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Line spectrum detection algorithm based on the phase feature of target radiated noise

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Journal of Systems Engineering and Electronics 2016年第1期27卷 72-80页

作者： Enming Zheng Huabing Yu Xinhua Chen changyu sun Institute of Acoustics Chinese Academy of Science

In order to improve the performance of line spectrum detection,according to the feature that the underwater target radiated noise containing stable line spectrum,the differences of the phase difference between line spectrum and background noise,a weighted line spectrum detection algorithm based on the phase variance is proposed in frequency *** phase difference alignment,the phase variance of line spectrum and the phase of background noise,respectively,are small and big in frequency domain,this method utilizes the weighted statistical algorithm to cumulate the frequency spectrum based on the phase variance,which can restrain the background noise disturbance,and enhance the signal to noise ratio（SNR）.The theory analysis and experimental results both verify that the proposed method can well enhance the energy of line spectrum,restrain the energy of background noise,and have better detection performance under lower SNR.

关键词： information processing underwater target detection line spectrum detection phase variance.

Thermal conductivity of hydrate and effective thermal conductivity of hydrate-bearing sediment

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Chinese Journal of Chemical Engineering 2024年第9期73卷 176-188页

作者： Cunning Wang Xingxun Li Qingping Li Guangjin Chen changyu sun State Key Laboratory of Heavy Oil Processing China University of Petroleum-BeijingBeijing 102249China State Key Laboratory of Natural Gas Hydrate CNOOC Research Institute Co.Ltd.Beijing 100027China

The research on the thermal property of the hydrate has recently made great progress,including the understanding of hydrate thermal conductivity and effective thermal conductivity(ETC)of hydratebearing *** thermal conductivity of hydrate is of great significance for the hydrate-related field,such as the natural gas hydrate exploitation and prevention of the hydrate plugging in oil or gas *** order to obtain a comprehensive understanding of the research progress of the hydrate thermal conductivity and the ETC of hydrate-bearing sediment,the literature on the studies of the thermal conductivity of hydrate and the ETC of hydrate-bearing sediment were summarized and reviewed in this ***,experimental studies of the reported measured values and the temperature dependence of the thermal conductivity of hydrate were discussed and ***,the studies of the experimental measurements of the ETC of hydrate-bearing sediment and the effects of temperature,porosity,hydrate saturation,water saturation,thermal conductivity of porous medium,phase change,and other factors on the ETC of hydrate-bearing sediment were discussed and ***,the research progress of modeling on the ETC of the hydrate-bearing sediment was *** thermal conductivity determines the heat transfer capacity of the hydrate reservoir and directly affects the hydrate exploitation *** efforts need to be devoted to obtain experimental data of the ETC of hydrate reservoirs and establish models to accurately predict the ETC of hydrate-bearing sediment.

关键词： Hydrate Thermal conductivity Hydrate-bearing sediment Preparation method Effective thermal conductivity Model

REAL—TIME AND GENERAL—PURPOSE TIME—COMPRESSED CORRELATOR

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Chinese Journal of Acoustics 1989年第3期8卷 193-197页

作者： Li, Qihu sun, Zeng sun, changyu Acad Sinica China

The time-compressed correlator has been widely applied in active sonar design since 1960's. The principles of DELTIC and MACORMATIC cannot be directly used in passive sonar due to the limitation of sampling frequency and data length. Otherwise the input data will be missed periodically in the system output. An Alternative Access Time-Compressed Correletor (ALATIC) is proposed in this paper. By using a buffer register the correlation operation of arbitrary length can be done in real time. This model is a general purpose correlator, which can be used in both active and passive sonars. The running positive order and inverse order register and the shift positive order and inverse order model are presented. The hardware implementation and the flow chart graph of ALATIC are also described. The model presented in this paper can be used in digital sonar design.

关键词： Computers Shift Registers Sonar Equipment

Clinical significance of miRNA-106a in non-small cell lung cancer patients who received cisplatin combined with gemcitabine chemotherapy

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Cancer Biology & Medicine 2018年第2期15卷 157-164页

作者： Ye Tian changyu sun Limeng Zhang Yuan Pan Department of Senior Ward Tianjin Medical University Cancer Institute and HospitalNational Clinical Research Center for CancerKey Laboratory of Cancer Prevention and TherapyTianjin Tianjin's Clinical Research Center for Cancer Tianjin 300060China Tianjin Taishan Cancer Hospital&International Personalized Cancer Center Tianjin 300450China

