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Growth characteristics of directionally solidified Al_2O_3/YAG/ZrO_2 ternary hypereutectic in situ composites under ultra-high temperature gradient

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International Journal of Minerals,Metallurgy and Materials 2011年第1期18卷 121-125页

作者： Hai-jun su jun Zhang Lin Liu Heng-zhi Fu State Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi＇an 710072 China

Oxide eutectic ceramic in situ composites have attracted significant interest in the application of high-temperature structural materials because of their excellent high-temperature strength,oxidation and creep resistance,as well as outstanding microstructural *** directionally solidified ternary Al2O3/YAG/ZrO2 hypereutectic in situ composite was successfully prepared by a laser zone remelting method,aiming to investigate the growth characteristic under ultra-high temperature *** microstructures and phase composition of the as-solidified hypereutectic were characterized by using scanning electron microscopy（SEM）,energy dispersive spectroscopy（EDS）,and X-ray diffraction（XRD）.The results show that the composite presents a typical hypereutectic lamellar microstructure consisting of fine Al2O3 and YAG phases,and the enriched ZrO2 phases with smaller sizes are randomly distributed at the Al2O3/YAG interface and in Al2O3 *** power and scanning rate strongly affect the sample quality and microstructure ***,coarse colony microstructures were also observed,and their formation and the effect of temperature gradient on the microstructure were discussed.

关键词： eutectics ceramic materials microstructure thermal gradients remelting solidification

Histological analysis of human pancreatic carcinoma following irreversible electroporation in a nude mouse model

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World Journal of Gastrointestinal Oncology 2018年第12期10卷 476-486页

作者： jun-jun su Kai Xu Peng-Fei Wang Hao-Yun Zhang Yong-Liang Chen Division of Gastroenterological surgery Depart-ment of SurgeryShanxi Provincial People’s Hospital Department of Hepatobiliary surgery Chinese People’s Liberation Army General Hospital

AIM To determine changes in the morphology and function of pancreatic cancer cells after irreversible electroporation(IRE) treatment, and to explore the clinical significance of IRE treatment for pancreatic cancer providing an experimental basis for the clinical application of IRE treatment. METHODS IRE was carried out in an athymic nude mouse model of pancreatic carcinoma generated with human pancreatic cancer cells 1. In therapy groups, IRE electrodes were inserted with 90 pulses per second at 800 V/cm applied to ablate the targeted tumor tissues. Histological assessment of the affected tissue was performed by hematoxylin and eosin staining(HE). Quantification of cell proliferation and apoptosis was performed by evaluating Ki67 and caspase-3 levels, respectively. Flow cytometry was used to assess cell apoptosis. Ultrasound imaging was carried out to evaluate IRE treatment results. Pathological correlation studies showed IRE is effective for the targeted ablation of pancreatic tumors in an orthotopic mouse *** IRE was efficacious in removing tumors in the orthotopic mouse model. The IRE-ablated zone displays characteristics of nude mouse models at different time-points as assessed by hematoxylin and eosin staining. Immunohistochemical analysis of samples from the pancreatic cancer models showed significantly enhanced caspase-3 cleavage and Ki67. Flow cytometry data corroborated the above findings that apoptosis in tumor cells was observed immediately on the first postoperative day, and with time the middle and late stages of apoptosis were observed. For ultrasound imaging studies, the IRE ablation zone became a hyperechoic area due to increasing inflammatory and immunologic cellular contents. CONCLUSION IRE is a promising new approach for pancreatic cancer, with many potential advantages over conventional ablation techniques.

关键词： Irreversible electroporation Pancreatic carcinoma Pathological evaluation Transplantation model Nude mouse

Quantum-enhanced microscopic imaging technology [Invited]

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Chinese Optics Letters 2024年第6期22卷 68-76页

作者： jun Liu Xiaolong su State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Opto-ElectronicsShanxi UniversityTaiyuan 030006China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

Microscopes are indispensable tools in modern biology and medicine. With the development of microscopy, the signal-tonoise ratio of microscopes is now limited by the shot noise. Recently, quantum-enhanced microscopic imaging provides a feasible approach for improving the signal-to-noise ratio since it can beat the shot-noise limit by using quantum light. In this review, we first briefly introduce quantum states applied in quantum-enhanced microscopic imaging, and then we provide an overview of the principle and progress of quantum-enhanced stimulated Raman scattering microscopy, entangled twophoton microscopy,and quantum-enhanced differential interference contrast microscopy.

