水分解是一种利用可再生能源驱动的绿色制氢方法,零碳排放特性使其成为解决氢能源生产的重要途径.在电化学水分解中,制备高活性和稳定性的催化剂至关重要.高熵合金(HEAs)由于独特的结构和性能使其成为理想的催化剂材料,其多元成分和可...水分解是一种利用可再生能源驱动的绿色制氢方法,零碳排放特性使其成为解决氢能源生产的重要途径.在电化学水分解中,制备高活性和稳定性的催化剂至关重要.高熵合金(HEAs)由于独特的结构和性能使其成为理想的催化剂材料,其多元成分和可调组成提供了丰富的表面活性位点和灵活的催化特性,有望提高水分解的效率并降低成本.然而,简易高效地制备HEAs仍面临挑战,且目前对HEA催化剂的结构-活性关系的了解存在不足.因此,探索一种简便有效的方法用以制备高性能HEAs催化剂,并深入理解其在水分解反应中的作用机制和结构演变,能够为未来绿色制氢技术的发展提供重要的科学基础和技术支持.本文采用了电化学测量、CuK-边和PtL3-边的原位同步辐射X射线吸收光谱(XAS)测试以及密度泛函理论(DFT)计算相结合的方法,系统地研究了高熵合金电催化剂PtPdRhRuCu/C的析氢反应(HER)活性、反应机制以及结构演变规律.PtPdRhRuCu HEAs纳米颗粒由简便的一步溶剂热法制备,直径约为6.7±0.6 nm,其合金结构和元素分布通过多种表征手段(扫描透射电子显微镜、X射线衍射和能量色散X射线光谱等)得到确认.XAS对Cu K-边和PtL3-边的分析结果显示,HEAs纳米颗粒表面的少量铜氧化物在HER过程中被还原至金属态.扩展X射线吸收精细结构的拟合结果表明,HEAs在工况HER中保持了金属态和无序的原子排列,没有新的分离相形成.电化学测试结果表明,得益于多金属活性位点,PtPdRhRuCu/C催化剂在酸性和碱性条件下均表现出较好的HER活性和耐久性.在10 m Acm^(-2)的电流密度下,该催化剂在1molL^(-1)KOH中具有23.3 m V的极低过电位,优于商业Pt/C催化剂(50.3 m V),其质量活性是Pt/C的7.9倍,达到3.0 Amg^(-1)Pt.PtPdRhRuCu的高熵效应显著提升了催化剂在HER中的长期稳定性,在稳定性测试中,PtPdRhRuCu/C催化剂在10000次循环伏安测试后�展开更多
<strong>Purpose:</strong><span style="font-family:Verdana;"> This study aims to evaluate the treatment plans of Volumetric-mo</span><span style="font-family:;" "=&qu...<strong>Purpose:</strong><span style="font-family:Verdana;"> This study aims to evaluate the treatment plans of Volumetric-mo</span><span style="font-family:;" "=""><span style="font-family:Verdana;">dulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT) techniques for </span><span style="font-family:Verdana;">cervical-thoracic esophageal cancers. </span><b><span style="font-family:Verdana;">Methods</span></b> <b><span style="font-family:Verdana;">and</span></b> <b><span style="font-family:Verdana;">Materials:</span></b><span style="font-family:Verdana;"> Sixty patients were retrospectively identified. Several parameters</span></span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">were evaluated based on target conformity and dose-volume histograms of organs at risk (lung, spinal cord, and heart). A phantom for time comparison was also assessed for each plan. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> The IMRT plans (5f-IMRT: V95% = </span></span><span style="font-family:Verdana;">99.4 ± 0.3, 7f-IMRT: V95% = 99.8 ± 0.1) results in better PTV coverage than RA plans (Single-arc: V95% = 95.8 ± 3.2, Double-arc: V95% = 95.4 ± 2.3). The target dose conformity of the 5f-IMRT plan was inferior to all plans (CI = 70.4 ± 7.1). The Single-arc plan achieved the best conformity (CI = 72.5 ± 4.6), whereas the Double-arc plan (CI = 72.1 ± 5.1) was slightly inferior to the Single-arc plan but superior to the 7f-IMRT plan (CI = 71.7 ± </span><span style="font-family:Verdana;">8.6). The total MU was reduced by 42.1% in VMAT plan. The average MU needed to deliver the dose of 60 Gy for Single-arc (423.5 ± 52.1 MU) was found to be the least. Similarly, the average MU for the 5f-IMRT, 7f-IMRT and Double-arc were 868.2 ± 182.0 MU, 870.0 ± 225.3 MU and 548.8 ± 47.2 MU, respectively. The delivery time in VMAT plans</span><span style="font-family:Verdana;"> was</span><span style="font-famil展开更多