Objective：Research has demonstrated that microRNA（miR）-106a is related to cisplatin *** investigated the expression of miR-106a in the serum of patients with non-small cell lung cancer（NSCLC）and their sensitivity to chemotherapy by cisplatin combined with ***：Eighty-five NSCLC patients,who completed four cycles of gemcitabine and cisplatin chemotherapy,volunteered for this study and their serum samples were *** samples from 60 healthy subjects were used as ***-time quantitative polymerase chain reaction（real-time q PCR）was used to quantify the level of miR-106a in the *** and survival data of these patients were collected for the ***：The expression of miR-106a in the serum of NSCLC patients was significantly higher than that of healthy subjects（P＆lt;0.001）.The expression of miR-106a was not correlated with patients＇gender,age,tumor size,lymphatic metastasis,and pathological types;but was correlated with patients＇tumor staging（P=0.003）.After chemotherapy,serum miR-106a expression decreased in *** decrease in miR-106a expression in the chemotherapy-sensitive group was much higher than that in the chemotherapy-resistant *** analysis shows that NSCLC patients with high expression of miR-106a have a poorer *** overall survival of NSCLC patients in the chemotherapy-sensitive group was significantly higher than that in the chemotherapy-resistant ***：High expression of miR-106a may be involved in the development of *** R-106a has significance in the prognosis of *** level of miR-106a in the serum can be a useful parameter in screening for drug resistance during cisplatin-based chemotherapy.

关键词： MiRNA-106a NSCLC cisplatin gemcitabine chemotherapy resistant

Experimental investigation of methane hydrate decomposition by depressurizing in porous media with 3-Dimension device

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Journal of Natural Gas Chemistry 2010年第3期19卷 210-216页

作者： Kehua Su changyu sun Xin Yang Guangjin Chen Shuanshi Fan State Key Laboratory of Heavy Oil Processing China University of Petroleum Beijing102249 China School of Chemistry and Chemical Engineering South China University of Technology Guangzhou 510641 Guangdong China

In order to simulate the behavior of gas hydrate formation and decomposition,a 3-Dimension experimental device was built,consisting of a high-pressure reactor with an inner diameter of 300 mm,effective height of 100 mm,and operation pressure of 16 *** thermal resistances were mounted in the porous media at different depthes and radiuses to detect the temperature distribution during the hydrate formation/*** collect the pressure,temperature,and flux of gas production data,the Monitor and Control Generated System（MCGS） was *** this device,the formation and decomposition behavior of methane hydrate in the 20 ～ 40 mesh natural sand with salinity of 3.35 wt% was *** was found that the front of formation or decomposition of hydrate can be judged by the temperature *** amount of hydrate formation can also be evaluated by the temperature *** the hydrate decomposition process,the temperature curves indicated that the hydrate in the top and bottom of reactor dissociated earlier than in the *** hydrate decomposition front gradually moved from porous media surface to inner and kept a shape of column form,with different moving speed at different surface *** proper decomposition pressure was also determined.

关键词： gas hydrate three-dimension depressurizing produce porous media

Fundamental mechanisms and phenomena of clathrate hydrate nucleation

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Chinese Journal of Chemical Engineering 2019年第9期27卷 2014-2025页

作者： Jinlong Cui Zhenfeng sun Xiaohui Wang Bin Yu Shudong Leng Guangjin Chen changyu sun State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China China Ship Design&Research Center Co. Ltd.Dalian 116001China

Insights into the mechanism of hydrate nucleation are of great significance for the development of hydrate-based technologies,hydrate relevant flow assurance,and the exploration of in situ natural gas *** with the thermodynamics of hydrate formation,understanding the nucleation mechanism is challenging and has drawn substantial attention in recent *** this paper,we attempt to give a comprehensive review of the recent progress of studies of clathrate hydrate ***,the existing hypotheses on the hydrate nucleation mechanism are introduced and ***,we summarize recent experimental studies on induction time,a key parameter evaluating the velocity of the nucleation ***,the memory effect is particularly discussed,followed by the suggestion of several promising research perspectives.

关键词： Hydrate Nucleation Mechanism Induction time Memory effect

TBAB hydrate formation and growth in a microdevice under static and dynamic conditions

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Petroleum Science 2024年第2期21卷 1396-1404页

作者： Xingxun Li Ming Liu Qingping Li Weixin Pang Guangjin Chen changyu sun State Key Laboratory of Heavy Oil Processing China University of Petroleum BeijingBeijing102249China State Key Laboratory of Natural Gas Hydrate CNOOC Research Institute Co.Ltd.Beijing100027China