关键词： squeezed state entangled state imaging microscopy

Postoperative inflammation as a possible cause of portal vein thrombosis after irreversible electroporation for locally advanced pancreatic cancer

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World Journal of Gastroenterology 2017年第32期23卷 6003-6006页

作者： jun-jun su Ming su Kai Xu Peng-Fei Wang Li Yan Shi-Chun Lu Wan-Qing Gu Yong-Liang Chen Division of Gastroenterological surgery Department of Surgery Shanxi Provincial People’s Hospital Department of Hepatobiliary surgery Chinese People’s Liberation Army General Hospital

Portal vein thrombosis(PVT) is a rare but serious postoperative complication associated with irreversible electroporation(IRE). We report a case of postoperative PVT in a 54-year-old woman who underwent IRE for locally advanced pancreatic cancer. Drain removal and discharge of the patient from the hospital were scheduled on postoperative day(POD) 7; however, a magnetic resonance imaging scan revealed the presence of PVT. We suspected postoperative inflammation in the pancreas as the main cause of PVT. However, the patient did not undergo any medical treatment because she did not have any clinical symptoms, and she was discharged on POD 8.

关键词： Irreversible electroporation Portal vein thrombosis Locally advanced pancreatic cancer Safety

Omnidirectional color wavelength tuning of stretchable chiral liquid crystal elastomers

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Light(Science & Applications) 2024年第6期13卷 1062-1074页

作者： Seungmin Nam Wontae jung jun Hyuk Shin su Seok Choi Department of Electrical Engineering Pohang University of Science and Technology(POSTECH)PohangKorea

Wavelength-tunable structural colors using stimuli-responsive materials,such as chiral liquid crystals(CLCs),have attracted increasing attention owing to their high functionality in various tunable photonic ***,on-demand omnidirectional wavelength control is highly desirable from the perspective of wavelength-tuning ***,despite numerous previous research efforts on tunable CLC structural colors,only mono-directional wavelength tuning toward shorter wavelengths has been employed in most studies to *** this study,we report the ideally desired omnidirectional wavelength control toward longer and shorter wavelengths with significantly improved tunability over a broadband wavelength *** using areal expanding and contractive strain control of dielectric elastomer actuators(DEAs)with chiral liquid crystal elastomers(CLCEs),simultaneous and omnidirectional structural color-tuning control was *** breakthrough in omnidirectional wavelength control enhances the achievable tuning freedom and versatility,making it applicable to a broad range of high-functional photonic applications.

关键词： tuning tunable directional

Usefulness of three-dimensional visualization technology in minimally invasive treatment for infected necrotizing pancreatitis

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World Journal of Gastroenterology 2018年第17期24卷 1911-1918页

作者： Peng-Fei Wang Zhi-Wei Liu Shou-Wang Cai jun-jun su Lei He Jian Feng Xian-Lei Xin Shi-Chun Lu Department of hepatobiliary surgery PLA General hospital

AIM To explore the value of three-dimensional(3 D) visualization technology in the minimally invasive treatment for infected necrotizing pancreatitis(INP). METHODS Clinical data of 18 patients with INP, who were admitted to the PLA General Hospital in 2017, were retrospectively analyzed. Two-dimensional images of computed tomography were converted into 3 D images based on 3 D visualization technology. The size, number, shape and position of lesions and their relationship with major abdominal vasculature were well displayed. Also, percutaneous catheter drainage(PCD) number and puncture paths were designed through virtual surgery(percutaneous nephroscopic necrosectomy) based on the principle of maximum removal of infected necrosis *** Abdominal 3 D visualization images of all the patients were well reconstructed, and the optimal PCD puncture paths were well designed. Infected necrosis was conveniently removed in abundance using a nephroscope during the following surgery, and the median operation time was 102(102 ± 20.7) min. Only 1 patient underwent endoscopic necrosectomy because of residual necrosis. CONCLUSION The 3 D visualization technology could optimize the PCD puncture paths, improving the drainage effect in patients with INP. Moreover, it significantly increased the efficiency of necrosectomy through the rigid nephroscope. As a result, it decreased operation times and improved the prognosis.

