MoTe₂ Lateral Homojunction Field-Effect Transistors Fabricated using Flux-Controlled Phase Engineering

Ma, Rui,Zhang, Huairuo,Yoo, Youngdong,Degregorio, Zachary Patrick,Jin, Lun,Golani, Prafful,Ghasemi Azadani, Javad,Low, Tony,Johns, James E.,Bendersky, Leonid A.,Davydov, Albert V.,Koester, Steven J. American Chemical Society 2019 ACS NANO Vol.13 No.7

<P>The coexistence of metallic and semiconducting polymorphs in transition-metal dichalcogenides (TMDCs) can be utilized to solve the large contact resistance issue in TMDC-based field effect transistors (FETs). A semiconducting hexagonal (2H) molybdenum ditelluride (MoTe<SUB>2</SUB>) phase, metallic monoclinic (1T′) MoTe<SUB>2</SUB> phase, and their lateral homojunctions can be selectively synthesized <I><I>in situ</I></I> by chemical vapor deposition due to the small free energy difference between the two phases. Here, we have investigated, in detail, the structural and electrical properties of <I>in situ</I>-grown lateral 2H/1T′ MoTe<SUB>2</SUB> homojunctions grown using flux-controlled phase engineering. Using atomic-resolution plan-view and cross-sectional transmission electron microscopy analyses, we show that the round regions of near-single-crystalline 2H-MoTe<SUB>2</SUB> grow out of a polycrystalline 1T′-MoTe<SUB>2</SUB> matrix. We further demonstrate the operation of MoTe<SUB>2</SUB> FETs made on these <I>in situ</I>-grown lateral homojunctions with 1T′ contacts. The use of a 1T′ phase as electrodes in MoTe<SUB>2</SUB> FETs effectively improves the device performance by substantially decreasing the contact resistance. The contact resistance of 1T′ electrodes extracted from transfer length method measurements is 470 ± 30 Ω·μm. Temperature- and gate-voltage-dependent transport characteristics reveal a flat-band barrier height of ∼30 ± 10 meV at the lateral 2H/1T′ interface that is several times smaller and shows a stronger gate modulation, compared to the metal/2H Schottky barrier height. The information learned from this analysis will be critical to understanding the properties of MoTe<SUB>2</SUB> homojunction FETs for use in memory and logic circuity applications.</P> [FIG OMISSION]</BR>

Effect of deflector angle and number on evaporation performance of desulfurization wastewater in a spray drying tower

Shaodan Jia,Lun Ma,Xinke Chen,Qingyan Fang,Cheng Zhang 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.116 No.-

Rotary spray drying technology with bypass flue is widely adopted to realize the zero-discharge of desulfurizationwastewater in coal-fired power stations. Significantly, the deflector structure of the dryingtower is an essential factor affecting the evaporation performance of desulfurization wastewater. Thispaper is aimed to study the effect of the angle and number of the deflectors on the evaporation performancein a drying tower of a 600 MW coal-fired station. Results show that the gas distributor dividesthe flue gas into internal and external parts, and the flue gas in the internal channel is the main factoraffecting the evaporation performance. The deflector angles (especially for the internal deflector) havea remarkable impact on the evaporation behaviors, while the deflector numbers just have a minor effecton that. When the deflector number is 24 and the angles of internal and external deflectors are set at 0and 45, respectively, a better evaporation performance is obtained with the weighted average time ofapproximately 0.17 s and the complete evaporation distance of approximately 3.93 m. These optimal settingsare adopted in the actual operation, and the industrial measured results show good performance isobtained.

Regular Difference Covers

Arasu, K.T.,Bhandari, Ashwani K.,Ma, Siu-Lun,Sehgal, Surinder Department of Mathematics 2005 Kyungpook mathematical journal Vol.45 No.1

We introduce the concept of what we call "regular difference covers" and prove many nonexistence results and provide some new constructions. Although the techniques employed mirror those used to investigate difference sets, the end results in this new setting are quite different.

Pestalotiolide A, a New Antiviral Phthalide Derivative from a Soft Coral-derived Fungus Pestalotiopsis sp.

Yan-Lai Jia,Fei-Fei Guan,Jie Ma,Chang-Yun Wang,Chang-Lun Shao 한국생약학회 2015 Natural Product Sciences Vol.21 No.4

Chemical investigation of the fermentation broth of a Soft Coral-Derived fungus Pestalotiopsis sp., led to the isolation of a new phthalide derivative, pestalotiolide A (1), three known analogues (2, 3 and 4), along with 5'-O-acetyl uridine (5) first isolated as a natural product. The structure of the new compound (1) was established by comprehensive spectroscopic analysis and chemical methods. Compounds 1 - 4 possessed varying degrees of antiviral activities, which was reported for the first time. Compared to the positive control ribavirin (IC50 = 418.0 μM), pestalotiolide A (1) exhibited significant anti-EV71 activity in vitro, with an IC50 value of 27.7 mM. Furthermore, the preliminary structure-activity relationship of antiviral activities was also discussed.

