Sustained electron tunneling at unbiased metal-insulator-semiconductor triboelectric contacts

Liu, Jun,Miao, Mengmeng,Jiang, Keren,Khan, Faheem,Goswami, Ankur,McGee, Ryan,Li, Zhi,Nguyen, Lan,Hu, Zhiyu,Lee, Jungchul,Cadien, Ken,Thundat, Thomas Elsevier 2018 Nano energy Vol.48 No.-

<P><B>Abstract</B></P> <P>Generating sufficient current density for powering electronic devices remains as one of the critical challenges of mechanical energy harvesting techniques based on piezo and triboelectricity, mainly due to the high impedance of the insulating material systems. Here we report on producing sustainable tunneling current using an unbiased, triboelectrically charged metal-insulator-semiconductor (MIS) point contact system, consisting of p-type silicon, silicon oxide and a metal tip. The native thin oxide (~ 1.6 nm) on the silicon surface provides a natural pathway for quantum mechanical tunneling of the triboelectrically generated electrons into the silicon substrate. Lateral back and forth sliding motion of the tip, irrespective of the direction of motion, generates a constant direct current (d.c.) with very high current density. The measured current shows an exponential decay with the thickness of oxide layer deposited with atomic layer deposition (ALD), confirming the quantum mechanical tunneling mechanism. It is proposed that the contact potential difference enhanced by triboelectric charging provides potential difference between metal point contact and the substrate. With single metallic micro probe sliding on a moderately doped p-type silicon, an open circuit voltage (<I>V</I> <SUB>oc</SUB>) of 300–400 mV and a short-circuit direct current (<I>I</I> <SUB>sc</SUB>) of 3–5 μA (a corresponding high current density, <I>J</I>, in the order of 1–10 A/m<SUP>2</SUP>) have been observed. It is predicted from conductive-atomic force microscopy (C-AFM) experiment that the theoretical <I>J</I> can be as high as 10<SUP>4</SUP> A/m<SUP>2</SUP>. This new concept has the potential as a green energy harvesting technique where a broad range of material candidates and device configurations could be used.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Quantum mechanical tunneling at triboelectrically charged interface through ultrathin oxide layer is demonstrated. </LI> <LI> Tribo-tunneling is found to be a universal phenomenon in MIS frictional contact system. </LI> <LI> High current density <I>J</I> of 5 A/m<SUP>2</SUP> is experimentally measured in doped silicon materials at macroscale. </LI> <LI> Ultrahigh C-AFM <I>J</I> of 10<SUP>4</SUP> A/m<SUP>2</SUP> is observed due to the nano-size probe-induced high electric field. </LI> <LI> This method can be used as cost-effective triboelectric DC current generator, due to easily available silicon wafers with native oxide. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Abietane Diterpenoids from Perovskia atriplicifolia and Their Anti-HBV Activities

Zhi-Yong Jiang,Zhong-Qiu Li,Chao-Guan Huang,Jun Zhou,Qiu-Fen Hu,Wen-Xing Liu,Xiang-Zhong Huang,Wei Wang,Li-Zhu Zhang,Fu-Ting Xia 대한화학회 2015 Bulletin of the Korean Chemical Society Vol.36 No.2

Bioassay-guided phytochemical investigation on the 90% EtOH extract of Perovskia atriplicifolia resulted in the isolation of eight abietane diterpenoids, including three new ones (1–3). Based on spectroscopic methods involving 1D and 2D NMR spectroscopy techniques, mass spectrometry, and optical rotation, the structures of the new compounds (1–3) were unambiguously characterized. Compounds 1–2 and 4–8 were evaluated for their anti-HBV (hepatitis B virus) activity in HepG 2.2.15 cell line. Results suggested rosmadial (8) had the most anti-HBV potency, suppressing the secretion of HBsAg and HBeAg, with IC50 values of 0.09 and 0.34 mM, respectively.

Static and free vibration analysis of shallow sagging inclined cables

Li, Zhi-Jiang,Li, Peng,He, Zeng,Cao, Ping Techno-Press 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.45 No.2

Based on link-model, we conducted a static analysis and computation of a three-span suspended cable structure in the present paper, and obtained the static configuration and tension distribution of the cable. Using the link and beam model based on finite element method, we analyzed the vibration modal of three-span suspended cable structure, and compared with the results obtained from ANSYS using link and beam element. The vibration modals of shallow sagging inclined cables calculated from proposed method agrees well with ANSYS results, which validates the proposed method. As a result, the influence of bend stiffness on in-plane natural frequencies is much greater than that on out-of-plane natural frequencies of inclined cables.

