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Fabrication of Core-Shell Hydrogel Bead Based on Sodium Alginate and Chitosan for Methylene Blue Adsorption
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作者 Xiaoyu Chen 《Journal of Renewable Materials》 EI CAS 2024年第4期815-826,共12页
A novel core-shell hydrogel bead was fabricated for effective removal of methylene blue dye from aqueous solutions.The core,made of sodium alginate-g-polyacrylamide and attapulgite nanofibers,was cross-linked by Calci... A novel core-shell hydrogel bead was fabricated for effective removal of methylene blue dye from aqueous solutions.The core,made of sodium alginate-g-polyacrylamide and attapulgite nanofibers,was cross-linked by Calcium ions(Ca^(2+)).The shell,composed of a chitosan/activated carbon mixture,was then coated onto the core.Fourier transform infrared spectroscopy confirmed the grafting polymerization of acrylamide onto sodium alginate.Scanning electron microscopy images showed the core-shell structure.The core exhibited a high water uptake ratio,facilitating the diffusion of methylene blue into the core.During the diffusion process,the methylene blue was first adsorbed by the shell and then further adsorbed by the core.Adsorption tests showed that the coreshell structure had a larger adsorption capacity than the core alone.The shell effectively enhanced the adsorption capacity to methylene blue compared to the single core.Methylene blue was adsorbed by activated carbon and chitosan in the shell,and the residual methylene blue diffused into the core and was further adsorbed. 展开更多
关键词 Core-shell structure hydrogel bead attapulgite nanofiber sodium alginate POLYACRYLAMIDE methylene blue adsorption material
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Drug-eluting bead transarterial chemoembolization as neoadjuvant therapy pre-liver transplantation for advanced-stage hepatocellular carcinoma
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作者 Zhao-Dan Ye Li Zhuang +4 位作者 Meng-Chen Song Zhe Yang Wu Zhang Jing-Feng Zhang Guo-Hong Cao 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第6期2476-2486,共11页
BACKGROUND The objectives of this study were to assess the safety and efficacy of drug-eluting bead transarterial chemoembolization(DEB-TACE)as neoadjuvant therapy before liver transplantation(LT)for advanced-stage he... BACKGROUND The objectives of this study were to assess the safety and efficacy of drug-eluting bead transarterial chemoembolization(DEB-TACE)as neoadjuvant therapy before liver transplantation(LT)for advanced-stage hepatocellular carcinoma(HCC)and to analyze the prognostic factors.AIM To determine whether DEB-TACE before LT is superior to LT for advanced-stage HCC.METHODS A total of 99 individuals diagnosed with advanced HCC were studied retrospectively.The participants were categorized into the following two groups based on whether they had received DEB-TACE before LT:DEB-TACE group(n=45)and control group(n=54).The participants were further divided into two subgroups based on the presence or absence of segmental portal vein tumor thrombus(PVTT).The DEB-TACE group consisted of two subgroups:Group A(n=31)without PVTT and group B(n=14)with PVTT.The control group also had two subgroups:Group C(n=37)without PVTT and group D(n=17)with PVTT.Data on patient demographics,disease characteristics,therapy response,and adverse events(AEs)were collected.The overall survival(OS)and recurrence-free survival(RFS)rates were assessed using Kaplan-Meier curves.Univariate and multivariate Cox regression analyses were conducted to determine the parameters that were independently related to OS and RFS.RESULTS The DEB-TACE group exhibited an overall response rate of 86.6%.Following