<strong>Objective:</strong> <span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">DNA copy number alterati...<strong>Objective:</strong> <span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">DNA copy number alterations and difference expression are frequently observed in ovarian cancer. The purpose of this way was to pinpoint gene expression change that w</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">as</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> associated with alterations in DNA copy number and could therefore enlighten some potential oncogenes and stability genes with functional roles in cancers, and investigated the bioinformatics significance for those correlated genes</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">. </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><b><span style="font-family:Verdana;">Method: </span></b></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">We obtained the DNA copy </span><span style="font-family:Verdana;">number and mRNA expression data from the Cancer Genomic Atlas and</span><span style="font-family:Verdana;"> identified the most statistically significant copy number alteration regions using the GISTIC. Then identified the significance genes between the tumor samples within the copy number alteration regions and analyzed the correlation using a binary matrix. The selected genes were subjected to bio</span><span><span style="font-family:Verdana;">informatics analysis using GSEA tool. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> GISTIC analysis results</span></span><span style="font-family:Verdana;"> showed there were 45 significance copy number amplification regions in the ovarian cancer, SAM and Fisher’s exact test found there have 40 genes can affect the expressi展开更多
<strong>Purpose: </strong><span><span style="font-family:""><span style="font-family:Verdana;">Verified the delivered dose distribution of lung cancer Stereotacti...<strong>Purpose: </strong><span><span style="font-family:""><span style="font-family:Verdana;">Verified the delivered dose distribution of lung cancer Stereotactic </span><span><span style="font-family:Verdana;">Body Radiotherapy (SBRT) using the cone-beam CT images. </span><b><span style="font-family:Verdana;">Methods:</span></b></span><b> </b><span style="font-family:Verdana;">Twenty </span><span style="font-family:Verdana;">lung cancer patients </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;">who </span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;">underwent SBRT with 100 CBCT images were</span></span><span><span style="font-family:""> <span style="font-family:Verdana;">enrolled in this study. Delivered dose distributions were recalculated on</span><span style="font-family:Verdana;"> CBCT images with </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;">the </span></span><span><span style="font-family:""><span style="font-family:Verdana;">deformed and non-deformed metho</span><span style="font-family:Verdana;">d</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span><span><span style="font-family:""><span style="font-family:Verdana;">, respectively. The </span><span style="font-family:Verdana;">planned and delivered dose distributions were compared using the</span><span style="font-family:Verdana;"> dose-volume histograms. </span><b><span style="font-family:Verdana;">Results: </span></b><span style="font-family:Verdana;">The delivered target coverage (V100) per patient inside target volume deviated on average were 0.83% ± 0.86% and 1.38% ±</span></span></span><span><span style="font-family:""> </span></span><span><span style="font-family:""><span style="font-family:Verdana;">1.40% for Pct </span><i><span style="font-family:Verdana;">vs</span></i><span style="font-family:Verdana;">. Pcbct and Pct </span><i><span style="font-family:Verdana;">vs</span></展开更多
