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1. chinaXiv:201911.00094 [pdf]

Copositivity for 3rd order symmetric tensors and applications

刘佳蕊; 宋义生
Subjects: Mathematics >> Mathematical Physics

The strict opositivity of 4th order symmetric tensor may apply to detect vacuum stability of general scalar potential. For finding analytical expressions of (strict) opositivity of 4th order symmetric tensor, we may reduce its order to 3rd order to better deal with it. So, it is provided that several analytically sufficient conditions for the copositivity of 3th order 2 dimensional (3 dimensional) symmetric tensors. Subsequently, applying these conclusions to 4th order tensors, the analytically sufficient conditions of copositivity are proved for 4th order 2 dimensional and 3 dimensional symmetric tensors. Finally, we apply these results to present analytical vacuum stability conditions for vacuum stability for $\mathbb{Z}_3$ scalar dark matter.

submitted time 2019-11-23 Hits136Downloads49 Comment 0

2. chinaXiv:201911.00096 [pdf]

共情对灾后青少年亲社会行为的影响:感恩、社会支持和创伤后成长的中介作用

王文超; 伍新春
Subjects: Psychology >> Clinical and Counseling Psychology

以雅安地震极重灾区芦山县的542名中学生为被试,在地震发生3.5年后,采用人际反应指数量表测查被试的共情能力,并在震后4.5年采用感恩问卷、社会关系网络问卷、创伤后成长问卷和亲社会行为问卷测查被试的感恩、社会支持、PTG和亲社会行为,从追踪的视角考察地震后青少年的共情能力对亲社会行为的影响,并探讨感恩、社会支持和创伤后成长(PTG)在其中的中介作用。结果显示,共情可直接正向预测亲社会行为;共情对亲社会行为的预测可分别通过感恩、社会支持和PTG的中介进行;共情还可以分别通过感恩经社会支持、感恩经PTG、社会支持经PTG、感恩经社会支持再经PTG的链式中介对亲社会行为起到正向预测作用。这一发现提示,未来的创伤后心理辅导工作应更加关注青少年的积极心理和社会行为的发展。

submitted time 2019-11-21 Hits239Downloads83 Comment 0

3. chinaXiv:201706.00761 [pdf]

神经科学偏见效应:可重复性及其心理机制的探索

殷继兴; 胡传鹏
Subjects: Psychology >> Legality Psychology

神经科学的发展对其他学科以及社会产生了重要的影响。虽然神经科学方法与行为研究方法都是探索人类心理与行为的有效手段并各有所长,但神经科学的研究结果却可能引起人们过度的解读和信任。研究者发现,当某一结论使用神经科学结果作为证据时,比使用行为科学结果或者心理生理学指标作为证据时更加让人信服,即使神经科学结果与该结论之间毫无关系,这种现象被称为神经科学偏见(neuroscience bias)。通过系统回顾近年来关于神经科学偏见的研究,我们发现:(1)虽然神经科学偏见存在可重复性的争论,但该效应确实存在;(2)神经科学偏见的产生可能是因为个体倾向于还原论的解释(即使用低层次、简单的机制来解释更高层次上的现象)及心理本质主义的影响(即人们认为心理与行为的本质是神经活动)。神经科学偏见反映了公众对科学结果解读的偏见,未来研究需要探讨这种偏见的心理机制,从而引导科学结果的正确解读和运用。

submitted time 2019-11-05 Hits21606Downloads2767 Comment 0

4. chinaXiv:201905.00013 [pdf]

人工智能基础理论的过去、现在及发展趋势思考

辛欣; 郭平
Subjects: Information Science and Systems Science >> Other Disciplines of Information Science and Systems Science

本文回顾了人工智能的发展历史,分析了当前国内外研究现状,指出了目前以深度学习为代表的人工智能基础研究困境。包括可解释性神经网络模型问题、网络模型的结构设计问题、小样本学习问题等。给出了今后人工智能发展趋势,认为基于统计物理思维构建协同学习系统可能是通往通用人工智能的路线之一。

submitted time 2019-10-16 Hits1743Downloads555 Comment 0

5. chinaXiv:201905.00003 [pdf]

急性应激损害对威胁刺激的注意解除

罗禹; 念靖晴; 鲍未; 张静静; 赵守盈; 潘运; 许爽; 张禹
Subjects: Psychology >> Cognitive Psychology

急性应激会增强个体对威胁刺激的注意偏向,但急性应激是增强了对威胁刺激的注意定向还是损害了对威胁刺激的注意解除还不清楚。本研究采用社会评估冷压任务和点探测任务,结合事件相关电位技术,考察急性应激对威胁刺激注意偏向影响的认知机制。在进行社会评估冷压任务后,应激组个体的状态焦虑和皮质醇浓度显著升高。在注意偏向中,应激组对威胁刺激的注意解除比控制组更慢,应激组和控制组在对威胁刺激的注意定向上无显著差异。ERP结果上,威胁刺激诱发应激组比控制组产生了更负的SPCN,在N2pc上没有显著差异。应激组和控制组皮质醇增量的差异和N2pc、SPCN的组间差异均有显著正相关。这些结果说明,急性应激增强对威胁刺激的注意偏向是因为其损害个体对威胁刺激的注意解除,这可能是因为急性应激损害了与注意解除相关的额-顶网络的功能所致。

submitted time 2019-09-28 Hits11225Downloads598 Comment 0

6. chinaXiv:201904.00087 [pdf]

