Two-Step Oxidation of Refractory Gold Concentrates with Different Microbial Communities^s

( Guo-hua Wang ),( Jian-ping Xie ),( Shou-peng Li ),( Yu-jie Guo ),( Ying Pan ),( Haiyan Wu ),( Xin-xing Liu ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.11

Bio-oxidation is an effective technology for treatment of refractory gold concentrates. However, the unsatisfactory oxidation rate and long residence time, which cause a lower cyanide leaching rate and gold recovery, are key factors that restrict the application of traditional bio-oxidation technology. In this study, the oxidation rate of refractory gold concentrates and the adaption of microorganisms were analyzed to evaluate a newly developed two-step pretreatment process, which includes a high temperature chemical oxidation step and a subsequent bio-oxidation step. The oxidation rate and recovery rate of gold were improved significantly after the two-step process. The results showed that the highest oxidation rate of sulfide sulfur could reach to 99.01 % with an extreme thermophile microbial community when the pulp density was 5%. Accordingly, the recovery rate of gold was elevated to 92.51%. Meanwhile, the results revealed that moderate thermophiles performed better than acidophilic mesophiles and extreme thermophiles, whose oxidation rates declined drastically when the pulp density was increased to 10% and 15%. The oxidation rates of sulfide sulfur with moderate thermophiles were 93.94% and 65.73% when the pulp density was increased to 10% and 15%, respectively. All these results indicated that the twostep pretreatment increased the oxidation rate of refractory gold concentrates and is a potential technology to pretreat the refractory sample. Meanwhile, owing to the sensitivity of the microbial community under different pulp density levels, the optimization of microbial community in bio-oxidation is necessary in industry.

Effects of solvent extraction on the microstructure of bituminous coal-based graphite

Wang Lipeng,Yao Zongxu,Guo Zhimin,Shen Xiaofeng,Li Zhiang,Zhou Zhengqi,Wang Yuling,Yang Jian-Guo 한국탄소학회 2022 Carbon Letters Vol.32 No.3

Coal-based graphite has become the main material of emerging industries. The microstructure of coal-based graphite plays an important role in its applications in many fields. In this paper, the effect of carbon disulfide/N-methyl-2-pyrrolidone solvent mixture extraction on the microstructure of bituminous coal-based graphite was systematically studied through preliminary extraction coupled with high-temperature graphitization. The graphitization degree g (75.65%) of the coal residue-based graphite was significantly higher than that of the raw coal-based graphite. The crystallite size La of the coal residue-based graphite was reduced by 47.06% compared with the raw coal-based graphite. The ID/ IG value of the coal residue-based graphite is smaller than that of the raw coal-based graphite. The specific surface area (16.72 m2/g) and total pore volume (0.0567 m3/g) of the coal residue-based graphite are increased in varying degrees compared with the raw coal-based graphite. This study found a carbon source that can be used to prepare coal-based graphite with high graphitization degree. The results are expected to provide a theoretical basis for further clean and efficient utilization of the coal residue resources.

Oxygen Uptake Rate Controlling Strategy Balanced with Oxygen Supply for Improving Coenzyme Q10 Production by Rhodobacter sphaeroides

Ze-Jian Wang,Xingzi Zhang,Ping Wang,Zhiwei Sui,Meijin Guo,Siliang Zhang,Yingping Zhuang 한국생물공학회 2020 Biotechnology and Bioprocess Engineering Vol.25 No.3

The effects of different oxygen uptake rates (OUR) on the physiological metabolism of Rhodobacter sphaeroides were investigated systematically in 50 L fermenters due to the significant influence on industrial coenzyme Q10 production under oxygen supply limitation. Meanwhile, the seriously decreased oxygen transfer rate caused by the increased broth viscosity was successfully prevented with OUR-directed continuous ammonium sulfate feeding in the late fermentation phase. The statistical analysis results showed that controlling OUR constantly at 45 ± 2.2 mmol/L/h by the oxygen supply level adjustment and the continuous ammonium sulfate feeding could greatly enhance Q10 production. This OUR-Stat controlling strategy successfully achieved the maximal coenzyme Q10 production (2584 ± 82 mg/L), which was 15.4% higher than that of the control. The highest specific CoQ10 content was 25.9 mg/(g DCW)), and the yield of CoQ10 to glucose consumption was up to 19.37 mg/g. These results demonstrated that the optimal OUR-Stat controlling strategy would be effective and economical for improving the industrial CoQ10 production.

