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Design of a large momentum acceptance proton therapy gantry utilizing AG-CCT magnets

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NUCLEAR SCIENCE AND TECHNIQUES 2024年第10期35卷 1-11页

作者： Liao, Yi-Cheng Liu, Xu Wang, Wei Yang, Zi-Yi Chen, Qu-Shan qin, bin Huazhong Univ Sci & Technol State Key Lab Adv Electromagnet Technol Wuhan 430074 Peoples R China

The application of superconducting (SC) technology enables magnets to excite strong fields with small footprints, which has great potential for miniaturizing proton therapy gantries. However, the slow ramping rate of SC magnets results in a low treatment efficiency compared with normal-conducting (NC) gantries. To address this problem, this study proposes a compact proton therapy gantry design with a large momentum acceptance utilizing alternating-gradient canted-cosine-theta (AG-CCT) SC magnets. In our design, a high-transmission degrader is mounted in the middle of the gantry, and the upstream beamline employs NC magnets with small apertures. Downstream of the degrader, large-bore AG-CCT magnets with strong alternating focusing gradients are set symmetrically as a local achromat, which realizes a momentum acceptance of 20% (or 40% in the energy domain). Therefore, only three magnetic working points are required to cover a treatment energy of 70-230 MeV. Owing to the large momentum acceptance, the proton beam after the degrader can be directly delivered to the isocenter without truncating its energy spectrum, which can significantly increase the treatment efficiency but causes severe dispersion effects during pencil beam scanning. Therefore, a compensation method was introduced by tuning the normal and skewed quadrupoles during the scanning process. As a result, the new gantry not only presents a remarkable reduction in the size and weight of the facility but also shows good potential for fast treatment.

关键词： Alternating-gradient canted-cosine-theta magnets Large momentum acceptance gantry Pencil beam scanning Proton therapy ENERGY DEGRADER BEAM OPTICS OPTIMIZATION

Wind Speed Prediction Based on Improved VMD-BP-CNN-LSTM Model

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Journal of Power and Energy Engineering 2024年第1期12卷 29-43页

作者： Chaoming Shu bin qin Xin Wang College of Railway Transportation Hunan University of Technology Zhuzhou China College of Electrical and Information Engineering Hunan University of Technology Zhuzhou China

Amid the randomness and volatility of wind speed, an improved VMD-BP-CNN-LSTM model for short-term wind speed prediction was proposed to assist in power system planning and operation in this paper. Firstly, the wind speed time series data was processed using Variational Mode Decomposition (VMD) to obtain multiple frequency components. Then, each individual frequency component was channeled into a combined prediction framework consisting of BP neural network (BPNN), Convolutional Neural Network (CNN) and Long Short-Term Memory Network (LSTM) after the execution of differential and normalization operations. Thereafter, the predictive outputs for each component underwent integration through a fully-connected neural architecture for data fusion processing, resulting in the final prediction. The VMD decomposition technique was introduced in a generalized CNN-LSTM prediction model;a BPNN model was utilized to predict high-frequency components obtained from VMD, and incorporated a fully connected neural network for data fusion of individual component predictions. Experimental results demonstrated that the proposed improved VMD-BP-CNN-LSTM model outperformed other combined prediction models in terms of prediction accuracy, providing a solid foundation for optimizing the safe operation of wind farms.

关键词： Wind Speed Forecast Long Short-Term Memory Network BP Neural Network Variational Mode Decomposition Data Fusion

The underlying mechanism of variety–water–nitrogen–stubble damage interactions on yield formation in ratoon rice with low stubble height under mechanized harvesting

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Journal of Integrative Agriculture 2024年第3期23卷 806-823页

作者： Jingnan Zou Ziqin Pang Zhou Li Chunlin Guo Hongmei Lin Zheng Li Hongfei Chen Jinwen Huang Ting Chen Hailong Xu bin qin Puleng Letuma Weiwei Lin Wenxiong Lin College of Life Sciences Fujian Agriculture and Forestry University(FAFU)/Fujian Key Laboratory for Agroecological Processes and Safety MonitoringFuzhou 350002China College of Agriculture FAFU/Fujian Key Laboratory for Crop Physiology and Molecular EcologyFuzhou 350002China Institute of Oceanography College of Geography and OceanographyMinjiang UniversityFuzhou 350108China Crop Science Department The National University of LesothoRoma 00100Lesotho The Agricultural Extension Station of Pucheng County Nanping 353400China