德性与德行:道德决策中的提问框架效应

刘传军; 廖江群
Subjects: Psychology >> Social Psychology

道德双加工理论预测关注德行的提问框架(道德行为)下相比关注德性的提问框架(道德判断)下,决策者具有更高的情绪卷入而会做出更偏向于义务论的决策或者对规范的敏感性更高;而认知失调的行动模型则认为在具有心理冲突性的情境下,决策者在道德行动框架相比于道德判断框架下为了实现失调减少会做出更偏离义务论的决策或者对规范的敏感性更低。本研究通过3个实验(总N = 960)探讨了这一道德决策中的提问框架效应。实验1使用经典道德两难情境法,使被试在道德判断框架和道德行动框架下对道德提议进行赞成度评分;实验2操纵规范和结果的组合,即规范提倡或禁止且结果利大于弊或弊大于利,并使用方差分析法探讨规范与结果对道德决策的交互影响;实验3使用CNI模型(Consequence, Norm and general Inaction/action preference)分离出结果敏感性,规范敏感性和一般性不作为/作为倾向。3个实验综合表明道德行动框架比道德判断框架增强了结果敏感性,削弱了规范敏感性,增强了一般性不作为倾向。道德行动框架比道德判断框架会导致更强的功利主义倾向,更弱的义务论倾向和更强的一般性不作为倾向,验证了Gawronski等(2017)的实验结果,支持认知失调的行动模型,说明道德决策会受到动机加工的影响。

submitted time 2019-09-16 Hits13597Downloads1541 Comment 0

7. chinaXiv:201909.00137 [pdf]

道德自我在认知加工中的优势

胡传鹏
Subjects: Psychology >> Social Psychology

道德自我指个体对自己在道德方面的评估。作为自我概念的核心部分,道德自我对人们的道德判断和道德行为均有重要影响。最近的研究表明,道德自我相比自我的其他方面具有优势,例如自我增强效应(self-enhancement effect)在道德方面比其他方面更强,即人们普遍认为自己在许多方面处于平均水平之上,而在道德方面这种优越感最强。但是,道德自我的优势是否也存在于认知加工中仍是未知的问题。本研究结合认知神经科学的方法,以社会联结学习为研究范式,系统地考查了道德自我在知觉中的加工优势,提出道德自我是指导个体行为的内在参照标准,本论文从行为学(第二~四章)和神经生物学(第五章)水平为这一理论提供实证证据。 首先,通过三个控制研究(第二章:研究1-3),验证了道德品质信息在知觉加工中的优势,同时排除了熟悉性和文字启动等可能的混淆变量,为道德信息能够对知觉起到自上而下的影响提供证据。如果道德自我是个体行为与认知加工的内在参照标准,则研究1-3的结果也受到这一标准的调控。因此,我们预期,当把自我与他人作为外显变量时,道德信息对知觉的调控效应主要反映在道德自我这一条件上。为了验证这一假设(第三章),研究4比较了道德意义上积极、中性和消极的自我以及他人在知觉匹配中加工的差异,发现道德品质信息对知觉的调节作用主要发生在与自我相关的条件。为进一步将道德信息与自我相关的交互作用,分别将道德(研究5)或者自我(研究6)作为与任务无关的刺激,检验道德与自我对知觉的内隐调节作用,结果发现道德与自我能够对知觉产生调节作用。为了讨论道德自我在知觉加工优势效应的稳定性,我们采用元分析进一步表明(研究7),道德自我信息相对于其他条件人加工优势在反应时上的效应量大约为Cohen’s d = 0.5左右,表现出中等的效应量。 为了深入理解道德自我的知觉机制,本研究采用模型分析的思路分解认知过程(第四章),使用扩散模型和指数高斯模型对研究4 ~ 6的数据分析,研究8发现道德自我对知觉决策的影响主要是通过加快道德自我条件下的信息累积速率,而不是改变被试的决策偏见。为考察道德自我的知觉加工中的跨任务稳定性,在研究9结合了知觉匹配任务与知觉分类任务,且在知觉分类任务中设置了多种标准,结果发现,道德自我在不同的任务中均表现出稳定的优势。 论文的第二部分,进一步研究了道德自我的神经机制。一方面,使用大样本的神经成像数据,探索了自我道德评估得分与大脑结构的关系(第五章)。通过基于体素的形态学分析(研究10),我们未能发现,道德自我评分与大脑灰质体积之间的相关。为了对参与道德自我任务的脑区进行评估,我们使用神经成像元分析(研究11)比较了道德认知与自我参照的神经成像研究,发现两者共同激活了背内侧前额叶和眶额皮层,为进一步功能成像研究提供了良好的基础。 本课题使用社会认知神经科学的方法,从功能、算法和硬件三个层次研究了道德自我概念,将社会心理学与认知心理学和计算模型结合起来。本研究的一系列实验表明,道德自我在知觉中具有稳定的优势,这种优势表现为积极的道德自我信息在知觉中能够更快地进行信息的累积,其神经基础可能是背内侧前额叶和眶额叶皮层。道德自我在认知加工中的优势,与社会心理学中自我增强的效应一起,共同反应了道德自我概念对于个体的重要性,为今后进一步改变道德行为提供了基础。

submitted time 2019-09-12 Hits5035Downloads506 Comment 0

8. chinaXiv:201607.00046 [pdf]