A GENERALIZATION OF LOCAL SYMMETRIC AND SKEW-SYMMETRIC SPLITTING ITERATION METHODS FOR GENERALIZED SADDLE POINT PROBLEMS

Li, Jian-Lei,Luo, Dang,Zhang, Zhi-Jiang The Korean Society for Computational and Applied M 2011 Journal of applied mathematics & informatics Vol.29 No.5

In this paper, we further investigate the local Hermitian and skew-Hermitian splitting (LHSS) iteration method and the modified LHSS (MLHSS) iteration method for solving generalized nonsymmetric saddle point problems with nonzero (2,2) blocks. When A is non-symmetric positive definite, the convergence conditions are obtained, which generalize some results of Jiang and Cao [M.-Q. Jiang and Y. Cao, On local Hermitian and Skew-Hermitian splitting iteration methods for generalized saddle point problems, J. Comput. Appl. Math., 2009(231): 973-982] for the generalized saddle point problems to generalized nonsymmetric saddle point problems with nonzero (2,2) blocks. Numerical experiments show the effectiveness of the iterative methods.

Clinical Determinants of Weight Loss in Patients with Esophageal Carcinoma During Radiotherapy: a Prospective Longitudinal View

Jiang, Nan,Zhao, Jin-Zhi,Chen, Xiao-Cen,Li, Li-Ya,Zhang, Li-Juan,Zhao, Yue Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.5

Purpose: The prevalence of weight loss in esophageal carcinoma patients is high and associated with impairment of physical function, increased psychological distress and low quality of life. It is not known which factors may contribute to weight loss in patients with esophageal carcinoma during radiotherapy in China. The objective of this study was to identify the associated demographic and clinical factors influencing weight loss. Methods: We evaluated 159 esophageal carcinoma patients between August 2010 and August 2013 in a crosssectional, descriptive study. Patient characteristics, tumor and treatment details, psychological status, adverse effects, and dietary intake were evaluated at baseline and during radiotherapy. A multivariate logistic regression analyss was performed to identify the potential factors leading to weight loss. Results: 64 (40.3%) patients had weight loss ${\geq}5%$ during radiotherapy. According to logistic regression analysis, depression, esophagitis, and loss of appetite were adverse factors linked to weight loss. Dietary counseling, early stage disease and total energy intake ${\geq}1441.3$ (kcal/d) were protective factors. Conclusions It was found that dietary counseling, TNM stage, total energy intake, depression, esophagitis, and loss of appetite were the most important factors for weight loss. The results underline the importance of maintaining energy intake and providing dietary advice in EC patients during RT. At the same time, by identifying associated factors, medical staff can provide appropriate medical care to reduce weight loss. Further studies should determine the effect of these factors on weight loss and propose a predictive model.

Static and free vibration analysis of shallow sagging inclined cables

Zhi-Jiang Li,Peng Li,Zeng He,Ping Cao 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.45 No.2

Based on link-model, we conducted a static analysis and computation of a three-span suspended cable structure in the present paper, and obtained the static configuration and tension distribution of the cable. Using the link and beam model based on finite element method, we analyzed the vibration modal of three-span suspended cable structure, and compared with the results obtained from ANSYS using link and beam element. The vibration modals of shallow sagging inclined cables calculated from proposed method agrees well with ANSYS results, which validates the proposed method. As a result, the influence of bend stiffness on in-plane natural frequencies is much greater than that on out-of-plane natural frequencies of inclined cables.

The application of the starfish hatching enzyme for the improvement of scar and keloid based on the fibroblast-populated collagen lattice.

