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991.
Hernandez Giovanni; Hamdani Selma; Rajabi Heshmat; Conover Kent; Stewart Jane; Arvanitogiannis Andreas; Shizgal Peter 《Canadian Metallurgical Quarterly》2006,120(4):888
Extracellular dopamine levels were measured in the rat nucleus accumbens by means of in vivo microdialysis. Delivery of rewarding medial forebrain bundle stimulation at a low rate (5 trains/min) produced a sustained elevation of dopamine levels, regardless of whether train onset was predictable. When the rate of train delivery was increased to 40 trains/min, dopamine levels rose rapidly during the first 40 min but then declined toward the baseline range. The rewarding impact of the stimulation was reduced following prior delivery of stimulation at the high, but not the low, rate. These results support the idea that dopamine tone plays an enabling role in brain stimulation reward and is elevated similarly by predictable and unpredictable stimulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
992.
This article responds to a critique by H. C. Barrett, D. A. Frederick, M. G. Haselton, and R. Kurzban (see record 2006-10940-009), wherein it is argued that manipulations of cognitive constraints cannot be used to test general evolutionary hypotheses regarding the architecture of mind. In making this argument, Barrett et al. focus on what they believe to be faulty logic in D. DeSteno, M. Y. Bartlett, J. Braverman, and P. Salovey's (see record 2002-18731-006) use of such techniques to examine proposed sex differences in jealousy. In presenting their argument, however, Barrett et al. appear to disregard central findings presented in DeSteno et al. (2002) and, in so doing, fail to grasp the interrelations among findings that might readily address their concerns. Here, the authors present arguments for why and when manipulations of cognitive resources may prove useful in investigating evolved psychological mechanisms and, in so doing, situate their use within the ongoing debate concerning evolved sex differences in jealousy. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
993.
Compensation of magnetic disturbances improves inertial and magnetic sensing of human body segment orientation. 总被引:5,自引:0,他引:5
Daniel Roetenberg Henk J Luinge Chris T M Baten Peter H Veltink 《IEEE transactions on neural systems and rehabilitation engineering》2005,13(3):395-405
This paper describes a complementary Kalman filter design to estimate orientation of human body segments by fusing gyroscope, accelerometer, and magnetometer signals from miniature sensors. Ferromagnetic materials or other magnetic fields near the sensor module disturb the local earth magnetic field and, therefore, the orientation estimation, which impedes many (ambulatory) applications. In the filter, the gyroscope bias error, orientation error, and magnetic disturbance error are estimated. The filter was tested under quasi-static and dynamic conditions with ferromagnetic materials close to the sensor module. The quasi-static experiments implied static positions and rotations around the three axes. In the dynamic experiments, three-dimensional rotations were performed near a metal tool case. The orientation estimated by the filter was compared with the orientation obtained with an optical reference system Vicon. Results show accurate and drift-free orientation estimates. The compensation results in a significant difference (p < 0.01) between the orientation estimates with compensation of magnetic disturbances in comparison to no compensation or only gyroscopes. The average static error was 1.4 degrees (standard deviation 0.4) in the magnetically disturbed experiments. The dynamic error was 2.6 degrees root means square. 相似文献
994.
Luis Galo Corzo Jose Antonio Peñaranda Peter Peer 《Machine Vision and Applications》2005,16(5):306-311
We present a technique to quickly estimate the Illumination Spectral Distribution (ISD) in an image illuminated by a fluorescent lamp. It is assumed that the object colors are a set of colors for which spectral reflectances are available (in our experiments we use spectral measurements of 12 colors checker chart), the sensitivities of the camera sensors are known and the camera response is linear. Thus, the ISD can be approximated by a finite linear combinations of a small number of basis functions. 相似文献
995.
Prof. Dr. Hans Ulrich Buhl Dr. Bernd Heinrich Prof. Dr. Peter Loos Prof. Dr. Ulrich Frank Visiting Prof. Daniel L. Moody PhD Prof. Jeffrey Parsons PhD Prof. Dr. Michael Rosemann Prof. Dr. Elmar J. Sinz Prof. Ron Weber PhD Achim Kindler Dr. Prof. Dr. Claus Rautenstrauch Dipl.-Wirt.-Inf. Peter Fettke 《WIRTSCHAFTSINFORMATIK》2005,47(2):152-161
996.
