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HEACTP-DOPO与二乙基次膦酸铝协同阻燃环氧树脂 被引量:1
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作者 张君营 郭润泽 +2 位作者 张志永 冷洋 李晓丽 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2023年第4期50-58,共9页
合成了一种新型阻燃剂六-(N-羟乙基氨基-DOPO-次甲基-苯氧基)-环三磷腈(HEACTP-DOPO),利用傅里叶变换红外光谱(FT-IR)、核磁共振波谱(1H-NMR、31P-NMR)和高分辨质谱(HRMS)确定了其结构,并将HEACTP-DOPO和二乙基次膦酸铝(ADP)复配用于环... 合成了一种新型阻燃剂六-(N-羟乙基氨基-DOPO-次甲基-苯氧基)-环三磷腈(HEACTP-DOPO),利用傅里叶变换红外光谱(FT-IR)、核磁共振波谱(1H-NMR、31P-NMR)和高分辨质谱(HRMS)确定了其结构,并将HEACTP-DOPO和二乙基次膦酸铝(ADP)复配用于环氧树脂DGEBA阻燃研究。采用极限氧指数(LOI)和垂直燃烧(UL-94)、热重分析(TGA)和锥形量热(Cone)研究了材料的热降解行为和阻燃性能。当100 g DGEBA中添加10 g HEACTP-DOPO和3 g ADP时,所得阻燃材料的LOI值为37.0%,垂直燃烧通过UL-94V-0级;TGA分析表明,阻燃材料能降低环氧树脂的初始降解温度,增加了高温时的残炭量;Cone数据计算发现,该阻燃材料与纯环氧树脂相比,热释放速率峰值(PHRR)、总热释放(THR)、平均有效燃烧热(Av-EHC)和烟释放总量(TSP)分别降低了39.9%,42.6%,57.6%和7.5%。扫描电镜(SEM)和Mapping结果表明,阻燃材料燃烧后,大量N,P和Al元素分布在致密炭层中,起到了良好的凝聚相阻燃作用。 展开更多
关键词 环三磷腈大分子 二乙基次膦酸铝 环氧树脂 阻燃性能
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金属载体强相互作用增强Au/TiO_(2)催化剂在3-硝基苯乙烯选择性加氢反应的活性 被引量:1
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作者 洪峰 王升扬 +4 位作者 张军营 付俊红 蒋齐可 孙科举 黄家辉 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第9期1530-1537,共8页
自Haruta与Hutchings于上世纪八十年代末发现金纳米催化剂优异的反应活性以来,科研人员对金催化的应用领域进行了广泛而深入地研究.对金催化科学和应用领域的研究一直在进行.大量的研究表明,金催化剂在各种选择性氧化反应中具有优异的... 自Haruta与Hutchings于上世纪八十年代末发现金纳米催化剂优异的反应活性以来,科研人员对金催化的应用领域进行了广泛而深入地研究.对金催化科学和应用领域的研究一直在进行.大量的研究表明,金催化剂在各种选择性氧化反应中具有优异的催化性能(高活性和高选择性).然而,在催化加氢反应中,尽管金催化剂相比于铂族金属显示出优越的选择性,但是由于金催化剂选择性加氢反应的活性较差,使其在选择性催化加氢反应中的应用受到了极大的限制.研究表明,金催化剂较弱的活化氢气能力是其催化加氢反应活性低的主要原因.研究发现,氢气活化的活性中心可能是界面、负价金、低配位的金原子等.金催化剂具有明显的载体效应,金属-载体之间的相互作用能够显著地改变金催化剂的催化性能.Tauster等研究发现,铂族金属与还原性载体之间存在强相互作用,能够引发载体包覆金属表面,并且使得电子从载体向金属迁移,导致金属带负电.受金属-载体强相互作用(SMSI)效应的启发,本文探究了Au/TiO_(2)催化剂中SMSI对金催化剂加氢性能的影响.在H_(2)或O_(2)气氛下高温焙烧Au/TiO_(2),获得一系列金催化剂(Au/TiO_(2)-TA,T为焙烧温度(℃):300、400、500和600;A为气氛:H_(2)或O_(2)).对比在3-硝基苯乙烯(3-NS)选择性加氢反应中的活性发现,Au/TiO_(2)-500H的TOF值是Au/TiO_(2)-500O的3.3倍;动力学测试表明,Au/TiO_(2)-500H和Au/TiO_(2)-500O的反应表观活化能分别为79.5和105.1 kJ/mol.这表明两类催化剂催化活性中心的结构存在差异.X射线光电子能谱测试结果表明,Au/TiO_(2)-H样品中Au带部分负电,而Au/TiO_(2)-O中Au显示为金属态.HAADF-STEM和EELS显示,Au/TiO_(2)-H中Au NPs的表面有TiOx物种,增加了Au-TiO_(2)的界面.EPR结果表明,Au/TiO_(2)-H中存在表面Ti3+物种,而Au/TiO_(2)-O样品中则没有.为确认加氢反应的活性中心到底是界面还是负价金物种,本文探究了不同温度下氢气处理的Au/TiO_(2)的结构与性能的关系,发现Au/TiO_(2)-300H/400H/500H催化剂都显示出较好的催化3-NS加氢活性,而Au/TiO_(2)-600H虽然具有更多的负价金物种,但是3-NS选择性加氢反应的活性反而降低,因此,负价金不是活性中心.这是因为不同温度处理的Au/TiO_(2)-H样品中,SMSI的强弱不同,在300、400、500 ℃下,SMSI能够增加Au-TiO_(2)的界面长度,从而增强了3-NS加氢反应的活性;而温度达到600℃,SMSI效应太强,Au NPs被包覆更密实,导致Au/TiO_(2)-600H的3-NS选择性加氢反应的活性下降.密度泛函理论计算表明,Au/TiO_(2)-H样品具有更低的H_(2)解离活化能以及氢转移活化能.氢氘交换反应也进一步验证了SMSI有利于H_(2)的活化. 展开更多
关键词 金催化 金属-载体强相互作用 界面 3-硝基苯乙烯选择性加氢 增强活性
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Inhibiting effect of tungstic compounds on glucose hydrogenation over Ru/C catalyst 被引量:3
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作者 junying zhang Baolin Hou +3 位作者 Xuefei Wang Zhenlei Li Aiqin Wang Tao zhang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2015年第1期9-14,共6页
The effect of acid component including various conventional acids and tungstic compounds on glucose hydrogenation over a series of binary catalyst system containing Ru/C catalyst was investigated. The results showed t... The effect of acid component including various conventional acids and tungstic compounds on glucose hydrogenation over a series of binary catalyst system containing Ru/C catalyst was investigated. The results showed that HC1, H2SO4, H3BO3, H3PO4, and HNO3 had negligible effect, while all the tungstic compounds imposed inhibiting effects on the hydrogenation of glucose over Ru/C catalyst, and the suppressing effect followed the order of H2WO4〉HPW〉WO3〉AMT〉HSiW. This order is the same as the order of ethylene glycol (EG) yields in the one-pot conversion of glucose to EG, suggesting the important role of competition between glucose hydrogenation and retro-aldol condensation in controlling the selectivity of EG. 展开更多
