Electrocatalyst designs based on oxophilic foreign atoms are considered a promising approach for developing efficient pH-universal hydrogen evolution reaction(HER)electrocatalysts by overcoming the sluggish alkaline H...Electrocatalyst designs based on oxophilic foreign atoms are considered a promising approach for developing efficient pH-universal hydrogen evolution reaction(HER)electrocatalysts by overcoming the sluggish alkaline HER kinetics.Here,we design ternary transition metals-based nickel telluride(Mo WNi Te)catalysts consisting of high valence non-3d Mo and W metals and oxophilic Te as a first demonstration of non-precious heterogeneous electrocatalysts following the bifunctional mechanism.The Mo WNi Te showed excellent HER catalytic performance with overpotentials of 72,125,and 182 mV to reach the current densities of 10,100,and 1000 mA cm^(-2),respectively,and the corresponding Tafel slope of 47,52,and 58 mV dec-1in alkaline media,which is much superior to commercial Pt/C.Additionally,the HER performance of Mo WNi Te is well maintained up to 3000 h at the current density of 100 mA cm^(-2).It is further demonstrated that the Mo WNi Te exhibits remarkable HER activities with an overpotential of 45 mV(31 mV)and Tafel slope of 60 mV dec-1(34 mV dec-1)at 10 mA cm^(-2)in neutral(acid)media.The superior HER performance of Mo WNi Te is attributed to the electronic structure modulation,inducing highly active low valence states by the incorporation of high valence non-3d transition metals.It is also attributed to the oxophilic effect of Te,accelerating water dissociation kinetics through a bifunctional catalytic mechanism in alkaline media.Density functional theory calculations further reveal that such synergistic effects lead to reduced free energy for an efficient water dissociation process,resulting in remarkable HER catalytic performances within universal pH environments.展开更多
Cycloaddition of CO_(2) and epoxide into cyclic carbonate is one of the most efficient ways for CO_(2) conversion with 100% atom-utilization. Metal–organic frameworks are a kind of potential heterogeneous catalysts, ...Cycloaddition of CO_(2) and epoxide into cyclic carbonate is one of the most efficient ways for CO_(2) conversion with 100% atom-utilization. Metal–organic frameworks are a kind of potential heterogeneous catalysts, however, high temperature, high pressure, and high-purity CO_(2) are still required for the reaction.Here, we report two new Zn(Ⅱ) imidazolate frameworks incoporating MoO_(4)^(2–)or WO_(4)^(2–)units, which can catalyse cycloaddition of CO_(2) and epichlorohydrin at room temperature and atomospheric pressure, giving 95% yield after 24 h in pure CO_(2) and 98% yield after 48 h in simulated flue gas(15% CO_(2)+ 85% N_(2)),respectively. For comparison, the analogic Zn(Ⅱ) imidazolate framework MAF-6 without non-3d metal oxide units showed 71% and 33% yields under the same conditions, respectively. The insightful modulation mechanisms of the MoO_(4)^(2–)unit in optimizing the electronic structure of Zn(Ⅱ) centre, facilitating the rate-determined ring opening process, and minimizing the reaction activation energy, were revealed by X-ray photoelectron spectroscopy, temperature programmed desorption and computational calculations.展开更多
目的:探究3D单孔胸腔镜在非小细胞肺癌(NSCLC)手术中的应用效果及对患者术后恢复的影响。方法:选取2022年8月—2024年8月南通市肿瘤医院行NSCLC手术的150例患者,依据手术方式分为研究组(n=78)和对照组(n=72)。对照组采用2D单孔胸腔镜手...目的:探究3D单孔胸腔镜在非小细胞肺癌(NSCLC)手术中的应用效果及对患者术后恢复的影响。方法:选取2022年8月—2024年8月南通市肿瘤医院行NSCLC手术的150例患者,依据手术方式分为研究组(n=78)和对照组(n=72)。对照组采用2D单孔胸腔镜手术治疗,研究组采用3D单孔胸腔镜手术治疗,比较两组患者手术相关指标、血清指标、免疫指标、术后并发症发生情况。结果:两组在术中出血量、淋巴结清扫数目、术后留管时间、术后72 h VAS评分方面的差异无统计学意义(P>0.05),但研究组手术时间长于对照组,住院时间、术后引流量、术后24 h VAS评分均低于对照组(P<0.05)。相较于术前,两组术后1 d Cor、去甲肾上腺素(NE)、丙二醛(MDA)水平均升高,超氧化物歧化酶(SOD)水平均降低(P<0.05),且研究组术后1 d Cor、NE、MDA、SOD水平均优于对照组(P<0.05)。研究组术后7 d IgA、IgM、IgG均高于对照组(P<0.05),且并发症总发生率较低(P<0.05)。结论:3D单孔胸腔镜在NSCLC手术中的应用效果良好,可有效缓解患者术后疼痛,改善免疫功能,减少应激反应和术后并发症发生率,促进术后恢复。展开更多
无人机辅助通信系统是未来无线通信系统的重要组成部分。为进一步提高无人机辅助通信系统中时频资源的利用率,本文研究了一种基于非正交多址技术的无人机辅助通信架构,并提出了一种基于双延迟深度确定性策略梯度的TD3-TOPATM(twin delay...无人机辅助通信系统是未来无线通信系统的重要组成部分。为进一步提高无人机辅助通信系统中时频资源的利用率,本文研究了一种基于非正交多址技术的无人机辅助通信架构,并提出了一种基于双延迟深度确定性策略梯度的TD3-TOPATM(twin delayedtrajectory optimization and power allocation for total throughput maximization)算法,以最大化总吞吐量为目标,在满足最大功率约束、空间约束、最大飞行速度和服务质量(quality of service,QoS)约束的情况下,联合优化无人机的功率分配策略和3D轨迹。仿真实验分析结果表明,与随机算法相比,TD3-TOPATM算法能够实现98%的性能增益;与基于DQN(deep Q-network)的轨迹优化与资源分配算法相比,TD3-TOPATM算法获得的性能增益为19.4%;与基于深度确定性策略梯度的轨迹优化与资源分配算法相比,TD3-TOPATM算法得到的总吞吐量增加了9.7%;与基于正交多址技术的无人机辅助通信方案相比,基于非正交多址技术的无人机辅助通信方案实现了55%的性能增益。展开更多
