期刊文献+
共找到2,070篇文章
< 1 2 104 >
每页显示 20 50 100
Farmers’ Practices for the Orchard’s Maintenance and Post-Harvest Treatment of Cocoa in Infiltrated Classified and Unclassified Zone of Méagui (South-West, Côte d’Ivoire)
1
作者 Trazié Kevin Guessan-Bi Kouadio Dagobert Kra +2 位作者 Koffi Éric Kwadjo Konan Lucien Kouame Mamadou Doumbia 《Health》 2023年第3期275-295,共21页
An important part of Ivorian cocoa production comes from infiltrated classified forests. The objective of this study is to investigate orchard maintenance and post-harvest cocoa treatment practices used by cocoa farme... An important part of Ivorian cocoa production comes from infiltrated classified forests. The objective of this study is to investigate orchard maintenance and post-harvest cocoa treatment practices used by cocoa farmers in infiltrated classified and unclassified areas of Méagui. To do this, 110 producers in two localities of the said zone were individually interviewed from February to April 2022, using a declarative questionnaire. It was found that cocoa orchards in the zone are aging. Nearly 68.55% of producers were heirs and 58.33% of those interviewed were under 46 years of age, with an average age of 43 years. Nearly 84.55% of the producers surveyed mainly use chemical insecticides to control the pests of greatest concern in these localities. Regarding the frequency of insecticide treatments, 11.82% of producers make 1 to 2 applications a year, 29.09% make 3 to 5 applications a year, and 43.64% make at least 6 applications a year. The active substances of the most used products belong to 99% of the Neonicotinoid and Pyrethroid families. Regarding cocoa harvesting and post-harvest operations, 93.64% of the producers carry out a single harvest/month;all do the shelling with mini machetes. Beans are fermented mainly in black plastic tarpaulins or in bags, for a period of 3 to 5 days (65.45%). Drying is done almost entirely (91.82%) on the black plastic tarp. This study shows that cocoa farmers in the areas surveyed do not respect the recommendations issued on phytosanitary practices and post-harvest treatment of cocoa. This non-compliance with the standards of good practices prescribed is particularly more accentuated in the locality located in infiltrated classified zone. It would, therefore, be judicious to revise or redefine the phytosanitary recommendations and carry out sensitization and training-follow-up programs for producers in this important cocoa production area of C?te d’Ivoire. 展开更多
关键词 Cocoa Farmers’ Practices Orchards Maintenance post-Harvest treatment Méagui
下载PDF
Farmers’ Practices for the Orchard’s Maintenance and Post-Harvest Treatment of Cocoa in Infiltrated Classified and Unclassified Zone of Méagui (South-West, Côte d’Ivoire)
2
作者 Trazié Kevin Guessan-Bi Kouadio Dagobert Kra +2 位作者 Koffi Éric Kwadjo Konan Lucien Kouame Mamadou Doumbia 《Journal of Agricultural Chemistry and Environment》 2023年第3期275-295,共21页
An important part of Ivorian cocoa production comes from infiltrated classified forests. The objective of this study is to investigate orchard maintenance and post-harvest cocoa treatment practices used by cocoa farme... An important part of Ivorian cocoa production comes from infiltrated classified forests. The objective of this study is to investigate orchard maintenance and post-harvest cocoa treatment practices used by cocoa farmers in infiltrated classified and unclassified areas of Méagui. To do this, 110 producers in two localities of the said zone were individually interviewed from February to April 2022, using a declarative questionnaire. It was found that cocoa orchards in the zone are aging. Nearly 68.55% of producers were heirs and 58.33% of those interviewed were under 46 years of age, with an average age of 43 years. Nearly 84.55% of the producers surveyed mainly use chemical insecticides to control the pests of greatest concern in these localities. Regarding the frequency of insecticide treatments, 11.82% of producers make 1 to 2 applications a year, 29.09% make 3 to 5 applications a year, and 43.64% make at least 6 applications a year. The active substances of the most used products belong to 99% of the Neonicotinoid and Pyrethroid families. Regarding cocoa harvesting and post-harvest operations, 93.64% of the producers carry out a single harvest/month;all do the shelling with mini machetes. Beans are fermented mainly in black plastic tarpaulins or in bags, for a period of 3 to 5 days (65.45%). Drying is done almost entirely (91.82%) on the black plastic tarp. This study shows that cocoa farmers in the areas surveyed do not respect the recommendations issued on phytosanitary practices and post-harvest treatment of cocoa. This non-compliance with the standards of good practices prescribed is particularly more accentuated in the locality located in infiltrated classified zone. It would, therefore, be judicious to revise or redefine the phytosanitary recommendations and carry out sensitization and training-follow-up programs for producers in this important cocoa production area of C?te d’Ivoire. 展开更多