关键词 glucose hydrogenation binary catalyst system suppressing effect retro-aldol condensation ethylene glycol tungstic compounds Ru/C cata-lyst
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Prognostic significance of PD-L1 expression in patients with colorectal cancer: a meta-analysis 被引量:1
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作者 Siwen Liu Rong Ma +7 位作者 Haixia Cao Dan Chen Changwen Jing Zhuo Wang junying zhang Yang Wu Jifeng Feng Jianzhong Wu 《Oncology and Translational Medicine》 2019年第2期68-74,共7页
Background The association between the expression of programmed cell death 1(PD-1) or its ligand [programmed cell death ligand-1(PD-L1)] and colorectal cancer(CRC) survival rates remains unclear. Thus, we conducted a ... Background The association between the expression of programmed cell death 1(PD-1) or its ligand [programmed cell death ligand-1(PD-L1)] and colorectal cancer(CRC) survival rates remains unclear. Thus, we conducted a meta-analysis to investigate the prognostic value of PD-L1 expression in CRC patients.Methods All eligible studies related to evaluation of PD-L1 expression and survival of CRC patients were searched in PubMed, Medline, Cochrane library, and the EMBASE database. Hazard ratios(HRs) and 95% confidence intervals(CI) of overall survival(OS) were examined to assess the effect of PD-L1 expression on the survival of CRC patients. The outcomes of this meta-analysis were synthesized based on randomeffects model. Subgroup analyses were also performed. Results Seven studies, wherein OS data were stratified according to the expression status of PD-L1, were analyzed. CRC patients showing positive PD-L1 expression were associated with significantly poorer prognoses in terms of overall survival, compared with those displaying negative PD-L1 expression(HR = 1.43, 95% CI: 1.07–1.92; P = 0.02). In the subgroup analyses, H-scores as well as the percentage of stained cells indicated that PD-L1 expression was significantly associated with poor prognosis(HR = 1.90, 95% CI: 1.38–2.62, P < 0.01; HR = 1.81, 95% CI: 1.08–3.03, P = 0.02). Immunohistochemical staining, utilizing a rabbit anti-PD-L1 antibody, revealed significantly superior survival in the PD-L1 negative group compared with the PD-L1 positive expression group(HR = 1.92; 95% CI, 1.40-2.63; P < 0.01). Moreover, PD-L1 expression was significantly associated with poor prognosis when polyclonal antibodies were used(HR = 1.84; 95% CI, 1.30–2.61; P < 0.01). Conclusion Our meta-analysis indicated that PD-L1 expression status is a significant prognostic factor for CRC patients. Positive PD-L1 expression was associated with worse CRC survival. Evaluation via different immunohistochemistry based techniques may partly account for the contradictory results. Therefore, further investigative studies using larger sample sizes are felt to be needed to elucidate the prognostic value of PD-L1 expression in CRC patients. 展开更多
关键词 COLORECTAL cancer (CRC) programmed cell DEATH ligand-1 (PD-L1) prognosis META-ANALYSIS
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Arsenic emission of high-arsenic coal combustion from southwestern Guizhou,China
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作者 junying zhang Yongchun ZHAO +5 位作者 Wenchun HUANG Yang LI Dangyu SONG Shifeng DAI Fenghua ZHAO Chuguang ZHENG 《Chinese Journal Of Geochemistry》 EI CAS 2006年第B08期49-50,共2页
