Recently, the spar platform concept develops quickly in the offshore oil and gas exploitations, especially in deep and ultra-deep water, owing to its benign motion performance, excellent stability and adaptation to wi...Recently, the spar platform concept develops quickly in the offshore oil and gas exploitations, especially in deep and ultra-deep water, owing to its benign motion performance, excellent stability and adaptation to wide range of water depth. Many new spar concepts have been put forward with the purpose of reducing fabrication difficulty and cost, while meeting the requirements of exploitation in the meantime Based on the aims mentioned above, a new spar concept was presented in this article and its hydrodynamics both in operating and survival conditions was studied by means of numerical simulation. Basic model tests were also conducted to calibrate the numerical approach. Following aspects are highlighted: (1) new spar concept, (2) global performance of the spar concept and (3) mooring line analysis.展开更多
The coupled hull, mooring and riser analysis techniques in time domain are widely recognized as the unique approach to predict the accurate global motions. However, these complex issues have not been perfectly solved ...The coupled hull, mooring and riser analysis techniques in time domain are widely recognized as the unique approach to predict the accurate global motions. However, these complex issues have not been perfectly solved due to a large number of nonlinear factors, e.g. forces nonlinearity, mooring nonlinearity, motion nonlinearity and so on. This paper investigates the coupled effects through the numerical uncoupled model, mooring coupled model and fully coupled model accounting mooring and risers based on a novel deep draft multi-spar which is especially designed for deepwater in 2009. The numerical static-offset, free-decay, wind-action tests are executed, and finally three hours simulations are conducted under 100-year return period of GOM conditions involving wave, wind and current actions. The damping contributions, response characteristics and mooring line tensions are emphatically studied.展开更多
Riboswitches are highly conserved RNA elements that located in the 5’-UTR of m RNAs,which undergo real-time structure conformational change to achieve the regulation of downstream gene expression by sensing their cog...Riboswitches are highly conserved RNA elements that located in the 5’-UTR of m RNAs,which undergo real-time structure conformational change to achieve the regulation of downstream gene expression by sensing their cognate ligands.S-adenosylmethionine(SAM)is a ubiquitous methyl donor for transmethylation reactions in all living organisms.SAM riboswitch is one of the most abundant riboswitches that bind to SAM with high affinity and selectivity,serving as regulatory modules in multiple metabolic pathways.To date,seven SAM-specific riboswitch classes that belong to four families,one SAM/SAH riboswitch and one SAH riboswitch have been identified.Each SAM riboswitch family has a well-organized tertiary core scaffold to support their unique ligand-specific binding pocket.In this review,we summarize the current research progress on the distribution,structure,ligand recognition and gene regulation mechanism of these SAM-related riboswitch families,and further discuss their evolutionary prospects and potential applications.展开更多
A modern teaching support platform was designed based on application integration and the Nolan model. The system design used top-level design, information-sharing, management modeling, and user experience. The system ...A modern teaching support platform was designed based on application integration and the Nolan model. The system design used top-level design, information-sharing, management modeling, and user experience. The system emphasized openness, compatibility, security, extensibility, and practicability. Multi-department management is realized by dividing function domains. Intercommunications and intercon-nections use a level-division modular design, so the system can be easily extended. The teaching support platform is people oriented with people foremost environment for the users, the associated application environment, the integrated data environment, and the operating environment for high availability. The system plays an important role in university information construction.展开更多
This paper focuses on the research of a semi-submersible platform equipped with a DP-assisted mooring system. Based on the working principles of the DP-assisted mooring system and the model of the platform motion, a t...This paper focuses on the research of a semi-submersible platform equipped with a DP-assisted mooring system. Based on the working principles of the DP-assisted mooring system and the model of the platform motion, a time domain simulation program is applied to analyze the impact, in the case of one line failure, on the platform motion, power consumption of the thrusters and the tension of the mooring lines. The results show that, under the 10-year wind dominant, a one line failure will have little impact on the tension of the mooring lines. When the failure line is windward, the power consumption will increase greatly with a weakened position of accuracy. However when the failure line is leeward, the power consumption will be reduced with a partly strengthened oosition of accuracy.展开更多
In recent decades,materials science has experienced rapid development and posed increasingly high requirements for the characterizations of structures,properties,and performances.Herein,we report on our recent establi...In recent decades,materials science has experienced rapid development and posed increasingly high requirements for the characterizations of structures,properties,and performances.Herein,we report on our recent establishment of a multi-domain(energy,space,time)highresolution platform for integrated spectroscopy and microscopy characterizations,offering an unprecedented way to analyze materials in terms of spectral(energy)and spatial mapping as well as temporal evolution.We present several proof-of-principle results collected on this platform,including in-situ Raman imaging(high-resolution Raman,polarization Raman,low-wavenumber Raman),time-resolved photoluminescence imaging,and photoelectrical performance imaging.It can be envisioned that our newly established platform would be very powerful and effective in the multi-domain high-resolution characterizations of various materials of photoelectrochemical importance in the near future.展开更多
基金the Major Fundamental Research Program of Science and Technology Commission of Shanghai Municipality (Grant No. 05DJ14001)the National High Technology Research and Development Program of China (863 Program, Grant No. 2006AA09A107).