therapy,there was a significant decrease in the median alpha-fetoprotein(AFP)level(275.1 ng/mL vs 41.7 ng/mL,P<0.001).The main AE was post-embolization syndrome.The 2-year rates of RFS and OS were significantly higher in the DEB-TACE group than in the control group(68.9%vs 38.9%,P=0.003;86.7%vs 63.0%,P=0.008).Within the subgroups,group A had higher 2-year rates of RFS and OS compared to group C(71.0%vs 45.9%,P=0.038;83.8%vs 62.2%,P=0.047).The 2-year RFS rate of group B was markedly superior to that of group D(64.3%vs 23.5%,P=0.002).Results from multivariate analyses showed that pre-LT DEB-TACE[hazard ratio(HR)=2.73,95%confidence interval(CI):1.44-5.14,P=0.04],overall target tumor diameter≤7 cm(HR=1.98,95%CI:1.05-3.75,P=0.035),and AFP level≤400 ng/mL(HR=2.34;95%CI:1.30-4.19,P=0.009)were significant risk factors for RFS.Additionally,pre-LT DEBTACE(HR=3.15,95%CI:1.43-6.96,P=0.004)was identified as a significant risk factor for OS.CONCLUSION DEB-TACE is a safe and efficient therapy for advanced-stage HCC and also enhances patient survival after LT. 展开更多
关键词 Hepatocellular carcinoma Liver transplantation Portal vein tumor thrombus Drug-eluting bead transarterial chemoembolization Neoadjuvant treatment
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Drug-eluting beads chemoembolization combined with programmed cell death 1 inhibitor and lenvatinib for large hepatocellular carcinoma
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作者 Hui Yang Guang-Ping Qiu +1 位作者 Jie Liu Tie-Quan Yang 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第11期4392-4401,共10页
BACKGROUND The combination of transarterial chemoembolization(TACE),lenvatinib,and programmed cell death 1(PD-1)inhibitor has been widely used in the treatment of advanced hepatocellular carcinoma(HCC)and has achieved... BACKGROUND The combination of transarterial chemoembolization(TACE),lenvatinib,and programmed cell death 1(PD-1)inhibitor has been widely used in the treatment of advanced hepatocellular carcinoma(HCC)and has achieved promising results.However,there are few studies comparing whether drug-eluting beads TACE(DTACE)can bring more survival benefits to patients with large HCC compared to conventional TACE(C-TACE)in this triplet therapy.AIM To compare the efficacy and adverse events(AEs)of triple therapy comprising DTACE,PD-1 inhibitors,and lenvatinib(D-TACE-P-L)and C-TACE,PD-1 inhibitors,and lenvatinib(C-TACE-P-L)in patients with large HCC(maximum diameter≥5 cm),and analyze the prognostic factors.METHODS Following a comprehensive review of our hospital’s medical records,this retrospective study included 104 patients:50 received D-TACE-P-L,and 54 received CTACE-P-L.We employed Kaplan-Meier estimation to assess the median progression-free survival(PFS)between the two groups,utilized Cox multivariate regression analysis to identify prognostic factors,and applied theχ2 test to evaluate AEs.RESULTS The objective response rate(ORR)and median PFS were significantly higher in the D-TACE-P-L group compared to the C-TACE-P-L group(ORR:66.0%vs 44.4%,P=0.027;median PFS:6.8 months vs 5.0 months,P=0.041).Cox regression analysis identified treatment option,portal vein tumor thrombus,and hepatic vein invasion as protective factors for PFS.AEs were comparable between the two CONCLUSION D-TACE-P-L may have significantly better PFS and ORR for large HCC,while exhibiting similar AEs to C-TACE-PL. 展开更多
关键词 Large hepatocellular carcinoma Conventional transarterial chemoembolization Drug-eluting beads transarterial chemoembolization Programmed cell death 1 inhibitor Lenvatinib
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Application of DEM modified with enlarged particle model to simulation of bead motion in a bead mill