We present a numerical formulation for resin flow based on the concept of quasi-steady state situation at the flow front. To be fit for complicated product shapes,we use the four-node unstructured tetrahedron mesh bas...We present a numerical formulation for resin flow based on the concept of quasi-steady state situation at the flow front. To be fit for complicated product shapes,we use the four-node unstructured tetrahedron mesh based on which the numerical formulation of temperature and degree of cure is developed. The validity of our method is established in the case where ffexible meshes are used. The results show that the numerical procedure,tested on known data,provides numerically valid and reasonably accurate predictions.展开更多
基金supported through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(2022M3H4A1A04096478)the support from the Supercomputing Center of Wuhan University。
文摘Electrocatalyst designs based on oxophilic foreign atoms are considered a promising approach for developing efficient pH-universal hydrogen evolution reaction(HER)electrocatalysts by overcoming the sluggish alkaline HER kinetics.Here,we design ternary transition metals-based nickel telluride(Mo WNi Te)catalysts consisting of high valence non-3d Mo and W metals and oxophilic Te as a first demonstration of non-precious heterogeneous electrocatalysts following the bifunctional mechanism.The Mo WNi Te showed excellent HER catalytic performance with overpotentials of 72,125,and 182 mV to reach the current densities of 10,100,and 1000 mA cm^(-2),respectively,and the corresponding Tafel slope of 47,52,and 58 mV dec-1in alkaline media,which is much superior to commercial Pt/C.Additionally,the HER performance of Mo WNi Te is well maintained up to 3000 h at the current density of 100 mA cm^(-2).It is further demonstrated that the Mo WNi Te exhibits remarkable HER activities with an overpotential of 45 mV(31 mV)and Tafel slope of 60 mV dec-1(34 mV dec-1)at 10 mA cm^(-2)in neutral(acid)media.The superior HER performance of Mo WNi Te is attributed to the electronic structure modulation,inducing highly active low valence states by the incorporation of high valence non-3d transition metals.It is also attributed to the oxophilic effect of Te,accelerating water dissociation kinetics through a bifunctional catalytic mechanism in alkaline media.Density functional theory calculations further reveal that such synergistic effects lead to reduced free energy for an efficient water dissociation process,resulting in remarkable HER catalytic performances within universal pH environments.
基金supported by the National Natural Science Foundation of China (Nos. 22090061, 21731007, 21890380 and 22161021)the Guangdong Pearl River Talents Program (No. 2017BT01C161)the support of Jiangxi Province (No. jxsq2018106041)。
文摘Cycloaddition of CO_(2) and epoxide into cyclic carbonate is one of the most efficient ways for CO_(2) conversion with 100% atom-utilization. Metal–organic frameworks are a kind of potential heterogeneous catalysts, however, high temperature, high pressure, and high-purity CO_(2) are still required for the reaction.Here, we report two new Zn(Ⅱ) imidazolate frameworks incoporating MoO_(4)^(2–)or WO_(4)^(2–)units, which can catalyse cycloaddition of CO_(2) and epichlorohydrin at room temperature and atomospheric pressure, giving 95% yield after 24 h in pure CO_(2) and 98% yield after 48 h in simulated flue gas(15% CO_(2)+ 85% N_(2)),respectively. For comparison, the analogic Zn(Ⅱ) imidazolate framework MAF-6 without non-3d metal oxide units showed 71% and 33% yields under the same conditions, respectively. The insightful modulation mechanisms of the MoO_(4)^(2–)unit in optimizing the electronic structure of Zn(Ⅱ) centre, facilitating the rate-determined ring opening process, and minimizing the reaction activation energy, were revealed by X-ray photoelectron spectroscopy, temperature programmed desorption and computational calculations.