Exact Solution for Three-Dimensional Ising Model

Zhang, Degang
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

Three-dimensional Ising model in zero external field is exactly solved by operator algebras, similar to the Onsager's approach in two dimensions. The partition function of the simple cubic crystal imposed by the periodic boundary condition along both $(0 1 0)$ and $(0 0 1)$ directions and the screw boundary condition along the $(1 0 0)$ direction is calculated rigorously. In the thermodynamic limit an integral replaces a sum in the formula of the partition function. A order-disorder transition in the infinite crystal occurs at a temperature $T=T_c$ determined by the condition: $\sinh\frac{2J}{k_BT_c}\sinh\frac{2(J_1+J_2)}{k_BT_c}=1$, where $(J_1 J_2 J)$ are the interaction energies in three directions, respectively. The analytical expressions for the internal energy and the specific heat are also given. It is also shown that the thermodynamic properties of 3D Ising model with $J_1=J_2$ are connected to those in 2D Ising model with the interaction energies $(J_1 J_{2D})$ by the relation $(\frac{J_{2D}}{k_BT})^*=(\frac{J}{k_BT})^*-\frac{J_1}{k_BT}$, where $x^*=\frac{1}{2}{\rm ln coth} x={\rm tanh}^{-1}(e^{-2x})$.

submitted time 2019-09-12 Hits4893Downloads1323 Comment 0

9. chinaXiv:201904.00091 [pdf]

Dynamics of infiltration rate and Field-Saturated soil hydraulic conductivity in a Wastewater-Irrigated cropland

Siyi Zhang; Isaac Hopkins; Li Guo; Henry Lin
Subjects: Geosciences >> Geography

The maintenance of a soil’s infiltration rate (IR) and field-saturated hydraulic conductivity (Kfs) is crucial for the long-term sustainable functioning of wastewater-irrigated lands. However, an effective procedure for reliably measuring in situ soil Kfs remains elusive. To address this issue, this study investigated the DualHead Infiltrometer (DHI), a novel instrument for automatically determining IR and Kfs, and compared it with a traditional Double-Ring Infiltrometer (DRI) under various field conditions. In the initial phase, we optimized the procedure and settings for the DHIs in a cropland that has been spray-irrigated with secondary-treated wastewater for decades in central Pennsylvania. Results showed that our optimized procedure, which used a single, long pressure cycle, yielded more robust measurements of IR than the originally recommended sequence of two short pressure cycles. The values of Kfs measured by the DHIs with optimized settings were similar to those measured by DRIs under many (but not all) field conditions, due to their differences in infiltration surface areas, operational procedures, length of infiltration time, and soil spatiotemporal variability. Viscosity-corrected Kfs on the irrigated cropland was 123.8±94.0 mm h-1, higher than that on the adjacent non-irrigated cropland (103.2±94.6 mm h-1), but the difference was not statistically significant, owing to the high degree of soil spatiotemporal variability and our limited number of measurements. Nevertheless, the higher Kfs values measured on irrigated cropland reflect observed changes in soil structure (e.g., soil pore characteristics) that have resulted from decades of irrigation. Seasonal variations in Kfs values existed between winter and summer conditions, but IRs during all seasons remained much higher than the current spray-irrigation rate (4.25 mm h-1), suggesting that the soil is still capable of handling the routine irrigation, even during winter. However, the coefficients of variation exceeded 67.0% across the field sites investigated and the time periods covered by our measurements were limited. As this specific site is permitted to discharge treated wastewater year-round, caution must still be exercised to ensure that soil Kfs remains high enough to prevent runoff generation, especially during winter frozen conditions.

submitted time 2019-09-06 Hits15645Downloads1221 Comment 0

10. chinaXiv:201904.00092 [pdf]

反驳文本对患方信任和道德判断的影响与机制

吕小康; 付春野; 汪新建
Subjects: Psychology >> Social Psychology

采用反驳文本范式对患方进行知识修正,提升患方对医方的信任和道德判断。预实验编制反驳文本并验证其有效性,实验1验证反驳文本可以显著提高患方的对医信任和道德判断,并发现医疗结果是影响患方信任和对医道德判断的重要因素。实验2和实验3探究了反驳文本有效性的作用机制及适用普遍性,发现不确定性容忍度和宽容度在反驳文本和患方信任及道德判断之间呈链式中介作用,且反驳文本可脱离医学情境提升普遍患方信任。

submitted time 2019-09-05 Hits15203Downloads1467 Comment 0

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