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Vortex identification based on the Liutex method and its effect on fish passage upstream

Journal of Hydrodynamics 2024年第1期36卷 130-141页

作者： Chun-ying Shen Rui-guo Yang Xiao-tao Shi ming-ming wang Shi-hua he Faculty of Electrical Power Engineering Kunming University of Science and TechnologyKunming650500China Hubei International Science and Technology Cooperation Base of Fish Passage China Three Gorges UniversityYichang443002China Shanghai Investigation Design and Research Institute Co.LtShanghai200434China

Fishway research is important for mitigating the fragmentation of river habitats caused by hydraulic projects.The vertical slit fishway is a broadly used fishway type because of its high efficiency and adaptability to water levels.However,the resulting vortex current disrupts the fish passage hence directly affecting fish migration.This study aims to accurately capture the vortex structure in the fishway and analyze the effect of vortex elements(vortex structure,vortex intensity,etc.)on fish.We conducted an analysis of the 3-D current flow field in the fishway through the utilization of an experimental model and the large eddy simulation(LES)method.Moreover,we captured the vortex information in the fishway at different flow rates using the Liutex vortex identification method and investigated the effect of the vortex on fish migration.The results revealed that the structures inside the fishway pool occupy most of the room,however,the areas with higher vortex strength were primarily located in the vortex near the vertical seam and the mainstream,the vortex strength inside the fishway gradually increases with increasing flow,suppressing fish migration.Fish experienced significantly increased resistance when encountering strong vortices.This suggests that the vortex may act as a physical barrier to fish migration.These findings highlight the potential negative effects of vortex on fish movement and reiterate the importance of understanding vortex dynamics for aquatic environmental management.As an effective tool for identifying vortices in fluid flow,the Liutex method demonstrates features of vortex within the fishway,thereby providing important insights into the interaction between fluid dynamics and aquatic organisms.

关键词： Vertical slit fishway vortex identification method Liutex large eddy simulation(LES) fish experiment computational fluid dynamics

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Reflective ultrathin light-sheet microscopy with isotropic 3D resolutions

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Photonics Research 2024年第2期12卷 271-281页

作者： YUE wang DASHAN DONG WENKAI YANG RENXI he ming LEI KEBIN SHI State Key Laboratory for Mesoscopic Physics Department of PhysicsPeking UniversityBeijing 100871China State Key Laboratory of Membrane Biology School of Life Sciencesand Biomedical Pioneering Innovation Center(BIOPIC)Peking UniversityBeijing 100871China School of Physics Xi’an Jiaotong UniversityXi’an 710049China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China Peking University Yangtze Delta Institute of Optoelectronics Nantong 226010China

Light-sheet fluorescence microscopy(LSFM)has played an important role in bio-imaging due to its advantages of high photon efficiency,fast speed,and long-term imaging capabilities.The perpendicular layout between LSFM excitation and detection often limits the 3D resolutions as well as their isotropy.here,we report on a reflective type light-sheet microscope with a mini-prism used as an optical path reflector.The conventional high NA objectives can be used both in excitation and detection with this design.Isotropic resolutions in 3D down to300 nm could be achieved without deconvolution.The proposed method also enables easy transform of a conventional fluorescence microscope to high performance light-sheet microscopy.

关键词： resolution excitation light

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A novel method for simulating nuclear explosion with chemical explosion to form an approximate plane wave: Field test and numerical simulation

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2137-2153页

作者： Wei ming Xiaojie Yang Yadong Mao Xiang wang Manchao he Zhigang Tao College of Civil and Architecture Engineering North China University of Science and TechnologyTangshan063210China State Key Laboratory for Tunnel Engineering China University of Mining and Technology-BeijingBeijing100083China School of Mechanics and Civil Engineering China University of Mining and Technology-BeijingBeijing100083China