关键词 Cocoa Farmers’ Practices Orchards Maintenance post-Harvest treatment Méagui
下载PDF
Effect of post weld heat treatment on properties of variable polarity TIG welded AA2219 aluminium alloy joints 被引量:13
3
作者 丁吉坤 王东坡 +1 位作者 王颖 杜辉 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第5期1307-1316,共10页
AA2219 aluminium alloy joints were fabricated by variable polarity tungsten inert gas (VPTIG) welding process and the effects of post weld heat treatment (PWHT) on the tensile properties, microstructure and fatigu... AA2219 aluminium alloy joints were fabricated by variable polarity tungsten inert gas (VPTIG) welding process and the effects of post weld heat treatment (PWHT) on the tensile properties, microstructure and fatigue behaviour of the welded joints were investigated. The VPTIG welding process was adopted because it could meet the need of cathode cleaning and meanwhile it could reduce the deterioration of tungsten electrode furthest. The welded samples were divided into as-welded (AW) sample and PWHT sample. The PWHT method used on the samples was solution treatment (535 ℃, 30 rain), water quenching and artificial aging (175 ℃, 12 h). The experimental results show that, compared with the AW samples, the microstructure characteristics and mechanical properties of the AA2219 joints after PWHT were significantly improved. The improvement of yield strength, ultimate tensile strength, and fatigue strength are 42.6%, 43.1% and 18.4%, respectively. 展开更多
关键词 AA2219 aluminium alloy variable polarity TIG post weld heat treatment mechanical properties MICROSTRUCTURE fatigue behaviour
下载PDF
Highly efficient solution-processed CZTSSe solar cells based on a convenient sodium-incorporated post-treatment method 被引量:9
4
作者 Biwen Duan Linbao Guo +7 位作者 Qing Yu Jiangjian Shi Huijue Wu Yanhong Luo Dongmei Li Sixin Wu Zhi Zheng Qingbo Meng 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2020年第1期196-203,I0007,共9页
In CZTSSe solar cells,a simple sodium-incorporation post-treatment method toward solution-processed Cu2Zn Sn S4precursor films is presented in this work.An ultrathin NaCl film is deposited on Cu2Zn Sn S4precursor film... In CZTSSe solar cells,a simple sodium-incorporation post-treatment method toward solution-processed Cu2Zn Sn S4precursor films is presented in this work.An ultrathin NaCl film is deposited on Cu2Zn Sn S4precursor films by spin-coating NaCl solution.In subsequent selenization process,the introduction of Na Cl is found to be benefacial for the formation of Cu2-xSe,which can further facilitate the element transportation,leading to dense and smooth CZTSSe films with large grains and less impurity Cu2Sn(S,Se)3phase.SIMS depth profiles confirm the gradient distribution of the sodium element in Na-doped absorbers.Photoluminescence spectra show that the introduction of appropriate sodium into the absorber can inhibit the band tail states.As high as 11.18% of power conversion efficiency(PCE)is achieved for the device treated with 5 mg mL^-1 NaCl solution,and an average efficiency of Na-doped devices is 10.71%,13%higher than that of the control groups(9.45%).Besides,the depletion width and the charge recombination lifetime can also have regular variation with sodium treatment.This work offers an easy modification method for high-quality Na-doped CZTSSe films and high-performance devices,in the meantime,it can also help to further understand the effects of sodium in CZTSSe solar cells. 展开更多
关键词 Thin film solar cell CZTSSe Sodium doping post-treatment Spin-coating method
下载PDF
Temperature field analysis of main steam pipe under local post weld heat treatment 被引量:4
5
作者 李培麟 樊睿智 陆皓 《China Welding》 EI CAS 2010年第4期20-24,共5页
In local post weld heat treatment, the temperature difference is the criterion of the process. The temperature field in the main stream pipe under local post weld heat treatment is simulated by finite element method. ... In local post weld heat treatment, the temperature difference is the criterion of the process. The temperature field in the main stream pipe under local post weld heat treatment is simulated by finite element method. A close-loop control program is designed to simulate the temperature field of two different pipes. Both the skin effect of induction heating and electro-thermal coupled effect are considered in the heating model. The local heat treatment temperature difference at the inner and outer side of the pipe is analyzed and the different convection conditions are also considered. The simulation results show that in appropriate induction heating process, the temperature difference in the pipe can be controlled within 30 ℃. 展开更多
关键词 local post weld heat treatment temperature field electro-thermal coupling numerical simulation
下载PDF
