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Analysis of impact pressure,rock-breaking effect,and ground vibration induced by the disposable CO_(2)fracturing tube

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第8期16卷 3099-3121页

作者： Chong Yu Yongan Ma Haibo Li Shouchun Deng Yafei hao kuan Zhu State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University of Chinese Academy of Sciences Beijing100049China Explosives Co.Ltd. Changsha410000China Wuhan University of Science and Technology Wuhan430000China Gezhouba EXPL(Hunan)Technology Co.Ltd. Liuyang410300China

The technology of expansion fracturing with liquid CO_(2)(EFLCO_(2))has attracted increasing attention due to reduced vibration and *** disposable fracturing tube has been developed and is gradually replacing the Cardox ***,there is a lack of impact pressure testing of disposable tubes under real working conditions,selection of gas explosion design parameters,and systematic analysis of blasting *** limitation has constrained the widespread application of disposable fracturing tubes in engineering.A joint monitoring of the pressure-time curves in the disposable tubes and boreholes was *** rock-breaking effect of varying hole spacing parameters in the EFLCO_(2)design was analyzed,and a systematic study was carried out on the vibration peak value,frequency,and energy *** results show that(1)the pressure distribution characteristics,stress peak value,and duration in the disposable tubes are different from those of Cardox tubes,which show multi-peak distribution,low-pressure peak value,and short *** correlation between the pressure in the disposable tube,filling pressure,and liquid CO_(2)weight is established,and a theoretical calculation method for the borehole wall pressure is proposed;(2)The hole spacing in rocks of different hardness is suggested;and(3)At the same scale distance,the peak particle velocity(PPV)caused by EFLCO_(2)(PPVCO_(2))is significantly smaller than that caused by blasting(PPVexplosive).The ratio of PPVexplosive to PPVCO_(2)is a power function related to scale distance,and a distance-related zonality exist in this *** frequency composition of the vibration signal caused by EFLCO_(2)is relatively simple with a narrow frequency *** PPV and energy are mainly concentrated in the low-frequency *** research contributes to the optimization of disposable fracturing tubes,gas explosion design,and vibration hazard control.

关键词： Disposable tube Liquid CO_(2) Impact pressure Hole spacing Vibration effect Cardox tube

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Gastric cancer incidence and mortality in Zhuanghe,China,between 2005 and 2010

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World Journal of Gastroenterology 2012年第11期18卷 1262-1269页

作者： jing-jing jing jin-kuan hao Li-Na Wang Yun-Ping Wang Li-Hua Sun Yuan Yuan Tumor Etiology and ScreeningDepartment of Cancer Institute and General Surgery The FirstAffiliated Hospital of China Medical University Key Labora-tory of Cancer Control in Liaoning Province Shenyang 110001Liaoning Province China Yun-Ping Wang The Center of Disease Prevention and Control Zhuanghe116400 Liaoning Province China Office for Cancer Prevention and Control andCancer Registry of Liaoning Province Shenyang 110001 Lia-oning Province China

AIM： To investigate the incidence and mortality of gastric cancer （GC） in Zhuanghe region, northeast China and the influencing factors for their changing trends.METHODS： All new cancer cases and deaths registered from 2005 to 2010 in Zhuanghe County were reviewed. The annual GC cases, constituent ratio, crude rates,age-standardized rates, their sex and age distribution and temporal trends were assessed. The method of annual percentage change （APC） was used to estimate the trends of GC.RESULTS： Altogether 2634 new cases of GC and 1722 related deaths were registered, which accounted for 21.04% and 19.13% of all cancer-related incidence and deaths, respectively. The age-standardized incidence rate steadily decreased from 57.48 in 2005 to 44.53 in 2010 per 10^5 males, and from 18.13 to 14.70 per 10s females, resulting in a APC of -5.81% for males and -2.89% for females over the entire period. The magnitude of APC in GC mortality amounted to -11.09% and -15.23%, respectively, as the agestandardized mortality rate steadily decreased from 42.08 in 2005 to 23.71 in 2010 per 10^5 males, and from 23.86 to 10.78 per 10^5 females. Females had a significantly lower incidence （a male/female ratio 2.80, P 〈 0.001） and mortality （a male/female ratio 2.30, P 〈 0.001）. In both genders, the peak incidence and mortality occurred in the 80-84 years age group. The age-standardized mortality/incidence ratio also decreased from the peak of 0.73 in 2005 to 0.53 in 2010 for males, and from 1.32 to 0.73 for females.CONCLUSION： Encouraging declines of incidence and mortality of GC were observed in Zhuanghe region between 2005 and 2010, possibly due to the economic development and efficient GC control strategies.

