013年J2侵入期推后和侵入率下降与3-4月份土壤干旱有关,而根内幼虫发育不良与4-5月份气温偏低有关。因此CCN侵染和发育关键期的干旱和低温可能是造成孢囊密度下降的主要原因。     

2012年7月我国中东部持续性强降水形成机制分析

利用NCEP/NCAR再分析资料,通过对2012年7月中旬我国中东部地区持续性强降水过程中东亚夏季风系统中主要成员的时空变化特征进行分析.结果表明,此次持续性强降水期间,副高北界、南亚高压脊线及中纬度锋区位置相对稳定,长江中下游地区一直处于南亚高压反气旋环流东侧偏北风与西风槽前偏南风之间的风向开口辐散区中;副高南撤时,强降水主要位于584 dagpm线北侧,副高北抬时,强降水主要位于584 dagpm线南侧;此次持续性强降水发生前期,大气为上干下湿不稳定层结,当西风带低槽频频携带冷空气南下影响,同时低空西南急流反复加强,其出口区左侧较强的风速梯度为暴雨的发生发展提供了动力条件;低层干空气的不断侵入,低槽和低涡间的垂直正反环流促使垂直上升运动维持或发展,进而造成持续性强降水;高空西风急流加强(减弱)超前低空西南急流加强(减弱)2～5 d,对持续性强降水有超前指示意义.