文摘目的:探究3D单孔胸腔镜在非小细胞肺癌(NSCLC)手术中的应用效果及对患者术后恢复的影响。方法:选取2022年8月—2024年8月南通市肿瘤医院行NSCLC手术的150例患者,依据手术方式分为研究组(n=78)和对照组(n=72)。对照组采用2D单孔胸腔镜手术治疗,研究组采用3D单孔胸腔镜手术治疗,比较两组患者手术相关指标、血清指标、免疫指标、术后并发症发生情况。结果:两组在术中出血量、淋巴结清扫数目、术后留管时间、术后72 h VAS评分方面的差异无统计学意义(P>0.05),但研究组手术时间长于对照组,住院时间、术后引流量、术后24 h VAS评分均低于对照组(P<0.05)。相较于术前,两组术后1 d Cor、去甲肾上腺素(NE)、丙二醛(MDA)水平均升高,超氧化物歧化酶(SOD)水平均降低(P<0.05),且研究组术后1 d Cor、NE、MDA、SOD水平均优于对照组(P<0.05)。研究组术后7 d IgA、IgM、IgG均高于对照组(P<0.05),且并发症总发生率较低(P<0.05)。结论:3D单孔胸腔镜在NSCLC手术中的应用效果良好,可有效缓解患者术后疼痛,改善免疫功能,减少应激反应和术后并发症发生率,促进术后恢复。
文摘无人机辅助通信系统是未来无线通信系统的重要组成部分。为进一步提高无人机辅助通信系统中时频资源的利用率,本文研究了一种基于非正交多址技术的无人机辅助通信架构,并提出了一种基于双延迟深度确定性策略梯度的TD3-TOPATM(twin delayedtrajectory optimization and power allocation for total throughput maximization)算法,以最大化总吞吐量为目标,在满足最大功率约束、空间约束、最大飞行速度和服务质量(quality of service,QoS)约束的情况下,联合优化无人机的功率分配策略和3D轨迹。仿真实验分析结果表明,与随机算法相比,TD3-TOPATM算法能够实现98%的性能增益;与基于DQN(deep Q-network)的轨迹优化与资源分配算法相比,TD3-TOPATM算法获得的性能增益为19.4%;与基于深度确定性策略梯度的轨迹优化与资源分配算法相比,TD3-TOPATM算法得到的总吞吐量增加了9.7%;与基于正交多址技术的无人机辅助通信方案相比,基于非正交多址技术的无人机辅助通信方案实现了55%的性能增益。
文摘We present a numerical formulation for resin flow based on the concept of quasi-steady state situation at the flow front. To be fit for complicated product shapes,we use the four-node unstructured tetrahedron mesh based on which the numerical formulation of temperature and degree of cure is developed. The validity of our method is established in the case where ffexible meshes are used. The results show that the numerical procedure,tested on known data,provides numerically valid and reasonably accurate predictions.
文摘磁共振成像(Magnetic Resonance Imaging,MRI)已经成为一种常见的影像检查方式,MRI的去噪算法影响着MRI的成像效果。基于深度学习的MRI去噪算法需要一定量的数据,绝大部分基于非深度学习的MRI去噪算法都是将MRI数据转化为实数之后进行去噪的,针对复数MRI中的复数数据类型的算法也存在着失真的问题。因此,提出一种通过单张MRI脑图像的原始数据进行噪点剔除的算法,以此更好得去除图像噪声。该算法从MRI的原始数据出发,利用了MRI噪声分布性质和MRI脑图像的特点,以判断MRI图像中噪声明显的点,从而剔除MRI中特定的莱斯分布的噪声。并将所提出的算法结合了MRI去噪中常用的非局部平均算法(Non-Local Means denoising,NLM)与三维块匹配算法(Block-Matching and 3D filtering,BM3D),并和不使用该算法剔除噪点的NLM、BM3D进行了对比评估。对比结果表明,在噪声密度不同的多种情况下,该算法总能优化与之相结合的图像去噪算法,在不同的噪声情况下使峰值信噪比(Peak Signal-to-Noise Ratio,PSNR)与结构相似性(Structural Similarity,SSIM)提高了1%~9%。最后将该算法结合BM3D,对比了DnCNN、低秩聚类算法(Weighted Nuclear Norm Minimization,WNNM)、BM3D、NLM等用于MRI去噪的算法,在莱斯噪声较多时,该算法在PSNR上有更好的表现。