The natural gas hydrate has become one of the most promising future green energy sources on the *** natural gas hydrates mostly exist in the sediments with porous structure, so a solid understanding of the hydrate formation and growth processes in the porous medium is of significance for the exploitation of natural gas hydrate. The micro-packed bed device is one of the efficient microfluidic devices in the engineering field, but it has been rarely used for the hydrate-based research. In this study, a transparent micro-packed bed device filled with glass beads was developed to mimic the porous condition of sediments, and used to in-situ visualize the hydrate formation and growth habits in the pore spaces under both static and dynamic conditions. For the static experiment, two types of hydrate growth patterns in porous medium were observed and identified in the micro-packed bed device, which were the graincoating growth and pore-filling growth. For the dynamic condition, the hydrate formation, growth,distribution habits and hydrate blockage phenomena in the pore spaces were in-situ visually *** impacts of flowrate and subcooling on the pressure variation of the micro-packed bed and the duration of the hydrate growth under dynamic flow condition in pores were in-situ monitored and analyzed. The higher flowrate could result in the faster hydrate growth and more severe blockage in pores, but the effect of subcooling condition might be less significant at the high flowrate.

关键词： Hydrate formation Hydrate growth Microdevice In-situ measurement

Enhanced gas production and CO_(2) storage in hydrate-bearing sediments via pre-depressurization and rapid CO_(2) injection

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Chinese Journal of Chemical Engineering 2024年第3期67卷 126-134页

作者： Hongnan Chen Yifei sun Bojian Cao Minglong Wang Ming Wang Jinrong Zhong changyu sun Guangjin Chen State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China School of Chemistry and Chemical Engineering Changsha University of Science&TechnologyChangsha 410114China

Carbon emission reduction and clean energy development are urgent demands for mankind in the coming *** an efficient CO_(2) storage method can significantly reduce CO_(2) emissions in the short *** this study,we attempted to construct sediment samples with different residual CH_(4) hydrate amounts and reservoir conditions,and then investigate the potentials of both CO_(2) storage and enhanced CH_(4) recovery in depleted gas hydrate deposits in the permafrost and ocean zones,*** results demonstrate that CO_(2) hydrate formation rate can be significantly improved due to the presence of residual hydrate seeds;However,excessive residual hydrates in turn lead to the decrease in CO_(2) storage *** by the T-P conditions of the reservoir,the storage amount of liquid CO_(2) can reach 8 times that of gaseous CO_(2),and CO_(2) stored in hydrate form reaches 2-4 ***,we noticed two other advantages of this *** is that CO_(2) injection can enhance CH_(4) recovery rate and increases CH_(4) recovery by 10%-20%.The second is that hydrate saturation in the reservoir can be restored to 20%-40%,which means that the solid volume of the reservoir avoids serious ***,this is crucial for protecting the goaf *** summary,this approach is greatly promising for high-efficient CO_(2) storage and safe exploitation of gas hydrate.

关键词： Hydrate Depressurization CO_(2) storage CH_(4) production Reservoir remediation

A review: Enhanced recovery of natural gas hydrate reservoirs

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Chinese Journal of Chemical Engineering 2019年第9期27卷 2062-2073页

作者： Fengguang Li Qing Yuan Tianduo Li Zhi Li changyu sun Guangjin Chen Shandong Provincial Key Laboratory of Molecular Engineering Qilu University of Technology(Shandong Academy of Science)Jinan 250653China School of Chemistry and Chemical Engineering Liaocheng UniversityLiaocheng 252059China State Key Laboratory of Heavy Oil Processing China University of Petroleum Beijing 102249China

Natural gas hydrate(NGH)is a highly efficient and clean energy,with huge reserves and widespread distribution in permafrost and marine *** all over the world are committed to developing an effective exploring technology for NGH *** this paper,four conventional in-situ hydrate production methods,such as depressurization,thermal stimulation,inhibitor injection and CO2 replacement,are briefly *** to the limitations of each method,there has been no significantly breakthrough in hydrate exploring *** by the development of unconventional oil and gas fields,researchers have put forward some new hydrate production *** summarize the enhanced hydrate exploiting methods,such as CO2/N2–CH4 replacement,CO2/H2–CH4 replacement,hydraulic fracturing treatment,and solid exploration;and potential hydrate mining techniques,such as self-generating heat fluid injection,geothermal stimulation,the well pattern optimization of hydrate *** importance of reservoir stimulation technology for hydrate exploitation is emphasized,and it is believed that hydrate reservoir modification technology is a key to open hydrate resources exploitation,and the major challenges in the process of hydrate exploitation are pointed *** combination of multiple hydrate exploring technologies and their complementary advantages will be the development trend in the future so as to promote the process of hydrate industrialization.

关键词： Hydrate Exploration/exploitation Recovery Production Stimulation technology