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Effect of welding process on the microstructure and properties of dissimilar weld joints between low alloy steel and duplex stainless steel

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International Journal of Minerals,Metallurgy and Materials 2012年第6期19卷 518-524页

作者： Jing Wang Min-xu Lu Lei Zhang Wei Chang li-ning Xu li-hua hu Institute for Advanced Materials and Technology University of Science and Technology Beijing Beijing 100083 China Research Institute of China National Offshore Oil Corporation Beijing 100027 China

To obtain high-quality dissimilar weld joints, the processes of metal inert gas （MIG） welding and tungsten inert gas （TIG） welding for duplex stainless steel （DSS） and low alloy steel were compared in this paper. The microstructure and corrosion morphology of dissimilar weld joints were observed by scanning electron microscopy （SEM）; the chemical compositions in different zones were detected by en- ergy-dispersive spectroscopy （EDS）; the mechanical properties were measured by microhardness test, tensile test, and impact test; the corro- sion behavior was evaluated by polarization curves. Obvious concentration gradients of Ni and Cr exist between the fusion boundary and the type II boundary, where the hardness is much higher. The impact toughness of weld metal by MIG welding is higher than that by TIG weld- ing. The corrosion current density of TIG weld metal is higher than that of MIG weld metal in a 3.5wt% NaC1 solution. Galvanic corrosion happens between low alloy steel and weld metal, revealing the weakness of low alloy steel in industrial service. The quality of joints pro- duced by MIG welding is better than that by TIG welding in mechanical performance and corrosion resistance. MIG welding with the filler metal ER2009 is the suitable welding process for dissimilar metals jointing between UNS $31803 duplex stainless steel and low alloy steel in practical application.

关键词： dissimilar metals welds stainless steel alloy steel microstructure mechanical properties corrosion

Environmental boundary and formation mechanism of different types of H2S corrosion products on pipeline steel

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International Journal of Minerals,Metallurgy and Materials 2017年第4期24卷 401-409页

作者： Lei Zhang hui-xin li Feng-xian Shi Jian-wei Yang li-hua hu Min-xu Lu Institute for Advanced Materials and Technology University of Science and Technology Beijing Beijing 100083 China Aircraft Engine Corporation of China Shanghai Commercial Aircraft Engine Manufacturing Co. Ltd. Shanghai 201306 China Shougang Research Institute of Technology Beijing 100043 China China National Offshore Oil Corporation Research Institute Beijing 100027 China

To establish an adequate thermodynamic model for the mechanism of formation of hydrogen sulfide (H2S) corrosion products, theoretical and experimental studies were combined in this work. The corrosion products of API X60 pipeline steel formed under different H2S corrosion conditions were analyzed by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction. A thermodynamic model was developed to clarify the environmental boundaries for the formation and transformation of different products. Presumably, a dividing line with a negative slope existed between mackinawite and pyrrhotite. Using experimental data presented in this study combined with previously published results, we validated the model to predict the formation of mackinawite and pyrrhotite on the basis of the laws of thermodynamics. The established relationship is expected to support the investigation of the H2S corrosion mechanism in the oil and gas industry. © 2017, University of Science and Technology Beijing and Springer-Verlag Berlin Heidelberg.

关键词： Energy dispersive spectroscopy Forecasting Gas industry Iron ores Pipelines Scanning electron microscopy Steel corrosion Steel pipe Thermodynamic properties Thermodynamics X ray diffraction X ray spectroscopy

Decomposition of Different litter Fractions in a Subtropical Bamboo Ecosystem as Affected by Experimental Nitrogen Deposition

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Pedosphere 2011年第6期21卷 685-695页

作者： TU li-hua hu Hong-ling hu Ting-Xing ZHANG Jian liU li li Ren-Hong DAI Hong-Zhong LUO Shou-hua Sichuan Provincial Key Laboratory of Forestry Ecological Engineering College of Forestry Sichuan Agricultural University Xingkang Road 46 Ya'an 625014 (China) Maize Research Institute Sichuan Agricultural University Ya'an 625014 (China) Sichuan Forestry Inventory and Plan Institute Chengdu 610081 (China)