Effect of post treatment temperature and humidity conditions onfixation performance of CCA-C treated red pine and southern pine 被引量:1
6
作者 郭爱龙 P.A.Cooper 《Journal of Forestry Research》 SCIE CAS CSCD 1999年第3期141-146,共6页
Rates of fixation in chromated copper arsenate (CCA-C) treated red pine (Pinus resinosa Ait.) and southern pine (Pinus spp) sapwood specimens using retention of 1.5, 2.0, 6.4 kg·m?3 are compared at temperature (T... Rates of fixation in chromated copper arsenate (CCA-C) treated red pine (Pinus resinosa Ait.) and southern pine (Pinus spp) sapwood specimens using retention of 1.5, 2.0, 6.4 kg·m?3 are compared at temperature (T) ranging from 70°C to 50°C and 5 different relative humidity (RH) conditions. The samples were investigated using the expressate method to follow chromium fixation. Red pine fixes faster than southern pine under all 11 post treatment schedules. The fixation rates for both species are not significantly different while the blocks were fixed under 6 fixation/drying schedules that differed only in the order of T/RH conditions applied. The rate of fixation of all samples in any fixation stage were reduced when the blocks were fixed under lower humidity conditions in spite of no change in chamber temperature. Some of this influence can be attributed to the effect of humidity on heat transfer into the wood and cooling of the wood surface. 展开更多
关键词 CCA-c FIXATION post treatment TEMPERATURE Relative humidity Red pine Southern pine
下载PDF
Role of ^(18)F-FDG PET/CT in pre and post treatment evaluation in head and neck carcinoma 被引量:5
7
作者 Bundhit Tantiwongkosi Fang Yu +1 位作者 Anand Kanard Frank R Miller 《World Journal of Radiology》 CAS 2014年第5期177-191,共15页
Head and neck cancer(HNC) ranks as the 6th most common cancer worldwide, with the vast majority being head and neck squamous cell carcinoma(HNSCC). The majority of patients present with complicated locally advanced di... Head and neck cancer(HNC) ranks as the 6th most common cancer worldwide, with the vast majority being head and neck squamous cell carcinoma(HNSCC). The majority of patients present with complicated locally advanced disease(typically stage Ⅲ and Ⅳ) requiring multidisciplinary treatment plans with combinations of surgery, radiation therapy and chemotherapy. Tumor staging is critical to decide therapeutic planning. Multiple challenges include accurate tumor localization with precise delineation of tumor volume, cervical lymph node staging, detection of distant metastasis as well as ruling out synchronous second primary tumors. Somepatients present with cervical lymph node metastasis without obvious primary tumors on clinical examination or conventional cross sectional imaging. Treatment planning includes surgery, radiation, chemotherapy or combinations that could significantly alter the anatomy and physiology of this complex head and neck region, making assessment of treatment response and detection of residual/ recurrent tumor very difficult by clinical evaluation and computed tomography(CT) or magnetic resonance imaging(MRI). 18F-2-fluoro-2-deoxyD-glucose positron emission tomography/CT(18F-FDG PET/CT) has been widely used to assess HNC for more than a decade with high diagnostic accuracy especially in detection of initial distant metastasis and evaluation of treatment response. There are some limitations that are unique to PET/CT including artifacts, lower soft tissue contrast and resolution as compared to MRI, false positivity in post-treatment phase due to inflammation and granulation tissues, etc. The aim of this article is to review the roles of PET/CT in both pre and post treatment management of HNSCC including its limitations that radiologists must know. Accurate PET/CT interpretation is the crucial initial step that leads to appropriate tumor staging and treatment planning. 展开更多
关键词 Head and NECK cancer POSITRON emission TOMOGRAPHY COMPUTED TOMOGRAPHY STAGING post treatment RECURRENCE
下载PDF
Association of post.treatment hypoalbuminemia and survival in Chinese patients with metastatic renal cell carcinoma 被引量:3
8
作者 Wen Cai Jin Zhang +4 位作者 Yonghui Chen Wen Kong Yiran Huang Jiwei Huang Lixin Zhou 《Chinese Journal of Cancer》 SCIE CAS CSCD 2017年第7期315-325,共11页