Li, Zhi Jiang,Kim, Sang Moo Humana Press 2014 Applied biochemistry and biotechnology Vol.173 No.4

<P>Various bioactivities of the starfish hatching enzyme (HE) including collagen gel contraction, MMPs activity, hydroxyproline release, and gene regulation based on the fibroblast-populated collagen lattice (FPCL) in three-dimensional medium were investigated for the improvement of scar and keloid. The starfish HE significantly inhibited the collagen gel contraction over 2?days of culture. MMP-2 and MMP-9 activities were also identified by gelatin zymography and RT-PCR products with both HE and collagenase treatments, which resulted in the high amount of hydroxyproline release. The HE treatment on the FPCL significantly inhibited the fibroblast proliferation at 3?days of culture. The LPS-induced NO level and iNOS mRNA expression at low concentrations of HE presented a certain ability to inflammatory response. The COX-2 mRNA from the FPCL indicated no significant inflammation-mediated activity at 5?μg/mL of HE, whereas the cytokines of TNF-α and IL-1β were significantly higher than those of the control. Hence, the starfish hatching enzyme can regulate the fibroblast-populated collagen gel conditions by the contraction, MMP production, inflammatory gene expression, etc. Therefore, the starfish HE could be a potential cosmeceutical to heal the scar and keloid tissue.</P>

Terpenoid composition and the anticancer activity of Acanthopanax trifoliatus

Dong-Li Li,Xi Zheng,Yu-Chan Chen,Sen Jiang,Wei-Min Zhang,Huaqian Wang,Zhi-Yun Du,Kun Zhang 대한약학회 2016 Archives of Pharmacal Research Vol.39 No.1

The petroleum ether and ethyl acetate fractions of extract from an edible and medicinal plant Acanthopanax trifoliatus were found to show significant inhibitory effects against SF-268, MCF-7, HepG2 and NCIH460 cancer cells. Two new ursane-type triterpenoids, acantrifoic acid C (1) and acantrifoic acid D (2), along with five known triterpenoids (3–7) and eight known diterpenoids (8–15) were obtained from these two fractions. To the best of our knowledge, this is the first report concerning the isolation of compounds (5–12, 14, 15) from A. trifoliatus. Among all the isolated compounds, 3, 5 and 8 from the ethyl acetate fraction showed the strongest inhibitory effects against cancer cells, while 12 and 13 from the petroleum ether fraction showed moderate activities. These terpenoid compounds may be responsible for the anticancer activities of A. trifoliatus. Our study provides the first evidence that terpenoids from A. trifoliatus exert anticancer activities and indicates that A. trifoliatus may be a useful edible plant for further development of anticancer health supplement.

Supercritical fluid extraction effectively removes phthalate plasticizers in spores of Ganoderma lucidum

Pan Li,Zuan-hao Liang,Zhuo Jiang,Ziyou Qiu,Bing Du,Yu-bing Liu,Wen-zhi Li,Li-hao Tan 한국식품과학회 2018 Food Science and Biotechnology Vol.27 No.6

Phthalate plasticizers residue in food is a serious threat to public health. Spores of Ganoderma lucidum are easy to be contaminated with phthalates during collection and processing. In this study, supercritical fluid extraction (SFE) was performed to remove phthalates in spores of G. lucidum, and the effects on acid and peroxide values of spores’ oil were also evaluated. The results showed SFE removed 100% of the residual di-iso-butyl phthalate, di-nbutyl phthalate and di-2-ethylhexyl phthalate in the spores of G. lucidum. No significant differences in polysaccharides content and fatty acid composition were observed between SFE and control spores. However, the triterpenoid extracts of SFE spores had a 7.45% increase, significantly higher than that in control spores. Accelerated oxidation tests further implied that SFE could improve the stability of spores’ oil. Our results suggested SFE is a potential approach to remove phthalate from food related products.

Effects of Supplementary Composts on Microbial Communities and Rice Productivity in Cold Water Paddy Fields

( Kai Zhi Xie ),( Pei Zhi Xu ),( Shao Hai Yang ),( Yu Sheng Lu ),( Rui Ping Jiang ),( Wen Jie Gu ),( Wen Ying Li ),( Li Li Sun ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.5

Cold water paddy field soils are relatively unproductive, but can be ameliorated by supplementing with inorganic fertilizer from animal waste-based composts. The yield of two rice cultivars was significantly raised by providing either chicken manure or cow dung-based compost. The application of these composts raised the soil pH as well as both the total nitrogen and ammonium nitrogen content, which improved the soil’s fertility and raised its nitrification potential. The composts had a measurable effect on the abundance of nitrogencycling- related soil microbes, as measured by estimating the copy number of various bacterial and archaeal genes using quantitative real-time PCR. The abundance of ammonia oxidizing archaea and bacteria was markedly encouraged by the application of chicken manure-based compost. Supplementation with the composts helped promote the availability of soil nitrogen in the cold water paddy field, thereby improving the soil’s productivity and increasing the yield of the rice crop.