As an important component of the global carbon （C） budget, litter decomposition in terrestrial ecosystems is greatly affected by the increasing nitrogen （N） deposition observed globally. We hypothesized that different litter fractions derived from a single tree species may respond to N deposition differently depending on the quality of the litter substrate. To test the hypothesis, a two-year field experiment was conducted using the litterbag method in a Pleioblastus amarus plantation in the rainy region of Southwest China. Four N treatment levels were applied： control （no N added）, low-N （50 kg N ha-1 year-1）, medium-N （150 kg N ha-a year-1）, and high-N （300 kg N ha-1 year-l）. We observed different patterns of mass loss for the three P. amarus litter fractions （leaves, sheaths, and twigs） of varying substrate quality in the control plots. There were two decomposition stages with different decay rates （fast rate in early stages and slow rate in the later stages） for leaves and sheaths, while we did not observe a slower phase for the decay of twigs during the 2-year study period. The annual decomposition rate （k） of twigs was significantly lower than that of leaves or sheaths. Addition of N slowed the decomposition of leaves and twigs in the later stages of decomposition by inhibiting the decay of lignin and cellulose, while addition of N did not affect the mass loss of sheaths during the study period. In the decomposition of all three litter fractions, experimental N deposition reduced the net N accumulation in the early stages and also decreased the net N release in the later stages. The results of this study suggest that litter substrate quality may be an important factor affecting litter decomposition in a bamboo ecosystem affected by N deposition.

关键词： decomposition rate litter substrate N dynamics plant biomass Pleioblastus amarus

Efficacy of concentrated growth factors combined with mineralized collagen on quality of life and bone reconstruction of guided bone regeneration

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Regenerative Biomaterials 2020年第3期7卷 313-320页

作者： Yan Dai Xiao-hui Han li-hua hu Hai-Wei Wu Sheng-Yun huang Yu-Peng Lu Department of Oral and Maxillofacial Surgery Central Hospital of ZiboShandong UniversityZibo 255036China Department of Oral and Maxillofacial Surgery Department of Prosthodontics Shandong Provincial Hospital Affiliated to Shandong UniversityJinan 250021China Key Laboratory for liquid-Solid Structural Evolution and Processing of Materials Ministry of EducationShandong UniversityJinan 250061China School of Materials Science and Engineering Shandong UniversityJinan 250061China

To evaluate the clinical efficacy of concentrated growth factors(CGFs)combined with mineralized collagen(MC)in guided bone regeneration(GBR).A retrospective study involving 29 patients treated with GBR technique,which was performed either CGF and MC complexes or MC *** were inserted simultaneously and cone-beam computed tomography was taken immediately,at 3 and 6 months *** were completed by all patients so as to evaluate the main symptoms and daily activities during the first week after *** outcomes of the two groups were statistically *** implants healed *** in both groups suffered from different levels of discomfort for the reason of swelling,pain and chewing impairment on 1-2 ***,swelling of the Trial group was weaker than the Control *** compared with the Control group,pain levels in Trial group were more rapidly reduced and patients took fewer analgesics from Day ***,the reconstitution mean value of the graft was thicker at 3 and 6 months in Trial *** complex with MC were beneficial to relieve the clinical symptoms,promote the peri-implant bone regeneration and shorten the healing time.

关键词： concentrated growth factors mineralized collagen guided bone regeneration bone augmentation osseointegration

Association between body mass index and the risk of bleeding in elderly patients with non-valvular atrial fibrillation taking dabigatran:a cohort study

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Journal of Geriatric Cardiology 2020年第4期17卷 193-201页

作者： Ming-hui li li-hua hu Yu-Rong XIONG Yu YU Wei ZHOU Tao WANG ling-Juan Zhu Xi liU hui-hui BAO Xiao-Shu CHENG Department of Cardiovascular Medicine the Second Affiliated Hospital of Nanchang UniversityJiangxiChina Center for Prevention and Treatment of Cardiovascular Diseases the Second Affiliated Hospital of Nanchang UniversityJiangxiChina Center of Cardiovascular Inner Mongolia People’s HospitalHohhotInner MongoliaChina

Background Uncertainty remains regarding the association between body mass index(BMI)and the risk of bleeding in patients with non-valvular atrial fibrillation(NVAF).We aimed to investigate the association between BMI and the risk of bleeding in elderly NVAF patients taking *** A total of 509 elderly NVAF patients,who were being treated at twelve centers in China from February 2015 to December 2017 and taking dabigatran,were *** exposure and outcome variables were BMI at baseline and bleeding events within the subsequent six months,*** proportional hazards regression analysis was used to evaluate the association between BMI and the risk of ***,the Cox proportional hazards regression with cubic spline functions and smooth curve fitting was *** During the six-month follow-up,50 participants experienced *** 1 kg/m^2 increase in BMI was associated with a 12%increased risk of bleeding(P=0.021).Compared to those with BMI values in Tertile 1(25.3 kg/m^2)were 2.71(95%CI:1.02–7.17)and 3.5(95%CI:1.21–8.70),*** Ptrend-value was significant in all *** adjusted smooth curve showed a linear association between BMI and *** of the stratified variables showed significant effect modification on the association between BMI and bleeding(Pinteraction>0.05).Conclusions BMI was significantly and positively associated with the risk of bleeding in elderly NVAF patients treated with dabigatran.

