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111. Activity Characteristics of Soil Hydrolase in Rape-Rice Rotations Farmland of the Erhai River Basin.

Author

ZHANG Qing, FU Bin, LI Minggang, WU Xiang, HE Xiang, ZOU Xuefeng, SHI Zhufeng, NI Ming, ZHU Hongye, HU Wanli, and YANG Peiwen

Abstract

Soil enzymes are important biological factors driving soil carbon and nitrogen conversion. In this study, long-term tests with 5 treatments (1 no-fertilizer application, 1 fertilizers usage and 3 organic material input combined with fertilizer) were set up in rape-rice rotations farmland in the Erhai River basin. The characteristics of soil carbon and nitrogen hydrolytic functional enzyme activity and their changes under the application of organic carbon source materials were investigated. The response characteristics of soil enzyme activity to organic carbon input were analyzed by Pearson correlation analysis and redundancy analysis (RDA). Results showed that pure application of chemical fertilizer had no significant effect on the activity of ββ -1,4 - glucosidase (GC) (P ≥ 0.05), but significantly increased the β -1,4-N-acetyl glucosidase activity (NAG) (P<0.05). The activity of GC and NAG was significantly increased in each treatment of organic carbon source with chemical fertilizer (P<0.05). Correlation analysis showed that there was a significant positive correlation between the activities of GC and NAG and the contents of organic matter and total nitrogen, a significant positive correlation between the activities of GC and C/N (P<0.01) and a significant positive correlation between the activities of NAG and C/N (P<0.05). The effect of soil OM and TN on the activity of hydrolase was the most explicable. By analyzing soil carbon and nitrogen codependency, it was concluded that applying suitable C/N organic carbon source with nitrogen fertilizer is necessary, and regulating the activity of GC enzyme and NAG enzyme to adjust the rate of soil carbon and nitrogen conversion, could maintain the soil C/N at an appropriate range. [ABSTRACT FROM AUTHOR]

Published
2020
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122. Application of quantitative grain fluorescence techniques to study subtle oil migration pathway of lithological reservoir

Author

LI Minggang, Pang Xiong-qi, Zhang Jun, and Chen Dongxia

Subjects
Fluorescence intensity, geography, geography.geographical_feature_category, Source rock, Geologic time scale, Lithology, Geochemistry, General Earth and Planetary Sciences, Geotechnical engineering, Fault (geology), Siltstone, Fluorescence, Geology
Abstract

This paper analyzes the quantitative grain fluorescence (QGF) and quantitative grain fluorescence on extract (QGF-E) properties of 101 rock samples by using quantitative grain fluorescence techniques. The samples are collected from five wells in tight sandstone and thin siltstone in the third sector of the Shahejie Formation in the Niuzhuang sag of the Dongying depression. It was observed that both the tight sandstone and thin siltstone show relatively high fluorescence intensity of hydrocarbon, which suggests that they are possibly good subtle oil-migration pathways in the present or geological time. These thin subtle oil-migration pathways afford important clues for the researches on hydrocarbon accumulation in lithological reservoirs in the middle and lower of Es 3 in deep sag zone, which has the hydrocarbon source from the upper of Es 4 when there is no apparent fault playing oil migration conduits to connect lithologic traps and deep source rocks. This study shows good prospect of QGF techniques in discriminating oil migration pathways and paleo-oil zones. The results of this study may be of great significance to the researches on hydrocarbon accumulation mechanism of subtle reservoirs in the Dongying depression and other areas.