关键词 水银 分布区域 散射 煤矿 贵州 燃烧
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Safety and efficacy of EFGR and VEGF signaling pathway inhibition therapy in patients with colorectal cancer: a meta-analysis
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作者 Siwen Liu Rong Ma +7 位作者 Haixia Cao Shaorong Yu Dan Chen Changwen Jing Zhuo Wang junying zhang Jifeng Feng Jianzhong Wu 《Oncology and Translational Medicine》 2019年第2期80-90,共11页
Objective Epidermal growth factor receptor(EGFR) and vascular endothelial growth factor(VEGF) inhibitors are two targeted therapies for metastatic colorectal cancer(mCRC). However, few studies have focused on the safe... Objective Epidermal growth factor receptor(EGFR) and vascular endothelial growth factor(VEGF) inhibitors are two targeted therapies for metastatic colorectal cancer(mCRC). However, few studies have focused on the safety and efficacy of combined targeted therapy against those of a single inhibition therapy of EFGR or VEGF. This meta-analysis aimed to compare the anti-tumor activity of the combined inhibition therapy and single inhibition therapy in patients with mCRC. Methods We searched PubMed, Medline, the Cochrane library, Embase, and annual meeting proceedings for relevant clinical trials. Objective response rate(ORR), progression-free survival(PFS), overall survival(OS), and adverse events were extracted and calculated.Results Nine trials comprising 3977 patients were selected for the analysis. The combined inhibition therapy showed a 3.7% improvement in ORR compared with single inhibition, and this difference was statistically significant [hazard ratio(HR) = 1.33; 95% confidence interval(CI), 1.01–1.74; P = 0.04]. Subgroup analysis showed that the combined EGFR and VEGF inhibitor therapy had an 11.65% improvement in ORR compared with VEGF inhibitor therapy(OR = 2.14; 95% CI, 1.34–3.40; P = 0.001). EGFR and VEGF inhibitor therapy and chemotherapy had an 18.08% improvement in ORR compared with chemotherapy(OR = 2.21; 95% CI, 1.05–4.64; P = 0.04). Moreover, EGFR and VEGF inhibitor therapy significantly improved PFS compared with VEGF inhibitor therapy(OR = 0.82; 95% CI, 0.69–0.97; P = 0.02). VEGF inhibitor therapy and chemotherapy significantly improved PFS compared with EGFR and VEGF inhibitor therapy and chemotherapy(OR = 1.20; 95% CI, 1.11–1.30; P = 0.00). In addition, EGFR and VEGF inhibitor therapy showed improved OS compared with VEGF inhibitor therapy(HR = 0.78, 95% CI: 0.65–0.94; P = 0.008). Finally, the combined inhibition therapy showed an obviously increased risk of cutaneous and mucosal effects(RR = 6.45; 95% CI: 2.71–15.36; P < 0.01), diarrhea/abdominal pain(RR = 1.97; 95% CI: 1.45–2.68; P < 0.01), fatigue/asthenia(RR = 1.60; 95% CI: 1.10–2.32; P = 0.01), dehydration or electrolyte disturbance(RR = 2.78; 95% CI: 1.48–5.21; P < 0.01), nail disorder(RR = 8.23; 95% CI: 1.52–44.57; P = 0.01), and dizziness/headache(RR = 3.43; 95% CI: 1.89–6.23; P < 0.01) compared with single inhibition therapy.Conclusion Compared with single inhibition therapy, the combined inhibition therapy significantly improved ORR, PFS, and OS in the treatment of mCRC patients. Compared with a single-targeted agent, the combined therapy of anti-EGFR and anti-VEGF drug provided an efficacy advantage, although it led to greater toxicity. 展开更多
关键词 colorectal cancer (CRC) EPIDERMAL GROWTH FACTOR receptor (EGFR) vascular endothelial GROWTH FACTOR (VEGF) META-ANALYSIS
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Breeding dominant genic male sterility restorer line of Brassica napus L.
