Historical Research Materials on Zhou Zuoren in the Possession of his Family

departmental bulletin pape

Reliability Analysis Approach For Operations Planning Of Hydropower Systems

Many existing hydropower storage facilities were built decades ago and components of these aging infrastructure facilities have higher risk of failure. Insufficient capacity or forced outages of the spillway and other waterway passage facilities during flooding incident could potentially increase the probability of dam safety incidents leading to public safety concerns. Currently approaches used to assess the risk and uncertainty in operational decision making are mainly based on qualitative assessment and expert judgment and can be significantly improved by the development of a framework that formally incorporates both qualitative and quantitative reliability analysis methods. Event tree analysis and fault tree analysis have traditionally been used in dam safety risk analysis, with results subject to data adequacy and availability. Our research shows that other methods, such as nonparametric analysis and Monte Carlo simulation techniques can yield good results as well. This study investigated the application of reliability analysis methods to existing hydropower storage facilities, with the objective of developing a new systems engineering based approach for risk and uncertainty analysis to assess and manage the risks of hydropower system operations. Our approach integrates reliability-based methods with hydro system optimization modeling to develop an operational reliability-based modeling framework and to formally treat risk and uncertainty in operations planning. This approach incorporates different sources of uncertainty that are typically encountered in operations planning of these systems, including failure probability of hydro system components such as non-power release structures and turbine facilities. This paper presents the framework we have developed and illustrates the application of our investigation for a hydropower system facility in British Columbia, Canada

A Multi-Objective Optimization Model For Operations Planning Of Multi-Reservoir Systems

This paper presents the development and evaluation of a multi-objective linear programming (LP) optimization tool for an operations planning platform (OPP). The LP optimization model is coded using a high level programming language called AMPL (A Mathematical Programming Language) and solved using a solver called CPLEX. This model was developed by closely working with operations planning engineers at BC Hydro, in Canada, with the support of a research team from the University of British Columbia. The optimization model incorporates two objectives to optimize the operation of a multi reservoir system: maximize revenue from power generation, and to minimize penalties resulting from deviations of reservoir elevations and spill releases from a preferred operating regime. Several multi-objective optimization techniques are being investigated including traditional methods such as the Weighting Method and the Constraint Method, as well as Goal Programming (GP) techniques. These methods would be tested for optimality and computational efficiency and would be generalized and used to study a number of multi-reservoir systems in British Columbia. Stochastic inflows would be considered in the model making use of chance-constraints and probability distribution functions based on historical inflow records. The model also incorporates features which simulate maintenance outages on hydropower plants. The goal is to determine the optimal maintenance schedules that minimize the cost of these outages. We present results of a case study to illustrate the capabilities of the model to provide decision makers with timely information on trade-off between different objectives. Maintenance schedules of generating units with and without optimization are also considered

The barrier risk to the ecological connectivity of plant diversity in karst landscapes in Guizhou Province, China

Ecological connectivity in landscapes is crucial for plant diversity conservation. The barrier risk to ecological connectivity represents the risk to ecological connectivity loss or weakening, resulting from the barrier to biological information exchange among habitats. Therefore, clarifying the barrier risk to the ecological connectivity of plant diversity in space can reveal the spatial impacts of reduced ecological connectivity on plant diversity. This study analyzed effects of karst peak, river network, arable land, and impervious surface on plant diversity in karst natural, countryside, urban, and island landscapes in Guizhou Province with fragile environment. Then, we calculated the barrier distance of ecological connectivity to reveal the barrier risk to the ecological connectivity of plant diversity in space. The results showed that karst peak was the source of high plant diversity, and plant diversity could diffuse about 400 m around karst peaks. River network and arable land enhanced the connectivity among karst peaks to maintain plant diversity, and the effect on enhancing the connectivity was about 300 m and 450 m, respectively, while the weakening effect of impervious surface on connectivity was about 350 m. Based on the distance for plant diversity diffusing around karst peaks, the barrier distance of ecological connectivity was determined by the combination type of river network, arable land and impervious surface in landscapes. From low to high, the barrier risk to the ecological connectivity of plant diversity was about 1,110 m in the combination of river network and arable land, about 790 m in the combination of river network, arable land and impervious surface, about 520 min the combination of arable land and impervious surface, about 400 m in the combination of river network and impervious surface. Our findings clarify the barrier risk to the ecological connectivity of plant diversity in space, and provide a scientific basis for plant diversity conservation from the perspective of ecological connectivity

Capsaicin Protects Cardiomyocytes against Anoxia/Reoxygenation Injury via Preventing Mitochondrial Dysfunction Mediated by SIRT1