Correction to: Effects of solvent extraction on the microstructure of bituminous coal‑based graphite

Lipeng Wang,Zongxu Yao,Zhimin Guo,Xiaofeng Shen,Zhiang Li,Zhengqi Zhou,Yuling Wang,Jian‑Guo Yang 한국탄소학회 2022 Carbon Letters Vol.32 No.3

Shikonin ameliorates salivary gland damage and inflammation in a mouse model of Sjögren's syndrome by modulating MAPK signaling pathway

Wenjing Guo,Xin Wang,Chao Sun,Jian Wang,Tao Wang The Korean Society of Pharmacology 2023 The Korean Journal of Physiology & Pharmacology Vol.27 No.4

Sjögren syndrome (SS) is a systemic inflammatory autoimmune disease that involves exocrine glands. Shikonin is extracted from comfrey, which is conventionally used as an anti-tumor, antibacterial, and antiviral drug in China. However, the application of Shikonin in SS remains unreported. This study aimed to verify the potential functions of Shikonin in SS progression. Firstly, non-obese diabetic mice were used as the SS mouse model, with C57BL/6 mice serving as the healthy control. It was demonstrated that the salivary gland damage and inflammation were aggravated in the SS mouse model. Shikonin improved salivary gland function decline and injury in the SS mouse model. Moreover, Shikonin reduced inflammatory cytokines and immune infiltration in the SS mouse model. Further experiments discovered that Shikonin attenuated the MAPK signaling pathway in the SS mouse model. Lastly, inhibition of the MAPK signaling pathway combined with Shikonin treatment further alleviated the symptoms of SS. In conclusion, Shikonin ameliorated salivary gland damage and inflammation in a mouse model of SS by modulating the MAPK signaling pathway. Our findings indicate that Shikonin may be a useful drug for SS treatment.

Field Emission from TiO2/Ti Nanotube Array Films Modified with Carbon Nanotubes

Cheng-Wei Wang,Rui-Sheng Guo,Jian-Biao Chen,Yan Li,Jian Wang,Wei-Min Liu 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.6

Well-aligned TiO2/Ti nanotube array films were synthesized by using anodic oxidation of titanium in 0.5-wt% HF and were modified with carbon nanotubes (CNTs) assembled by using catalyzed chemical vapor deposition (CVD) at 650 ˚C. The morphology and the quality of the films were assessed with field emission scanning electron microscopy and Raman spectrometry (325 nm). The field emission characteristics of such TiO2/Ti nanostructures were investigated before and after being modified with CNTs. The results show that the TiO2/Ti nanotube arrays possess a moderate turn-on electric field of 7.4 V/µm, a field emission current density of 2.7 mA/cm2 at 23 V/µm. It is noteworthy that the turn-on field of the TiO2/Ti nanotube arrays modified with CNTs is decreased significantly to 1.3 V/µm, and the emission current density is increased to 10 mA/cm2 at 5.6 V/µm. This novel structure shows high emission efficiency as a field emitter. Well-aligned TiO2/Ti nanotube array films were synthesized by using anodic oxidation of titanium in 0.5-wt% HF and were modified with carbon nanotubes (CNTs) assembled by using catalyzed chemical vapor deposition (CVD) at 650 ˚C. The morphology and the quality of the films were assessed with field emission scanning electron microscopy and Raman spectrometry (325 nm). The field emission characteristics of such TiO2/Ti nanostructures were investigated before and after being modified with CNTs. The results show that the TiO2/Ti nanotube arrays possess a moderate turn-on electric field of 7.4 V/µm, a field emission current density of 2.7 mA/cm2 at 23 V/µm. It is noteworthy that the turn-on field of the TiO2/Ti nanotube arrays modified with CNTs is decreased significantly to 1.3 V/µm, and the emission current density is increased to 10 mA/cm2 at 5.6 V/µm. This novel structure shows high emission efficiency as a field emitter.

Extraction, Distribution, and Precipitation Mechanism of TiN–MnS Complex Inclusions in Al-Killed Titanium Alloyed Interstitial Free Steel

Shuai Gao,Min Wang,Jian‑long Guo,Hao Wang,Jian‑guo Zhi,Yan‑ping Bao 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.5

The TiN–MnS complex inclusions in Al-killed titanium alloyed interstitial free steel were extracted from the slabs using anelectrolytic aqueous solution method. Scanning electron microscopy with energy spectroscopy analysis and an automaticscanning electron microscope were employed to analyze the size and distribution of TiN–MnS inclusions in the thicknessdirection of the slab. It was found that TiN–MnS complex inclusions were primarily concentrated in the 1/4 thickness directionfrom the inner and outer surfaces, and the size of the complex inclusions in the slab center was approximately 8 μm.TiN began to precipitate when the solidification rate reached 0.646–0.680 in the δ phase, and MnS would appear in the γphase when the solidification rate exceeded 0.450 through thermodynamic analysis. Also, the formation mechanism of thecomplex TiN–MnS was investigated under a crystal structure during solidification.