Background:Hypoalbuminemia adversely affects the clinical outcomes of various cancers.The purpose of this study was to estimate the prognostic value of hypoalbuminemia 3-5 weeks after treatment in patients with metast... Background:Hypoalbuminemia adversely affects the clinical outcomes of various cancers.The purpose of this study was to estimate the prognostic value of hypoalbuminemia 3-5 weeks after treatment in patients with metastatic renal cell carcinoma(mRCC) who received sorafenib or sunitinib as first-line treatment.Methods:In this single-center,retrospective study,we assessed the progression-free survival(PFS) and overall survival(OS) of 184 mRCC patients who received first-line sorafenib or sunitinib treatment.PFS and OS were compared between patients with post-treatment hypoalbuminemia(post-treatment albumin level <36.4 g/L) and those with normal post-treatment albumin level(albumin level≥36.4 g/L).The Memorial Sloan Kettering Cancer Center(MSKCC)risk model stratified mRCC patients into three risk categories.Prognostic values of all patient characteristics including MSKCC risk category were determined by using univariate and multivariate Cox regression models.Prognostic value was further determined using the Harrell concordance index and receiver operating characteristic curve analysis.Results:The median PFS and OS of the 184 patients were 11 months(95%confidence interval[CI]9-12 months)and 23 months(95%CI 19-33 months),respectively.Patients with post-treatment hypoalbuminemia had significantly shorter median PFS(6 months[95%CI 5-7 months]) and OS(11 months[95%CI 9-15 months]) than patients who had normal post-treatment albumin levels(PFS:12 months[95%CI 11-16 months],P < 0.001;OS:31 months[95%CI24-42 months],P < 0.001),respectively.Multivariate analysis showed that post-treatment hypoalbuminemia was an independent predictor of PFS(hazard ratio[HR],2.113;95%CI 1.390-3.212;P < 0.001) and OS(HR,2.388;95%CI 1.591-3.585;P < 0.001).Post-treatment hypoalbuminemia could also be combined with the MSKCC risk category for better prediction about OS.The model that included post-treatment hypoalbuminemia and MSKCC risk category improved the predictive accuracy for PFS and OS(c-index:0.68 and 0.73,respectively) compared with the basic MSKCC risk model(c-index:0.67 and 0.70,respectively).The prognostic values for PFS and OS of the integrated MSKCC risk model involving post-treatment hypoalbuminemia were significantly more accurate than the basic MSKCC risk model using likelihood ratio analysis(both P < 0.001).Conclusions:Post-treatment hypoalbuminemia can be considered an independent prognostic factor for patients with mRCC who undergo first-line treatment with tyrosine kinase inhibitors.Additionally,integrating post-treatment serum albumin level into the basic MSKCC risk model can improve the accuracy of this model in predicting patient overall survival and progression-free survival. 展开更多
关键词 METASTATIC RENAL cell carcinoma post-treatment HYPOALBUMINEMIA Prognosis TYROSINE KINASE inhibitors
下载PDF
Effect of post weld heat treatment on microstructure and mechanical properties of gas tungsten arc welded AA6061-T6 alloy 被引量:4
9
作者 Firouz FADAEIFARD Khamirul Amin MATORI +2 位作者 Farhad GARAVI Muath Al-FALAHI Gholamreza Vahedi SARRIGANI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第12期3102-3114,共13页
Double-V butt TIG welding process was performed on two plates of AA6061-T6 using ER5356 filler. The microstructure,mechanical and nanomechanical properties of the joint were evaluated in as-welded and after post weld ... Double-V butt TIG welding process was performed on two plates of AA6061-T6 using ER5356 filler. The microstructure,mechanical and nanomechanical properties of the joint were evaluated in as-welded and after post weld heat treatment (PWHT) usingXRD, FESEM, EBSD, nanoindentation and tensile tests. The results show that PWHT led to microstructural recovery of the heataffected zone (HAZ) in addition to the appearance of β-phase (Al3Mg2) at the grain boundaries of weld zone. The hardness (Hnano) inall zones increased after PWHT while the elastic modulus (Enano) was improved from 69.93 GPa to 81 GPa in weld area. All resultsindicate that PWHT has created a homogenous microstructure in the weld zone in addition to outstanding improvement inmechanical properties for the weld zone which surpass the base metal. 展开更多
关键词 AA6061-T6 alloy ER5356 gas tungsten arc welding post weld heat treatment NANOINDENTATION microstructure
下载PDF
Curcumin pretreatment and post-treatment both improve the antioxidative ability of neurons with oxygen-glucose deprivation 被引量:8
10
作者 Jing-xian Wu Lu-yu Zhang +3 位作者 Yan-lin Chen Shan-shan Yu Yong Zhao Jing Zhao 《Neural Regeneration Research》 SCIE CAS CSCD 2015年第3期481-489,共9页
Recent studies have shown that induced expression of endogenous antioxidative enzymes thr- ough activation of the antioxidant response element/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway may be a neur... Recent studies have shown that induced expression of endogenous antioxidative enzymes thr- ough activation of the antioxidant response element/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway may be a neuroprotective strategy. In this study, rat cerebral cortical neurons cultured in vitro were pretreated with 10 ktM curcumin or post-treated with 5 pM curcumin, respectively before or after being subjected to oxygen-glucose deprivation and reoxygenation for 24 hours. Both pretreatment and post-treatment resulted in a significant decrease of cell injury as indicated by propidium iodide/Hoechst 33258 staining, a