Published
2007

123. [Construction of yeast strains expressing long-acting glucagon-like peptide-1 (GLP-1) and their therapeutic effects on type 2 diabetes mellitus mouse model]

Author

Wu, Ri, Ma, Chao, Li, Xiaodan, Duan, Huikun, Ji, Yanli, Wang, Yu, Jiang, Pingzhe, Wang, Haisong, Tu, Peipei, Li, Miao, Ni, Ganggang, Ma, Baicheng, and Li, Minggang

Subjects
Blood Glucose, Mice, Inbred C57BL, Mice, Diabetes Mellitus, Type 2, Glucagon-Like Peptide 1, Animals, Saccharomyces cerevisiae, Streptozocin, Diabetes Mellitus, Experimental, Plasmids
Abstract

Probiotics, i.e., bacteria expressing therapeutic peptides (protein), are used as a new type of orally administrated biologic drugs to treat diseases. To develop yeast strains which could effectively prevent and treat type 2 diabetes mellitus, we firstly constructed the yeast integrating plasmid pNK1-PGK which could successfully express green fluorescent protein (GFP) in Saccharomyces cerevisiae. The gene encoding ten tandem repeats of glucagon-like peptide-1(10 × GLP-1) was cloned into the vector pNK1-PGK and the resulting plasmids were then transformed into the S. cerevisiae INVSc1. The long-acting GLP-1 hypoglycemic yeast (LHY) which grows rapidly and expresses 10 × GLP-1 stably was selected by nutrition screening and Western blotting. The amount of 10 × GLP-1 produced by LHY reached 1.56 mg per gram of wet cells. Moreover, the oral administration of LHY significantly reduced blood glucose level in type 2 diabetic mice induced by streptozotocin plus high fat and high sugar diet.

Published
2015

124. Novel Method for Preparing a High-Performance Auxetic Foam Directly from Polymer Resin by a One-Pot CO2Foaming Process

Author

Fan, Donglei, Shi, Zhiyuan, Li, Niexin, Qiu, Jian, Xing, Haiping, Jiang, Zhiwei, Li, Minggang, and Tang, Tao

Abstract

So far, negative Poisson’s ratio foam (auxetic foam) is usually prepared by the transformation of conventional polymer foam, and it is a challenge to prepare auxetic foam directly from polymer resin. In this work, a novel method based on the synergism between the phase transition of water and the permeability rate difference of the CO2blowing agent from air in the foaming process is put forward to prepare auxetic foam directly from the polymer resin. Using this method, herein, nylon elastomer (NE) foam with auxetic behavior is successfully prepared from NE resin by a one-pot CO2foaming method inside an autoclave aided by water; the obtained auxetic foam has a Poisson’s ratio value of −1.29 and has excellent tensile cycle stability and energy absorption performance. This method breaks through the bottleneck for preparing auxetic foams from the polymer resin directly, which is also green and environment-friendly. It is believed that the abovementioned method also applies to other thermoplastic polymers, which paves a way for designing and preparing multifunctional auxetic foam materials in the future via a one-pot CO2foaming process. Furthermore, this work first demonstrates that the transformation between auxetic foam and positive Poisson’s ratio foam is reversible due to the closed cell structure, which provides an opportunity to reversibly adjust the performance and the shape of polymer foam materials.

Published
2020
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125. Time-Dependent Evolution of Ti-Bearing Oxide Inclusions During Isothermal Holding at 1573 K (1300 °C).

Author

Li, Minggang, Matsuura, Hiroyuki, and Tsukihashi, Fumitaka

Subjects
STEEL metallurgy, SHIPBUILDING, OXYGEN content of steel, TITANIUM, HEAT treatment of steel, ISOTHERMAL efficiency
Abstract

Ti-bearing oxide inclusions are utilized to enhance the properties of steel used in shipbuilding, multi-purpose gas carriers, and pipelines in accordance with the principles of oxide metallurgy. Conventionally, Ti-bearing oxide inclusions have been assumed to be stable during isothermal holding. The authors propose the possibility of modifying Ti-bearing oxide inclusions by appropriate heat treatment. To provide fundamental information on the evolution of Ti-bearing inclusions in solid steel during isothermal holding, the effect of the isothermal holding time on their evolution at 1573 K (1300 °C) was studied systematically. For heterogeneous phase Al+Ti oxide in the as-cast alloys, the composition and size distribution were maintained during isothermal holding. In contrast, homogeneous phase Al-Ti oxide in the as-cast alloys changed to a heterogeneous oxide consisting of an Al-rich part and a Ti-rich part and its shape changed from spherical to irregular. The composition of the Al-Ti oxide changed upon isothermal holding for 0.5 hour, and it occurred earlier in the Al-Ti oxide with a higher Al content. The evolution mechanism is considered to involve the precipitation of Al2O3 from the Al-Ti oxide owing to crystallization of glassy oxide during isothermal holding. The results challenge the long-held opinion that Ti-bearing oxide inclusions are maintained in solid steel during isothermal holding, which is the first step toward modifying oxide inclusions by heat treatment as a new concept in oxide metallurgy. [ABSTRACT FROM AUTHOR]