Agronomic measures are the key to promote the sustainable development of ratoon rice by reducing the damage from mechanical crushing to the residual stubble of the main crop, thereby mitigating the impact on axillary bud sprouting and yield formation in ratoon rice. This study used widely recommended conventional rice Jiafuzhan and hybrid rice Yongyou 2640 as the test materials to conduct a four-factor block design field experiment in a greenhouse of the experimental farm of Fujian Agricultural and Forestry University, China from 2018 to *** treatments included fertilization and no fertilization, alternate wetting and drying irrigation and continuous water flooding irrigation, and plots with and without artificial crushing damage on the rice stubble. At the same time, a 13C stable isotope in-situ detection technology was used to fertilize the pot experiment. The results showed significant interactions among varieties, water management, nitrogen application and stubble *** to the long-term water flooding treatment, the treatment with sequential application of nitrogen fertilizer coupled with moderate field drought for root-vigor and tiller promotion before and after harvesting of the main crop, significantly improved the effective tillers from low position nodes. This in turn increased the effective panicles per plant and grains per panicle by reducing the influence of artificial crushing damage on rice stubble and achieving a high yield of the regenerated rice. Furthermore, the partitioning of 13C assimilates to the residual stubble and its axillary buds were significantly improved at the mature stage of the main crop, while the translocation rate to roots and rhizosphere soil was reduced at the later growth stage of ratooning season rice. This was triggered by the metabolism of hormones and polyamines at the stem base regulated by the interaction of water and fertilizer at this time. We therefore suggest that to achieve a high yield of ratoon rice

关键词： mechanized harvesting ratoon rice rice stubble yield attributes

Characteristics of early gastric tumors with different differentiation and predictors of long-term outcomes after endoscopic submucosal dissection

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World Journal of Gastroenterology 2024年第14期30卷 1990-2005页

作者： Hong-Yi Zhu Jie Wu Yuan-Miao Zhang Fang-Lan Li Jin Yang bin qin Jiong Jiang Ning Zhu Meng-Yao Chen Bai-Cang Zou Department of Gastroenterology The Second Affiliated Hospital of Xi'an Jiaotong UniversityXi'an 710004Shaanxi ProvinceChina Department of Pathology The Second Affiliated Hospital of Xi'an Jiaotong UniversityXi'an 710004Shaanxi ProvinceChina Department of Gastroenterology Xianyang Hospital of Yan'an UniversityXianyang 712000Shaanxi ProvinceChina Department of Gastroenterology The First Hospital of Xi'anXi'an 710000Shaanxi ProvinceChina

BACKGROUND Gastric cancer is a common malignant tumor of the digestive tract,and endosco-pic submucosal dissection(ESD)is the preferred treatment for early-stage gastric *** analysis of the epidemiological characteristics of gastric mucosal tumors with different differentiation degrees and the influencing factors of long-term ESD efficacy may have certain significance for revealing the development of gastric cancer and *** To analyze the features of gastric mucosal tumors at different differentiation levels,and to explore the prognostic factors of *** We retrospectively studied 301 lesions in 285 patients at The Second Affiliated Hospital of Xi'an Jiaotong University from 2014 to 2021,according to the latest Japanese guidelines(sixth edition),and divided them into low-grade intrae-pithelial neoplasia(LGIN),high-grade intraepithelial neoplasia(HGIN),and computed tomography at 3,6 and 12 months after *** compared clinicopathologic characteristics,ESD efficacy,and complications with different degrees of differentiation,and analyzed the related factors associated with *** HGIN and differentiated carcinoma patients were significantly older compared with LGIN patients(P<0.001)and accounted for more 0-IIc(P<0.001),atrophic gastritis was common(P<0.001),and irregular microvascular patterns(IMVPs)and demarcation lines(DLs)were more obvious(P<0.001).There was more infiltration in the undifferentiated carcinoma tissue(P<0.001),more abnormal folds and poorer mucosal peristalsis(P<0.001),and more obvious IMVPs,irregular microsurface patterns and DLs(P<0.05)than in the LGIN and HGIN *** disease-free survival rates at 2,5,and 8 years after ESD were 95.0%,90.1%,and 86.9%,***-tiated lesions(HR 5.066),white moss(HR 7.187),incomplete resection(HR 3.658),and multiple primary cancers(HR 2.462)were significantly associated with poor *** Differentiations of gastric mucosal tumors have different epidemiological and

关键词： Gastric mucosal epithelial neoplasia Differentiated early gastric cancer Undifferentiated early gastric cancer Endoscopic submucosal dissection Long-term outcomes

