The Class-Ⅲ oil reservoirs of Lasaxing oilfield in the Daqing Oil Fields complex have geological oil reserves of 1.86 billion tonnes,an oil recovery of 39%,with remaining reserves accounting for more than 45%of the t...The Class-Ⅲ oil reservoirs of Lasaxing oilfield in the Daqing Oil Fields complex have geological oil reserves of 1.86 billion tonnes,an oil recovery of 39%,with remaining reserves accounting for more than 45%of the total geological reserves of the oilfield.Therefore,they have considerable potential for future oil production.The current layered injection technologies fail to achieve effective control over the low single-layer injection rates since they can only produce low throttle differential pressure under low injection rates(5-20 m^(3)/d).In this study,a symmetrically-structured double-offset-hole injection allocator and a novel throttling component were developed.Their spatial layout was constructed and mechanical parameters were optimized using finite element analysis,which allows for expanding the flow rate range at low injection rates.According to experimental results,the throttle differential pressure increased from 0.2 MPa to 0.8 MPa at an injection rate of 5 m^(3)/d,and the range of the single-layer flow rates expanded from 20-70 m^(3)/d to 5-70 m3/d.The field test results show that the effective production of oil layers with medium and low permeability was achieved and that the ratio of producing oil layer thickness to the total reservoir thickness increased by 9.7%on average.Therefore,this study provides valuable technical support for the effective chemical-flooding-based development of Class-Ⅲ oil reservoirs.展开更多
Secure control against cyber attacks becomes increasingly significant in cyber-physical systems(CPSs).False data injection attacks are a class of cyber attacks that aim to compromise CPS functions by injecting false d...Secure control against cyber attacks becomes increasingly significant in cyber-physical systems(CPSs).False data injection attacks are a class of cyber attacks that aim to compromise CPS functions by injecting false data such as sensor measurements and control signals.For quantified false data injection attacks,this paper establishes an effective defense framework from the energy conversion perspective.Then,we design an energy controller to dynamically adjust the system energy changes caused by unknown attacks.The designed energy controller stabilizes the attacked CPSs and ensures the dynamic performance of the system by adjusting the amount of damping injection.Moreover,with the disturbance attenuation technique,the burden of control system design is simplified because there is no need to design an attack observer.In addition,this secure control method is simple to implement because it avoids complicated mathematical operations.The effectiveness of our control method is demonstrated through an industrial CPS that controls a permanent magnet synchronous motor.展开更多
Objective: To assess the secondary sex ratio (SSR) of assisted reproduction technology babies within a fertility clinic in Melbourne, Australia. Methods: A retrospective cohort study was conducted on 3369 babies who w...Objective: To assess the secondary sex ratio (SSR) of assisted reproduction technology babies within a fertility clinic in Melbourne, Australia. Methods: A retrospective cohort study was conducted on 3369 babies who were born following single embryo transfer between 2011 and 2016. Variables examined included embryo creation date, maternal and paternal ages, maternal body mass index (BMI), type of infertility, sperm parameters, fertilization method, type of embryo and stage of transfer. Multivariate regression analysis was performed on the data set using STRATA V9.2. Results: More males were found to be born to embryos created in summer (adjusted odds ratio=1.46, 95% confidence interval: 1.08-1.95;P=0.01). Lower BMI of mother (≤30 kg/m 2) and younger age of parents (≤35 years) were associated with an increase in SSR (50.1% vs. 47.1%;50.6% vs. 48.8%;50.0% vs. 48.9%) respectively. Decreased SSR value was associated with primary subfertility, using in-vitro fertilization procedure and fresh embryo compared to those with secondary subfertility, using intracytoplasmic sperm injection procedure and thawed embryo (49.3% vs. 50.6%;47.1% vs. 50.8%;49.4% vs. 50.1%) respectively. Conclusions: The fertilization methods, type of embryo, stage of embryo transfer, parameters of the sperm and status of subfertility do not significantly affect the SSR. SSR is affected by the seasonality, maternal age, and BMI.展开更多
Ultrasonic seismic model experiment plays an important role in engineering multi wave seismic prospecting(EMSP), which has been used to do the complex engineering seismic exploration. It is introduced that the applic...Ultrasonic seismic model experiment plays an important role in engineering multi wave seismic prospecting(EMSP), which has been used to do the complex engineering seismic exploration. It is introduced that the application of the technology in quality test of Yongjiang river submarine tunnel tube foundation in the paper. The material of the model was got from on the spot. The successful test has been made with results of the model experiment.展开更多