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作者 Yasuhiro Yamamoto Rikio Soda +1 位作者 Junya Kano Fumio Saito 《Particuology》 SCIE EI CAS CSCD 2014年第3期103-108,共6页
We applied the discrete element method (DEM) of simulation modified by an enlarged particle model to simulate bead motion in a large bead mill. The stainless-steel bead mill has inner diameter of 102 mm and mill len... We applied the discrete element method (DEM) of simulation modified by an enlarged particle model to simulate bead motion in a large bead mill. The stainless-steel bead mill has inner diameter of 102 mm and mill length of 198 mm. The bead diameter and filling ratio were fixed respectively at 0.5 mm and 85%. The agitator rotational speed was changed from 1863 to 3261 rpm. The bead motion was monitored experimentally using a high-speed video camera through a transparent mill body. For the simulation, enlarged particle sizes were set as 3-6 mm in diameter. With the DEM modified by the enlarged particle model, the motion of enlarged particles in a mill was simulated.The velocity data of the simulated enlarged particles were compared with those obtained in the experiment. The simulated velocity of the enlarged particles depends on the virtual frictional coefficient in the DEM model. The optimized value of the virtual frictional coefficient can be determined by considering the accumulated mean value. Results show that the velocity of the enlarged particles simulated increases with an increase in the optimum virtual frictional coefficient, but the simulated velocity agrees well with that determined experimentally by optimizing the virtual frictional coefficient in the simulation. The computing time in the simulation decreases with increased particle size. 展开更多
关键词 Discrete element simulation bead mill bead motion Enlarged particle model
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Improved dissolution and oral absorption by co-grinding active drug probucol and ternary stabilizers mixtures with planetary beads-milling method 被引量:5
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作者 Fang Li Linsen Li +6 位作者 Shaoning Wang Yan Yang Jia Li Dongchun Liu Sijie Zhang Siling Wang Hui Xu 《Asian Journal of Pharmaceutical Sciences》 SCIE CAS 2019年第6期649-657,共9页
The objective of this work is to construct a nanosuspension drug delivery system of probucol,a BCS II drug,in order to improve its dissolution and oral bioavailability.The wet milling procedure using planetary beads-m... The objective of this work is to construct a nanosuspension drug delivery system of probucol,a BCS II drug,in order to improve its dissolution and oral bioavailability.The wet milling procedure using planetary beads-milling equipment was utilized to grind the raw probucol to ultrafine nanoparticle/nanocrystal aqueous suspension that was further solidified by freeze-drying process.Cellulose derivatives of different substitution groups and molecular weights,including HPMC,HPC,and MC,were evaluated as the primary stabilizer of probucol nanosuspension.Ternary stabilizers system composed of a primary stabilizer(cellulose derivative,i.e.HPC),a nonionic surfactant(Pluronic R F68),and an anionic surfactant(SDS)was employed to obtain probucol nanosuspension of finer particle size and enhanced dissolution in aqueous media.The probucol nanosuspension with good physical stability showed no obvious change of particle size even after storing over 7 d at 4°C or 25°C.The solidified probucol nanosuspension with trehalose as the cryoprotectant showed the highest dissolution rate(>60%at 2 h)compared to other cryoprotectant.The in vivo pharmacokinetic evaluation indicated about 15-folds higher AUC value of the probucol nanosuspension compared to that of coarse probucol suspension after oral administration to rats.The probucol nanosuspension prepared by wet-milling and ternary stabilizers system may find wide applications for improving the dissolution and oral absorption of water-insoluble drugs. 展开更多