关键词： Gastric cancer Incidence Mortality Trend High-risk areas

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Strategic regulation of nitrogen-containing intermediates for enhanced nitrate reduction over Co_(3)O_(4)/SiC catalyst having multiple active centers

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Journal of Energy Chemistry 2024年第9期96卷 291-299页

作者： Ming-hao Guan hao-Nan Xu jin Liu Tao Wu An-Hui Lu State Key Laboratory of Fine Chemicals Liaoning Key Laboratory for Catalytic Conversion of Carbon ResourcesSchool of Chemical EngineeringDalian University of TechnologyDalian 116024LiaoningChina

Regulating the intermediates involved in the electrocatalytic nitrate reduction reaction(NO_(3)RR)is crucial for the enhancement of reaction ***,it remains a great challenge to regulate the reaction intermediates through active site manipulation on the surface of the ***,a family of n%-Co_(3)O_(4)/SiC(n=5,8,12,20)catalysts with a delicate percentage of Co^(2+)and Co^(3+)were prepared for NO_(3)*** found that Co^(3+)primarily acts as the active site for NO_(3)^(−)reduction to NO_(2)^(−),while Co^(2+)is responsible for the conversion of NO_(2)^(−)to NH_(3).Moreover,the conversion of these intermediates over the active sites is autonomous and separately *** processes synergistically accomplish the reduction of nitrate ions to synthesize *** the experimental studies and density functional theory(DFT)calculations,it is discovered the pathway(^(*)NHO→^(*)NHOH→^(*)NH_(2)OH→^(*)NH_(2)→^(*)NH_(3))is more favorable due to the lowerΔG value(0.25 eV)for the rate-limiting step(^(*)NO→^(*)NHO).The NH_(3)yield rate of 8%-Co_(3)O_(4)/SiC reached 1.08 mmol/(cm^(2)h)with a Faradaic efficiency of 96.4%at−0.89 V versus the reversible hydrogen electrode(RHE),surpassing those of most reported non-noble NO_(3)RR *** strategy not only provides an efficient catalyst for NO_(3)RR but also serves as an illustrative model for the regulation of multi-step reaction intermediates through the design of distinct active sites,thereby presenting a new approach to enhance the efficiency of intricate reactions.

关键词： Electrocatalysis Nitratereduction Co_(3)O_(4)/SiC catalysts Intermediates control

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Updated roles of the gut microbiota in exploring shrimp etiology, polymicrobial pathogens, and disease incidence

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Zoological Research 2024年第4期45卷 910-923页

作者： jin-Bo Xiong hao-Nan Sha Jiong Chen State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products School of Marine SciencesNingbo UniversityNingboZhejiang 315211China Key Laboratory of Aquacultural Biotechnology Ministry of EducationSchool of Marine SciencesNingbo UniversityNingboZhejiang 315211China Laboratory of Biochemistry and Molecular Biology School of Marine SciencesNingbo UniversityNingboZhejiang 315211China

Litopenaeus vannamei is the most extensively cultured shrimp species globally,recognized for its scale,production,and economic ***,its aquaculture is plagued by frequent disease outbreaks,resulting in rapid and massive *** research often lags behind the emergence of new diseases,leaving the causal agents of some shrimp diseases unidentified and leading to nomenclature based on symptomatic presentations,especially in cases involving co-and polymicrobial *** data on shrimp disease statuses remain *** this review,we summarize current knowledge on shrimp diseases and their effects on the gut ***,we also propose a workflow integrating primary colonizers,“driver”taxa in gut networks from healthy to diseased states,disease-discriminatory taxa,and virulence genes to identify potential polymicrobial *** examine both abiotic and biotic factors(e.g.,external and internal sources and specific-disease effects)that influence shrimp gut microbiota,with an emphasis on the“holobiome”concept and common features of gut microbiota response to diverse *** excluding the effects of confounding factors,we provide a diagnosis model for quantitatively predicting shrimp disease incidence using disease common-discriminatory taxa,irrespective of the causal *** to the conservation of functional genes used in designing specific primers,we propose a practical strategy applying qPCR-assayed abundances of disease common-discriminatory functional *** review updates the roles of the gut microbiota in exploring shrimp etiology,polymicrobial pathogens,and disease incidence,offering a refined perspective for advancing shrimp aquaculture health management.

