Large Magnetoresistance over an Extended Temperature Regime in Monophosphides of Tantalum and Niobium

We report extremely large magnetoresistance (MR) in an extended temperature regime from 1.5 K to 300 K in non-magnetic binary compounds TaP and NbP. TaP exhibits linear MR around $1.8\times 10^4$ at 2 K in a magnetic field of 9 Tesla, which further follows its linearity up to $1.4\times 10^5$ in a magnetic field of 56 Tesla at 1.5 K. At room temperature the MR for TaP and NbP follows a power law of the exponent about $1.5$ with the values larger than $300\%$ in a magnetic field of 9 Tesla. Such large MR in a wide temperature regime is not likely only due to a resonance of the electron-hole balance, but indicates a complicated mechanism underneath.Comment: 13 pages, 4 figures; submitted in May 20, 2015; accepted for publicatio

Calcium–magnesium–alumina–silicate (CMAS) resistance of LaPO4 thermal barrier coatings

Nanostructured LaPO4 thermal barrier coatings (TBCs) were prepared by air plasma spraying, and their resistance to calcium–magnesium–alumina–silicate (CMAS) attack at 1250 °C, 1300 °C and 1350 °C was investigated. The reaction products were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy and transmission electron microscopy. Exposed to CMAS attack for 0.5 h, a continuous dense reaction layer formed, which was mainly composed of P–Si apatite based on Ca2+xLa8-x(PO4)x(SiO4)6-xO2, anorthite and spinel phases. Beneath the reaction layer, little evidence of CMAS trace could be found. With the increase in temperature and heat treatment duration, the reaction layer became thick, while penetration depth of the molten CMAS changed slightly. Due to the formation of a reaction layer suppressing CMAS further infiltration, LaPO4 TBCs are highly resistant to CMAS attack

美国负面清单管理模式下的投资准入障碍研究——以中国企业对美投资为视角

郭成龙，工信部国际经济技术合作中心，涉外法律研究所副所长（主持工作），法学博士。【中文摘要】作为负面清单管理模式的积极倡导者和践行者，美国一直标榜该模式下其投资准入的自由化。但与美国所标榜的其外商投资环境高度开放和自由形成较大反差的是，很多国家的企业尤其是我国企业在对美投资过程中不断遭遇行业限制、政治干扰、复杂的法律环境、国家安全审查和技术性壁垒等方面的障碍，而且这些限制和障碍大都呈现为法律的形式，使赴美投资的企业时常受困于无处不在的“玻璃门”和“旋转门”。为此，一方面需要政府通过推动中美投资协定谈判和各种形式的多双边对话，尽量降低这些风险，抵制投资保护主义干扰；另一方面要充分发挥行业商协会的作用，中介组织和企业一道以更加积极的心态和有效的策略来妥善应对投资风险和壁垒，充分利用和发掘美国对于中国企业的投资价值。 【Abstract】As an active advocator and practitioner of the negative list management mode, America has always advertised the liberalization and opening of its investment access under the mode. But, with a big contrast, many countries' enterprises, especially Chinese enterprises often encounter industry restrictions, political interference,the complex legal environment, national security review and technical barriers, and are beset by ubiquitous “glass doors” and “revolving doors”. To this end, on the one hand, the Chinese Government needs to promote the Sino-US investment treaty negotiations and various bilateral and multilateral dialogues to minimize these risks, to resist investment protectionism; the other hand, to give full play to the role of industry associations, industry associations and enterprises should hold a more positive attitude and effective strategies to properly deal with investment risks and barriers to make full use of and explore investment value of American market

MqsR/MqsA Toxin/Antitoxin System Regulates Persistence and Biofilm Formation in Pseudomonas putida KT2440

Bacterial toxin/antitoxin (TA) systems have received increasing attention due to their prevalence, diverse structures, and important physiological functions. In this study, we identified and characterized a type II TA system in a soil bacterium Pseudomonas putida KT2440. This TA system belongs to the MqsR/MqsA family. We found that PP_4205 (MqsR) greatly inhibits cell growth in P. putida KT2440 and Escherichia coli, the antitoxin PP_4204 (MqsA) neutralizes the toxicity of the toxin MqsR, and the two genes encoding them are co-transcribed. MqsR and MqsA interact with each other directly in vivo and MqsA is a negative regulator of the TA operon through binding to the promoter. Consistent with the MqsR/MqsA pair in E. coli, the binding of the toxin MqsR to MqsA inhibits the DNA binding ability of MqsA in P. putida KT2440. Disruption of the mqsA gene which induces mqsR expression increases persister cell formation 53-fold, while overexpressing mqsA which represses mqsR expression reduces persister cell formation 220-fold, suggesting an important role of MqsR in persistence in P. putida KT2440. Furthermore, both MqsR and MqsA promote biofilm formation. As a DNA binding protein, MqsA can also negatively regulate an ECF sigma factor AlgU and a universal stress protein PP_3288. Thus, we revealed an important regulatory role of MqsR/MqsA in persistence and biofilm formation in P. putida KT2440

Impact of Traffic Sign on Pedestrians’ Walking Behavior

To study the impact of traffic sign on pedestrian walking behavior, the paper applies cellular automaton to simulate one-way pedestrian flow. The channel is defined as a rectangle with one open entrance and two exits of equal width. Traffic sign showing that exit is placed with some distance in the middle front of the two exits. In the simulation, walking environment is set with various input density, width of exit, width and length of the channel, and distance of the traffic sign to exit. Simulation results indicate that there exists a critical distance from the traffic sign to exit for a given channel layout. At the critical distance, pedestrian flow fluctuates. Below such critical distance, flow is getting larger with the increase of input density. However, the flow drops sharply when the input density is over a critical level. If the distance is a little bit further than the critical distance, the largest flow occurs and the flow can remain steady no matter what input density will be