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作者 junying zhang Jianxia Jiang +6 位作者 Liyong Yang Meiyan Jiang Yanli Li Weirong Wang Chaocai Sun Jifeng Zhu Xirong Zhou 《Oil Crop Science》 2020年第2期90-95,共6页
To facilate breeding process of Brassica napus,a microspore culture and molecular marker-assisted screening combined system were proposed in this research.At early flowering stage,F1 offspring of hybridized combinatio... To facilate breeding process of Brassica napus,a microspore culture and molecular marker-assisted screening combined system were proposed in this research.At early flowering stage,F1 offspring of hybridized combination HY15 A×HF06 was used as donor for microspore culture to analyze effects of colchicine concentration on embryogenic and diploid rates of microspore.Treatment with 50 mg/L colchicine resulted in embryogenic rate of3.56 embryos/bud,which was substantially higher than control(0.78 embryos/bud).A total of 1,387 embryos and 862 single plants were obtained after induction culture.Ploidy detection was performed for the regenerated plants by flow cytometry.Diploid rates of microspores treated with 50 mg/L and 70 mg/L colchicine were 17.2%and 21.0%respectively,which was significantly higher than control(10.5%).Totally 108 single plants that doubled successfully were randomly selected and screened using molecular marker BE10.Approximately 54 of108 plants generated a 305 bp amplification product,whereas the other 54 plants showed a 398 bp band,thereby satisfying 1:1 separation ratio(x0.052=0.0093).These coincided with field identification results.Findings of this study indicated that homozygous breeding material could be obtained by microspore culture in a short time,thereby remarkably accelerate breeding. 展开更多
关键词 Brassica napus L. MICROSPORES Double haploid Restorer line COLCHICINE
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Effect of oxide interactions on chromium speciation transformation during simulated municipal solid waste incineration
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作者 Guodong Zhao Chong Tian +6 位作者 Peidong Wu Xuguang zhang Zhikang Wang Xiaoxiang Chen Zhuo Xiong Yongchun Zhao junying zhang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2024年第8期11-20,共10页
Chromium released during municipal solid waste incineration(MSWI)is toxic and carcinogenic.The removal of chromium from simulated MSWI flue gas by four sorbents(CaO,bamboo charcoal(BC),powdered activated carbon(PAC),a... Chromium released during municipal solid waste incineration(MSWI)is toxic and carcinogenic.The removal of chromium from simulated MSWI flue gas by four sorbents(CaO,bamboo charcoal(BC),powdered activated carbon(PAC),and Al_(2)O_(3))and the effects of four oxides(SiO_(2),Al_(2)O_(3),Fe_(2)O_(3),and CaO)on chromium speciation transformationwere investigated.The results showed that the removal rates of total Cr by the four sorbents were Al_(2)O_(3)<CaO<PAC<BC,while the removal rates of Cr(Ⅵ)by the four sorbents were Al_(2)O_(3)<PAC<BC<CaO.CaO had a strong oxidizing effect on Cr(Ⅲ),while BC and PAC had a better-reducing effect on Cr(Ⅵ).SiO_(2)was better for the reduction of Na_(2)CrO_(4)and K_(2)CrO_(4)above 1000℃due to its strong acidity,and the addition of CaO significantly inhibited the reduction of Cr(Ⅵ).MgCrO_(4)decomposed above 700℃to form MgCr_(2)O_(4),and the reaction between MgCrO_(4)and oxides also existed in the form of a more stable trivalent spinel.Furthermore,when investigating the effect of oxides on the oxidation of Cr(Ⅲ)in CrC_(l3),it was discovered that CaO promoted the conversion of Cr(Ⅲ)to Cr(Ⅵ),while the presence of chlorine caused chromium to exist in the form of Cr(V),and increasing the content of CaO and extending the heating time facilitated the oxidation of Cr(Ⅲ).In addition,silicate,aluminate,and ferrite were generated after the addition of SiO_(2),Al_(2)O_(3),and Fe_(2)O_(3),which reduced the alkalinity of CaO and had an important role in inhibiting the oxidation of Cr(Ⅲ).The acidic oxides can not only promote the reduction of Cr(Ⅵ)but also have an inhibitory effect on the oxidation of Cr(Ⅲ)ascribed to alkali metals/alkaline earth metals,and the proportion of acidic oxides can be increased moderately to reduce the generation of harmful substances in the hazardous solid waste heat treatment. 展开更多