A nuclear explosion in the rock mass medium can produce strong shock waves,seismic shocks,and other destructive effects,which can cause extreme damage to the underground protection infrastructures.With the increase in nuclear explosion power,underground protection engineering enabled by explosion-proof impact theory and technology ushered in a new challenge.This paper proposes to simulate nuclear explosion tests with on-site chemical explosion tests in the form of multi-hole explosions.First,the mechanism of using multi-hole simultaneous blasting to simulate a nuclear explosion to generate approximate plane waves was analyzed.The plane pressure curve at the vault of the underground protective tunnel under the action of the multi-hole simultaneous blasting was then obtained using the impact test in the rock mass at the site.According to the peak pressure at the vault plane,it was divided into three regions:the stress superposition region,the superposition region after surface reflection,and the approximate plane stress wave zone.A numerical simulation approach was developed using PFC and FLAC to study the peak particle velocity in the surrounding rock of the underground protective cave under the action of multi-hole blasting.The time-history curves of pressure and peak pressure partition obtained by the on-site multi-hole simultaneous blasting test and numerical simulation were compared and analyzed,to verify the correctness and rationality of the formation of an approximate plane wave in the simulated nuclear explosion.This comparison and analysis also provided a theoretical foundation and some research ideas for the ensuing study on the impact of a nuclear explosion.

关键词： Approximate plane wave Multi-hole simultaneous blasting Chemical explosion Nuclear explosion Pressure sensor inclusion

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Adhesive Contact of Elastic Solids with Self-Affine Fractal Rough Surfaces

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Acta Mechanica Solida Sinica 2024年第2期37卷 265-270页

作者： Xuan-ming Liang Shi-Wen Chen Si-he wang Zhen-Yuan Gong Jun Feng Gang-Feng wang Department of Engineering Mechanics SVL and MMMLXi’an Jiaotong UniversityXi’an710049China OPPO Mobile Telecommunications Corporation Ltd. Dongguan523860China

The elastic adhesive contact of self-affine fractal rough surfaces against a rigid flat is simulated using the finite element method. An array of nonlinear springs, of which the force-separation law obeys the Lennard–Jones potential, is introduced to account for the interfacial adhesion. For fractal rough surfaces, the interfacial interaction is generally attractive for large mean gaps, but turns repulsive as the gap continuously shrinks. The interfacial interactions at the turning point corresponding to the spontaneous contact are shown for various surfaces. For relatively smooth surfaces, the probability density distributions of repulsion and attraction are nearly symmetric. However, for rougher surfaces, the simulation results suggest a uniform distribution for attraction but a monotonously decreasing distribution with a long tail for repulsion. The pull-off force rises with increasing ratio of the work of adhesion to the equilibrium distance, whereas decreases for solids with a higher elastic modulus and a larger surface roughness. The current study will be helpful for understanding the adhesion of various types of rough solids.

关键词： Fractal rough surfaces Adhesion Contact mechanics Lennard-Jones potential

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Stress corrosion cracking behavior of buried oil and gas pipeline steel under the coexistence of magnetic field and sulfate-reducing bacteria

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Petroleum Science 2024年第2期21卷 1320-1332页

作者： Jian-Yu he Fei Xie Dan wang Guang-Xin Liu ming Wu Yue Qin College of Petroleum Engineering Liaoning Petrochemical UniversityFushun113001LiaoningChina Key Laboratory of Oil and Gas Storage and Transportation Technology in Liaoning Province Fushun113001LiaoningChina State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing100084China PipeChina West East Gas Pipeline Company Shanghai200120China

Magnetic field and microorganisms are important factors influencing the stress corrosion cracking(SCC)of buried oil and gas pipelines. Once SCC occurs in buried pipelines, it will cause serious hazards to the soil environment. The SCC behavior of X80 pipeline steel under the magnetic field and sulfate-reducing bacteria(SRB) environment was investigated by immersion tests, electrochemical tests, and slow strain rate tensile(SSRT) tests. The results showed that the corrosion and SCC sensitivity of X80 steel decreased with increasing the magnetic field strength in the sterile environment. The SCC sensitivity was higher in the biotic environment inoculated with SRB, but it also decreased with increasing magnetic field strength, which was due to the magnetic field reduces microbial activity and promotes the formation of dense film layer. This work provided theoretical guidance on the prevention of SCC in pipeline steel under magnetic field and SRB coexistence.