prominent increase of Nrf2 protein expression as indicated by western blot analysis, and a remarkable increase of protein expression and enzyme activity in whole cell lysates of thioredoxin before ischemia, after ischemia, and after reoxygenation. In addition, post-treatment with curcumin inhibited early DNA/RNA oxidation as indicated by immunocytochemistry and increased nuclear Nrf2 protein by inducing nuclear accumulation of Nrf2. These findings suggest that curcumin activates the expression of thi- oredoxin, an antioxidant protein in the Nrf2 pathway, and protects neurons from death caused by oxygen-glucose deprivation in an in vitro model of ischemia/reperfusion. We speculate that pharmacologic stimulation of antioxidant gene expression may be a promising approach to neu- roprotection after cerebral ischemia. 展开更多
关键词 nerve regeneration brain injury CURCUMIN ischemia/reperfusion injury OXIDATIVESTRESS primary cell culture cortical neurons oxygen-glucose deprivation PREtreatment post-treatment NSFC grant neural regeneration
下载PDF
Comparison of pre-treatment and post-treatment use of selenium in retinal ischemia reperfusion injury 被引量:3
11
作者 Alper Yazici Hasan Aksit +6 位作者 Esin Sogutlu Sari Arzu Yay Haydar Ali Erken Dilek Aksit Harun Cakmak Kamil Seyrek Sitki Samet Ermis 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2015年第2期263-268,共6页
AIM: To investigate the effects of selenium in rat retinal ischemia reperfusion(IR) model and compare pretreatment and post-treatment use.METHODS: Selenium pre-treatment group(n =8) was treated with intraperitoneal(i.... AIM: To investigate the effects of selenium in rat retinal ischemia reperfusion(IR) model and compare pretreatment and post-treatment use.METHODS: Selenium pre-treatment group(n =8) was treated with intraperitoneal(i.p.) selenium 0.5 mg/kg for7 d and terminated 24 h after the IR injury. Selenium posttreatment group( n = 8) was treated with i. p. selenium0.5 mg/kg for 7d after the IR injury with termination at the end of the 7d period. Sham group(n =8) received i.p.saline injections identical to the selenium volume for 7d with termination 24 h after the IR injury. Control group(n =8) received no intervention. Main outcome measures were retina superoxide dismutase(SOD), glutathione(GSH),total antioxidant status(TAS), malondialdehyde(MDA),DNA fragmentation levels, and immunohistological apoptosis evaluation.RESULTS: Compared to the Sham group, selenium pre-treatment had a statistical difference in all parameters except SOD. Post-treatment selenium also resulted in statistical differences in all parameters except the MDA levels. When comparing selenium groups, the pre-treatment selenium group had a statistically higher success in reduction of markers of cell damage such as MDA and DNA fragmentation. In contrast, the post-selenium treatment group had resulted in statisticallyhigher levels of GSH. Histologically both selenium groups succeeded to limit retinal thickening and apoptosis. Pre-treatment use was statistically more successful in decreasing apoptosis in ganglion cell layer compared to post-treatment use.CONCLUSION: Selenium was successful in retinal protection in IR injuries. Pre-treatment efficacy was superior in terms of prevention of tissue damage and apoptosis. 展开更多
关键词 RETINA SELENIUM ISCHEMIA-REPERFUSION APOPTOSIS pre-treatment post-treatment oxidative stress
下载PDF
Microstructure,mechanical and corrosion behavior of high strength AA7075aluminium alloy friction stir welds-Effect of post weld heat treatment 被引量:21
12
作者 P.Vijaya Kumar G.Madhusudhan Reddy K.Srinivasa Rao 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2015年第4期362-369,共8页
High strength aluminium alloy AA7075(Al-Zn-Mg-Cu) is a precipitate hardenable alloy widely used in the aerospace,defense,marine and automobile industries.Use of the heat treatable aluminium alloys in all these sectors... High strength aluminium alloy AA7075(Al-Zn-Mg-Cu) is a precipitate hardenable alloy widely used in the aerospace,defense,marine and automobile industries.Use of the heat treatable aluminium alloys in all these sectors is ever-increasing owing to their excellent strength-toweight ratio and reasonably good corrosion resistance.The shortage in corrosion resistance,however,usually poses negative concern about their reliability and lifetime when they service in the variable marine environments.These alloys also exhibit low weldability due to poor solidification microstructure,porosity in fusion zone and lose their mechanical properties when they are welded by fusion welding techniques.Friction stir welding(FSW) is a reliable technique to retain the properties of the alloy as the joining takes place in the solid state.The welds are susceptible to corrosion due to the microstructural changes in the weld nugget during FSW.In this work,the effect of post weld treatments,viz.,peak aging(T6) and retrogression & reaging(RRA),on the