中国特色

纵观中国当代历史,中国一直受困于政治正确乃唯一正当的实践模式这种思维(例如在思考是否采用"西方模式"时),尽管这种观点仍有待证明。在中国,每个面临机遇、想要抓住机遇的人总会因为担心冒犯他人而分外谨小慎微,以免做出任何挑衅正统的行为;具有"国际风格"的建筑和模仿西方经典的建筑往往冒着被谴责为投诚西方资本主义的风险,而具有中国特色的     

Increased maternal corticosterone levels in rats: Effects on brain 5-HT1A receptors and behavioral coping with stress in adult offspring.

This study examined the consequences of elevated corticosterone levels in lactating rats on their offspring's serotonergic 5-hydroxytryptamine (5-HT)1A receptor system and behavioral coping with stress. The mothers received normal drinking water or water with corticosterone, which, via the milk, enters the circulation and brains of the pups, In adulthood, the corticosterone-nursed offspring showed a consistently more passive way of coping with environmental challenges. However, they did not seem to be more anxious. Autoradiographic analysis of the 5-HT1A receptor system revealed a decrease in the adult 5-HT1A receptor binding in the hippocampal CAI region. The results support the hypothesis that differences in behavioral coping with stress by adult rats are associated with differences in the serotonergic system. At the same time, it suggests that adult coping and its neuronal substrates are not solely determined by genes but depend on subtle developmental factors as well. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impacts of agricultural phosphorus use in catchments on shallow lake water quality: About buffers, time delays and equilibria

Phosphorus (P) losses caused by intensive agriculture are known to have potentially large negative effects on the water quality of lakes. However, due to the buffering capacity of soils and lake ecosystems, such effects may appear long after intensive agriculture started. Here we present the study of a coupled shallow lake catchment model, which allows a glimpse of the magnitude of these buffer-related time delays. Results show that the buffering capacity of the lake water was negligible whereas buffering in the lake sediment postponed the final lake equilibrium for several decades. The surface soil layer in contact with runoff water was accountable for a delay of 5-50 years. The most important buffer, however, was the percolation soil layer that may cause a delay of 150-1700 years depending on agricultural P surplus levels. Although the buffers could postpone final lake equilibria for a considerable time, current and target agricultural surplus levels eventually led to very turbid conditions with total P concentrations of 2.0 and 0.6 mg L(-1) respectively. To secure permanent clear water states the current agricultural P surplus of 15 kg P ha(-1) yr(-1) should drop to 0.7 kg P ha(-1) yr(-1). We present several simple equations that can be used to estimate the sustainable P surplus levels, buffer related time delays and equilibrium P concentrations in other catchment-lake systems.     

“超大”在亚洲:雷姆·库哈斯与三好将夫的对话

原文最初刊于《MUAE 2:崩塌的新建筑》一书,后经许可转载于杜克大学出版社国际期刊《界限2》第24卷第2册。文章记录了雷姆·库哈斯与三好将夫围绕一系列话题所展开的丰富而热烈的讨论,题目包括建筑学的意义、亚洲的城市化现象、全球化背景下的建筑发展趋势。在谈话中,库哈斯还进一步解释了其两部著作《小,中,大,超大》、《癫狂的纽约》中的内容,同时也对自己的多重身份进行了阐述。     

An improved molecular dynamics potential for the Al-O system

Molecular dynamics (MD) simulations of aluminum oxide material and the aluminum oxidation process require a sufficiently sophisticated and well-calibrated potential, one that takes into account locally varying Al/O ratios and adaptive charge transfer between Al and O atoms. In this work we show that the Charge Transfer Ionic Potential (CTIP) by Zhou et al. [X.W. Zhou, H.N.G. Wadley, J.-S. Filhol, M.N. Neurock, Phys. Rev. B 69 (2004) 035402] in combination with a new, “Reference Free” version of the Modified Embedded Atom Method (RFMEAM) potential performs well for this purpose. This new potential has been parameterized by systematically fitting it to a large database of different Al_xO_y crystal energies, over a range of lattice constants and elastic deformations, using a recent method which separates the electrostatic and non-electrostatic fitting steps. The resulting potential yields more realistic atomic charges, crystal energies and lattice constants than earlier potentials. In particular, we show that the angular forces in the MEAM part are essential for α-Al₂O₃ to be the lowest-energy aluminum oxide. We compare the performance of our potential with the potential of Zhou et al., which lacks angular forces and was parameterized using a less involved fitting procedure, and show the results of a few molecular dynamics simulations. The two-step fitting method is generally applicable and can be adopted for constructing potentials for other metal-oxide systems.     