关键词： Magnetic field Sulfate-reducing bacteria Film layer Stress corrosion cracking Oil and gas pipelines

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N-acetylcysteine ameliorates erectile dysfunction in rats with hyperlipidemia by inhibiting oxidative stress and corpus cavernosum smooth muscle cells phenotypic modulation

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Asian Journal of Andrology 2024年第1期26卷 99-106页

作者： Wei Ding Jun-Hong Fan Li-Ren Zhong Nan-Xiong wang Lu-Hao Liu Hai-Bo Zhang Li wang ming-Qiang wang Bing-Lin he An-Yang Wei Department of Urology The First Affiliated Hospital of Guizhou University of Traditional Chinese MedicineGuiyang 550002China Department of Urology Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhou 510000China Department of Urology Nanfang HospitalSouthern Medical UniversityGuangzhou 510000China Department of Urology Shenzhen Immigration Inspection General Station HospitalShenzhen 518000China Department of Organ Transplantation The Second Affiliated Hospital of Guangzhou Medical UniversityGuangzhou 510000China Department of Endocrinology The First Affiliated Hospital of Guizhou University of Traditional Chinese MedicineGuiyang 550002China

Hyperlipidemia is a major risk factor for erectile dysfunction(ED).Oxidative stress and phenotypic modulation of corpus cavernosum smooth muscle cells(CcSMCs)are the key pathological factors of ED.N-acetylcysteine(NAC)can inhibit oxidative stress;however,whether NAc can alleviate pathological variations in the corpus cavernosum and promote erectile function recovery in hyperlipidemic rats remains unclear.A hyperlipidemia model was established using 27 eight-week-old male Sprague-Dawley(SD)rats fed a high-fat and high-cholesterol diet(hyperlipidemic rats,HR).In addition,9 male SD rats were fed a normal diet to serve as controls(NC).HR rats were divided into three groups:HR,HR+normal saline(NS),and HR+NAC(n=9 for each group;NS or NAc intraperitoneal injections were administered daily for 16 weeks).Subsequently,the lipid profiles,erectile function,oxidative stress,phenotypic modulation markers of ccsMCs,and tissue histology were analyzed.The experimental results revealed that erectile function was significantly impaired in the HR and HR+NS groups,but enhanced in the HR+NAC group.Abnormal lipid levels,over-activated oxidative stress,and multi-organ lesions observed in the HR and HR+NS groups were improved in the HR+NAC group.Moreover,the HR group showed significant phenotypic modulation of CCSMCs,which was also inhibited by NAC treatment.This report focuses on the therapeutic effect of NAc in restoring erectile function using a hyperlipidemic rat model by preventing CcSMC phenotypic modulationand attenuating oxidativestress.

关键词： erectile dysfunction hyperlipidemia N-acetylcysteine oxidative stress henotypic modulation

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No Incidence of Liver Cancer Was Observed in A Retrospective Studyof Patients with Aristolochic Acid Nephropathy

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Chinese Journal of Integrative Medicine 2024年第2期30卷 99-106页