SDSS J013127.34-032100.1: A NEWLY DISCOVERED RADIO-LOUD QUASAR AT <i>z</i> = 5.18 WITH EXTREMELY HIGH LUMINOSITY

Yi, Wei-Min,Wang, Feige,Wu, Xue-Bing,Yang, Jinyi,Bai, Jin-Ming,Fan, Xiaohui,Brandt, William N.,Ho, Luis C.,Zuo, Wenwen,Kim, Minjin,Wang, Ran,Yang, Qian,Zhang, Ju-jia,Wang, Fang,Wang, Jian-Guo,Ai, Yanl IOP Publishing 2014 ASTROPHYSICAL JOURNAL LETTERS - Vol.795 No.2

<P>Very few of the z > 5 quasars discovered to date have been radio-loud, with radio-to-optical flux ratios (radio-loudness parameters) higher than 10. Here we report the discovery of an optically luminous radio-loud quasar, SDSS J013127.34-032100.1 (J0131-0321 in short), at z = 5.18 +/- 0.01 using the Lijiang 2.4 m and Magellan telescopes. J0131-0321 has a spectral energy distribution consistent with that of radio-loud quasars. With an i-band magnitude of 18.47 and a radio flux density of 33 mJy, its radio-loudness parameter is similar to 100. The optical and near-infrared spectra taken by Magellan enable us to estimate its bolometric luminosity to be L-bol similar to 1.1 x 10(48) erg s(-1), approximately 4.5 times greater than that of the most distant quasar known to date. The black hole mass of J0131-0321 is estimated to be 2.7 x 10(9) M-circle dot, with an uncertainty up to 0.4 dex. Detailed physical properties of this high-redshift, radio-loud, potentially super-Eddington quasar can be probed in the future with more dedicated and intensive follow-up observations using multi-wavelength facilities.</P>

A rapid modeling method and accuracy criteria for common-cause failures in Risk Monitor PSA model

Zhang, Bing,Chen, Shanqi,Lin, Zhixian,Wang, Shaoxuan,Wang, Zhen,Ge, Daochuan,Guo, Dingqing,Lin, Jian,Wang, Fang,Wang, Jin Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.1

In the development of a Risk Monitor probabilistic safety assessment (PSA) model from the basic PSA model of a nuclear power plant, the modeling of common-cause failure (CCF) is very important. At present, some approximate modeling methods are widely used, but there lacks criterion of modeling accuracy and error analysis. In this paper, aiming at ensuring the accuracy of risk assessment and minimizing the Risk Monitor PSA models size, we present three basic issues of CCF model resulted from the changes of a nuclear power plant configuration, put forward corresponding modeling methods, and derive accuracy criteria of CCF modeling based on minimum cut sets and risk indicators according to the requirements of risk monitoring. Finally, a nuclear power plant Risk Monitor PSA model is taken as an example to demonstrate the effectiveness of the proposed modeling method and accuracy criteria, and the application scope of the idea of this paper is also discussed.

Galectin-9 Acts as a Prognostic Factor with Antimetastatic Potential in Hepatocellular Carcinoma

Zhang, Zhao-Yang,Dong, Jia-Hong,Chen, Yong-Wei,Wang, Xian-Qiang,Li, Chong-Hui,Wang, Jian,Wang, Guo-Qiang,Li, Hai-Lin,Wang, Xue-Dong Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.6

Considerable research has been conducted concerning galectin-9 and carcinomas, but little information is available about any relation with the hepatocellular carcinoma. In this study, we employed a small interfering RNA (siRNA) targeting galectin-9 to down-regulate the expression in HepG2 cells. As a result, after galectin-9 expression was reduced, cell aggregation was suppressed, while other behaviour such as the proliferation, adhesion and invasion to ECM, cell-endothelial adhesion and transendothelial invasion of the cells were markedly enhanced. When tumors of 200 patients with hepatocellular carcinoma were tested for galectin-9 expression by immunohistochemistry, binding levels demonstrated intimate correlations with the histopathologic grade, lymph node metastasis, vascular invasion and intrahepatic metastasis (P<0.05). Moreover, survival analysis indicated that patients with galectin-9 expression had much longer survival time than those with negative lesions, and the Log-rank test indicated that this difference was statistical significant (P<0.0001). The Cox proportional hazards model suggested that negative galectin-9 expression in hepatocellular carcinoma represented a significant risk factor for patient survival. We propose that galectin-9 might be a new prognostic factor with antimetastatic potential in patients with hepatocellular carcinoma.