Activation of serotonergic neurotransmission during the performance of aggressive behavior in rats.

High aggression is often linked to lowered serotonin (5-HT) neurotransmission. Although this may hold for high aggression as a trait characteristic of an individual, serotonergic activity is probably increased during performance of aggressive behavior. To test this hypothesis, first, the 5-HT1A agonist alnespirone and gamma aminobutyric acid-A agonist muscimol were administered into the dorsal raphe nucleus. These treatments which inhibit 5-HT neuronal activity, were shown to decrease performance of aggressive behavior. Second, after a resident-intruder test, the activation of 5-HT neurons (measured by c-fos expression) was increased in high-aggressive rats, compared with low-aggressive rats or control rats that were not subjected to a social confrontation. Results show that performance of aggressive behavior increases 5-HT neuronal activity and that preventing this activation inhibits expression of aggressive behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hyperspectral reflectance features of water hyacinth growing under feeding stresses of Neochetina spp. and different heavy metal pollutants

Spectral signatures of water hyacinth grown with biocontrol agents (Neochetina eichornia and N. bruchi) and various heavy metal pollutants were collected at the plant canopy level using a hand-held spectrometer to detect the biocontrol agent and heavy metal-induced plant stresses and the interaction between the two stressors. Water hyacinth was grown in 65l tubs, each with a single element from one of: As (1 mg l^?1), Au (1 mg l^?1), Cu (2 mg l^?1), Fe (0.5, 2 and 4 mg l^?1), Hg (1 mg l^?1), Mn (0.5, 2, and 4 mg l^?1), U (1 mg l^?1), and Zn (4 mg l^?1), with the exception of the control treatment. Three weeks after the metal treatments, the weevils were added to each tub, including those of the control treatment. Spectral measurements were taken before and after the addition of the weevils. Several spectral indicators of plant stress including red edge normalized difference vegetation index (RE-NDVI), modified red edge NDVI (mNDVI₇₀₅), modified simple ratio (mSR), photochemical reflectance index (PRI), and red edge position (REP) calculated using first derivative and linear extrapolation and water band index (WBI) were used to identify the plant stresses of water hyacinth. The spectral indicators of both metal and weevil plant stressors were correlated with the leaf chlorophyll content from the SPAD-502 readings at the end of the experiment. Correlations of mNDVI₇₀₅ with SPAD-502 readings were the highest followed by the indicators of REP. Cu-, Hg-, and Zn-treated plants showed significantly lower chlorophyll contents compared with the control treatment. A similar trend with four additional treatments (As, Fe-M, Mn-L, and Mn-H) was seen after the release of the weevils, indicating plant stress due to feeding by the biocontrol agent. However, adult and larval feeding was significantly reduced by Cu, Hg, and Zn elements, of which Cu was the most stressful. These results indicate that hyperspectral remote sensing has potential as a tool to determine the health status of water hyacinth from a remote location, to inform management interventions in control of the weed. However, its usage at a larger scale requires further studies.     

Surface reconstruction and elastic behavior of silicon nanobeams: The impact of applied deformation

Using molecular dynamics calculations with a recently developed modified embedded atom method (MEAM) potential, the overall elastic behavior of silicon (100) nanobeams under externally applied strain at room temperature is investigated. As uniaxial tensile strain increases, the stability range of any relevant reconstructions changes, thus, the surface region undergoes a series of reconstructions. In nanostructures, such as nanoplates, nanobeams, and nanowires, this phenomenon is significant and changes the elastic response. The results indicate that the elastic behavior of nanostructures is not only size-dependent, but also load-dependent.