New encapsulation method using low-melting-point alloy for sealing micro heat pipes

Congming Li,Xiaodong Wang,Chuanpeng Zhou,Yi Luo,Zhixin Li,Sidi Li 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.6

This study proposed a method using Low-melting-point alloy (LMPA) to seal Micro heat pipes (MHPs), which were made of Si substrates and glass covers. Corresponding MHP structures with charging and sealing channels were designed. Three different auxiliary structures were investigated to study the sealability of MHPs with LMPA. One structure is rectangular and the others are triangular with corner angles of 30° and 45°, respectively. Each auxiliary channel for LMPA is 0.5 mm wide and 135 µm deep. LMPA was heated to molten state, injected to channels, and then cooled to room temperature. According to the material characteristic of LMPA, the alloy should swell in the following 12 hours to form strong interaction force between LMPA and Si walls. Experimental results show that the flow speed of liquid LMPA in channels plays an important role in sealing MHPs, and the sealing performance of triangular structures is always better than that of rectangular structure. Therefore, triangular structures are more suitable in sealing MHPs than rectangular ones. LMPA sealing is a plane packaging method that can be applied in the thermal management of high-power IC device and LEDs. Meanwhile, implanting in commercialized fabrication of MHP is easy.

Blow up of solutions to a semilinear parabolic system with nonlocal source and nonlocal boundary

Congming Peng,Zuodong Yang 한국전산응용수학회 2009 Journal of applied mathematics & informatics Vol.27 No.5

In this paper we investigate the blow up properties of the positive solutions to a semilinear parabolic system with coupled nonlocal sources ut = Δu+k1 ∫Ωuα(y, t)vp(y, t)dy, vt = Δv+k2∫Ω uq (y, t)vβ(y, t)dy with nonlocal Dirichlet boundary conditions. We establish the conditions for global and non-global solutions respectively and obtain its blow up set.. In this paper we investigate the blow up properties of the positive solutions to a semilinear parabolic system with coupled nonlocal sources ut = Δu+k1 ∫Ωuα(y, t)vp(y, t)dy, vt = Δv+k2∫Ω uq (y, t)vβ(y, t)dy with nonlocal Dirichlet boundary conditions. We establish the conditions for global and non-global solutions respectively and obtain its blow up set..

BLOW UP OF SOLUTIONS TO A SEMILINEAR PARABOLIC SYSTEM WITH NONLOCAL SOURCE AND NONLOCAL BOUNDARY

Peng, Congming,Yang, Zuodong The Korean Society for Computational and Applied M 2009 Journal of applied mathematics & informatics Vol.27 No.5

In this paper we investigate the blow up properties of the positive solutions to a semi linear parabolic system with coupled nonlocal sources $u_t={\Delta}u+k_1{\int}_{\Omega}u^{\alpha}(y,t)v^p(y,t)dy,\;v_t={\Delta}_v+k_2{\int}_{\Omega}u^q(y,t)v^{\beta}(y,t)dy$ with non local Dirichlet boundary conditions. We establish the conditions for global and non-global solutions respectively and obtain its blow up set.

Sb-doped SnS2 nanosheets enhance electrochemical reduction of carbon dioxide to formate

Luntong Yan,Zelin Wu,Congming Li,Junying Wang 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.123 No.-

Electrocatalytic carbon dioxide (CO2) is a forward-looking strategy to convert renewable energy into fuel. Herein, we show that the novel Sb-doped SnS2 nanosheets were synthesized by a simple hydrothermalmethod for efficient electroreduction of CO2, and the atomic ratio of Sb/Sn was controllable. The introductionof Sb significantly enhanced the current density and Faradaic efficiency for formate products comparedto pristine SnS2 nanosheets. When the Sb content was 1%, the Sb-SnS2 nanosheets achieved aremarkable Faradaic efficiency of 90.86% for formate products at 1.1 V vs. RHE. The experimental resultsshowed that 1% Sb-doped SnS2 nanosheets changed the electronic structure of the Sn element, allowingthe catalyst to reconfigure to generate Sn0 during the electrochemical reaction, while the singlet tin had asynergistic effect with Sn4+, making it easier to transport electrons on the surface and promoting the activationprocess of CO2, which is a key factor to improve the electroreduction performance of CO2.