microstructure,mechanical properties and pitting corrosion has been studied.Friction stir welding of 8 mm-thick AA7075 alloy was carried out.The microstructural changes of base metal and nugget zone of friction stir welds were studied using optical microscopy,scanning electron microscopy and transmission electron microscopy.Tensile and hardness test of base metal and welds has been carried out.Pitting corrosion resistance was determined through dynamic polarization test.It was observed that the hardness and strength of weld were observed to be comparatively high in peak aged(T6) condition but the welds showed poor corrosion resistance.The resistance to pitting corrosion was improved and the mechanical properties were maintained by RRA treatment.The resistance to pitting corrosion was improved in RRA condition with the minimum loss of weld strength. 展开更多
关键词 7075铝合金 高强度铝合金 搅拌摩擦焊 耐腐蚀性 热处理效果 微观结构 焊缝 机械性能
下载PDF
Microstructure and pitting corrosion of armor grade AA7075 aluminum alloy friction stir weld nugget zone-Effect of post weld heat treatment and addition of boron carbide 被引量:6
13
作者 P.VIJAYA KUMAR G.MADHUSUDHAN REDDY K.SRINIVASA RAO 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2015年第2期166-173,共8页
Friction stir welding(FSW) of high strength aluminum alloys has been emerged as an alternative joining technique to avoid the problems during fusion welding.In recent times FSW is being used for armor grade AA7075 alu... Friction stir welding(FSW) of high strength aluminum alloys has been emerged as an alternative joining technique to avoid the problems during fusion welding.In recent times FSW is being used for armor grade AA7075 aluminum alloy in defense,aerospace and marine applications where it has to serve in non uniform loading and corrosive environments.Even though friction stir welds of AA7075 alloy possess better mechanical properties but suffer from poor corrosion resistance.The present work involves use of retrogression and reaging(RRA) post weld heat treatment to improve the corrosion resistance of welded joints of aluminum alloys.An attempt also has been made to change the chemical composition of the weld nugget by adding B4C nano particles with the aid of the FSW on a specially prepared base metal plate in butt position.The effects of peak aged condition(T6),RRA and addition of B4C nano particles on microstructure,hardness and pitting corrosion of nugget zone of the friction stir welds of AA7075 alloy have been studied.Even though RRA improved the pitting corrosion resistance,its hardness was slightly lost.Significant improvement in pitting corrosion resistance was achieved with addition of boron carbide powder and post weld heat treatment of RRA. 展开更多
关键词 7075铝合金 搅拌摩擦焊 焊后热处理 碳化硼颗粒 抗点蚀 微观结构 装甲 7075合金
下载PDF
Post-treatment of TS-1 with Mixtures of TPAOH and Ammonium Salts and the Catalytic Properties in Propylene Epoxidation 被引量:1
14
作者 Yaquan Wang Xinpeng Han +1 位作者 Haoyang Li Xiao Wang 《Transactions of Tianjin University》 EI CAS 2018年第5期461-470,共10页
TS-1/SiO_2 extrudate was post-treated with mixed solution of tetrapropyl ammonium hydroxide(TPAOH)and various ammonium salts solution(NH_4F,(NH_4)_3PO_4,(NH_4)_2CO_3,(NH_4)_2SO_4,NH_4CH_3CO_2,NH_4NO_3,NH_4Cl and(NH_4)... TS-1/SiO_2 extrudate was post-treated with mixed solution of tetrapropyl ammonium hydroxide(TPAOH)and various ammonium salts solution(NH_4F,(NH_4)_3PO_4,(NH_4)_2CO_3,(NH_4)_2SO_4,NH_4CH_3CO_2,NH_4NO_3,NH_4Cl and(NH_4)_2TiF_6).The obtained hierarchical TS-1 catalysts were characterized by many techniques and tested for propylene epoxidation using hydrogen peroxide as an oxidant in a fixed-bed reactor.It was shown that the physicochemical and catalytic properties of the treated TS-1/SiO_2 extrudate depended on the types of ammonium salts added.Compared to the treatment with TPAOH alone,the treatment with a mixed solution of TPAOH and some ammonium salts can greatly improve the catalytic properties of the treated TS-1/SiO_2 extrudate.Some of these ammonium salts were favorable for the incorporation of titanium in the framework,and the beneficial effect depended on the types of ammonium salt.TS-1/SiO_2 extrudate treated with a mixed solution of TPAOH and(NH_4)_3PO_4 exhibited the highest catalyst stability in propylene epoxidation.Such catalytic property can be correlated to high crystallinity,more framework titanium,large specific surface area and large external surface area. 展开更多
关键词 AMMONIUM SALT post-treatment Catalyst stability TS-1/SiO2 EXTRUDATE EPOXIDATION
下载PDF
Effect of post weld heat treatment on tensile properties and microstructure characteristics of friction stir welded armour grade AA7075-T651aluminium alloy 被引量:13
15
作者 P.SIVARAJ D.KANAGARAJAN V.BALASUBRAMANIAN 《Defence Technology(防务技术)》 SCIE EI CAS 2014年第1期1-8,共8页