Objective:To investigate the incidence of neonatal birth defects in assisted reproductive technology(ART)by in vitro fertilization(IVF)and intracytoplasmic sperm injection(ICSI).Methods:The clinical data of 4229 cases...Objective:To investigate the incidence of neonatal birth defects in assisted reproductive technology(ART)by in vitro fertilization(IVF)and intracytoplasmic sperm injection(ICSI).Methods:The clinical data of 4229 cases of singleton deliver by infertile patients under 35 years old who received IVF/ICSI-ET in our center were analyzed.According to different fertilization methods,they were divided into IVF group(2967 cases)and ICSI group(1262 cases).The general situation of birth,birth defects and the location of defects were compared between the two groups.Results:a total of 38 cases of neonatal birth defects were found,the incidence of birth defects was 0.89%,including 30 cases(1.01%)in IVF group and 8 cases(0.64%)in ICSI group.There was no significant difference in the incidence of birth defects between the two groups(P>0.05).There was also no significant difference in birth weight,gestational age and gender ratio between the two groups(P>0.05).Conclusion:Different fertilization methods in assisted reproductive technology do not increase the incidence of neonatal birth defects.展开更多
BZ Oilfield is a medium-sized oilfield with shallow delta facies deposits in Bohai Bay of China,compared with fluvial and delta facies oilfields,there is no mature experience for reference of reservoir configuration,w...BZ Oilfield is a medium-sized oilfield with shallow delta facies deposits in Bohai Bay of China,compared with fluvial and delta facies oilfields,there is no mature experience for reference of reservoir configuration,well pattern arrangement and development model in offshore oilfields in China.In view of the difficulty in describing the reservoir configuration of shallow water delta,the single distributary sand dam in shallow water delta is characterized by well-seismic combination and multi-attribute constraints.The mathematical mechanism model of pinch-out position of sand body is established,fine characterization of BZ shallow water delta reservoir is put forward.The horizontal well pattern arrangement type for shallow water delta reservoir is proposed and the method of well pattern optimization based on vertical displacement theory is put forward.A method of inversion of reservoir connectivity using production dynamic data by numerical well testing is proposed and a new method for optimizing water injection rate in water injection wells is proposed aiming at the difficulty of recognizing injection-production connectivity of shallow water delta reservoirs.The fine configuration of BZ shallow water delta reservoir based on distributary sand dam is proposed,which guides the recognition of remaining oil distribution law.By deploying adjustment wells,the water flooding coincidence degree of actual drilling is 86% compared with that of pre-drilling prediction,which indicates that the research results of reservoir configuration can effectively guide the understanding of oilfield geology.Through the theoretical well arrangement type of vertical displacement of single sand body in horizontal wells of shallow water delta reservoir,a high water flooding recovery rate of 35% is achieved in primary well pattern.The connectivity coefficients of injection-production boundary of shallow water delta reservoir configuration are calculated,and the water injection distribution coefficients are obtained by normalizing the directional coefficients.This paper presents a configuration method based on multi-attribute fusion under the constraints of sedimentary process.In this paper,a shallow water delta reservoir configuration method based on multi-attribute fusion constrained by sedimentary process is proposed,and the injection-production connectivity coefficient and injection well distribution coefficient of the configuration boundary are calculated.展开更多
In this article,an adaptive security control scheme is presented for cyber-physical systems(CPSs)suffering from false data injection(FDI)attacks and time-varying state constraints.Firstly,an adaptive bound estimation ...In this article,an adaptive security control scheme is presented for cyber-physical systems(CPSs)suffering from false data injection(FDI)attacks and time-varying state constraints.Firstly,an adaptive bound estimation mechanism is introduced in the backstepping control design to mitigate the effect of FDI attacks.Secondly,to solve the unknown sign time-varying statefeedback gains aroused by the FDI attacks,a type of Nussbaum function is employed in the adaptive security control.Then,by constructing a barrier Lyapunov function,it can be ensured that all signals of controlled system are bounded and the time-varying state constraints are not transgressed.Finally,the provided simulation examples demonstrate the effectiveness of the proposed controller.展开更多
检索PubMed、Web of Science、中国知网等数据库中有关喉返神经损伤(RLNI)在甲状腺手术中的研究。关键词包括喉返神经修复、注射喉成形术、Ⅰ型甲状腺成形术、杓状软骨内收术、神经组织工程技术等。总结和比较目前RLNI的常见治疗方法。...检索PubMed、Web of Science、中国知网等数据库中有关喉返神经损伤(RLNI)在甲状腺手术中的研究。关键词包括喉返神经修复、注射喉成形术、Ⅰ型甲状腺成形术、杓状软骨内收术、神经组织工程技术等。总结和比较目前RLNI的常见治疗方法。结果显示,喉返神经直接缝合是目前修复的首选术式,颈袢-喉返神经吻合术最常用于临床,其他修复方式各有其优、缺点。大多数治疗方法可在一定程度上获得不同的效果,但仍存在需进一步克服的缺点。此外神经组织工程技术及中医康复治疗值得进一步探索关注。展开更多
基金sponsored by the key consulting project of the Chinese Academy of Engineering entitled Research on the Sustainable Development Strategy of China's High Water-cut Old Oilfields(No.2019-XZ-15)the National major project entitled Large Oil and Gas Field and Coalbed Methane Development(No.:2016ZX05010006).
