Successiveness discrimination as a two-state, quantal process

The duration of the "psychophysical time quantum" measured through the application of a two-state model of successiveness discrimination is equal in magnitude to the modal zero-crossing interval of the alpha rhythm. The two quantities have similar distributions and they are correlated over individuals.     

Replamineform: a new process for preparing porous ceramic, metal, and polymer prosthetic materials

The replamineform process (meaning replicated life forms) is a technique for duplicating the microstructure of carbonate skeletal components in ceramic, metal, or polymer materials. The special pore structures of marine invertebrate skeletal materials such as echinoid spines and corals, which are difficult or impossible to create artificially, can thus be copied in useful materials. Of immediate interest is the possibility of using these replicated microstructures in the fabrication of orthopedic prosthetic devices. By means of this technique, prosthetic materials having a controlled pore microstructure for optimum strength and tissue ingrowth may be obtained.     

Recovery from retrograde amnesia: a learning process

Retrograde amnesia was produced in rats by electroconvulsive shock. Memory recovered if the animals were given repeated test trials. Memory did not recover if steps were taken to reduce the conditioning properties of the test trials; the manipulations included eliminating the response, altering the apparatus cues, or extinguishing conditioned "fear" by confining animals to the apparatus during the first test trial.     

Application of two-step laser mass spectrometry to cosmogeochemistry: direct analysis of meteorites

Polycyclic aromatic hydrocarbons in C1, C2, and C3 carbonaceous chondrites and in some ordinary chondrites have been directly analyzed by two-step laser desorption/ laser multiphoton ionization mass spectrometry, a selective and sensitive method requiring only milligram samples. At the ionization wavelength of 266 nanometers, parent ion peaks of polycyclic aromatic hydrocarbons dominate the mass spectra. Quantitative analysis is possible; as an example, the concentration of phenanthrene in the Murchison meteorite was determined to be 5.0 parts per million.     

铁氨氧化:新型的厌氧氨氧化过程及其生态意义

近年研究发现,以胞外电子受体(铁锰氧化物)代替亚硝酸盐,在以铵离子为唯一电子供体的条件下驯化,可以氧化铵离子同步实现金属离子的还原,这种兼具"厌氧氨氧化"和"铁还原"特点的生物化学过程,称为铁氨氧化.在本质上,铁氨氧化是微生物催化氨氧化耦合铁还原的生物反应过程.在微生物生态学领域,铁氨氧化过程作为一种新型的观点,是地球生态系统氮素循环的重要途径,这种观点对于理解地球化学元素诸如驱动地球上微小动植物生长的氮和铁的循环有重要作用,然而目前还很少关于铁氨氧化过程的理论研究,本文总结了铁氨氧化的发现历程,阐述了铁氨氧化过程的电子传递机制及其影响因素,从氮循环、铁循环和胞外电子呼吸等方面详细论述了铁氨氧化过程在生态学方面的意义,并指出了铁氨氧化的研究方向以及重点.     

Ordered metal nanohole arrays made by a two-step replication of honeycomb structures of anodic alumina

A highly ordered metal nanohole array (platinum and gold) was fabricated by a two-step replication of the honeycomb structure of anodic porous alumina. Preparation of the negative porous structure of porous alumina followed by the formation of the positive structure with metal resulted in a honeycomb metallic structure. The metal hole array of the film has a uniform, closely packed honeycomb structure approximately 70 nanometers in diameter and from 1 to 3 micrometers thick. Because of its textured surface, the metal hole array of gold showed a notable color change compared with bulk gold.     

Non-GMO vs organic labels: purity or process guarantees in a GMO contaminated landscape

Since 2010, demand for non-GMO food products has grown dramatically. Two non-GMO labels dominate the market: USDA Organic and the Non-GMO Project Verified (the Project). However, the non-GMO status of Organic is not obvious from the label and many consumers are unaware of this. As sales of products carrying the Project’s non-GMO label have exploded, concern has increased among some Organic proponents that demand for non-GMO threatens the organic market. In response, both sides are seeking to build legitimacy and authority for their label by emphasizing the value of their standards for determining a food product’s non-GMO status within a GMO contaminated agrifood system. Drawing on in-depth interviews with key informants with knowledge of non-GMO standards and labels, we examine the knowledge systems, discourses and actors that proponents of the Project and USDA Organic privilege in their effort to legitimize their standards. Here, the Project emphasizes its application of technoscientific norms, especially thresholds and testing, which they argue provide the best means for preventing GMO contamination and helping consumers find (relative) non-GMO ‘purity’. In contrast, proponents of Organic favor a process standard that excludes GMOs, arguing that non-GMO ‘purity’ is unrealistic in today’s agrifood system that is widely contaminated by GMOs and where mandatory testing would unnecessarily harm organic producers. We conclude that tensions between the two groups are unlikely to be easily reconciled since these two distinct marketing labels rely on different knowledge and verification claims to vie for consumers and increase market share.     

Bidirectional transmission at the rectifying electrotonic synapse: a voltage-dependent process

Rectifying properties of electrotonic synapses established by the crayfish giant motor fiber are associated with a more negative resting membrane potential in the presynaptic than in the postsynaptic side of the junction. An increased junctional conductance and bidirectional transmission are produced, with almost no delay, by inverting this polarization.     