关键词 Cr(Ⅵ)reduction Cr(Ⅲ)oxidation Alkali oxides Acidic oxides Municipal solid waste incineration
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Photo-induced tunable luminescence from an aggregated amphiphilic ethylene-pyrene derivative in aqueous media
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作者 junying zhang Ruochen Li +2 位作者 Haihua Wang Wenbing Kang Xing-Dong Xu 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第6期303-306,共4页
An amphiphilic derivative with a large Stokes shift by introducing flexible hydrophilic long chains into a rigid ethylene-pyrene compound have been successfully synthesized.The alkylated compound exhibited a notable c... An amphiphilic derivative with a large Stokes shift by introducing flexible hydrophilic long chains into a rigid ethylene-pyrene compound have been successfully synthesized.The alkylated compound exhibited a notable change in charge distribution,facilitating cation-π interactions.Through the process of amphiphilic self-assembly,the formation of highly ordered aggregates enabled effective photo-dimerization under 449 nm LED irradiation.Notably,this photo-responsive technology not only exhibited advanced multi-color emission effects,including white light emission but also exhibited environmentally friendly behavior in the aqueous phase. 展开更多
关键词 Supramolecular chemistry Amphiphilic assembly Stimuli-responsive materials Tunable luminescence Pyrene derivative
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1D/2D CeO_(2)/ZnIn_(2)S_(4)Z-scheme异质结光催化剂实现高效可见光分解水制氢 被引量:3
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作者 姜人倩 毛梁 +6 位作者 赵宇龙 张俊英 Eugene B.Chubenko Vitaly Bondarenko 隋艳伟 顾修全 蔡晓燕 《Science China Materials》 SCIE EI CAS CSCD 2023年第1期139-149,共11页
开发具有高效电荷转移效率的光催化剂已成为太阳能-氢能转换的关键科学方法.本研究通过在CeO_(2)纳米棒表面原位生长ZnIn_(2)S_(4)纳米片,成功制备了具有Z-scheme异质结的1D/2D CeO_(2)/ZnIn_(2)S_(4)光催化剂.在无助催化剂的情况下,15 ... 开发具有高效电荷转移效率的光催化剂已成为太阳能-氢能转换的关键科学方法.本研究通过在CeO_(2)纳米棒表面原位生长ZnIn_(2)S_(4)纳米片,成功制备了具有Z-scheme异质结的1D/2D CeO_(2)/ZnIn_(2)S_(4)光催化剂.在无助催化剂的情况下,15 wt%CeO_(2)/85 wt%ZnIn_(2)S_(4)样品在可见光下实现了3.29 mmol g^(-1)h-1的最佳H2产量,该值分别比原始ZnIn_(2)S_(4)和CeO_(2)分别高2.7倍和92.6倍.优异的光催化活性可能是由于光生载流子的有效分离和Z-scheme异质结的形成保留了ZnIn_(2)S_(4)中用于产氢的强还原电子.密度泛函理论计算和开尔文探针力显微镜证明了CeO_(2)和ZnIn_(2)S_(4)之间存在内部电场.此外,电子顺磁共振光谱以及原位辐照X射线光电子能谱证实了CeO_(2)O2/ZnIn_(2)S_(4)异质结中的光生载流子按照Zscheme路径转移.这项工作可为开发用于太阳能水分解制氢的高效Zscheme光催化剂提供一些见解. 展开更多
关键词 光生载流子 密度泛函理论计算 X射线光电子能谱 光催化剂 分解水制氢 异质结 原位生长
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Retention of trace elements in coal-fired flue gas by a novel heterogeneous agglomeration technology 被引量:3
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作者 Yushan Ji Xiangzheng Cui +5 位作者 Jingchao Liu Tianle zhang Shuzhou Wei Junfeng zhang Yongchun Zhao junying zhang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2023年第3期234-243,共10页
Heterogeneous agglomeration (HA) is a very potential technology for coal-fired flue gas treatment.In this paper,the distribution and migration mechanisms of trace elements (TEs such as Se,As and Pb in CFPPs were studi... Heterogeneous agglomeration (HA) is a very potential technology for coal-fired flue gas treatment.In this paper,the distribution and migration mechanisms of trace elements (TEs such as Se,As and Pb in CFPPs were studied on a 30,000 m^(3)/hr pilot-scale experimental plat form.The influences of HA on the removal efficiency of gaseous and particulate TEs were well analyzed.The results showed that Se,As and Pb were enriched in fly ash,and their sen sitivity to particle size is quite different.The content of Se was the highest in PM1,reaching193.04 mg/kg at the electrostatic precipitator (ESP) outlet.The average particle size of the total dust before ESP increased significantly from 21.686 to 62.612μm after injecting the heterogeneous agglomeration adsorbent,conducive to its further removal by ESP.In addi tion,the concentrations of gaseous Se,As and Pb in the flue gas decreased after adsorben spray,and accordingly,their contents in the hierarchical particles increased,indicating tha the adsorbent could effectively promote the adsorption of gaseous trace elements in fly ash and reduce the possibility of their escape to the atmosphere.Total concentrations of Se,As and Pb emitted by wet flue gas desulfurization (WFGD) are 0.223,0.668 and 0.076μg/m^(3)which decreased by 59.98%,47.69%and 90.71%,respectively.Finally,a possible HA mecha nism model was proposed,where chemical adsorption,physical condensation and collision agglomeration of gaseous TEs and fine particles with adsorbent droplets occurred to form larger agglomerates. 展开更多