文摘The Class-Ⅲ oil reservoirs of Lasaxing oilfield in the Daqing Oil Fields complex have geological oil reserves of 1.86 billion tonnes,an oil recovery of 39%,with remaining reserves accounting for more than 45%of the total geological reserves of the oilfield.Therefore,they have considerable potential for future oil production.The current layered injection technologies fail to achieve effective control over the low single-layer injection rates since they can only produce low throttle differential pressure under low injection rates(5-20 m^(3)/d).In this study,a symmetrically-structured double-offset-hole injection allocator and a novel throttling component were developed.Their spatial layout was constructed and mechanical parameters were optimized using finite element analysis,which allows for expanding the flow rate range at low injection rates.According to experimental results,the throttle differential pressure increased from 0.2 MPa to 0.8 MPa at an injection rate of 5 m^(3)/d,and the range of the single-layer flow rates expanded from 20-70 m^(3)/d to 5-70 m3/d.The field test results show that the effective production of oil layers with medium and low permeability was achieved and that the ratio of producing oil layer thickness to the total reservoir thickness increased by 9.7%on average.Therefore,this study provides valuable technical support for the effective chemical-flooding-based development of Class-Ⅲ oil reservoirs.
基金supported in part by the National Science Foundation of China(61873103,61433006)。
文摘Secure control against cyber attacks becomes increasingly significant in cyber-physical systems(CPSs).False data injection attacks are a class of cyber attacks that aim to compromise CPS functions by injecting false data such as sensor measurements and control signals.For quantified false data injection attacks,this paper establishes an effective defense framework from the energy conversion perspective.Then,we design an energy controller to dynamically adjust the system energy changes caused by unknown attacks.The designed energy controller stabilizes the attacked CPSs and ensures the dynamic performance of the system by adjusting the amount of damping injection.Moreover,with the disturbance attenuation technique,the burden of control system design is simplified because there is no need to design an attack observer.In addition,this secure control method is simple to implement because it avoids complicated mathematical operations.The effectiveness of our control method is demonstrated through an industrial CPS that controls a permanent magnet synchronous motor.
文摘Objective: To assess the secondary sex ratio (SSR) of assisted reproduction technology babies within a fertility clinic in Melbourne, Australia. Methods: A retrospective cohort study was conducted on 3369 babies who were born following single embryo transfer between 2011 and 2016. Variables examined included embryo creation date, maternal and paternal ages, maternal body mass index (BMI), type of infertility, sperm parameters, fertilization method, type of embryo and stage of transfer. Multivariate regression analysis was performed on the data set using STRATA V9.2. Results: More males were found to be born to embryos created in summer (adjusted odds ratio=1.46, 95% confidence interval: 1.08-1.95;P=0.01). Lower BMI of mother (≤30 kg/m 2) and younger age of parents (≤35 years) were associated with an increase in SSR (50.1% vs. 47.1%;50.6% vs. 48.8%;50.0% vs. 48.9%) respectively. Decreased SSR value was associated with primary subfertility, using in-vitro fertilization procedure and fresh embryo compared to those with secondary subfertility, using intracytoplasmic sperm injection procedure and thawed embryo (49.3% vs. 50.6%;47.1% vs. 50.8%;49.4% vs. 50.1%) respectively. Conclusions: The fertilization methods, type of embryo, stage of embryo transfer, parameters of the sperm and status of subfertility do not significantly affect the SSR. SSR is affected by the seasonality, maternal age, and BMI.
文摘Ultrasonic seismic model experiment plays an important role in engineering multi wave seismic prospecting(EMSP), which has been used to do the complex engineering seismic exploration. It is introduced that the application of the technology in quality test of Yongjiang river submarine tunnel tube foundation in the paper. The material of the model was got from on the spot. The successful test has been made with results of the model experiment.
