Pseudoneglect and embryonic light stimulation in the avian brain.

A bias to allocate attention to the left hemispace, similar to the well-known pseudoneglect phenomenon shown by humans, has been recently reported in domestic chicks and other species of birds. Asymmetrical light exposure of the embryo of the domestic chick in a critical period before hatching is known to be responsible for a structural asymmetry in the visual ascending projections of the thalamofugal pathway and for lateralization of some visual behaviors. Thus the animal model provided by the chick makes possible investigation of the prenatal factors that may influence asymmetry in spatial attention. Here chicks coming from eggs exposed to light (light incubated, Li-chicks) and chicks incubated in darkness (dark incubated, Di-chicks) were tested in a task in which they were required to explore an area in front of them and to sample grains of food. The results showed that Li-chicks attended more to target stimuli located in the left hemispace, whereas no asymmetry was shown by Di-chicks. When grains of food were presented with small novel pebbles as distractors, both Li- and Di-chicks tended to allocate attention toward the left hemispace. When, however, chicks were tested after familiarization with pebbles, no bias was shown by either Li- and Di-chicks. Hence it seems that cerebral lateralization associated with right hemispheric involvement in response to novelty, interacts with the modulatory effect of asymmetric embryonic light stimulation on preferential allocation of spatial attention in the left hemispace (right hemisphere) and right eye (left hemisphere) control of visual discrimination during feeding. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

A Combi-Stroop test for measuring food-related attentional bias.

There are methodological complexities with the supraliminal–lexical versions of the modified versions of the Stroop tests that could be responsible for inconsistencies across the literature (Field & Cox, 2008). We tested whether a combination of subliminal–pictorial and classic Stroop tests can differentiate between dieters' and nondieters' food attentional bias (FAB). Participants were dieters (n = 30) and nondieters (n = 32) who were tested 3 hr after having a meal. Each picture from among 24 high-calorie and 24 low-calorie food pictures was presented for 32 ms before the appearance of a congruent or an incongruent color word, in response to which participants were required to manually report, via a tagged keyboard, the correct color of the word as quickly and accurately as possible. Color-naming latencies and interference scores were calculated. Dieters showed the highest reaction times to incongruent color words following high-calorie food pictures; overall, dieters showed significantly higher FABs than nondieters. The Combi-Stroop test has differential validity. Moreover, findings suggest that FAB can result from early allocation of dieters' attention to food-related stimuli. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Intercomparison of Humidity and Temperature Sensors:GTS1, Vaisala RS80, and CFH

GTS1 digital radiosonde, developed by the Shanghai Changwang Meteorological Science and Technology Company in 1998, is now widely used in operational radiosonde stations in China. A preliminary comparison of simultaneous humidity measurements by the GTS1 radiosonde, the Vaisala RS80 radiosonde, and the Cryogenic Frostpoint Hygrometer (CFH), launched at Kunming in August 2009, reveals a large dry bias produced by the GTS1 humidity sensor. The average relative dry bias is in the order of 10% below 500 hPa,increasing rapidly to 30% above 500 hPa, and up to 55% at 310 hPa. A much larger dry bias is observed in the daytime, and this daytime effect increases with altitude. The GTS1 radiosonde fails to respond to humidity changes in the upper troposphere, and sometimes even in the middle troposphere. The failure of GTS1 in the middle and upper troposphere will result in significant artificial humidity shifts in radiosonde climate records at stations in China where a transition from mechanical to digital radiosondes has occurred.A comparison of simultaneous temperature observations by the GTS1 radiosonde and the Vaisala RS80 radiosonde suggests that these two radiosondes provide highly reproducible temperature measurements in the troposphere, but produce opposite biases for daytime and nighttime measurements in the stratosphere.In the stratosphere, the GTS1 shows a warm bias (＜0.5 K) in the daytime and a relatively large cool bias (-0.2 K to -1.6 K) at nighttime.     