Combined effect of initial biomass density and nitrogen concentration on growth and astaxanthin production of Haematococcus pluvialis (Chlorophyta) in outdoor cultivation

Wang, Junfeng,Sommerfeld, Milton R.,Lu, Congming,Hu, Qiang The Korean Society of Phycology 2013 ALGAE Vol.28 No.2

Nitrogen availability and cell density each affects growth and cellular astaxanthin content of Haematococcus pluvialis, but possible combined effects of these two factors on the content and productivity of astaxanthin, especially under outdoor culture conditions, is less understood. In this study, the effects of the initial biomass densities IBDs of 0.1, 0.5, 0.8, 1.5, 2.7, 3.5, and 5.0 g $L^{-1}$ DW and initial nitrogen concentrations of 0, 4.4, 8.8, and 17.6 mM nitrate on growth and cellular astaxanthin content of H. pluvialis Flotow K-0084 were investigated in outdoor glass column photobioreactors in a batch culture mode. A low IBD of 0.1 g $L^{-1}$ DW led to photo-bleaching of the culture within 1-2 days. When the IBD was 0.5 g $L^{-1}$ and above, the rate at which the increase in biomass density and the astaxanthin content on a per cell basis was higher at lower IBD. When the IBD was optimal (i.e., 0.8 g $L^{-1}$), the maximum astaxanthin content of 3.8% of DW was obtained in the absence of nitrogen, whereas the maximum astaxanthin productivity of 16.0 mg $L^{-1}\;d^{-1}$ was obtained in the same IBD culture containing 4.4 mM nitrogen. The strategies for achieving maximum Haematococcus biomass productivity and for maximum cellular astaxanthin content are discussed.

One-pot synthesis of lactic acid from cellulose over a sulfonated Sn-KIT6 catalyst

Weijie Cai,Qing Chen,Hao Xuan,Congming Li,Hao Yu,Li Cui,Zhihui Yu,Shaoyin Zhang,Fengzuo Qu 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.4

A sulfonated Sn-doped KIT-6 catalyst (Sn-KIT-6-Pr-SO3H) was successfully prepared via the hydrothermal self-assembly method, and its performance towards to value-added lactic acid production from one-pot conversion of renewable cellulose was investigated. Indeed, the physicochemical features of the as-prepared catalysts were deeply characterized by various techniques, including XRD, BET, SEM, FT-IR, XPS, UV-vis and TGA-DSC. The results confirmed its high BET surface area with an ultrahigh cross-linked framework and promising acid strength (co-existence of Brønsted and Lewis acidity). Additionally, the impact of different reaction factors, such as the type of catalysts, temperature, time, recyclability on cellulose conversion and the yield of targeted lactic acid, were determined. Meanwhile, the developed catalyst depicted the promising activity and stability under the optimal reaction conditions. It could be recycled at least four times without any obvious deactivation. This provides insight into developing efficient catalytic systems to convert renewable biomass into value-added chemicals.

Combined effect of initial biomass density and nitrogen concentration on growth and astaxanthin production of Haematococcus pluvialis (Chlorophyta) in outdoor cultivation

Junfeng Wang,Milton R. Sommerfeld,Congming Lu,Qiang Hu 한국조류학회I 2013 ALGAE Vol.28 No.2

Nitrogen availability and cell density each affects growth and cellular astaxanthin content of Haematococcus pluvialis, but possible combined effects of these two factors on the content and productivity of astaxanthin, especially under outdoor culture conditions, is less understood. In this study, the effects of the initial biomass densities IBDs of 0.1, 0.5, 0.8, 1.5, 2.7, 3.5, and 5.0 g L-1 DW and initial nitrogen concentrations of 0, 4.4, 8.8, and 17.6 mM nitrate on growth and cellular astaxanthin content of H. pluvialis Flotow K-0084 were investigated in outdoor glass column photobioreactors in a batch culture mode. A low IBD of 0.1 g L-1 DW led to photo-bleaching of the culture within 1-2 days. When the IBD was 0.5 g L-1 and above, the rate at which the increase in biomass density and the astaxanthin content on a per cell basis was higher at lower IBD. When the IBD was optimal (i.e., 0.8 g L-1), the maximum astaxanthin content of 3.8% of DW was obtained in the absence of nitrogen, whereas the maximum astaxanthin productivity of 16.0 mg L-1 d-1 was obtained in the same IBD culture containing 4.4 mM nitrogen. The strategies for achieving maximum Haematococcus biomass productivity and for maximum cellular astaxanthin content are discussed.