纯电动汽车高速工况下底盘后部空腔引起低频噪声问题的分析改进

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汽车工程 2024年第3期46卷 520-525,545页

作者：沈龙张军秦宾浙江智马达智能科技有限公司宁波315336 吉利汽车研究院(宁波)有限公司宁波315336

随着电机驱动技术以及空气动力学技术的不断提升,纯电动汽车高速化趋势愈发明显。纯电动汽车高速行驶时,底盘后部空腔引起的低频气动噪声峰值可超过60 dB(A),严重影响驾乘舒适性。以某纯电动汽车高速工况下的低频噪声问题为案例,系统地... 详细信息

随着电机驱动技术以及空气动力学技术的不断提升,纯电动汽车高速化趋势愈发明显。纯电动汽车高速行驶时,底盘后部空腔引起的低频气动噪声峰值可超过60 dB(A),严重影响驾乘舒适性。以某纯电动汽车高速工况下的低频噪声问题为案例,系统地阐述了低频噪声问题的排查分析及产生机理分析验证过程。首先,分析了高速行驶激励源类型,并通过声学风洞进行激励源分离试验,锁定低频噪声为气动噪声类型;其次,对低频气动噪声形成的潜在机理进行推断,并设计试验进行潜在机理排查分析,确定底盘后部空腔涡声耦合自激振荡是引起低频气动噪声的原因;最后,通过仿真分析、半经验公式计算和实车试验验证了潜在机理,并设计工程化方案解决了该低频噪声问题。这对纯电动汽车高速工况气动噪声问题的分析识别与解决具有重要的工程意义。

关键词：纯电动汽车空腔自激振荡耦合气动噪声

Loss of monopolar spindle-binding protein 3B expression promotes colorectal cancer malignant behaviors by activation of target of rapamycin kinase/autophagy signaling

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World Journal of Gastroenterology 2024年第26期30卷 3229-3246页

作者： Juan Sun Jin-Xiu Zhang Meng-Shi Li Meng-bin qin Ruo-Xi Cheng qing-Ru Wu Qiu-Ling Chen Dan Yang Cun Liao Shi-Quan Liu Jie-An Huang Department of Gastroenterology The Second Affiliated Hospital of Guangxi Medical UniversityNanning 530007Guangxi Zhuang Autonomous RegionChina Department of Colorectal&Anal Surgery The First Affiliated Hospital of Guangxi Medical UniversityNanning 530021Guangxi Zhuang Autonomous RegionChina

BACKGROUND Monopolar spindle-binding protein 3B(MOB3B)functions as a signal transducer and altered MOB3B expression is associated with the development of human *** To investigate the role of MOB3B in colorectal cancer(CRC).METHODS This study collected 102 CRC tissue samples for immunohistochemical detection of MOB3B expression for association with CRC *** overexpression and knockdown of MOB3B expression were induced in CRC cell lines,changes in cell viability,migration,invasion,and gene expression were *** cell autophagy was detected using transmission electron microscopy,while nude mouse xenograft experiments were performed to confirm the in-vitro *** MOB3B expression was reduced in CRC vs normal tissues and loss of MOB3B expression was associated with poor CRC *** of MOB3B protein in vitro attenuated the cell viability as well as the migration and invasion capacities of CRC cells,whereas knockdown of MOB3B expression had the opposite effects in CRC *** the molecular level,microtubule-associated protein light chain 3 II/I expression was elevated,whereas the expression of matrix metalloproteinase(MMP)2,MMP9,sequestosome 1,and phosphorylated mechanistic target of rapamycin kinase(mTOR)was downregulated in MOB3B-overexpressing RKO *** contrast,the opposite results were observed in tumor cells with MOB3B *** nude mouse data confirmed these in-vitro findings,i.e.,MOB3B expression suppressed CRC cell xenograft growth,whereas knockdown of MOB3B expression promoted the growth of CRC cell *** Loss of MOB3B expression promotes CRC development and malignant behaviors,suggesting a potential tumor suppressive role of MOB3B in CRC by inhibition of mTOR/autophagy signaling.