亚临界R134a体系中的绿色酶促反应研究(英文)

以环境友好的亚临界1,1,1,2-四氟乙烷(R134a)作为反应介质,用磷脂酶D催化卵磷脂(PC)的酰基转移反应制备磷脂酰丝氨酸(PS)。探讨了压力、温度、水分、酶量、底物对酶促反应的影响。结果表明,磷脂酶D在亚临界R134a中(303～323 K、2～8MPa)表现出较高的催化活性。与传统的有机溶剂反应体系相比,亚临界R134a体系能够改善酶促反应动力学,即需要较少的酶量即可迅速达到较高的转化率;在亚临界R134a体系压力6 MPa、体系温度313 K的条件下,9.6 U磷脂酶D催化反应240 min,磷脂酰丝氨酸的含量达到84.88%。     

基于两阶段DEA的山东棉花生产效率评价研究

采用两阶段DEA即DEA-Tobit两步法对山东棉花的生产效率进行了实证测算分析.结果表明:虽然2000-2008年间山东棉花的综合生产效率水平较高,但尚未达到资源的有效配置,要素配置有待进一步改进;地区间的生产效率差异明显;在环境影响因素方面,基础设施对棉花生产效率没有显著影响,而农业种植结构对棉花生产效率具有负效应.     

Oblique impact: a process for obtaining meteorite samples from other planets

Cratering flow calculations for a series of oblique to normal (10 degrees to 90 degrees ) impacts of silicate projectiles onto a silicate halfspace were carried out to determine whether or not the gas produced upon shock-vaporizing both projectile and target material would form a downstream jet that could entrain and propel SNC meteorites from the Martian surface. The difficult constraints that the impact origin hypothesis for SNC meteorites has to satisfy are that these meteorites are lightly to moderately shocked and yet have been accelerated to speeds in excess of the Martian escape velocity (more than 5 kilometers per second). Two-dimensional finite difference calculations were performed that show that at highly probable impact velocities (7.5 kilometers per second), vapor plume jets are produced at oblique impact angles of 25 degrees to 60 degrees and have speeds as great as 20 kilometers per second. These plumes flow nearly parallel to the planetary surface. It is shown that upon impact of projectiles having radii of 0.1 to 1 kilometer, the resulting vapor jets have densities of 0.1 to 1 gram per cubic centimeter. These jets can entrain Martian surface rocks and accelerate them to velocities greater than 5 kilometers per second. This mechanism may launch SNC meteorites to earth.     

Impact-induced seismic activity on asteroid 433 Eros: a surface modification process

High-resolution images of the surface of asteroid 433 Eros revealed evidence of downslope movement of a loose regolith layer, as well as the degradation and erasure of small impact craters (less than approximately 100 meters in diameter). One hypothesis to explain these observations is seismic reverberation after impact events. We used a combination of seismic and geomorphic modeling to analyze the response of regolith-covered topography, particularly craters, to impact-induced seismic shaking. Applying these results to a stochastic cratering model for the surface of Eros produced good agreement with the observed size-frequency distribution of craters, including the paucity of small craters.     

加工型马铃薯新品种“大西洋"多点试验

为评价筛选适宜云南种植的马铃薯优质、抗病、炸片加工型品种，特设置了国际流行的炸片加工型品种（系）“大西洋”（白花株系）在云南的多点试验，并对其在云南各地（特别是在冬季或早春种植区）的丰产性、内在品质、加工性能以及经济效益等进行了分析。试验结果，该品种（系）2年6点的平均产量达到22100.7kg/hm^2，比对照品种增产9．07％。收获后的薯块干物质含量为19．93％，还原糖含量为0．049％；鲜样含淀粉18．29％，干样含淀粉91．77％。薯块炸片的感官评价为9．5级。作为炸片加工用原料，该品种（系）有一定推广价值。     

湖北国际物流核心枢纽机场2016年12月一次大雾天气过程特征分析

利用常规观测资料、区域自动观测站资料以及NCEP 1°×1°再分析资料对2016年12月1—2日湖北国际物流核心枢纽机场1次大雾天气过程进行诊断分析。结果表明,本次大雾过程是在高、中、低层天气系统相互配合下出现的,具有明显辐射雾特征;大雾阶段地面10 m以风速小于1.0 m/s的偏东风为主,风速增大或风向转为偏北风有利于雾的消散;对流层低层涡度和散度较小,中低层都以下沉运动为主;地面比湿维持在5 g/kg左右,温度露点差在3℃左右,温度露点差的急剧增大能表征大雾消散。大雾出现之前低层相对湿度维持在60%以上,800～600 hPa维持相对湿度小于20%的相对干区;950～900 hPa附近有逆温或中性层结存在,在低层存在冷平流,中高层存在暖平流,并且冷平流从地面先随高度增大,在上层转为冷平流随高度减小、暖平流随高度增加,900 hPa附近存在的冷平流随高度减小,在更小范围内形成上暖下冷的稳定结构。