关键词 PROBUCOL NANOSUSPENSION Ternary STABILIZERS systems PLANETARY beads-milling Bioavailability
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H_4SiW_(12)O_(40)/TiO_2/beads光催化降解亚甲基蓝的研究 被引量:14
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作者 黄卫红 王晶博 +2 位作者 薛金娟 闫永胜 阮介兵 《环境工程学报》 CAS CSCD 北大核心 2009年第7期1193-1198,共6页
以钛酸四丁酯为原料,空心微珠为载体,采用溶胶-凝胶法制备TiO2/beads光催化剂载体,然后浸渍法制备出H4SiW12O40/TiO2/beads表面负载修饰型复合光催化剂,并运用SEM、XRD、FT-IR和DRS对催化剂进行表征和分析。研究了H4SiW12O40/TiO2/bead... 以钛酸四丁酯为原料,空心微珠为载体,采用溶胶-凝胶法制备TiO2/beads光催化剂载体,然后浸渍法制备出H4SiW12O40/TiO2/beads表面负载修饰型复合光催化剂,并运用SEM、XRD、FT-IR和DRS对催化剂进行表征和分析。研究了H4SiW12O40/TiO2/beads对亚甲基蓝降解的光催化活性,考察了光强度、pH值、曝气量、底物浓度和催化剂用量等对催化效率的影响。实验结果表明,在中性条件下,H4SiW12O40/TiO2/beads催化剂的投加量为0.25 g/L,浓度为7.5 mg/L的亚甲基蓝溶液在250 W的紫外灯和600 W的可见光灯下光照60 min降解率分别可达到94.5%和55%。 展开更多
关键词 H4SiW12O40/TiO2/beads 光催化 亚甲基蓝 降解
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附载型复合光催化剂TiO_2·SiO_2/beads降解有机磷农药 被引量:8
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作者 张新荣 杨平 赵梦月 《环境污染与防治》 CAS CSCD 北大核心 2002年第4期196-198,共3页
研究以四异丙醇钛 [Ti( iso- O C3 H7) 4]、硅酸乙酯为原料 ,以空心玻璃微球为载体 ,用溶胶—凝胶法制备可漂浮附载型复合光催化剂 Ti O2 · Si O2 / beads的过程 ,利用附载型复合光催化剂降解有机磷农药。结果表明 ,复合型光催化剂... 研究以四异丙醇钛 [Ti( iso- O C3 H7) 4]、硅酸乙酯为原料 ,以空心玻璃微球为载体 ,用溶胶—凝胶法制备可漂浮附载型复合光催化剂 Ti O2 · Si O2 / beads的过程 ,利用附载型复合光催化剂降解有机磷农药。结果表明 ,复合型光催化剂 Ti O2 · Si O2 摩尔比存在最佳值 ,n ( Ti O2 ) / m ( Si O2 ) =30 / 70时 ,光催化剂活性最高 ,其活性是同样降解条件下、同样含量 Degussa P- 2 5Ti O2 的 2倍左右。该光催化剂比表面大 ,吸附性强。并用 XRD和 展开更多
关键词 附载型 TiO2·SiO2/beads 降解 有机磷农药 复合型光催化剂 玻璃微球 农药 废水处理
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TiO_2·SiO_2/beads降解有机磷农药的研究 被引量:10
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作者 张新荣 杨平 赵梦月 《工业水处理》 CAS CSCD 2001年第3期13-15,39,共4页
研究以四氯化钛 ,硅酸乙酯为原料 ,以空心玻璃微球为载体 ,用浸涂法制备TiO2 ·SiO2 /beads负载型复合光催化剂的过程。对利用负载型复合光催化剂降解有机磷农药进行了活性评价。结果表明 :TiO2 ·SiO2 /beads光活性显著提高 ,... 研究以四氯化钛 ,硅酸乙酯为原料 ,以空心玻璃微球为载体 ,用浸涂法制备TiO2 ·SiO2 /beads负载型复合光催化剂的过程。对利用负载型复合光催化剂降解有机磷农药进行了活性评价。结果表明 :TiO2 ·SiO2 /beads光活性显著提高 ,最佳光催化剂活性是同样降解条件下、同样含量的DegussaP - 2 5TiO2 光活性的 1.35倍左右。另外 ,对TiO2 ·SiO2 /beads的吸附性和比表面进行测试 ,同时从微观角度对负载型复合光催化剂的表面状态和光催化剂颗粒尺寸进行分析。 展开更多
关键词 负载型复合类催化剂 农药降解 废水处理 有机磷农药 TiO2·SiO2/beads
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Bead模型的不确定性范围查询与修剪算法 被引量:3
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作者 叶李 秦志光 +1 位作者 杨昕梅 王娟 《电子测量与仪器学报》 CSCD 2010年第8期722-729,共8页
针对时空范围内,移动目标数据库中由于移动目标轨迹的不确定性导致的范围查询问题,在基于Bead/Necklace不确定性模型的基础上,将查询问题映射为2D平面的计算几何问题进行解决。针对时空中五种不同句法的不确定性范围查询类型确定了对应... 针对时空范围内,移动目标数据库中由于移动目标轨迹的不确定性导致的范围查询问题,在基于Bead/Necklace不确定性模型的基础上,将查询问题映射为2D平面的计算几何问题进行解决。针对时空中五种不同句法的不确定性范围查询类型确定了对应的定性查询算法,并通过查询多边形的偏置和轨迹点位置查询的方法实现新的修剪算法,其算法复杂度与查询区域边的数目呈线性关系。实验结果显示,提出的修剪策略更加有效地提高了系统的查询效率。 展开更多
关键词 修剪算法 不确定性范围查询 bead/Necklace模型 移动目标轨迹 移动目标数据库
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载药动脉栓塞微球DC Bead^(TM)研究进展 被引量:3
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作者 金雪锋 许颖 +2 位作者 沈晓兰 陈祥峰 宗在伟 《药学与临床研究》 2012年第4期319-325,共7页
载药洗脱微球结合了栓塞与局部化疗的优势,其经微导管注射,选择性对肿瘤供血动脉进行栓塞,使肿瘤缺血坏死;同时其向病灶部位持久缓慢地释放药物,形成局部高浓度,对肿瘤细胞产生显著的细胞毒效应。近年来载药DC BeadTM用于肝癌的栓塞化... 载药洗脱微球结合了栓塞与局部化疗的优势,其经微导管注射,选择性对肿瘤供血动脉进行栓塞,使肿瘤缺血坏死;同时其向病灶部位持久缓慢地释放药物,形成局部高浓度,对肿瘤细胞产生显著的细胞毒效应。近年来载药DC BeadTM用于肝癌的栓塞化疗研究取得了较快的发展。本文就其制备方法、载药特点、体外释放方法、体内药动学及临床研究等方面进行了综述。 展开更多
关键词 载药洗脱微球 DC bead 阿霉素 肝细胞癌 动脉化疗栓塞
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溶胶-凝胶法制备TiO_2·SiO_2/beads及其光催化性能的研究 被引量:7
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作者 张新荣 杨平 《太阳能学报》 EI CAS CSCD 北大核心 2002年第2期150-153,共4页