Capsaicin (Cap) has been reported to have beneficial effects on cardiovascular system, but the mechanisms underlying these effects are still poorly understood. Apoptosis has been shown to be involved in mitochondrial dysfunction, and upregulating expression of SIRT1 can inhibit the apoptosis of cardiomyocytes induced by anoxia/reoxygenation (A/R). Therefore, the aim of this study was to test whether the protective effects of Cap against the injury to the cardiomyocytes are mediated by SIRT1. The effects of Cap with or without coadministration of sirtinol, a SIRT1 inhibitor, on changes induced by A/R in the cell viability, activities of lactate dehydrogenase (LDH), creatine phosphokinase (CPK), levels of intracellular reactive oxygen species (ROS), and mitochondrial membrane potential (MMP), related protein expression, mitochondrial permeability transition pore (mPTP) opening, and apoptosis rate in the primary neonatal rat cardiomyocytes were tested. Cap significantly increased the cell viability, upregulated expression of SIRT1 and Bcl-2, and decreased the LDH and CPK release, generation of ROS, loss of MMP, mPTP openness, activities of caspase-3, release of the cytochrome c, and apoptosis of the cardiomyocytes. Sirtinol significantly blocked the cardioprotective effects of Cap. The results suggest that the protective effects of Cap against A/R-induced injury to the cardiomyocytes are involved with SIRT1

Case report: A novel 5'-UTR-exon1-intron1 deletion in MLYCD in an IVF child with malonyl coenzyme A decarboxylase deficiency and literature review

The subject of the study is an 11-month old IVF baby girl with the typical clinical manifestation of malonyl coenzyme A decarboxylase deficiency, including developmental delay, limb weakness, cardiomyopathy, and excessive excretion of malonic acid and methylmalonic acid. Whole genome sequencing (WGS) revealed a novel heterozygous nonsense mutation (c.672delG, p.Trp224Ter) in the MLYCD gene of the proband and her father and a novel heterozygous deletion in 5'-UTR-exon1-intron1 of the MLYCD gene of the proband and her mother. The patient's cardiac function and limb weakness improved considerably after 3 months of a low-fat diet supplemented with L-carnitine. Furthermore, mapping of gene mutations and clinical manifestations was done by case collection

Reliability-based hydro reservoir operation modeling

A wide variety of factors make reservoir operation a complex and dynamic problem, including multiple operational objectives, hydrological uncertainties and dam safety considerations. Concerns have grown in recent years regarding reliability of existing hydropower storage and discharge facilities, as many of these facilities are aging and their failure could significantly impact reservoir operations and pose threats to dam safety. A number of reliability methods were investigated in this study and a formal reliability analysis process has been adopted to assess the reliability of water release facilities using censored failure data. The nonparametric product-limit estimation method was used to analyze the time-dependent reliability of different types of spillway gates and hydropower turbines, and parametric model fitting techniques were subsequently applied to fit reliability functions. Failure and repair events were simulated using Monte Carlo simulation, which provided random variables to capture the uncertainty of availability for hydro facilities. The reliability analysis process was integrated into a simulation-optimization operations planning model to develop a reliability-based modeling framework that quantitatively treats risk and uncertainties in hydro operations. A specific reservoir system in British Columbia was selected as to illustrate the model application. Results and analyses provided guidelines for evaluating and comparing alternative reservoir operating plans that incorporate reliability assessment and failure simulation. It is demonstrated that dam overtopping is more likely to occur due to a simultaneous occurrence of high inflow events and spillway gate failures than being caused by an extreme inflow event. The presented work highlights the needs to systematically collect and archive reliability data and to conduct reliability analysis for hydropower water release facilities whenever new information and data become available.Applied Science, Faculty ofCivil Engineering, Department ofGraduat

周作人与冰心 : 早期冰心女士与我祖父的交往

前言 / 一、冰心入学美国威尓斯利女子学院以前(1922-1923) / ニ、冰心在美国求学期间(1923-1926) / 三、冰心留学回国后(1926-1939) / 四、结

Registration and Combined Adjustment for the Laser Altimetry Data and High-Resolution Optical Stereo Images of the GF-7 Satellite

The GF-7 satellite is China’s first civil sub-meter resolution stereo mapping satellite, aiming at 1:10,000-scale mapping. To achieve this goal, apart from the stereo optical cameras that reach sub-meter resolution, the GF-7 satellite is equipped with a laser altimetry system capable of obtaining three-dimensional laser points (LPs) with high elevation accuracy. However, the combination of laser altimetry data and optical stereo images has not been thoroughly studied. In this paper, we exploit the images recorded by the highly integrated laser footprint cameras and propose a hierarchical phase correlation method based on a geographic pyramid for the registration of laser altimetry data and high-resolution optical stereo images, which lays a solid foundation for the following combined adjustment. Experiments show that the proposed registration method can automatically locate the LPs on high-resolution stereo images and meet the requirements of bundle adjustment. A series of bundle adjustment experiments were carried out, showing that laser altimetry data can significantly enhance the vertical accuracy of optical image stereo mapping and that elevation accuracy can reach roughly 1.0 m (RSME) without ground control points. Therefore, this study could be a good guide for global high-precision DSM acquisition with the GF-7 satellite