关键词： Colorectal cancer Monopolar spindle-binding protein 3B Mechanistic target of rapamycin kinase Autophagy Prognosis

非营利组织监事制度有效性研究——基于“制度——文化”理论的分析

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南通大学学报（社会科学版） 2024年第5期40卷 112-124,160页

作者：康晓光秦彬彬中国人民大学公共管理学院中国人民大学中国公益创新研究院

监事制度是非营利组织治理结构的重要组成部分,然而现有研究忽视了对其有效性的探讨。由新制度主义理论切入,构建非营利组织监事制度有效性“制度—文化”模型,采用清晰集定性比较分析方法进行多案例分析,研究发现:非营利组织的监事制... 详细信息

监事制度是非营利组织治理结构的重要组成部分,然而现有研究忽视了对其有效性的探讨。由新制度主义理论切入,构建非营利组织监事制度有效性“制度—文化”模型,采用清晰集定性比较分析方法进行多案例分析,研究发现:非营利组织的监事制度、组织文化、主导者态度、监事态度和能力、监事行为、理事会和秘书处的配合度,对于监事制度有效性有着重要影响。监事有所作为是监事制度有效的必要条件。监事行为受到制度规则、组织文化和主导者态度的强烈影响。在已经具有监事制度规则的条件下,监事制度有效性取决于组织文化和制度相关人的态度,即“文化发挥决定性作用”。研究结论揭示了非营利组织监事制度有效性的影响因素及因果机制,对于提升非营利组织监事制度有效性,改变长期以来的内部监督缺失局面,推动非营利组织健康、有序、高质量发展具有重要意义。

关键词：非营利组织监事制度监事制度有效性新制度主义

不同预载机制和过盈量下角接触球轴承的动力学特性

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航空动力学报 2024年第4期39卷 267-278页

作者：李震王青山王瑞华秦斌中南大学机电工程学院长沙410012 中南大学交通运输工程学院长沙410015

基于Hertz弹性接触理论和无滚道控制理论,建立了不同预载机制下五自由度角接触球轴承拟静力学分析模型,采用牛顿拉夫逊法对已建立的模型进行数值求解,探究预载机制和过盈量对角接触球轴承动力学特性的影响。通过将已建立模型求解接触角... 详细信息

基于Hertz弹性接触理论和无滚道控制理论,建立了不同预载机制下五自由度角接触球轴承拟静力学分析模型,采用牛顿拉夫逊法对已建立的模型进行数值求解,探究预载机制和过盈量对角接触球轴承动力学特性的影响。通过将已建立模型求解接触角和轴承刚度结果与已有文献结果进行对比,验证模型的有效性。分别探究了过盈量对内外圈装配压力和滚道接触变形量的影响以及过盈量和预载机制对轴承刚度的影响。结果表明:随过盈量增加,内外圈装配压力增加,初始接触角减小;随着过盈量增加,轴承径向刚度增加,轴向刚度和角刚度减小;与定压预紧相比,定位预紧能够提高轴承刚度;探究转速对接触变形和装配压力的影响,确定了松脱旋转速度约为40000 r/min。

关键词：过盈量预载机制牛顿拉夫逊轴承刚度接触角

直接甲醇燃料电池含氧空穴CaTiO_(3)阴极助催化剂研究

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电源技术 2024年第6期48卷 996-1002页

作者：霍鑫秦斌孙海中国科学院大连化学物理研究所辽宁大连116023 中国科学院大学北京100039

作为便携移动电源,直接甲醇燃料电池(DMFC)在高海拔、低氧浓度条件下的性能变化直接影响其实际应用效果。针对低氧浓度条件下,DMFC阴极极化损失增大问题,通过水热模板法合成CaTiO_(3)助催化剂,与商品Pt/C催化剂进行不同比例掺杂,对掺杂... 详细信息

作为便携移动电源,直接甲醇燃料电池(DMFC)在高海拔、低氧浓度条件下的性能变化直接影响其实际应用效果。针对低氧浓度条件下,DMFC阴极极化损失增大问题,通过水热模板法合成CaTiO_(3)助催化剂,与商品Pt/C催化剂进行不同比例掺杂,对掺杂催化剂进行了X射线衍射光谱法(XRD)、扫描电子显微镜法(SEM)和透射电子显微镜法(TEM)等表征分析以及旋转圆盘电极(RDE)、单电池电化学测试。与商品Pt/C催化剂相比,掺杂(CaTiO_(3)与Pt/C的质量比为1∶1)催化剂的半波电位正移39 mV;当氧浓度从100%逐渐降低到10%,Pt/C膜电极峰值功率密度降低了38.62%,Pt/CCTO膜电极峰值功率密度降低15.03%。在10%低氧浓度下,Pt/C-CTO膜电极峰值功率密度较Pt/C膜电极峰值功率密度高40.54%。

关键词：直接甲醇燃料电池阴极催化剂