研究以四异丙醇钛 [Ti (iso OC3 H7) 4 ]、硅酸乙酯为原料 ,以空心玻璃微球为载体 ,用溶胶 凝胶法制备可漂浮附载型复合光催化剂TiO2 ·SiO2 /beads的过程 ,利用附载型复合光催化剂降解有机磷农药。结果表明 :附载型复合光催化剂... 研究以四异丙醇钛 [Ti (iso OC3 H7) 4 ]、硅酸乙酯为原料 ,以空心玻璃微球为载体 ,用溶胶 凝胶法制备可漂浮附载型复合光催化剂TiO2 ·SiO2 /beads的过程 ,利用附载型复合光催化剂降解有机磷农药。结果表明 :附载型复合光催化剂活性显著提高 ,牢固性增强 ,TiO2 ·SiO2 摩尔比存在最佳值。n (TiO2 ) /m (SiO2 ) =30 / 70时 ,光催化剂活性最高 ,其活性是同样降解条件下 ,同样含量DegussaP 2 5TiO2 的 展开更多
关键词 溶胶-凝胶法 TiO2·SiO2/beads 半导体 光催化剂 可漂浮附载型 降解 有机磷农药 有机污染物 二氧化钛 二氧化硅
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Sensitivity model for prediction of bead geometry in underwater wet flux cored arc welding 被引量:1
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作者 石永华 郑泽培 黄晋 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第7期1977-1984,共8页
To investigate influence of welding parameters on weld bead geometry in underwater wet flux cored arc welding (FCAW), orthogonal experiments of underwater wet FCAW were conducted in the hyperbaric chamber at water d... To investigate influence of welding parameters on weld bead geometry in underwater wet flux cored arc welding (FCAW), orthogonal experiments of underwater wet FCAW were conducted in the hyperbaric chamber at water depth from 0.2 m to 60 m and mathematical models were developed by multiple curvilinear regression method from the experimental data. Sensitivity analysis was then performed to predict the bead geometry and evaluate the influence of welding parameters. The results reveal that water depth has a greater influence on bead geometry than other welding parameters when welding at a water depth less than 10 m. At a water depth deeper than 10 m, a change in travel speed affects the bead geometry more strongly than other welding parameters. 展开更多
关键词 underwater welding bead geometry sensitivity analysis flux cored arc welding (FCAW)
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CoPcS/TiO_2/beads及TiO_2/beads光催化降解水面漂浮植物油
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作者 张晓叶 闫永胜 +1 位作者 孔峰 王赟 《应用化工》 CAS CSCD 2007年第10期1003-1006,1010,共5页
以钛酸四丁酯为原料,以空心玻璃微珠为载体,采用溶胶-凝胶法制备出TiO2/beads光催化剂,用浸渍法制备出CoPcS/TiO2/beads光催化剂。研究了TiO2/beads及CoPcS/TiO2/beads光催化降解水面漂浮植物油的最优条件。结果表明,酸性或中性条件下,3... 以钛酸四丁酯为原料,以空心玻璃微珠为载体,采用溶胶-凝胶法制备出TiO2/beads光催化剂,用浸渍法制备出CoPcS/TiO2/beads光催化剂。研究了TiO2/beads及CoPcS/TiO2/beads光催化降解水面漂浮植物油的最优条件。结果表明,酸性或中性条件下,375 W中压汞灯照射2~3 h,TiO2/beads与CoPcS/TiO2/beads的投加量分别为3 g与1 g时,植物油的去除率达90%以上,投加微量的H2O2,可大大提高两者的光催化去除率。 展开更多
关键词 CoPcS/TiO2/beads TiO2/beads 植物油 去除率
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Performance Study of Dynamic Intake and Exhaust Fa鏰des in Hot and Dry Climates:Iraq Case Study
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作者 S.M.Hosseinalipour S.Asiaei Ammar A.Hussain Al-Taee 《Frontiers in Heat and Mass Transfer》 EI 2024年第3期747-767,共21页
This paper is part of a series addressing the urgent need for effective technologies to reduce energy demand and mitigate climate impact.This study focused on the implementation and development of dynamic insulation t... This paper is part of a series addressing the urgent need for effective technologies to reduce energy demand and mitigate climate impact.This study focused on the implementation and development of dynamic insulation technology for a sustainable and energy-efficient future in the region,especially in Iraq.The study assessed the energy efficiency of dynamic insulation technology by analyzing three wallmodels(static,dynamic,and modified)during thewinter season.This paper expands the analysis to include a hot,dry summer scenario,providing valuable insights into the year-round performance of dynamic walls and enabling sustainable and energy-efficient solutions for Iraq’s climate.The study evaluates the thermal efficiency of the dynamic intake and exhaust facades during the cooling season for the city of Baghdad.The finding indicated that the dynamic intake facade reduces energy consumption by 16.3%for the dynamic wall and 17.2%for the modified dynamic wall.In addition,the dynamic exhaust front reduces energy consumption by 46%during the cooling season,with the maximum permissible exhaust air level.Dynamic insulation is suitable for hot and dry climates,improving energy consumption. 展开更多