关键词 Heterogeneous agglomeration Hazardous trace elements Particulate matter Flue gas Pilot experiments
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Nanoarchitectonics of MnO_(2)nanotubes as sea urchin-like aggregates for dielectric response and microwave absorption with a wide concentration domain 被引量:1
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作者 Zhi-Ling Hou Kunrong Du +2 位作者 Yiqin zhang Song Bi junying zhang 《Nano Research》 SCIE EI CSCD 2023年第2期2604-2610,共7页
Designing highly reliable and practical microwave absorbers is one of the most important research directions in the microwave absorbing field.Many absorbents suffer from concentration-sensitivity and environmental-sen... Designing highly reliable and practical microwave absorbers is one of the most important research directions in the microwave absorbing field.Many absorbents suffer from concentration-sensitivity and environmental-sensitivity dilemmas in practical applications.Here,sea urchin-like aggregates of MnO_(2)nanotubes were synthesized by a simple hydrothermal method,which exhibit an outstanding impedance matching characteristic.The composites based on sea urchin-like aggregates of MnO_(2)nanotubes show excellent microwave absorption performance in a wide concentration domain from 20 wt.%to 70 wt.%,corresponding to electrical conductivities from 1.86×10^(−7)to 1.85×10^(−5)S/m.Such a wide concentration range of absorbent for excellent microwave absorption is mainly attributed to the beneficial impedance matching properties of sea urchin-like aggregates of hollow nanotubes.A competitive absorption bandwidth of 3.36 GHz is achieved at 1 mm thickness,which can be broadened to 13.4 GHz by structural design.This work shows a new scheme for designing reliable and practical microwave absorbers benefit from the wide absorbent concentration domain. 展开更多
关键词 MnO_(2)nanotubes sea urchin-like aggregates broadband microwave absorption wide filling range
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社区老年脑健康体检与痴呆风险筛查体系构建与实践——北京方案 被引量:11
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作者 张占军 姜淼 +14 位作者 张俊英 李鹤 李馨 陈姚静 卢朋 卫东锋 关青 王君 舒妮 韩在柱 夏佳楠 安海婷 王燕平 罗跃嘉 王永炎 《科学通报》 EI CAS CSCD 北大核心 2020年第14期1339-1347,共9页
2019年5月6日,"北京老年脑健康体检(痴呆风险筛查)项目启动及培训会"在北京师范大学举行,标志着北京市老年脑健康体检(痴呆风险筛查)项目正式启动.北京市东城区、西城区、朝阳区、海淀区、丰台区、石景山区共6个辖区内的9.6万... 2019年5月6日,"北京老年脑健康体检(痴呆风险筛查)项目启动及培训会"在北京师范大学举行,标志着北京市老年脑健康体检(痴呆风险筛查)项目正式启动.北京市东城区、西城区、朝阳区、海淀区、丰台区、石景山区共6个辖区内的9.6万名65岁以上常住老年人将免费接受脑健康体检服务.该项目由北京市卫生健康委员会立项,旨在通过结合老年痴呆早期发现、及时防治的主动健康管理理念,建立社区痴呆及轻度认知障碍(mild cognitive impairment,MCI)综合防控系统,提升北京市老年群体脑健康水平,同时也为政府在全国老年痴呆疾病领域的科学决策提供数据及技术支持. 展开更多
关键词 轻度认知障碍 老年痴呆 北京市东城区 体检服务 老年脑 健康体检 风险筛查 综合防控
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Hierarchical-structure anatase TiO2 with conductive network for high-rate and high-loading lithium-ion battery 被引量:6
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作者 Xinghua Liu Lijiang Zhao +5 位作者 Shitong Wang Meng Chao Yutong Li Jin Leng junying zhang Zilong Tang 《Science Bulletin》 SCIE EI CAS CSCD 2019年第16期1148-1151,共4页
Titanium dioxides have been extensively investigated as promising anodes for Lithium ion batteries(LIBs)because of the high–rate capacity and cyclability,as well as the improved safety over graphite anode(1,2)However... Titanium dioxides have been extensively investigated as promising anodes for Lithium ion batteries(LIBs)because of the high–rate capacity and cyclability,as well as the improved safety over graphite anode(1,2)However,as a typical insertion–type anode,anatase TiO2 exhibits low conductivity(10–12S cm-1 for electron conductivity[3]and 10–17–10–10 cm2 s1 for Li+ion diffusion coefficient[4])and poor specific capacity(only accommodate<0.5 Li per bulk TiO2 unit[5]),severely limiting its practical applications. 展开更多
关键词 TiO Hierarchical-structure ANATASE TiO2 with conductive network for high-rate and high-loading lithium-ion battery
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Reversible 3D optical data storage and information encryption in photo-modulated transparent glass medium 被引量:7