关键词： infected necrotizing pancreatitis threedimensional visualization percutaneous catheter drainage percutaneous nephroscopic necrosectomy

Iterative physical optics method based on efficient occlusion judgment with bounding volume hierarchy technology

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Journal of Electronic Science and Technology 2024年第1期22卷 1-12页

作者： Yang su Yu-Mao Wu jun Hu Key Laboratory for Information Science of Electromagnetic Waves(MoE) School of Information Science and TechnologyFudan UniversityShanghai200433China School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu611731China

This paper builds a binary tree for the target based on the bounding volume hierarchy technology,thereby achieving strict acceleration of the shadow judgment process and reducing the computational complexity from the original O(N^(3))to O(N^(2)logN).Numerical results show that the proposed method is more efficient than the traditional *** is verified in multiple examples that the proposed method can complete the convergence of the ***,the proposed method avoids the error of judging the lit-shadow relationship based on the normal vector,which is beneficial to current iteration and *** with the brute force method,the current method can improve the simulation efficiency by 2 orders of *** proposed method is more suitable for scattering problems in electrically large cavities and complex scenarios.

关键词： Bounding volume hierarchy Cavity scattering Iterative physical optics(IPO)

Understanding adversarial attacks on observations in deep reinforcement learning

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Science China(Information Sciences) 2024年第5期67卷 69-83页

作者： You QIAOBEN Chengyang YING Xinning ZHOU Hang su jun ZHU Bo ZHANG Department of Computer Science and Technology Beijing National Research Center for Information Science and Technology Tsinghua-Bosch Joint Center for Machine Learning Institute for Artificial Intelligence Tsinghua University Peng Cheng Laboratory

Deep reinforcement learning models are vulnerable to adversarial attacks that can decrease the cumulative expected reward of a victim by manipulating its observations. Despite the efficiency of previous optimization-based methods for generating adversarial noise in supervised learning, such methods might not achieve the lowest cumulative reward since they do not generally explore the environmental ***, a framework is provided to better understand the existing methods by reformulating the problem of adversarial attacks on reinforcement learning in the function space. The reformulation approach adopted herein generates an optimal adversary in the function space of targeted attacks, repelling them via a generic two-stage framework. In the first stage, a deceptive policy is trained by hacking the environment and discovering a set of trajectories routing to the lowest reward or the worst-case performance. Next, the adversary misleads the victim to imitate the deceptive policy by perturbing the observations. Compared to existing approaches, it is theoretically shown that our adversary is strong under an appropriate noise level. Extensive experiments demonstrate the superiority of the proposed method in terms of efficiency and effectiveness, achieving state-of-the-art performance in both Atari and MuJoCo environments.

关键词： deep learning reinforcement learning adversarial robustness adversarial attack

A continuous and long-term in-situ stress measuring method based on fiber optic. Part I: Theory of inverse differential strain analysis

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Petroleum Science 2024年第2期21卷 1171-1189页

作者： Kun-Peng Zhang Mian Chen Chang-jun Zhao su Wang Yong-Dong Fan State Key Laboratory of Petroleum Resources and Prospecting China University of PetroleumBeijing102249China MOE Key Laboratory of Petroleum Engineering in China University of Petroleum Beijing102249China Beijing International Center for Gas Hydrate School of Earth and Space SciencesPeking UniversityBeijing100871China

A method for in-situ stress measurement via fiber optics was proposed. The method utilizes the relationship between rock mass elastic parameters and in-situ stress. The approach offers the advantage of long-term stress measurements with high spatial resolution and frequency, significantly enhancing the ability to measure in-situ stress. The sensing casing, spirally wrapped with fiber optic, is cemented into the formation to establish a formation sensing nerve. Injecting fluid into the casing generates strain disturbance, establishing the relationship between rock mass properties and treatment ***, an optimization algorithm is established to invert the elastic parameters of formation via fiber optic strains. In the first part of this paper series, we established the theoretical basis for the inverse differential strain analysis method for in-situ stress measurement, which was subsequently verified using an analytical model. This paper is the fundamental basis for the inverse differential strain analysis method.

关键词： In-situ stress Fiber optic Orthotropic elastic Differential evolution ABAQUS