关键词： Shrimp disease Gut microbiota Polymicrobial pathogens Diagnosis model Disease common-discriminatory taxa Disease prediction

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Analytical libration control law for electrodynamic tether system with current constraint

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Astrodynamics 2024年第2期8卷 237-246页

作者： Shidong Xu Ti Chen hao Wen Dongping jin State Key Laboratory of Mechanics and Control for Aerospace Structures Nanjing University of Aeronautics and AstronauticsNanjing210016China

This study focuses on stabilizing the libration dynamics of an electrodynamic tether system(EDTS)using generalized torques induced by the Lorentz *** contrast to existing numerical optimization methods,a novel analytical feedback control law is developed to stabilize the in-plane and out-of-plane motions of a tether by modulating the electric current *** saturation constraint on the current is accounted for by adding an auxiliary dynamic system to the *** enhance the robustness of the proposed controller,multiple perturbations of the orbital dynamics,modeling uncertainties,and external disturbances are approximated using a neural network in which the weighting matrix and approximation error are estimated simultaneously,such that these perturbations are well compensated for during the control design of the ***,a dynamically scaled generalized inverse is utilized to address the singular matrix in the control *** closed-loop system is proven to be ultimately bounded based on Lyapunov stability ***,numerical simulations are performed to demonstrate the effectiveness of the proposed analytical control law.

关键词： electrodynamic tether system(EDTS) libration dynamics analytical control current constraint

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Calculation method for the formation time of dynamic filter cake in slurry shield tunneling

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Frontiers of Structural and Civil Engineering 2024年第9期18卷 1337-1349页

作者： Yinzun YANG Dajun YUAN Changyan DU Dalong jin Jun hao Key Laboratory of the Ministry of Education for Urban Underground Engineering Beijing Jiaotong UniversityBeijing 100044China School of Civil Engineering Beijing Jiaotong UniversityBeijing 100044China China Railway 14th Bureau Group Mega Shield Engineering Co. Ltd.Nanjing 211800China

In slurry shield tunneling,the stability of tunnel face is closely related to the filter *** cutting of the cutterhead has negative impact on the formation of filter *** study focuses on the formation time of dynamic filter cake considering the filtration effect and rotation of *** effect is the key factor for slurry infiltration.A multilayer slurry infiltration experiment system is designed to investigate the variation of filtrate rheological property in infiltration *** mass concentration C_(L),soil permeability coefficient k,the particle diameter ratio between soil equivalent grain size and representative diameter of slurry particles d_(10)/D_(85) are selected as independent design variables to fit the computational formula of filtration *** on the relative relation between the mass of deposited particles in soil pores and infiltration time,a mathematical model for calculating the formation time of dynamic filter cake is proposed by combining the formation criteria and formation rate of external filter *** accuracy of the proposed model is verified through existing experiment *** results show that filtration coefficient is positively correlated with slurry mass concentration,while negatively correlated with the soil permeability coefficient and the particle diameter ratio between soil and *** infiltration distance increases,the adsorption capacity of soil skeleton to slurry particles gradually *** formation time of external filter cake is significantly lower than internal filter cake and the ratio is approximately *** the dynamic cutting of the cutterhead,the formation time is positively associated with the rotation speed of cutter head,while negatively with the phase angle difference between adjacent cutter *** formation rate of external filter cake is greater than 98%when d_(10)/D_(85)≤*** increasing the content or decreasing the diameter size of solid-phase

关键词： slurry infiltration filtration coefficient dynamic filter cake formation time rotation speed phase angle

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Online control for pressure regulation of oxygen mask based on neural network

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Control Theory and Technology 2024年第3期22卷 487-501页

作者： Ligan Zhao Qinglin Sun hao Sun jin Tao Zengqiang Chen College of Artificial Intelligence Nankai UniversityTianjin 300350China Silo Al Helsinki 00100Finland

The aviation oxygen mask,which has a small volume of less than 1L and strong air tightness,imposes extremely high requirements on control performance of the oxygen *** on analyses of the operation principle of oxygen supply system,the dynamic model is established through the combination of mechanism analysis and experimental *** that the traditional fixed-parameter controllers are difficult to meet the control requirements with changes in pulmonary ventilation,this paper presents an online feedback controller based on neural network compensation(NNC),with connection weights that can be updated without *** mathematical simulations at different respiratory parameters,such as respiratory rate,are performed to verify the superior lower inspiratory resistance of controller with *** terms of hardware,an embedded AI control platform is to complete the experimental ***,the work may have downward compatibility to achieve stable oxygen supply in civil fields,such as medical ventilators,high-altitude expeditions.