Published
2019
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131. Numerical Investigation of Flow and Heat Transfer Characteristics in Wire-Wrap Tight Lattice 19-Rod Bundle

Author

Xiao Yan, Zumao Yang, Feng Xie, Jun Wang, Li Minggang, Huang Yanping, and Nie Changhua

Subjects
Pressure drop, Materials science, Turbulence, Bundle, Heat transfer, Turbulence modeling, Thermodynamics, Mechanics, Secondary flow, Nusselt number, Rod
Abstract

Flow and heat transfer characteristics in wire-wrap tight lattice rod bundle have been investigated through CFD code ANSYS CFX 13.0. The bundle consists of 19 fuel rods with triangular tight lattice configuration. The rod ratio of rod pitch to rod diameter is 1.167. Four wires with a diameter of 0.5 mm are helically wrapped on the surface of each fuel rod. The ratio of wire-wrap helical pitch to the rod diameter is varied from 27.5 to 52.5. Through simulating wire-wrap 3-rod bundle with tetrahedron and hexahedron grid systems, the grid system which applies to simulating the wire-wrap tight lattice rod bundle has been obtained. The predicted results of eddy viscosity based turbulence models (k–ε, SST) and Reynolds stress turbulence models (BSL, SSG) are compared with each other and several experimental correlations for friction factor and Nusselt number. The predicted results of all the turbulence models are almost the same in some respects, but the friction factor predicted by the eddy viscosity models is higher than that predicted by the RSM. The effect of wire-wrap on pressure drop, friction factor, secondary flow, heat transfer, velocity distribution and temperature distribution in different subchannels (interior, edge and corner) has been analyzed by comparing with those of the bare rod bundle. The effect of wire-wrap pitch on the flow and heat transfer characteristics has also been studied.

Published
2013

132. The first two leading modes of the tropical Pacific and their linkage without global warming

Author

Li, Yang, Chen, QuanLiang, Liu, XiaoRan, Xing, Nan, Cheng, ZhiGang, Cai, HongKe, Zhou, Xin, Chen, Dong, Wu, XiaoFei, and Li, MingGang

Abstract

A discrepancy remains in the first two leading empirical orthogonal function (EOF) modes of the tropical Pacific sea surface temperature anomaly (SSTA) based on observations since the 1980s. The EOF1 mode, representing the El Niño‐Southern Oscillation (ENSO), is a robust result. However, the EOF2 features either El Niño Modoki (EM) or ENSO evolution during different periods, which is probably associated with the impacts of global warming. The underlying question is what the EOF2 mode of the tropical Pacific would be without global warming. Using the CMIP5 preindustrial scenario to exclude the influence of global warming, we find that the EOF1 mode of the tropical Pacific SSTA represents ENSO and that the EOF2 mode is not EM. According to the lead–lag correlation between the ENSO and EOF2 modes, the linkage between these two modes is as follows: …El Niño → EOF2 → La Niña → –EOF2 → El Niño…. By analyzing the evolution of sea surface temperature, surface wind, and subsurface ocean temperature anomalies, we find the mechanism linking the ENSO and EOF2 modes is the air–sea interaction associated with the ENSO cycle. This result suggests that the EOF2 mode represents an aspect of ENSO evolution under preindustrial conditions. Therefore, this study further indicates that the EM is probably due to the influence of global warming.