This paper reports the effects of post weld heat treatments, namely artificial ageing and solution treatment followed by artificial ageing, on microstructure and mechanical properties of 12 mm thick friction stir weld... This paper reports the effects of post weld heat treatments, namely artificial ageing and solution treatment followed by artificial ageing, on microstructure and mechanical properties of 12 mm thick friction stir welded joints of precipitation hardenable high strength armour grade AA7075-T651 aluminium alloy. The tensile properties, such as yield strength, tensile strength, elongation and notch tensile strength, are evaluated and correlated with the microhardness and microstructural features. The scanning electron microscope is used to characterie the fracture surfaces. The solution treatment followed by ageing heat treatment cycle is found to be marginally beneficial in improving the tensile properties of friction stir welds of AA7075-T651 aluminium alloy. 展开更多
关键词 搅拌摩擦焊 铝合金接头 焊后热处理 微观结构 拉伸性能 装甲 扫描电子显微镜 焊接
下载PDF
Etiology and Treatment of Post-surgical Blepharoptosis 被引量:4
16
作者 Lijun Huo Dongmei Cui +2 位作者 Xiao Yang Zhenya Gao Junwen Zeng 《Eye Science》 CAS 2013年第3期134-139,共6页
Purpose: To investigate the etiology and the treatment of acquired blepharoptosis inpatients,.especially secondary to surgery.Methods: The clinical records of 65 consecutive patients with acquired ptosis were reviewed... Purpose: To investigate the etiology and the treatment of acquired blepharoptosis inpatients,.especially secondary to surgery.Methods: The clinical records of 65 consecutive patients with acquired ptosis were reviewed from an eye center and a comprehensive hospital..Potential factors responsible for acquired ptosis were investigated..Surgical management principles and post-operative exposure keratitis are discussed.Results:.The top three causes of acquired ptosis were postsurgical ptosis(20 / 65, 30.8%), traumatic ptosis(17 / 65,26.2%) and senile aponeurotic ptosis(12 / 65, 18.5%). Twenty patients had post-surgical ptosis secondary to orbital surgery(8 / 20, 40.0%), enucleation and hydroxyapatite(HA) artificial eye implantation(4 / 20, 20%), eyelid surgery(3 / 20,15%), cataract or glaucoma surgery(2 / 20, 10%), conjunctive surgery(2 / 20, 10%).and superior oblique muscle surgery(1 / 20, 5%). The levator palpebrae superioris(LPS) muscle of ten eyes(10 / 20, 50%) was found during exploration and reattached to the tarsal plate, with shortening of the LPS. Nine eyes(9 / 20, 45%) underwent a frontalis suspension(FS) operation because the LPS muscle was missing. One(1 / 20, 5%)patient was not operated on due to a poor Bell's phenomenon.Two patients(2 / 65, 3.1%)—one patient with post-surgical ptosis and another with aponeurotic ptosis—developed exposure keratitis after ptosis correction.Conclusion: Post-surgical ptosis is one of the most common causes of acquired ptosis. It is important to explore LPS muscle during surgery. LPS reattachment is performed if the muscle is found; otherwise, a FS operation is chosen. Exposure keratitis after correction should be monitored. 展开更多
关键词 手术治疗 下垂 眼睑 病因 综合性医院 角膜炎 羟基磷灰石 暴露性
下载PDF
Effective treatment of depression improves post-myocardial infarction survival 被引量:8
17
作者 Soudabeh Khojasteh Banankhah Erika Friedmann Sue Thomas 《World Journal of Cardiology》 CAS 2015年第4期215-223,共9页
AIM: To examine the contribution of treatment resistant depression(TRD) to mortality in depressed postmyocardial infarction(MI) patients independent of biological and social predictors.METHODS: This secondary analysis... AIM: To examine the contribution of treatment resistant depression(TRD) to mortality in depressed postmyocardial infarction(MI) patients independent of biological and social predictors.METHODS: This secondary analysis study utilizes the Enhancing Recovery in Coronary Heart Disease(ENRICHD) clinical trial data.From 1834 depressed patients in the ENRICHD study,there were 770 depressed post-MI patients who were treated for depression.In this study,TRD is defined as having a less than 50% reduction in Hamilton Depression(HAM-D) score from baseline and a HAM-D score of greater than 10 in 6 mo after depression treatment began.Cox regression analysis was used to examine the independent contributions of TRD to mortality after controlling for the biological and social predictors.RESULTS: TRD occurred in 13.4%(n = 103) of the 770 patients treated for depression.Patients with TRD were significantly younger in age(P = 0.04)(mean = 57.0 years,SD = 11.7) than those without TRD(mean = 59.2 years,SD = 12.0).There was a significantly higher percentage of females with TRD(57.3%) compared to females without TRD(47.4%) [χ2(1) = 4.65,P = 0.031].There were significantly more current smokers with TRD(44.7%) than without TRD(33.0%) [χ2(1) = 7.34,P = 0.007].There were no significant differences in diabetes(P = 0.120),history of heart failure(P = 0.258),prior MI(P = 0.524),and prior stroke(P = 0.180) between patients with TRD and those without TRD.Mortality was 13%(n = 13) in