提出一种含分布式电源的配电网潮流可行解调节方法。在配电网进行无功控制分区的基础上,定义了配电网分区负载率,然后设计考虑电压自动控制系统AVC站配协调控制的无功平衡优化调节方法。具体包含:配电网无功补偿分区平衡优化调节方法和...提出一种含分布式电源的配电网潮流可行解调节方法。在配电网进行无功控制分区的基础上,定义了配电网分区负载率,然后设计考虑电压自动控制系统AVC站配协调控制的无功平衡优化调节方法。具体包含:配电网无功补偿分区平衡优化调节方法和变电站AVC站配协调调节方法,并且在调节过程中前者优先于后者。对于前者模型采用免疫遗传算法进行求解,对于后者采用直接法进行计算。所提方法通过对配变低压侧无功补偿柜、分布式电源进行无功补偿分区平衡和变电站AVC的电压协调控制,调节出无功分区平衡、各个节点电压满足合格要求、有功网损较低的潮流可行解。成都某实际10 k V 55节点配电网的仿真结果验证了该方法的有效性。展开更多
文摘水分解是一种利用可再生能源驱动的绿色制氢方法,零碳排放特性使其成为解决氢能源生产的重要途径.在电化学水分解中,制备高活性和稳定性的催化剂至关重要.高熵合金(HEAs)由于独特的结构和性能使其成为理想的催化剂材料,其多元成分和可调组成提供了丰富的表面活性位点和灵活的催化特性,有望提高水分解的效率并降低成本.然而,简易高效地制备HEAs仍面临挑战,且目前对HEA催化剂的结构-活性关系的了解存在不足.因此,探索一种简便有效的方法用以制备高性能HEAs催化剂,并深入理解其在水分解反应中的作用机制和结构演变,能够为未来绿色制氢技术的发展提供重要的科学基础和技术支持.本文采用了电化学测量、CuK-边和PtL3-边的原位同步辐射X射线吸收光谱(XAS)测试以及密度泛函理论(DFT)计算相结合的方法,系统地研究了高熵合金电催化剂PtPdRhRuCu/C的析氢反应(HER)活性、反应机制以及结构演变规律.PtPdRhRuCu HEAs纳米颗粒由简便的一步溶剂热法制备,直径约为6.7±0.6 nm,其合金结构和元素分布通过多种表征手段(扫描透射电子显微镜、X射线衍射和能量色散X射线光谱等)得到确认.XAS对Cu K-边和PtL3-边的分析结果显示,HEAs纳米颗粒表面的少量铜氧化物在HER过程中被还原至金属态.扩展X射线吸收精细结构的拟合结果表明,HEAs在工况HER中保持了金属态和无序的原子排列,没有新的分离相形成.电化学测试结果表明,得益于多金属活性位点,PtPdRhRuCu/C催化剂在酸性和碱性条件下均表现出较好的HER活性和耐久性.在10 m Acm^(-2)的电流密度下,该催化剂在1molL^(-1)KOH中具有23.3 m V的极低过电位,优于商业Pt/C催化剂(50.3 m V),其质量活性是Pt/C的7.9倍,达到3.0 Amg^(-1)Pt.PtPdRhRuCu的高熵效应显著提升了催化剂在HER中的长期稳定性,在稳定性测试中,PtPdRhRuCu/C催化剂在10000次循环伏安测试后�
基金sponsored by the National Key Research and Development Program of China(No.2018YFB0704400)Key Research Project of Zhejiang Laboratory,China(No.2021PE0AC02)+1 种基金Key Program of Science and Technology of Yunnan Province,China(Nos.202002AB080001-2,202102AB080019-3)Key Project of Shanghai Zhangjiang National Independent Innovation Demonstration Zone,China(No.ZJ2021-ZD-006)。
基金supported by the National Natural Science Foundation of China(21872104,51908408,21872163,and 22072090)the National Key Research and Development Program of China(2017YFB0602200,2020YFA0211000,and 2020YFA0211003)+3 种基金the Innovative Research Team of Tianjin Municipal Education Commission(TD13-5008)Tianjin Science and Technology Planning Project(21ZYQCSY00050)the support from the Natural Science Foundation of Tianjin for Distinguished Young Scholar(20JCJQJC00150)the support from the Tencent Foundation through the XPLORER PRIZE。
文摘<strong>Purpose:</strong><span style="font-family:Verdana;"> This study aims to evaluate the treatment plans of Volumetric-mo</span><span style="font-family:;" "=""><span style="font-family:Verdana;">dulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT) techniques for </span><span style="font-family:Verdana;">cervical-thoracic esophageal cancers. </span><b><span style="font-family:Verdana;">Methods</span></b> <b><span style="font-family:Verdana;">and</span></b> <b><span style="font-family:Verdana;">Materials:</span></b><span style="font-family:Verdana;"> Sixty patients were retrospectively identified. Several parameters</span></span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">were evaluated based on target conformity and dose-volume histograms of organs at risk (lung, spinal cord, and heart). A phantom for time comparison was also assessed for each plan. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> The IMRT plans (5f-IMRT: V95% = </span></span><span style="font-family:Verdana;">99.4 ± 0.3, 7f-IMRT: V95% = 99.8 ± 0.1) results in better PTV coverage than RA plans (Single-arc: V95% = 95.8 ± 3.2, Double-arc: V95% = 95.4 ± 2.3). The target dose conformity of the 5f-IMRT plan was inferior to all plans (CI = 70.4 ± 7.1). The Single-arc plan achieved the best conformity (CI = 72.5 ± 4.6), whereas the Double-arc plan (CI = 72.1 ± 5.1) was slightly inferior to the Single-arc plan but superior to the 7f-IMRT plan (CI = 71.7 ± </span><span style="font-family:Verdana;">8.6). The total MU was reduced by 42.1% in VMAT plan. The average MU needed to deliver the dose of 60 Gy for Single-arc (423.5 ± 52.1 MU) was found to be the least. Similarly, the average MU for the 5f-IMRT, 7f-IMRT and Double-arc were 868.2 ± 182.0 MU, 870.0 ± 225.3 MU and 548.8 ± 47.2 MU, respectively. The delivery time in VMAT plans</span><span style="font-family:Verdana;"> was</span><span style="font-famil
文摘<strong>Objective:</strong> <span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">DNA copy number alterations and difference expression are frequently observed in ovarian cancer. The purpose of this way was to pinpoint gene expression change that w</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">as</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> associated with alterations in DNA copy number and could therefore enlighten some potential oncogenes and stability genes with functional roles in cancers, and investigated the bioinformatics significance for those correlated genes</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">. </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><b><span style="font-family:Verdana;">Method: </span></b></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">We obtained the DNA copy </span><span style="font-family:Verdana;">number and mRNA expression data from the Cancer Genomic Atlas and</span><span style="font-family:Verdana;"> identified the most statistically significant copy number alteration regions using the GISTIC. Then identified the significance genes between the tumor samples within the copy number alteration regions and analyzed the correlation using a binary matrix. The selected genes were subjected to bio</span><span><span style="font-family:Verdana;">informatics analysis using GSEA tool. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> GISTIC analysis results</span></span><span style="font-family:Verdana;"> showed there were 45 significance copy number amplification regions in the ovarian cancer, SAM and Fisher’s exact test found there have 40 genes can affect the expressi
文摘提出一种含分布式电源的配电网潮流可行解调节方法。在配电网进行无功控制分区的基础上,定义了配电网分区负载率,然后设计考虑电压自动控制系统AVC站配协调控制的无功平衡优化调节方法。具体包含:配电网无功补偿分区平衡优化调节方法和变电站AVC站配协调调节方法,并且在调节过程中前者优先于后者。对于前者模型采用免疫遗传算法进行求解,对于后者采用直接法进行计算。所提方法通过对配变低压侧无功补偿柜、分布式电源进行无功补偿分区平衡和变电站AVC的电压协调控制,调节出无功分区平衡、各个节点电压满足合格要求、有功网损较低的潮流可行解。成都某实际10 k V 55节点配电网的仿真结果验证了该方法的有效性。