Published
2019
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142. The effect of nanosized carbon black on the morphology and sc-CO2foaming behavior of LLDPE/PS blends at semi-solid state

Author

Zhang, Shaofeng, Zhang, Guangchun, Qiu, Jian, Jiang, Zhiwei, Xing, Haiping, Li, Minggang, and Tang, Tao

Abstract

The influences of nanosized carbon black (CB) on the morphology of immiscible cocontinuous LLDPE/PS blends and their foaming behavior under the sc-CO2batch foaming was studied. The morphologies and cellular structures of LLDPE/PS blends and LLDPE/PS/CB nanocomposites were characterized by scanning electron microscope (SEM). The results indicated that the introduction of CB nanoparticles could effectively improve foaming ability of LLDPE/PS=50/50 blends, when enough amount of CB nanofillers was added. This was ascribed to the morphology transformation from cocontinuous structure to sea-island structure due to the presence of CB nanofillers. Furthermore the critical amount of CB for dramatically improving the foaming capacity depended on the foaming temperature. In contrast, the addition of CB in the LLDPE/PS blends with spherical dispersed phase (such as 80/20 or 20/80, by weight) did not dramatically change the foaming behavior of the blends.

Published
2018
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144. Ni3Sn4-composed die bonded interface rapidly formed by ultrasonic-assisted soldering of Sn/Ni solder paste for high-temperature power device packaging.

Author

Ji, Hongjun, Li, Minggang, Ma, Shu, and Li, Mingyu

Subjects
*NICKEL-tin alloys, *INTERFACES (Physical sciences), *ULTRASONICS, *SOLDER & soldering, *SOLDER pastes, *HIGH temperatures
Abstract

The time-consuming of transient-liquid-phase is a big challenge for the die bonding. In this paper, a novel rapid bonding method plus alloying design was proposed to cheaply fabricate Sn Ni intermetallic joint for high temperature electronic packaging. The ultrasonic effect and the evolution of the joint microstructures, shear strength as a function of Ni content were systemically investigated. The amount of Ni 3 Sn 4 in the joint increased with the addition of Ni, and when the Ni content reached 24 wt.%, the joint consisted of nearly sole Ni 3 Sn 4 with a high shear strength of 43.4 MPa was achieved. After aging at 300 °C for 72 h in air, the shear strength of the joint obtained with smaller Ni content solder showed great improvement because of the phase transformation of residual Sn to Ni 3 Sn 4 , but for the Sn-24 wt.%Ni and Sn-30 wt.%Ni, it showed a little decrease due to the grains coarsening of Ni 3 Sn 4 . The acoustic cavitation and streaming effects dramatically accelerates the reaction of Ni and Sn during the ultrasonic-assisted soldering. The joint obtained by the Sn-24 wt.%Ni solder has the best potential to be applied in the power electronic packaging. [ABSTRACT FROM AUTHOR]

Published
2016
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146. Characterization of Optimized Functional-Complementary Dual Insulinotorpic Peptide rolGG

Author

Zhang, Yaofang, Du, Li, Xu, Yanling, Tian, Lin, Tu, Peipei, and Li, Minggang

Abstract

Background: Glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP) play a similar but complementary role in the regulation of glucose levels in islet β-cells. This study was aimed to develop a fusion peptide, which combines 4 tandem repeated GLP-1 and 4 tandem repeated GIP (4rolGG), and to investigate its therapeutic effect on type 2 diabetes using a diabetic mice model. Methods: A 4rolGG expression plasmid was constructed and expressed in BL21 (DE3). By inducting with IPTG, 4rolGG was expressed at a high level, which was confirmed by SDS-PAGE electrophoresis and Western Blotting. Subsequently, 4rolGG was purified by Ni-NTA affinity chromatography and the purity of 4rolGG was up to 90%. Result and Conclusion: After oral administration of 4rolGG for 4 weeks, streptozotocin-induced diabetic mice showed a dramatic reduction in the levels of plasma glucose, GHbA1C, TC and TG, while the insulin levels were increased significantly.

Published
2017

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