关键词： Neural network Online control Pressure regulation AI platform

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Numerical modeling of fracture propagation of supercritical CO_(2)compound fracturing

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2607-2628页

作者： hao Chen Yong Kang Wanchun jin Changhai Li Can Cai School of Mechanical Engineering Southwest Petroleum UniversityChengdu610500China Laboratory of High-pressure Jet Theory and Application Technology Southwest Petroleum UniversityChengdu610500China Hubei Key Laboratory of Waterjet Theory and New Technology Wuhan UniversityWuhan430072China Sinopec International Petroleum Exploration and Production Corporation Beijing 100029China

The exploitation of shale gas is promising due to depletion of the conventional energy and intensification of the greenhouse *** this paper,we proposed a heat-fluid-solid coupling damage model of supercritical CO_(2)(SC-CO_(2))compound fracturing which is expected to be an efficient and environmentally friendly way to develop shale *** coupling model is solved by the finite element method,and the results are in good agreement with the analytical solutions and fracturing *** on this model,the fracture propagation characteristics at the two stages of compound fracturing are studied and the influence of pressurization rate,in situ stress,bedding angle,and other factors are *** results show that at the SC-CO_(2)fracturing stage,a lower pressurization rate is conducive to formation of the branches around main fractures,while a higher pressurization rate inhibits formation of the branches around main fractures and promotes formation of the main *** bedding and in situ stress play a dominant role in the fracture *** the in situ stress ratio(δ_(x)/δ_(y))is 1,the presence of bedding can reduce the initiation pressure and failure ***,it will cause the fracture to propagate along the bedding direction,reducing the fracture *** rocks without bedding,hydraulic fracturing has the lengthening and widening effects for SC-CO_(2)induced *** shale,fractures induced at the hydraulic fracturing stage are more likely to be dominated by in situ stresses and have a shorter reorientation ***,fracture branches propagating along the maximum principal stress direction may be generated around the main fractures induced by SC-CO_(2)at the hydraulic fracturing *** the branches converge with the main fractures,fracture zones are easily formed,and thus the fracture complexity and damage area can be significantly *** results are instructive for the design and application of SC

关键词： Compound fracturing Fracture propagation Finite element method Damage evolution

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A clean disposal method of carbide slag with carbon emission reduction:Used as a flux for iron ore sintering Author links open overlay panel

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Particuology 2024年第8期91卷 303-314页

作者： Hanxiao Meng Jiankang Wang Xiang Liu Kelang jin Lei Zhang hao Zhou State Key Laboratory of Clean Energy Utilization Institute for Thermal Power EngineeringZhejiang UniversityHangzhou310027China

Limestone or quicklime is a necessary flux in the iron ore sintering *** production and application process will cause CO_(2) emissions and various environmental pollution,but this has not attracted enough *** slag(CS)is a calcium-rich solid waste produced in acetylene production,the harmless disposal of which is still incomplete,resulting in soil and groundwater *** study investigated the granulation characteristics and sintering performance of the sintering mixture with different proportions of *** results show that replacing limestone with an appropriate proportion of CS is promising and beneficial to the formation of high-quality bonding *** CS accounts for 75%of the total mass of CS and limestone,the tumbler index increases by 8.10%and the comprehensive index decreases only from 100 to 96.16,which is within the acceptable *** application of CS in iron ore sintering can achieve a clean disposal of it and a considerable carbon emission reduction,as the main component of which is Ca(OH)2.

关键词： Ironore sintering Carbide slag Flux Carbon emission Comprehensive index

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Post-treatment of Ti-MWW zeolite with potassium fluoride for propylene epoxidation

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Frontiers of Chemical Science and Engineering 2024年第8期18卷 37-47页

作者： Xintong Li Xianchen Gong Jilong Wang Shengbo jin hao Xu Peng Wu State Key Laboratory of Petroleum Molecular&Process Engineering Shanghai Key Laboratory of Green Chemistry and Chemical ProcessesSchool of Chemistry and Molecular EngineeringEast China Normal UniversityShanghai 200062China

Epoxidation of propylene to propylene oxide(PO)with hydrogen peroxide(HPPO)is an environmentally friendly and cost-efficient process in which titanosilicates are used as ***-MWW is a potential industrial catalyst for this process,which involves the addition of HPPO to *** silanol groups generated during secondary crystallization unavoidably result in ring-opening of PO and inefficient decomposition of HPPO,which diminish the PO selectivity and the lifespan of *** address this issue,we conducted post-treatment modifications of the structured Bf-Ti-MWW catalyst with potassium fluoride aqueous *** quenching the silanol groups with potassium fluoride and implanting electron-withdrawing fluoride groups into the Ti-MWW framework,both the catalytic activity and HPPO utilization efficiency were ***,the ring opening reaction of PO was *** a continuous fixed-bed liquid-phase propylene epoxidation reaction,the KF-treated structured Ti-MWW catalyst displayed an exceptionally long lifespan of 2700 h,with a PO yield of 590 g·kg^(-1)·h^(-1).

关键词： titanosilicates Ti-MWW propylene epoxidation structured catalyst KF modification

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