关键词： Atrial fibrillation Bleeding Body mass index Dabigatran

Inhibition of nuclear factor-κB activity enhanced chemosensitivity to cisplatin in human lung adeno-carcinoma A549 cells under chemical hypoxia conditions

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Chinese Medical Journal 2013年第17期126卷 3276-3282页

作者： li Fang huaNG li SU Xiao-li GU Qi-hua hu Cheng-ping Department of Respiratory Diseases Xiangya Hospital Central South University Changsha Hunan 410007 China

Background Tumor hypoxia, one of the features of solid tumors, is associated with chemo-resistance. Recently, nuclear factor-KB （NF-κB） was found to be activated during hypoxia. However, the impact of NF-κB activation on chemo-resistance during hypoxia remains unknown. Methods human lung adenocarcinoma A549 cells were transfected with NF-κB p65siRNA and treated with cobalt chloride （COCI2） to mimic hypoxia in the presence or absence of cisplatin. NF-KB expression was measured by Western blotting, immune-fluorescence and real-time PCR. Hypoxia-inducible factor-1α （HIF-1α） and Bcl-2 expression were determined by Western blotting. Cell apoptosis and survival with half-maximum inhibitory concentration （IC50） of cisplatin were determined by Annexin V-FITC/PI and 3-（4, 5-dimethylthiazol-2-yl）-2, 5-diphenyltetrazolium bromide （MTT）, respectively. Results Exposure ofA549 cells to COCl2 increased nuclear HIF-1α protein expression, and enhanced NF-KB p65 protein nuclear accumulation （the mark of NF-κB activation） in a time and dose dependant manner. COCI2 did not promote apoptosis in A549 cells; on the contrary, it reduced cisplatin-induced apoptosis and increased the IC50 of cisplatin. However, when we inhibited CoCI2-induced activation of NF-κB through NF-κB p65siRNA, cisplatin-induced apoptosis was increased and IC50 of cisplatin was reduced to levels similar to those in control cells. Meanwhile, CoCI2-induced Bcl-2 over- expression was down-regulated in the presence of cisplatin when NF-κB activity was inhibited. Conclusion Up-regulating Bcl-2 might be involved in NF-κB activation induced resistance to cisplatin in A549 cells under CoCl2-induced chemical hypoxia.

关键词： lung adenocarcinoma nuclear factor-κB chemical hypoxia chemotherapy Bcl-2

Dome Combustion Hot Blast Stove for huge Blast Furnace

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Journal of Iron and Steel Research International 2012年第9期19卷 1-7页

作者： ZHANG Fu-ming , MAO Qing-wu , MEI Cong-hua , li Xin , hu Zu-rui ( Beijing Shougang International Engineering Technology Co Ltd , Beijing 100043 , China ) Beijing Shougang International Engineering Technology Co Ltd Beijing China

In Shougang Jingtang 5 500m 3 huge blast furnace ( BF ) design , dome combustion hot blast stove ( DCHBS ) technology is *** process is optimized and integrated , and reasonable hot blast stove ( HBS ) technical parameters are *** model is established and adopted by computational fluid dynamics ( CFD ) .The transmission theory is studied for hot blast stove combustion and gas flow , and distribution results of HBS velocity field , CO density field and temperature field are *** test model and hot trail unit are established , and the numeral calculation result is verified through test and investigation.3-D simulation design is *** process flow and process layout are optimized and *** air two-stage high temperature preheating technology is designed and *** sets of small size DCHBSs are adopted to preheat the combustion air to 520-600℃.With the precondition of BF gas combustion , the hot blast stove dome temperature can exceed 1 420 ℃. According to DCHBS technical features , reasonable refractory structure is *** technical measures are adopted to prevent hot blast stove shell intercrystalline stress *** blast stove hot pipe and lining system are optimized and *** blowing in , the blast temperature keeps increasing , and the monthly average blast temperature reaches 1 300℃ when burning single BF gas.

关键词： dome combustion hot blast stove high blast temperature ceramic burner high temperature combustion air preheating CFD

Association between mandibular posterior alveolar morphology and growth pattern in a Chinese population with normal occlusion

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2013年第1期14卷 25-32页

作者： Min HAN Rong-yang WANG Hong liU Xiu-juan Zhu Fu-lan WEI Tao LV Na-na WANG li-hua hu Guo-ju li Dong-xu liU Chun-ling WANG Department of Orthodontics Shandong Provincial Key Laboratory of Oral Biomedicine Shandong University Jinan 250012 China Department of Radiology Shandong Provincial Key Laboratory of Oral Biomedicine Shandong University Jinan 250012 China