基金Major Science and Technology Project of Hainan Province(No.ZDKJ2017007)Key Research and Development Project of Hainan Provincial Science and Technology Department(No.ZDYF2019158)Scientific Research Project of Health and Family Planning Industry in Hainan Province(No.19A200124)。
文摘Objective:To investigate the incidence of neonatal birth defects in assisted reproductive technology(ART)by in vitro fertilization(IVF)and intracytoplasmic sperm injection(ICSI).Methods:The clinical data of 4229 cases of singleton deliver by infertile patients under 35 years old who received IVF/ICSI-ET in our center were analyzed.According to different fertilization methods,they were divided into IVF group(2967 cases)and ICSI group(1262 cases).The general situation of birth,birth defects and the location of defects were compared between the two groups.Results:a total of 38 cases of neonatal birth defects were found,the incidence of birth defects was 0.89%,including 30 cases(1.01%)in IVF group and 8 cases(0.64%)in ICSI group.There was no significant difference in the incidence of birth defects between the two groups(P>0.05).There was also no significant difference in birth weight,gestational age and gender ratio between the two groups(P>0.05).Conclusion:Different fertilization methods in assisted reproductive technology do not increase the incidence of neonatal birth defects.
文摘BZ Oilfield is a medium-sized oilfield with shallow delta facies deposits in Bohai Bay of China,compared with fluvial and delta facies oilfields,there is no mature experience for reference of reservoir configuration,well pattern arrangement and development model in offshore oilfields in China.In view of the difficulty in describing the reservoir configuration of shallow water delta,the single distributary sand dam in shallow water delta is characterized by well-seismic combination and multi-attribute constraints.The mathematical mechanism model of pinch-out position of sand body is established,fine characterization of BZ shallow water delta reservoir is put forward.The horizontal well pattern arrangement type for shallow water delta reservoir is proposed and the method of well pattern optimization based on vertical displacement theory is put forward.A method of inversion of reservoir connectivity using production dynamic data by numerical well testing is proposed and a new method for optimizing water injection rate in water injection wells is proposed aiming at the difficulty of recognizing injection-production connectivity of shallow water delta reservoirs.The fine configuration of BZ shallow water delta reservoir based on distributary sand dam is proposed,which guides the recognition of remaining oil distribution law.By deploying adjustment wells,the water flooding coincidence degree of actual drilling is 86% compared with that of pre-drilling prediction,which indicates that the research results of reservoir configuration can effectively guide the understanding of oilfield geology.Through the theoretical well arrangement type of vertical displacement of single sand body in horizontal wells of shallow water delta reservoir,a high water flooding recovery rate of 35% is achieved in primary well pattern.The connectivity coefficients of injection-production boundary of shallow water delta reservoir configuration are calculated,and the water injection distribution coefficients are obtained by normalizing the directional coefficients.This paper presents a configuration method based on multi-attribute fusion under the constraints of sedimentary process.In this paper,a shallow water delta reservoir configuration method based on multi-attribute fusion constrained by sedimentary process is proposed,and the injection-production connectivity coefficient and injection well distribution coefficient of the configuration boundary are calculated.
基金Funds of National Science of China(Grant no.61973146,62173172,61833001)the Doctoral Research Initiation of Foundation of Liaoning Province(No.20180540047)the Distinguished Young Scientific Research Talents Plan in Liaoning Province(No.XLYC1907077,JQL201915402).
文摘In this article,an adaptive security control scheme is presented for cyber-physical systems(CPSs)suffering from false data injection(FDI)attacks and time-varying state constraints.Firstly,an adaptive bound estimation mechanism is introduced in the backstepping control design to mitigate the effect of FDI attacks.Secondly,to solve the unknown sign time-varying statefeedback gains aroused by the FDI attacks,a type of Nussbaum function is employed in the adaptive security control.Then,by constructing a barrier Lyapunov function,it can be ensured that all signals of controlled system are bounded and the time-varying state constraints are not transgressed.Finally,the provided simulation examples demonstrate the effectiveness of the proposed controller.
文摘检索PubMed、Web of Science、中国知网等数据库中有关喉返神经损伤(RLNI)在甲状腺手术中的研究。关键词包括喉返神经修复、注射喉成形术、Ⅰ型甲状腺成形术、杓状软骨内收术、神经组织工程技术等。总结和比较目前RLNI的常见治疗方法。结果显示,喉返神经直接缝合是目前修复的首选术式,颈袢-喉返神经吻合术最常用于临床,其他修复方式各有其优、缺点。大多数治疗方法可在一定程度上获得不同的效果,但仍存在需进一步克服的缺点。此外神经组织工程技术及中医康复治疗值得进一步探索关注。