作者： SU Tao FANG Zhi-e GUO Yu-ming wang Chun-yu wang Jia-bo JI Dong BAI Zhao-fang YANG Li XiAO Xiao-he Renal Division Department of MedicinePeking University First HospitalBeijing(100034)China Department of Pharmacy Chongqing Hospital of Traditional Chinese MedicineChongqing(400021)China Department of hepatology Fifth Medical Center of Chinese PLA General HospitalBeijing(100039)China China Military Institute of Chinese Materia Fifth Medical Center of Chinese PLA General HospitalBeijing(100039)China Phase I Clinical Trials Unit Department of Medicine for Infectious DiseasesFifth Medical Center of Chinese PLA General HospitalBeijing(100039)China Department of Pharmacy Affiliated Hospital of Shandong University of Traditional Chinese MedicineJinan(250000)China National Key Laboratory of Kidney Diseases Beijing(100039)China

Objective:To assess the risk of aristolochic acid(AA)-associated cancer in patients with AA nephropathy(AAN).Methods:A retrospective study was conducted on patients diagnosed with AAN at Peking University First Hospital from January 1997 to December 2014.Long-term surveillance and follow-up data were analyzed to investigate the influence of different factors on the prevalence of cancer.The primary endpoint was the incidence of liver cancer,and the secondary endpoint was the incidence of urinary cancer during 1 year after taking AA-containing medication to 2014.Results:A total of 337 patients diagnosed with AAN were included in this study.From the initiation of taking AA to the termination of follow-up,39 patients were diagnosed with cancer.No cases of liver cancer were observed throughout the entire follow-up period,with urinary cancer being the predominant type(34/39,87.17%).Logistic regression analysis showed that age,follow-up period,and diabetes were potential risk factors,however,the dosage of the drug was not significantly associated with urinary cancer.Conclusions:No cases of liver cancer were observed at the end of follow-up.However,a high prevalence of urinary cancer was observed in AAN patients.Establishing a direct causality between AA and HCC is challenging.

关键词： aristolochic acid hepatocellular carcinoma urinary cancer drug safety retrospective study

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Clinical features, treatment strategies and outcomes of craniocervical junction arteriovenous fistulas: a cohort study of 193 patients

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Stroke & Vascular Neurology 2024年第1期9卷 18-29页

作者： Yongjie Ma Zihao Song Yinqing wang Jiachen wang Chuan he Guilin Li Peng Zhang Tao Hong Liyong Sun Peng Hu ming Ye Hongqi Zhang Department of Neurosurgery Xuanwu Hospital Capital Medical University

Background Craniocervical junction(CCJ)arteriovenous fistulas(AVFs)are rare.The current treatment strategies for AVFs with different angioarchitecture need to be clarified.The present study aimed to analyse the correlation between angioarchitecture and clinical characteristics,share our experience in treating this disease and identify risk factors associated with subarachnoid haemorrhage(SAH)and poor outcomes.Methods A total of 198 consecutive patients with CCJ AVFs from our neurosurgical centre were retrospectively reviewed.The patients were grouped according to their clinical manifestations,and their baseline clinical characteristics,angioarchitecture,treatment strategies and outcomes were summarised.Results The patients’median age was 56 years(IQR 47–62 years).The majority of patients were men with 166(83.8%)patients.The most common clinical manifestation was SAH(52.0%),followed by venous hypertensive myelopathy(VHM)(45.5%).The most common CCJ AVFs type was dural AVF,with 132(63.5%)fistulas.The most frequent fistula location was C-1(68.7%)and dural branch of vertebral artery(70.2%)was the most involved arterial feeders for fistulas.The most common direction of venous drainage was descending intradural drainage(40.9%),followed by ascending intradural drainage(36.5%).Microsurgery was the most common treatment strategy applied for 151(76.3%)patients,15(7.6%)patients were treated with interventional embolisation only,and 27(13.6%)received both interventional embolisation and microsurgical treatment.The learning curve for microsurgery only was analysed by cumulative summation method,and the turning point was the 70th case,and blood loss in post-group was lower than that in pre-group(p=0.034).At the last follow-up,there were 155(78.3%)patients with favourable outcomes(modified Rankin Scale(mRS)he clinical manifestation(OR 4.102,95%CI 2.108 to 7.982,p<0.001)and pretreatment mRS≥3(OR 3.127,95%CI 1.617 to 6.047,p<0.001)were significantly associated with poor out