文摘Recently, the spar platform concept develops quickly in the offshore oil and gas exploitations, especially in deep and ultra-deep water, owing to its benign motion performance, excellent stability and adaptation to wide range of water depth. Many new spar concepts have been put forward with the purpose of reducing fabrication difficulty and cost, while meeting the requirements of exploitation in the meantime Based on the aims mentioned above, a new spar concept was presented in this article and its hydrodynamics both in operating and survival conditions was studied by means of numerical simulation. Basic model tests were also conducted to calibrate the numerical approach. Following aspects are highlighted: (1) new spar concept, (2) global performance of the spar concept and (3) mooring line analysis.
基金supported by the National High Technology Research and Development Program of China(863 Program,Grant Nos.2006AA09A103 and 2006AA09A104)
文摘The coupled hull, mooring and riser analysis techniques in time domain are widely recognized as the unique approach to predict the accurate global motions. However, these complex issues have not been perfectly solved due to a large number of nonlinear factors, e.g. forces nonlinearity, mooring nonlinearity, motion nonlinearity and so on. This paper investigates the coupled effects through the numerical uncoupled model, mooring coupled model and fully coupled model accounting mooring and risers based on a novel deep draft multi-spar which is especially designed for deepwater in 2009. The numerical static-offset, free-decay, wind-action tests are executed, and finally three hours simulations are conducted under 100-year return period of GOM conditions involving wave, wind and current actions. The damping contributions, response characteristics and mooring line tensions are emphatically studied.
基金supported by the National Natural Science Foundation of China(32022039,31870810,91940302,91640104)the National Key Research and Development Project of China(2021YFC2300300)+2 种基金the China Postdoctoral Science Foundation(2022M713637)the Outstanding Youth Fund of Zhejiang Province(LR19C050003)the Fundamental Research Funds for the Central Universities(2017QN81010)。
文摘Riboswitches are highly conserved RNA elements that located in the 5’-UTR of m RNAs,which undergo real-time structure conformational change to achieve the regulation of downstream gene expression by sensing their cognate ligands.S-adenosylmethionine(SAM)is a ubiquitous methyl donor for transmethylation reactions in all living organisms.SAM riboswitch is one of the most abundant riboswitches that bind to SAM with high affinity and selectivity,serving as regulatory modules in multiple metabolic pathways.To date,seven SAM-specific riboswitch classes that belong to four families,one SAM/SAH riboswitch and one SAH riboswitch have been identified.Each SAM riboswitch family has a well-organized tertiary core scaffold to support their unique ligand-specific binding pocket.In this review,we summarize the current research progress on the distribution,structure,ligand recognition and gene regulation mechanism of these SAM-related riboswitch families,and further discuss their evolutionary prospects and potential applications.
基金Supported by the National Education Promoting Program of China(No. 054500001)the Beijing Teaching Reformation and Research Program for Higher Education (No. 110000014)
文摘A modern teaching support platform was designed based on application integration and the Nolan model. The system design used top-level design, information-sharing, management modeling, and user experience. The system emphasized openness, compatibility, security, extensibility, and practicability. Multi-department management is realized by dividing function domains. Intercommunications and intercon-nections use a level-division modular design, so the system can be easily extended. The teaching support platform is people oriented with people foremost environment for the users, the associated application environment, the integrated data environment, and the operating environment for high availability. The system plays an important role in university information construction.
基金Suppirted by the Programme of Introducing Talents of Discipline to Universities(B07019)
文摘This paper focuses on the research of a semi-submersible platform equipped with a DP-assisted mooring system. Based on the working principles of the DP-assisted mooring system and the model of the platform motion, a time domain simulation program is applied to analyze the impact, in the case of one line failure, on the platform motion, power consumption of the thrusters and the tension of the mooring lines. The results show that, under the 10-year wind dominant, a one line failure will have little impact on the tension of the mooring lines. When the failure line is windward, the power consumption will increase greatly with a weakened position of accuracy. However when the failure line is leeward, the power consumption will be reduced with a partly strengthened oosition of accuracy.
基金supported by the National Key Research and Development Program of China(No.2016YFA0200602,No.2017YFA0303500,and No.2018YFA0208702)the National Natural Science Foundation of China(No.21573211,No.21633007,No.21803067,and No.91950207)+1 种基金the Anhui Initiative in Quantum Information Technologies(AHY090200)the USTC-NSRL Joint Funds(UN2018LHJJ).
文摘In recent decades,materials science has experienced rapid development and posed increasingly high requirements for the characterizations of structures,properties,and performances.Herein,we report on our recent establishment of a multi-domain(energy,space,time)highresolution platform for integrated spectroscopy and microscopy characterizations,offering an unprecedented way to analyze materials in terms of spectral(energy)and spatial mapping as well as temporal evolution.We present several proof-of-principle results collected on this platform,including in-situ Raman imaging(high-resolution Raman,polarization Raman,low-wavenumber Raman),time-resolved photoluminescence imaging,and photoelectrical performance imaging.It can be envisioned that our newly established platform would be very powerful and effective in the multi-domain high-resolution characterizations of various materials of photoelectrochemical importance in the near future.