关键词 Polystyrene beads static and dynamic facades hot and dry climate indoor air quality
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CoPcS/TiO2/beads及TiO2/beads光催化降解水面浮油
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作者 张晓叶 闫永胜 +3 位作者 孔峰 赵瑞平 陈林 钱华伟 《印染助剂》 CAS 2008年第6期20-23,共4页
以钛酸四丁酯为原料,空心玻璃微珠(beads)为载体,采用溶胶-凝胶法制备出TiO2/beads光催化剂,用浸渍法制备出CoPcS/TiO2/beads新型光催化剂.研究了利用TiO2/beads及CoPcS/TiO2/beads光催化剂降解水面漂浮植物油的最优条件.结果表明:(1)溶... 以钛酸四丁酯为原料,空心玻璃微珠(beads)为载体,采用溶胶-凝胶法制备出TiO2/beads光催化剂,用浸渍法制备出CoPcS/TiO2/beads新型光催化剂.研究了利用TiO2/beads及CoPcS/TiO2/beads光催化剂降解水面漂浮植物油的最优条件.结果表明:(1)溶胶-凝胶法制备TiO2/beads的最佳条件为:空心玻璃微珠浸渍3次,450~550℃下焙烧2 h.用CoPcS对TiO2/beads进行改性时,TiO2/beads的最佳浸渍时间为30 min.(2)在中性或酸性条件下,375 W中压汞灯光照2~3 h,TiO2/beads与CoPcS/TiO2/beads的最佳用量分别为3 g和1 g(植物油3 g),在此条件下,植物油的去除率都高达90%.(3)微量H2O2对TiO2/beads和CoPcS/TiO2/beads的光催化活性都有很大的提高.对于TiO2/beads催化剂,H2O2的最佳用量为5~11 mmol/L;对于CoPcS/TiO2/beads催化剂,H2O2的最佳用量为5~30 mmol/L.(4)新型光催化剂CoPcS/TiO2/beads比TiO2/beads具有更好的除油性能. 展开更多
关键词 CoPcS/TiO2/beads TiO2/beads 水面浮油 去除率
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A Different Brachistochrone Problem with Counterintuitive Results
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作者 Pirooz Mohazzabi 《Journal of Applied Mathematics and Physics》 2024年第4期1426-1431,共6页
A problem similar to the famous brachistochrone problem is examined in which, instead of a smooth curve, the path consists of two straight-line sections, one slant and one horizontal. The condition for minimum sliding... A problem similar to the famous brachistochrone problem is examined in which, instead of a smooth curve, the path consists of two straight-line sections, one slant and one horizontal. The condition for minimum sliding time is investigated, producing results that are both counterintuitive and interesting. 展开更多
关键词 BRACHISTOCHRONE CYCLOID bead SLIDING Minimum Time Counterintuitive
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PHYSICAL MODELING FOR THE MECHANISMS OF BEAD FORMATION DEFECTS BASED ON THE STABILITY OF LIQUID METAL 被引量:28
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作者 S. Y. Yin L. Feng J. Z. Ding and S. J. Chan( 1) Beijing Polytechnic University, Beijing 100022, China 2) National Key Laboratory of Advanced Wdlding Production Technology, HIT, Harbin 150001, China) 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2000年第1期123-127,共5页
Based on the theory of stability of the liquid metal under the action of surface tension,a physical mod- el is established for the mechanisms of the bead formation deferct' humping', which is generated durin... Based on the theory of stability of the liquid metal under the action of surface tension,a physical mod- el is established for the mechanisms of the bead formation deferct' humping', which is generated during high - speed welding.A boundary function is introduced to correct the model,theoretical results got by the model correspond well with the experimental phenomena. A two - dimensional conducting model is adoopted in the simulation of the temperature field during high - speed welding.Finally, the factors acting upon the stability of liquid metal are analyzed. 展开更多
关键词 high - speed welding bead formation STABILITY
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Pb(Ⅱ) biosorption using chitosan and chitosan derivatives beads: Equilibrium, ion exchange and mechanism studies 被引量:20