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作者 Zhen Hu Xiongjian Huang +4 位作者 Zhengwen Yang Jianbei Qiu Zhiguo Song junying zhang Guoping Dong 《Light(Science & Applications)》 SCIE EI CAS CSCD 2021年第8期1485-1493,共9页
Transparent glass has been identified as a vital medium for three-dimensional(3D)optical information storage and multi-level encryption.However,it has remained a challenge for directly writing 3D patterning inside a t... Transparent glass has been identified as a vital medium for three-dimensional(3D)optical information storage and multi-level encryption.However,it has remained a challenge for directly writing 3D patterning inside a transparent glass using semiconductor blue laser instead of high-cost femtosecond laser.Here,we demonstrate that rare earth ions doped transparent glass can be used as 3D optical information storage and data encryption medium based on their reversible transmittance and photoluminescence manipulation.The color of tungsten phosphate glass doped with rare earth ions change reversibly from light yellow to blue upon alternating 473 nm laser illumination and temperature stimulation,resulting in the reversible luminescence modulation.The information data could be repeatedly written and erased in arbitrary 3D space of transparent glass,not only showing the ability of the excellent reproducibility and storage capacity,but also opening opportunities in information security.The present work expands the application fields of luminescent glass,and it is conducive to develop a novel 3D data storage and information encryption media. 展开更多
关键词 ENCRYPTION optical TRANSPARENT
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MnⅡ掺杂二维杂化钙钛矿(C4H9NH3)2PbCl4的机械力化学合成及其发光性能研究(英文) 被引量:5
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作者 周国君 郭少强 +4 位作者 赵静 Maxim Molokeev 刘泉林 张俊英 夏志国 《Science China Materials》 SCIE EI CSCD 2019年第7期1013-1022,共10页
简单和高效的机械力化学合成方法在先进功能材料的合成领域备受关注.本论文通过机械力化学合成手段,将二价锰离子(MnⅡ)成功掺杂于二维层状钙钛矿(C4H9NH3)2PbCl4中.研究发现,仅通过室温研磨便能观察到二维杂化钙钛矿中,迅速出现MnⅡ的... 简单和高效的机械力化学合成方法在先进功能材料的合成领域备受关注.本论文通过机械力化学合成手段,将二价锰离子(MnⅡ)成功掺杂于二维层状钙钛矿(C4H9NH3)2PbCl4中.研究发现,仅通过室温研磨便能观察到二维杂化钙钛矿中,迅速出现MnⅡ的橙红色荧光.其中,掺杂的MnⅡ占据了Pb的格位,其荧光特性源于(C4H9NH3)2Pb1–xMnxCl4的带边发射和MnⅡ的4T1→6A1跃迁之间的能量传递;与此同时,利用第一性原理计算了钙钛矿(C4H9NH3)2Pb1–xMnxCl4掺杂前后的形成能,从理论上证明了具有特殊结构的二维杂化钙钛矿使得Mn2+易于替代Pb2+.鉴于机械力化学合成方法在二维层状钙钛矿中不仅易掺杂且光谱可调的优势,将为新材料领域的进一步开发和应用提供新的机遇. 展开更多
关键词 机械力化学合成 层状钙钛矿 MN^2+ 二维 掺杂 发光性能 杂化 化学合成方法
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Investigating the interlayer electron transport and its in?uence on the whole electric properties of black phosphorus 被引量:3
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作者 Bensong Wan Shaoqiang Guo +4 位作者 Jiacheng Sun Yufei zhang Yuyan Wang Caofeng Pan junying zhang 《Science Bulletin》 SCIE EI CAS CSCD 2019年第4期254-260,共7页
Two-dimensional(2D) nanomaterials have attracted great attention in next generation electronic and optoelectronic technologies due to the unique layered structure and excellent physical and chemical properties. Howeve... Two-dimensional(2D) nanomaterials have attracted great attention in next generation electronic and optoelectronic technologies due to the unique layered structure and excellent physical and chemical properties. However, the mechanism of transmission along the vertical direction of 2D semiconductor materials has not been investigated. Here, we use first-principles calculations to explore the bandgap energies along different directions, and fabricate a vertical, a lateral and a mixture-structured black phosphorus field effect transistor(BPFET) to study the electrical characteristics along different directions under variable temperatures. The variable temperature test indicates that the mixture-structured device performs more like a lateral device, while the conductance along the vertical direction is hard to be tuned by temperature and electrical field. The unchanged conductance under electric field and variable temperatures allows the vertical device to act as a fixed resistor, promising possible application for the prospective electronic and optoelectronic devices. 展开更多
关键词 BLACK PHOSPHORUS TRANSISTOR Transmission VERTICAL VARIABLE temperature
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Synthesis,Characterization and Photocatalytic Activity of TiO_2 Film/Bi_2O_3 Microgrid Heterojunction 被引量:3