patients with TRD and 7%(n = 49) in patients without TRD,with a mean follow-up of 29 mo(18 mo minimum and maximum of 4.5 years).TRD was a significant independent predictor of mortality(HR =1.995; 95%CI: 1.011-3.938,P = 0.046) after controlling for age(HR = 1.036; 95%CI: 1.011-1.061,P = 0.004),diabetes(HR = 2.912; 95%CI: 1.638-5.180,P < 0.001),heart failure(HR = 2.736; 95%CI: 1.551-4.827,P = 0.001),and smoking(HR = 0.502; 95%CI: 0.228-1.105,P = 0.087).CONCLUSION: The analysis of TRD in the ENRICHD study shows that the effective treatment of depression reduced mortality in depressed post-MI patients.It is important to monitor the effectiveness of depression treatment and change treatments if necessary to reduce depression and improve cardiac outcomes in depressed post-MI patients. 展开更多
关键词 DEPRESSION treatment post-myocardial INFARCTION Mortality ANTI-DEPRESSANT Cognitive behavioral therapy
下载PDF
Effect of Post Weld Heat Treatment on Microstructure and Fracture Toughness of Friction Welded Joint 被引量:1
18
作者 吴素君 han bo +2 位作者 zhao dalong ji yingping shao ling 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2016年第6期1347-1351,共5页
The effect of post weld heat treatment on the microstructure and fracture toughness of friction welded joints of Ti-6.5Al-1Mo-1V-2Zr alloy was studied. The experimental results show that equiaxial grains were formed a... The effect of post weld heat treatment on the microstructure and fracture toughness of friction welded joints of Ti-6.5Al-1Mo-1V-2Zr alloy was studied. The experimental results show that equiaxial grains were formed at the center of the weld metal while highly deformed grains were observed in the thermomechanically affected zone. The fracture toughness of the weld metal was lower than that of the thermomechanically affected zone under as-weld and post weld heat treatment conditions. With increasing temperature of post weld heat treatment, the fracture toughness of weld center and thermomechanically affected zone increased. The fractographic observation revealed that the friction welded joints fractured in a ductile mode. 展开更多
关键词 titanium alloy post weld heat treatment microstructure fracture toughness
下载PDF
Microstructure characterization of electron beam welded joints of Ti_3Al after post-weld heat treatment 被引量:3
19
作者 HE Jingshan,WU Qingsheng,ZHANG Binggang,LIU Wei,and FENG Jicai State Key Laboratory of Advanced Welding Production Technology,Harbin Institute of Technology,Harbin 150001,China 《Rare Metals》 SCIE EI CAS CSCD 2007年第S1期242-245,共4页
The effect of post-weld heat treatment on the microstructure characterization of electron beam welded(EBW) joints of Ti3Al-Nb was investigated.The results show that the microstructure of the weld is predominantly meta... The effect of post-weld heat treatment on the microstructure characterization of electron beam welded(EBW) joints of Ti3Al-Nb was investigated.The results show that the microstructure of the weld is predominantly metastable,the columnar crystal metastructure of B2 phase.The microstructure morphology of the weld is significantly influenced by the method of the heat treatment.The microstructure of the weld is laminar structure(Widmanstaten structure) consisted of interphase α2 and B2 after post-weld heat treatment of 1000 ℃/2 h.The mechanism of the post-weld heat treatment makes the hardness distribution of joints homogeneous,but makes the whole joint somehow softened. 展开更多
关键词 Ti_3Al electron beam welding post-weld heat treatment MICROSTRUCTURE
下载PDF
Effect of Post-Treatment Conditions on the Inactivation of MS2 Bacteriophage as Indicator for Pathogenic Viruses after the Composting Process 被引量:1
20
作者 Hamidatu S. Darimani Ryusei Ito +1 位作者 Naoyuki Funamizu Amadou H. Maiga 《Journal of Agricultural Chemistry and Environment》 2018年第2期73-80,共8页
A rural model composting toilet system still had some pathogens in the compost after months of operation and hence requires a post-treatment. The aim of the study was to sanitize compost withdrawn from the composting ... A rural model composting toilet system still had some pathogens in the compost after months of operation and hence requires a post-treatment. The aim of the study was to sanitize compost withdrawn from the composting toilet by setting post-treatment conditions. The kinetics inactivation of MS2 bacteriophage, selected as indicator for pathogenic viruses were determined during post-treatment at different temperatures (30°C, 40°C and 50°C) with varying moisture contents (50%, 60% and 70%). As a result, the inactivation rates during the post-treatment were 0.093 - 0.020 h-1, 0.025 - 0.088 h1, 0.447 - 0.100 h-1 at 30°C, 40°C and 50°C respectively. The inactivation rate coefficient (k) values of MS2 bacteriophage depended on higher temperature but not on moisture content. 展开更多
关键词 COMpostING TOILET MS2 BACTERIOPHAGE Temperature Moisture Content post-treatment
下载PDF
上一页 1 2 104 下一页 到第
使用帮助 返回顶部