关键词： patients treatment hypertensive

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Highly Conductive Ag/pCF/MVQ Composite Rubber for Efficient Electromagnetic Interference Shielding

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Chinese Journal of Polymer Science 2024年第6期42卷 864-873页

作者： Yang Chen Xiao-ming Shao Liang he Yi-Nuo Xu Qi-Yuan Yao Ding Feng Wen-Cai wang State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing100029China Key Laboratory of Beijing City for Preparation and Processing of Novel Polymer Materials Beijing University of Chemical TechnologyBeijing100029China Sino-german School of Engineering Qingdao University of Science and TechnologyQingdao266400China

In this study,flexible and highly conductive composite rubber at low filler content was successfully prepared through polydopamine-assisted electroless silver plating plus mechanical mixing.Firstly,carbon fibers(CF)were activated by polydopamine(PDA)to improve the surface activity by self-polymerization reaction.Next,because of the metal chelating ability of PDA,silver layer was firmly deposited on the surface of CF through a facile electroless silver plating method.Finally,flexible silver-plated carbon fibers(Ag/pCF)silicone rubber composites prepared by mechanical mixing.By using X-ray photoelectron spectroscopy(XPS)and X-ray diffraction(XRD),the chemical composition and crystal structure of Ag/pCF were examined,and scanning electron microscopy(SEM)was used to assess the surface morphology of the Ag/pCF.The results showed that a uniform and dense silver layer was formed on the surface of the CF,and the conductivity of the Ag/pCF could reach 7885 S/cm.It was noteworthy that the composite rubber filled with only 45 phr Ag/pCF had a high electromagnetic interference shielding effectiveness(100 dB)due to the low density and high aspect ratio of Ag/pCF.The composite rubber has excellent potential for application in the field of electromagnetic interference shielding.

关键词： Carbon fibers Polydopamine Electroless plating Silver Electromagnetic interference shielding

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Enhancing the electrocatalytic performance of nitrate reduction to ammonia by in-situ nitrogen leaching

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Chinese Chemical Letters 2024年第2期35卷 564-569页

作者： Mimi Fu Yini Mao Hua wang Wei Luo Yimin Jiang Wei Shen ming Li Rongxing he College of Chemistry and Chemical Engineering Southwest UniversityChongqing 400715China

Electrochemical nitrate reduction reaction (NITRR) is regarded as a “two birds-one stone” method for the treatment of nitrate contaminant in polluted water and the synthesis of valuable ammonia, which is retarded by the lack of highly reactive and selective electrocatalysts .herein, for the first time, nickel foam supported Co_(4) N was designed as a high-performance NITRR catalyst by an in-situ nonmetal leaching-induced strategy.At the optimal potential, the Co_(4) N/NF catalyst achieves ultra-high Faraday efficiency and NH_(3) selectivity of 95.4% and 99.4%, respectively.Ex situ X-ray absorption spectroscopy (XAS), together with other experiments powerfully reveal that the nitrogen vacancies produced by nitrogen leaching are stable and play a key role in boosting nitrate reduction to ammonia.Theoretical calculations confirm that Co_(4) N with abundant nitrogen vacancies can optimize the adsorption energies of NO_(3)^(-) and intermediates, lower the free energy (Δ G ) of the potential-determining step (*NH_(3) to NH_(3) ) and inhibit the formation of N-containing byproducts.In addition, we also conclude that the nitrogen vacancies can stabilize the adsorbed hydrogen, making H_(2) quite difficult to produce, and lowering ΔG from *NO to *NOH, which facilitates the selective reduction of nitrate.This study reveals significant insights about the in-situ nonmetal leaching to enhance the NITRR activity.

关键词： Co4N Nitrate reduction In-situ nonmetal leaching Nitrogen vacancy Mechanism

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