Objective:To investigate the relationship between growth patterns and mandibular posterior tooth-alveolar bone complex morphology in a Chinese population with normal ***:Forty-five patients with normal occlusion(23 males,22 females) were included in this *** these patients,20 displayed the vertical growth pattern,and 20 had the horizontal growth pattern,while the remaining patients displayed the average growth *** of the patients underwent dental cone beam computed tomography(CBCT),which included the region of the mandibular posterior teeth and the alveolar.A linear regression analysis and a correlation analysis between the facial height index(FHI) and the alveolar bone morphology were ***:The inclination of the molars,the thickness of the cortical bone,and the height of the mandibular bone differed significantly between patients with the horizontal growth pattern and those with the vertical growth pattern(Plination of the molars;the FHI and the thickness of the cortical bone;and the FHI and the height of the mandibular ***:The mandibular posterior tooth-alveolar bone complex morphology may be affected by growth patterns.

关键词： Cone beam computed tomography (CBCT) Growth pattern Alveolar morphology Normal occlusion

Early hepatitis B viral DNA clearance predicts treatment response at week 96

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World Journal of Gastroenterology 2017年第16期23卷 2978-2986页

作者： Xiao-Yu Fu De-Ming Tan Cui-Mei liu Bin Gu li-hua hu Zhong-Tian Peng Bin Chen Yuan-lin Xie huan-Yu Gong Xiao-Xuan hu lian-hui Yao Xiao-Ping Xu Zheng-Yuan Fu Lang-Qiu He Si-Hai li Yun-Zhu Long De-hui li Ji-Long Gu Shi-Fang Peng Key Laboratory of Viral Hepatitis Department of Infectious DiseasesXiangya HospitalCentral South UniversityChangsha 410008Hunan ProvinceChina The Second People’s Hospital of Chenzhou Chenzhou 423000Hunan ProvinceChina The Third People’s Hospital of Hengyang Hengyang 421005Hunan ProvinceChina The First Affiliated Hospital of Nanhua University Hengyang 421001Hunan ProvinceChina The First Affiliated Hospital of hunan Traditional Chinese Medicine University Changsha 430100Hunan ProvinceChina The First Hospital of Changsha Changsha 430100Hunan ProvinceChina The Third Xiangya Hospital Changsha 410008Hunan ProvinceChina The People’s Hospital of hunan Province Changsha 410005Hunan ProvinceChina Wangwang Hospital of Changsha Changsha 410005Hunan ProvinceChina The People’s Hospital of Xiangxi Jishou 416000Hunan ProvinceChina The First People’s Hospital of huaihua Huaihua 418000Hunan ProvinceChina The Central Hospital of Xiangtan Xiangtan 411100Hunan ProvinceChina The First People’s Hospital of Yueyang Yueyang 414000Hunan ProvinceChina The Central Hospital of Zhuzhou Zhuzhou 412007Hunan ProvinceChina The First People’s Hospital of Changde Changde 415003Hunan ProvinceChina The Central Hospital of Shaoyang Shaoyang 422000Hunan ProvinceChina

AIM To investigate whether hepatitis viral DNA load at 24 wk of treatment predicts response at 96 wk in patients with chronic hepatitis *** A total of 172 hepatitis B envelope antigen(HBe Ag)-positive chronic hepatitis B patients who received initial treatment at 16 tertiary hospitals in hunan Province, China were enrolled in this study. All patients received conventional doses of lamivudine and adefovir dipivoxil, telbivudine, entecavir dispersible tablets, or entecavir tablets for 96 wk. Patients who used other antiviral drugs or antitumor and immune regulation therapy were excluded. Patients were stratified into three groups according to their viral DNA load at 24 wk: 103 IU/m L(group 3). Correlations of 24-wk DNA load with HBe Ag negative status and HBe Ag seroconversion at 96 wk were analyzed. Receiver operating characteristic curve analysis was used to test the predictive value of the HBV DNA load at 24 wk for long-term *** The rates of conversion to HBe Ag negative status and HBe Ag seroconversion rates were 53.7% and 51.9%, respectively, in group 1; 35.21% and 32.39% in group 2; and 6.38% and 6.38% in group 3. The receiver operating characteristic curves for the three subgroups revealed that the lowest DNA load(lifying and sequencing viral DNA in patients with a viral DNA load > 200 IU/m L at 96 wk; resistance mutations involving different loci were present in 26 patients, and three of these patients had a viral DNA load 10-103 IU/m L at 96 wk. CONCLUSION Hepatitis B viral DNA load at 24 wk of antiviral treatment in patients with chronic hepatitis B is a predictor of the viral load and response rate at 96 wk.

关键词： Chronic hepatitis B Nucleoside analogue Viral DNA load Hepatitis B antigens Hepatitis B antibodies Hepatitis B virus DNA Hepatitis B virus