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作者 Liugang Wang junying zhang +3 位作者 Chunzhi Li Hailing Zhu Wenwen Wang Tianmin Wang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2011年第1期59-63,共5页
关键词 Thin films TiO2 Bi2O3 microgrid PHOTOCATALYSIS
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Integrated removal of NO and mercury from coal combustion flue gas using manganese oxides supported on TiO_2 被引量:11
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作者 Shibo zhang Yongchun Zhao +3 位作者 Zonghua Wang junying zhang Lulu Wang Chuguang Zheng 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2017年第3期141-150,共10页
A catalyst composed of manganese oxides supported on titania (MnOx/TiO2) synthesized by a sol-gel method was selected to remove nitric oxide and mercury jointly at a relatively low temperature in simulated flue gas ... A catalyst composed of manganese oxides supported on titania (MnOx/TiO2) synthesized by a sol-gel method was selected to remove nitric oxide and mercury jointly at a relatively low temperature in simulated flue gas from coal-fired power plants. The physico-chemical characteristics of catalysts were investigated by X-ray fluorescence (XRF), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) analyses, etc. The effects of Mn loading, reaction temperature and individual flue gas components on denitration and Hg0 removal were examined. The results indicated that the optimal MrgTi molar ratio was 0.8 and the best working temperature was 240℃for NO conversion. 02 and a proper ratio of [NH3]/[NO] are essential for the denitration reaction. Both NO conversion and Hg0 removal efficiency could reach more than 80% when NO and Hg0 were removed simultaneously using Mn0.8Ti at 240℃. Hg0 removal efficiency slightly declined as the Mn content increased in the catalysts. The reaction temperature had no significant effect on Hg0 removal efficiency. 02 and HCI had a promotional effect on Hg0 removal. SO2 and NH3 were observed to weaken Hg0 removal because of competitive adsorption. NO first facilitated Hg0 removal and then had an inhibiting effect as NO concentration increased without 02, and it exhibited weak inhibition of Hg0 removal efficiency in the presence of 02. The oxidation of Hg0 on MnOx/ TiO= follows the Mars-Maessen and Langmuir-Hinshelwood mechanisms. 展开更多
关键词 ManganeseTitaniaNitric oxideMercurySCR
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Effects of Bi-dopant and co-catalysts upon hole surface trapping on La_(2)Ti_(2)O_(7) nanosheet photocatalysts in overall solar water splitting 被引量:1
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作者 Xiaoyan Cai Liang Mao +4 位作者 Mamoru Fujitsuka Tetsuro Majima Sujan Kasani Nianqiang Wu junying zhang 《Nano Research》 SCIE EI CSCD 2022年第1期438-445,共8页
Pristine and Bi-doped lanthanum titanium oxide(La_(2)Ti_(2)O_(7))nanosheets have been synthesized as photocatalysts for overall solar water splitting.The surface hole trap is a critical factor that limits the photocat... Pristine and Bi-doped lanthanum titanium oxide(La_(2)Ti_(2)O_(7))nanosheets have been synthesized as photocatalysts for overall solar water splitting.The surface hole trap is a critical factor that limits the photocatalytic activity of pristine La_(2)Ti_(2)O_(7)-Deposition of cobalt phosphate(Co-Pi)and platinum(Pt)nanoparticles on La_(2)Ti_(2)O_(7) cannot remove the surface traps although they are essential for enabling the oxygen and hydrogen evolution reactions.It is interesting that doping bismuth(Bi)into La_(2)Ti_(2)O_(7) nanosheets has eliminated the surface traps due to surface enrichment of Bi.The Co-Pi/Bi-La_(2)Ti_(2)O_(7)/Pt nanosheets exhibit increasing photocatalytic activity toward overall water splitting with increasing the Bi-dopant level up to 5 at.%.Further increasing the Bi-dopant level leads to the formation of localized states above the valence band,leading to the lifetime reduction of photogenerated charge-carriers,and jeopardizing the photocatalytic activity.This work proposes an effective strategy to address the surface trapping and surface catalysis issues in the nanostructured metal oxide photocatalysts. 展开更多
关键词 photocatalyst water splitting surface trap CO-CATALYST solar fuel
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