偏压对反应磁控溅射TiN薄膜结构以及性能的影响

本文采用直流反应磁控溅射技术,以Ar和N2为反应前驱气体制备了TiN功能装饰薄膜.重点研究了衬底负偏压对沉积TiN薄膜的色泽、性能及微结构的影响.采用台阶轮廓仪、X射线衍射仪、EDS能谱仪、纳米压痕仪等分析了薄膜的粗糙度、晶相、组分、纳米硬度以及弹性模量.结果表明,采用适宜的衬底负偏压调控轰击离子能量,能够有效阻止薄膜结构中空位以及缺陷的产生,从而有效避免薄膜表面的紫黑色氧化钛的生成,有利于表面光滑的金黄色TiN薄膜制备,同时使薄膜具备更优异的力学性能.实验结果还表明基体偏压可显著影响TiN薄膜的择优生长取向:随偏压增加,薄膜由(111)晶相择优生长转变为(200)晶相的择优生长,(200)晶相的薄膜比(111)晶相薄膜具有更佳的力学性能.     

外加偏压对未退火Co/n-poly-SiGe肖特基接触特性的影响

采用直流离子束溅射法,在n型单晶硅衬底上淀积Si1-xGex薄膜.俄歇电子谱(AES)测得Si1-xGex薄膜的Ge含量约为0.15.对薄膜进行高温磷扩散后,经XRD测试为多晶态,即得n-poly-Si0.85Ge0.15.在n-poly-Si0.85Ge0.15上溅射一层薄的Co膜,做成Co/n-poly-Si085Ge0.15肖特基结样品.在90～332 K范围对未退火样品做I-V-T测试.研究发现,随着外加偏压增大,表观理想因子缓慢上升,肖特基势垒高度(SBH)下降.基于SBH的不均匀分布建模,得到了二者近似为线性负相关的结论.     

基于双频光栅的微分干涉相衬方法

针对传统微分干涉相衬技术对双折射性物体成像会有伪像的问题,用双频闪耀光栅取代传统微分干涉相衬的分光元件诺曼斯基棱镜,设计了一种微分干涉相衬方法.对双频闪耀光栅设计,模拟入射平面波通过它之后的光强分布,结果表明它能产生两束剪切角很小的光.用双频光栅微分干涉相衬方法对纯相位样品模拟成像,仿真结果和物体的相位轮廓一致.分析了...     

带有直流偏置的毫米波单刀双掷开关仿真与设计

采用阶跃阻抗传输线和扇形微带短截线,实现了单刀双掷开关的直流偏置,使直流支路与毫米波支路之间的隔离度大于30dB,带宽超过25%,在中心频率30GHz附近回波损耗大于40dB。采用这种直流偏置电路和PIN梁式引线二极管,基于LTCC工艺对单刀双掷开关串联结构进行仿真。设计结果表明在28.5～31.5GHz频率范围内,串联开关的插入损耗小于1.5dB,回波损耗大于15dB,隔离度大于20dB。     

偏压对铀表面多弧离子镀Ti/TiN多层膜的结构及抗腐蚀性能影响研究

在不同偏压下,利用多弧离子镀技术在U和Si基体上制备了Ti/TiN多层薄膜。利用X射线衍射仪和扫描电镜对多层膜的组织结构和薄膜界面形貌进行了分析。研究表明：脉冲偏压不但影响多层膜物相各衍射峰的强度,还诱导新相Ti₂N的出现。制备的多层膜呈“犬牙”交错的层状、柱状结构生长。随脉冲偏压的增加,柱状晶结构细化,薄膜变得更加致密。通过50μg/gCl^－溶液腐蚀研究表明：Ti/TiN多层膜提高抗腐蚀性能源于层状失效,使得腐蚀介质到达基体更加困难,抗腐蚀性能优良。     

微型航姿系统中三轴MEMS加速度计组合误差建模方法

根据微机械(MEMS)加速度计的测鲢原理对其误差源进行了分析,并研究了微型航姿系统中加速度计的非正交零偏以及温度特性.基于加速度计输出电压随温度变化的规律,利用分温度段对加速度计进行六位置标定的方法建立加速度计的误差模型,并应用于微型航姿系统,实现加速度计的实时补偿.多次实验结果表明,加速度计的误差模型校正了加速度计的...