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作者 W. S. Wan Ngah S. Fatinathan 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2010年第3期338-346,共9页
The study examined the adsorption of Pb(II) ions from aqueous solution onto chitosan, chitosan-GLA and chitosan-alginate beads. Several important parameters influencing the adsorption of Pb(II) ions such as initia... The study examined the adsorption of Pb(II) ions from aqueous solution onto chitosan, chitosan-GLA and chitosan-alginate beads. Several important parameters influencing the adsorption of Pb(II) ions such as initial pH, adsorbent dosage and different initial concentration of Pb(II) ions were evaluated. The mechanism involved during the adsorption process was explored based on ion exchange study and using spectroscopic techniques. The adsorption capacities obtained based on non–linear Langmuir isotherm for chitosan, chitosan-GLA and chitosan-alginate beads in single metal system were 34.98, 14.24 and 60.27 mg/g, respectively. However, the adsorption capacity of Pb(II) ions were reduced in the binary metal system due to the competitive adsorption between Pb(II) and Cu(II) ions. Based on the ion exchange study, the release of Ca2+, Mg2+, K+ and Na+ ions played an important role in the adsorption of Pb(II) ions by all three adsorbents but only at lower concentrations of Pb(II) ions. Infrared spectra showed that the binding between Pb(II) ions and the adsorbents involved mostly the nitrogen and oxygen atoms. All three adsorbents showed satisfactory adsorption capacities and can be considered as an efficient adsorbent for the removal of Pb(II) ions from aqueous solutions. 展开更多
关键词 chitosan and chitosan derivatives beads ion exchange MECHANISM
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Doxorubicin-eluting bead vs conventional transcatheter arterial chemoembolization for hepatocellular carcinoma before liver transplantation 被引量:12
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作者 Daniele Nicolini Gianluca Svegliati-Baroni +9 位作者 Roberto Candelari Cinzia Mincarelli Alessandra Mandolesi Italo Bearzi Federico Mocchegiani Andrea Vecchi Roberto Montalti Antonio Benedetti Andrea Risaliti Marco Vivarelli 《World Journal of Gastroenterology》 SCIE CAS 2013年第34期5622-5632,共11页
AIM:To assess the possible effect of two different types of preoperative transcatheter arterial chemoembolization(TACE)on recurrence-free survival after liver transplantation(LT)in patients with hepatocellular carcino... AIM:To assess the possible effect of two different types of preoperative transcatheter arterial chemoembolization(TACE)on recurrence-free survival after liver transplantation(LT)in patients with hepatocellular carcinoma(HCC)and to analyze the effects of TACE on tumor histology.METHODS:We retrospectively analyzed the histological features of 130 HCC nodules in 63 native livers removed at transplantation.Patients who received any other type of treatment such as radiofrequency tumor ablation,percutaneous ethanol ablation or who were not treated at all were excluded.All patients in the present study were within the Milan Criteria at the last imaging findings before transplantation.Doxorubicineluting bead TACE(DEB-TACE)was performed in 22patients(38 nodules),and conventional TACE(c-TACE)in 16(25 nodules).Patients’and tumors’characteristics were retrospectively reviewed.We performed a pernodule analysis of the explanted livers to establish the mean percentage of necrosis of any nodule treated by TACE(conventional or DEB)and a per-patient analysis to establish the percentage of necrosis in the cumulative tumor area,including 21 nodules not reached by TACE.Inflammatory and fibrotic changes in the tissue surrounding the tumor nodule were analyzed and categorized as poor/absent,moderate and enhanced