Sudipto Ghosh Robert B. France Devon M. Simmonds Abhijit Bare Brahmila Kamalakar Roopashree P. Shankar Gagan Tandon Peter Vile Shuxin Yin 《Software》2005,35(12):1131-1154
An innovative middleware‐transparent approach to developing distributed applications is presented. The approach uses an aspect‐oriented software development technique to separate an application's middleware‐independent functionality from its middleware‐specific functionality. Application elements that are specific to the middleware are localized in aspects that can be seamlessly integrated into middleware‐independent application designs. The middleware‐transparent approach is used to decouple business functionality from middleware‐specific functionality. The decoupling allows developers to change middleware application elements without significantly modifying business functionality. Middleware technologies such as Java Remote Method Invocation (RMI), Jini, Simple Object Access Protocol (SOAP) remote procedure call (RPC) and .Net are used as examples to illustrate the approach. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
997.
Theodore Chung Jae Limb Jae-Hyun Ryou Wonseok Lee Peng Li Dongwon Yoo Xue-Bing Zhang Shyh-Chiang Shen Russell D. Dupuis David Keogh Peter Asbeck Ben Chukung Milton Feng Dimitri Zakharov Zusanne Lilienthal-Weber 《Journal of Electronic Materials》2006,35(4):695-700
The design and growth of GaN/InGaN heterojunction bipolar transistors (HBTs) by metalorganic chemical vapor deposition (MOCVD)
are studied. Atomic-force microscopy (AFM) images of p+InGaN base layers (∼100 nm) deposited under various growth conditions indicate that the optimal growth temperature is limited
to the range between 810 and 830°C due to a trade-off between surface roughness and indium incorporation. At these temperatures,
the growth pressure must be kept above 300 Torr in order to keep surface pit density under control. An InGaN graded-composition
emitter is adopted in order to reduce the number of V-shaped defects, which appear at the interface between GaN emitter and
InGaN base and render an abrupt emitter-base heterojunction nearly impossible. However, the device performance is severely
limited by the high p-type base contact resistance due to surface etching damage, which resulted from the emitter mesa etch. 相似文献
998.
Peter Singer 《集成电路应用》2006,(6):14-14
Intel采用45nm工艺技术制作了该行业第一块全功能SRAM芯片,目标是于2007年采用该技术在300mm晶圆上开始制造芯片。目前Intel在Arizona和Oregon有两个制造厂制造65nm芯片,今年在Ireland和Oregon将有两个以上新厂投入生产。 相似文献
999.
Tribological Properties of DLC Film Prepared by C ^+ Ion Beam-assisted Deposition (IBAD) 总被引:1,自引:1,他引:1
BAI Xiuqin Peter Boehm LI Jian YAN Xinping 《武汉理工大学学报(材料科学英文版)》2006,21(1):49-52
C ^+ ion beam-assisted deposition was utilized to prepare deposit diamond-like carbon ( DLC ) film. With the help of a series of experiments such as Raman spectroscopy, FT-IR spectroscopy, AFM and nanoindentation , the DLC film has been recognized as hydrogenated DLC film and its tribologicul properties have been evaluated. The bull-on-disc testing results show that the hardness and the tribologicul properties of the DLC film produced by C^ + ion beam- assisted deposition are improved significantly. DLC film produced by C ^+ ion beam- assisted deposition is positive to have a prosperous tribologicul application in the near future. 相似文献
1000.
Jennifer H. Miller Wendell P. Ela Kevin E. Lansey Peter L. Chipello Robert G. Arnold 《Canadian Metallurgical Quarterly》2006,132(10):1298-1306
Depth-dependent oxygen concentrations and aqueous-phase total ammonia and nitrate/nitrite ion concentrations were measured in the field during the infiltration of wastewater effluent. Measurements illustrated the dependence of nitrogen fate and transport on oxygen availability. Infiltration basins were operated by alternating wet (infiltration) and dry periods. During infiltration periods, ammonia was removed within the top few feet of sediments via adsorption. Biochemical activity rapidly eliminated residual molecular oxygen in the infiltrate, making the soil profile anoxic. During dry periods, oxygen reentered the basin profile and sorbed ammonia was converted to nitrate via nitrification. Oxygen penetrated to a depth of about 0.6?m?(2?ft) within the first few days of dry periods. At greater depths, oxygen levels increased more slowly due to a combination of slow transport kinetics and biochemical (nitrogenous) oxygen demand. During normal wet/dry basin cycles consisting of about 4 wet and 4 dry days, the local vadose zone remained anoxic at depths greater than about 1.5?m?(5?ft) below land surface. As a consequence, conditions for denitrification were satisfied in the deeper sediments. That is, the nitrate nitrogen produced in near surface sediments moved freely downward with infiltrating water where it encountered an extensive anoxic zone before reaching local monitoring or extraction wells. The relative importance of dissolved organics and sorbed ammonia as electron donors for denitrification reactions remains to be established. 相似文献