Impact of numerical choices on water conservation in the E3SM Atmosphere Model version 1 (EAMv1)

Zhang, Kai,Rasch, Philip J.,Taylor, Mark A.,Wan, Hui,Leung, Ruby,Ma, Po-Lun,Golaz, Jean-Christophe,Wolfe, Jon,Lin, Wuyin,Singh, Balwinder,Burrows, Susannah,Yoon, Jin-Ho,Wang, Hailong,Qian, Yun,Tang, Q Copernicus GmbH 2018 Geoscientific model development Vol.11 No.5

<P><p><strong>Abstract.</strong> The conservation of total water is an important numerical feature for global Earth system models. Even small conservation problems in the water budget can lead to systematic errors in century-long simulations. This study quantifies and reduces various sources of water conservation error in the atmosphere component of the Energy Exascale Earth System Model.</p> <p>Several sources of water conservation error have been identified during the development of the version 1 (V1) model. The largest errors result from the numerical coupling between the resolved dynamics and the parameterized sub-grid physics. A hybrid coupling using different methods for fluid dynamics and tracer transport provides a reduction of water conservation error by a factor of 50 at 1<span class='inline-formula'>^∘</span> horizontal resolution as well as consistent improvements at other resolutions. The second largest error source is the use of an overly simplified relationship between the surface moisture flux and latent heat flux at the interface between the host model and the turbulence parameterization. This error can be prevented by applying the same (correct) relationship throughout the entire model. Two additional types of conservation error that result from correcting the surface moisture flux and clipping negative water concentrations can be avoided by using mass-conserving fixers. With all four error sources addressed, the water conservation error in the V1 model becomes negligible and insensitive to the horizontal resolution. The associated changes in the long-term statistics of the main atmospheric features are small.</p> <p>A sensitivity analysis is carried out to show that the magnitudes of the conservation errors in early V1 versions decrease strongly with temporal resolution but increase with horizontal resolution. The increased vertical resolution in V1 results in a very thin model layer at the Earth's surface, which amplifies the conservation error associated with the surface moisture flux correction. We note that for some of the identified error sources, the proposed fixers are remedies rather than solutions to the problems at their roots. Future improvements in time integration would be beneficial for V1.</p> </P>

Family History of Cancer and Head and Neck Cancer Risk in a Chinese Population

Huang, Yu-Hui Jenny,Lee, Yuan-Chin Amy,Li, Qian,Chen, Chien-Jen,Hsu, Wan-Lun,Lou, Pen-Jen,Zhu, Cairong,Pan, Jian,Shen, Hongbing,Ma, Hongxia,Cai, Lin,He, Baochang,Wang, Yu,Zhou, Xiaoyan,Ji, Qinghai,Zho Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.17

Background: The aim of this study was to investigate whether family history of cancer is associated with head and neck cancer risk in a Chinese population. Materials and Methods: This case-control study included 921 cases and 806 controls. Recruitment was from December 2010 to January 2015 in eight centers in East Asia. Controls were matched to cases with reference to sex, 5-year age group, ethnicity, and residence area at each of the centers. Results: We observed an increased risk of head and neck cancer due to first degree family history of head and neck cancer, but after adjustment for tobacco smoking, alcohol drinking and betel quid chewing the association was no longer apparent. The adjusted OR were 1.10 (95% CI=0.80-1.50) for family history of tobacco-related cancer and 0.96 (95%CI=0.75-1.24) for family history of any cancer with adjustment for tobacco, betel quid and alcohol habits. The ORs for having a first-degree relative with HNC were higher in all tobacco/alcohol subgroups. Conclusions: We did not observe a strong association between family history of head and neck cancer and head and neck cancer risk after taking into account lifestyle factors. Our study suggests that an increased risk due to family history of head and neck cancer may be due to shared risk factors. Further studies may be needed to assess the lifestyle factors of the relatives.

Comparison of Microbial Diversity and Composition in the Jejunum and Colon of Alcohol-Dependent Rats

( Yang Fan ),( Zhao Ya-e ),( Wei Ji-dong ),( Lu Yu-fan ),( Zhang Ying ),( Sun Ya-lun ),( Ma Meng-yu ),( Zhang Rui-ling ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 Journal of microbiology and biotechnology Vol.28 No.11

Alcohol dependence is a global public health problem, yet the mechanisms of alcohol dependence are incompletely understood. The traditional view has been that ethanol alters various neurotransmitters and their receptors in the brain and causes the addiction. However, an increasing amount of experimental evidence suggests that gut microbiota also influence brain functions via gut-to-brain interactions, and may therefore induce the development of alcohol use disorders. In this study, a rat model of alcohol dependence and withdrawal was employed, the gut microbiota composition was analyzed by high-throughput 16S rRNA gene sequencing, and the metagenome function was predicted by PICRUSt software. The results suggested that chronic alcohol consumption did not significantly alter the diversity and richness of gut microbiota in the jejunum and colon, but rather markedly changed the microbiota composition structure in the colon. The phyla Bacteroidetes and eight genera including Bacteroidales S24-7, Ruminococcaceae, Parabacteroides, Butyricimonas, et al were drastically increased, however the genus Lactobacillus and gauvreauii in the colon were significantly decreased in the alcohol dependence group compared with the withdrawal and control groups. The microbial functional prediction analysis revealed that the proportions of amino acid metabolism, polyketide sugar unit biosynthesis and peroxisome were significantly increased in the AD group. This study demonstrated that chronic alcohol consumption has a dramatic effect on the microbiota composition structure in the colon but few effects on the jejunum. Inducement of colonic microbiota dysbiosis due to alcohol abuse seems to be a factor of alcohol dependence, which suggests that modulating colonic microbiota composition might be a potentially new target for treating alcohol addiction.