reaction.Uni-and multivariate analysis of risk factors for HCC-recurrence were performed.RESULTS:The number and diameter of the nodules,the time spent on the waiting list and the number of treatments were similar in the two groups.A trend towards higher appropriate response rates(necrosis≥90%)was observed in the DEB-TACE group(44.7%vs32.0%,P=0.2834).The mean percentage of necrosis in the cumulative tumor area was 58.8%±36.6%in the DEB-TACE group and 50.2%±38.1%in the c-TACE group(P=0.4856).Fibrotic and inflammatory reactions surrounding the tumor nodule were markedly more common in the DEB-TACE group(P<0.0001,for both the parameters).The three-year recurrence-free survival was higher in DEB-TACE-treated patients than in conventionally treated patients(87.4%vs 61.5%,P=0.0493).Other factors affecting recurrence-free survival included viable tumor beyond Milan Criteria on histopathological examination,the percentage of necrosis on CTA≤50%and a pre-transplant serum-fetoprotein level greater than 70 ng/mL.On multivariate analysis,the lack of treatment with DEB-TACE,high levels of-fetoprotein and viable tumor beyond Milan Criteria at histology examination were identified as independent predictors of tumor recurrence.CONCLUSION:DEB-TACE can effectively promote tumor necrosis and improves recurrence-free survival after LT in HCC. 展开更多
关键词 Liver transplantation Hepatocellular carcinoma TRANSCATHETER arterial CHEMOEMBOLIZATION Doxorubicin-eluting bead Tumor HISTOLOGY Recurrence-free survival LOCOREGIONAL therapies
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Synthesis of phosphate-embedded calcium alginate beads for Pb(Ⅱ) and Cd(Ⅱ) sorption and immobilization in aqueous solutions 被引量:8
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作者 Yun-yan WANG Wen-bin YAO +3 位作者 Qing-wei WANG Zhi-hui YANG Li-fen LIANG Li-yuan CHAI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第8期2230-2237,共8页
The phosphate-embedded calcium alginate beads were successfully synthesized based on sodium alginate, calcium dihydrogen phosphate and sodium hydrogen carbonate. Scanning electron microscopy, Fourier transformed infra... The phosphate-embedded calcium alginate beads were successfully synthesized based on sodium alginate, calcium dihydrogen phosphate and sodium hydrogen carbonate. Scanning electron microscopy, Fourier transformed infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were conducted to characterize the morphology and structure of the phosphate-embedded calcium alginate beads. The effects of pH and the initial concentration of the metal ions on Pb(II) and Cd(II) sorption by the beads were investigated. The optimal pH values for Pb(II) and Cd(II) sorption are 4.0 and 5.5, respectively. The optimal initial concentrations of Pb(II) and Cd(II) are 200 mg/L and 25 mg/L, correspondingly, and the removal efficiencies are 94.2% and 80%,respectively. The sorption mechanism is that the heavy metal ions accessed the beads firstly due to the large surface area, combinedwith OH?, and then precipitated with phosphate radical, which was proven by FTIR and XRD. The sorption of Pb(II) and Cd(II) isfitted to Langmuir isotherm model with R2 values of 0.9957 and 0.988, respectively. The sorption capacities of Pb(II) and Cd(II) are263.16 mg/g and 82.64 mg/g, respectively. The results indicate that the phosphate-embedded calcium alginate beads could be appliedto treating Pb(II)/Cd(II)-containing wastewater and it could be implied that the synthesized beads also could be used as a kind of soil ameliorant for remediation of the heavy metal contaminated paddy soil. 展开更多
关键词 adsorption IMMOBILIZATION lead CADMIUM phosphate-embedded calcium alginate beads
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