Research on Comprehensive Control of Power Quality of Port Distribution Network Considering Large-Scale Access of Shore Power Load

In view of the problem of power quality degradation of port distribution network after the large-scale application of shore power load,a method of power quality management of port distribution network is proposed.Based on the objective function of the best power quality management effect and the smallest investment cost of the management device,the optimization model of power quality management in the distribution network after the large-scale application of large-capacity shore power is constructed.Based on the balance between the economic demand of distribution network resources optimization and power quality management capability,the power quality of distribution network is considered comprehensively.The proposed optimization algorithm for power quality management based on Matlab and OpenDSS is proposed and analyzed for port distribution networks.The simulation results show that the proposed optimizationmethod can maximize the power qualitymanagement capability of the port distribution network,and the proposed optimization algorithm has good convergence and global optimization finding capability.

关于《GB/T531.1-2008硫化橡胶或热塑性橡胶压入硬度试验方法邵氏硬度计法(邵尔硬度)》的解读

本文就许多企业、测量机构、人员在对橡胶制品的检测工作当中,依据或参照现行GB/531.1-2008时,所遇到一些问题,以及结合本人专业对标准理解在进行读解,以达到帮助相关部门、人员能掌握和应用标准。

老年性痴呆的遗传学研究

近年来,人口迅速增长,人的寿命普遍延长。目前,65岁以上老年人约占总人口的11％。在这些人中,痴呆患者高达15％,其中15～30％是可以治疗的。 Katzman(1976)估计65岁以上器质性痴呆中,Alzheimer病患病率为40～58％。Shore(1980)认为80岁以上的老年人中可能有20％的人患Alzheimer病。

Failure Envelopes of Wide-Shallow Composite Bucket Foundation for Offshore Wind Turbines in Silty Sand

The wide-shallow composite bucket foundation(WSCBF) is a new type of offshore wind power foundation that can be built on land and rapidly installed offshore, there by effectively reducing the construction time and costs of offshore wind power foundation. In this study, the horizontal bearing capacity is calculated by finite element simulation and compared with test results to verify the validity of results. In this process, the vertical load and bending load are respectively calculated by the finite element simulation. Under the vertical load effect, the bucket foundation and the soil inside are regarded as a whole, and the corresponding buckling failure mode is obtained. The ultimate vertical bearing capacity is calculated using empirical and theoretical formulas; the theoretical formula is also revised by finite element results. Under bending load, the rotational center of the composite bucket foundation(in a region close to the bucket bottom) gradually moves from the left of the central axis(reverse to loading direction) to the nearby compartment boards along the loading direction. The H–M envelope line shows a linear relationship, and it is determined that the vertical and bending ultimate bearing capacities can be improved by an appropriate vertical load.

Dynamic Ice-Induced Responses of Offshore Fixed Platforms

The dynamic responses of offshore fixed platforms under ice loads are analysed in this paper. The responses calculated include the displacement and the hot spot stresses on the basis of a dynamic equation of ice-induced forced vibration for offshore structures. The results obtained can be cited and used for the design and operation of offshore fixed platforms against ice loading.

THE EROSIONAL PROCESS OF THE SOFT SHORE OF CHINA IN THE RECENT DECADES

ＴＨＥ ＥＲＯＳＩＯＮＡＬ ＰＲＯＣＥＳＳ ＯＦ ＴＨＥ ＳＯＦＴ ＳＨＯＲＥ ＯＦ ＣＨＩＮＡ ＩＮ ＴＨＥ ＲＥＣＥＮＴ ＤＥＣＡＤＥＳ ＷａｎｇＷｅｎｈａｉ（王文海）；ＷｕＳａｎｇｙｕｎ（吴桑云）；ＸｉａＤｏｎｇｘｉｎｇ（夏东兴）（ＦｉｒｓｔＩ...

St. Lawrence Seaway: Navigation on Gulf of Saint Lawrence Estuary and the St. Lawrence River

The entire Great Lakes watershed drains through Lake Ontario and flows into the St. Lawrence River near Cape Vincent, New York. The St. Lawrence River then flows northeast through Quebec and Ontario and into the largest estuary in the world, the Gulf of Saint Lawrence. The St. Lawrence River, between Ontario, Canada and New York, United States is part of the international boundary. The St. Lawrence Seaway permits ocean-going vessels to go from the Great Lakes of North America to the Atlantic Ocean. Navigation of the St. Lawrence was not possible until canals were built around the Lachine Rapids near Montreal. The canals allowed ships to by-passes the rapids and travel into Lake Ontario. In 1954, the United States agreed to joint development of the international sections of the St. Lawrence River. The St. Lawrence Seaway was opened in 1959 and permits ocean-going ships to go all the way to the southwest corner of Lake Superior near Duluth, Minnesota. During WWII, German U-boats sank several merchant marine ships and three Canadian warships in the lower St. Lawrence River, the Strait of Belle Isle, Cabot Strait and the Gulf of Saint Lawrence. The bottom of the St. Lawrence River is littered with the wreckage of these ships and other ships which were lost during storms. The International Joint Commission recommended that the Canada and United States jointly improve navigation on the St. Lawrence River from Lake Ontario to Montreal. This lead to the signing of the St. Lawrence Treaty. Steel companies supported the treaties since the new St. Lawrence Seaway could get Labrador iron ore to the United States mills in the Great Lakes region. The Seaway’s power dams generate 3.5 million kilowatts of electricity which is provided to industry and to thousands of consumers in the New York State, New England and parts of Canada. The electric power generated by the project would be shared equally. This paper highlights how the geological and landscape properties of the St. Lawrence River watershed were responsible for the successful economic development of this important and historically-rich region of North America. Planned economic and urban development of the St. Lawrence River basin by USACE was blocked by the “Save the River” campaign. Environmental challenges include disposal of treated and untreated wastewater, water pollution, and shore erosion, invasive species and flooding.

高压岸电系统在40万t矿砂船上的应用

结合40万t矿砂船建造,对高压岸电系统的实船方案进行介绍,分析高压电缆型号及长度的选用,解读DNV-GL船级社"SHORE POWER"附加符号的特殊要求,基于船队航线考虑,提出优化40万t矿砂船的高压岸电系统方案的建议。

Three-dimensional numerical prediction of vertical temperature structure of the Huanghai and the Bohai Seas

In the paper, the sea is divided into two layers with density jumping, assuming that the physical parameters in each layer are independent of depth. Two-layer flow field with tide and wind currents is calculated with extended ADI method, after the calculation for flow field is stable , coupled with temperature diffusion equations and thermohaline depth prediction equation, a four-day time prediction of the surface, bottom temperature and thermohaline depth of the Huanghai and the Bohai Seas. At the same time, three dimensional temperature field of sea water is predicted through vertical temperature distribution function. The result indicates that the prediction quality of the whole model and the fitting degree between the predicted result and the measured values are satisfactory.

Effect of Sintering Temperature and Hydrophobic Treatment on the Microstructure and Properties of Copper-Graphite Composites

Copper-graphite composites were prepared by spark plasma sintering(SPS)using coppercoated graphite powder.Hydrophobic surfaces were successfully constructed by chemical etching and surface treatment.The density,metallographic structure,microstructure,Shore hardness,resistivity,water contact angle,and friction/wear properties of the composites were investigated using the Archimedes drainage method,a metallographic microscope,a scanning electron microscope,a hardness tester,a resistometer,a surface science tester,and a friction tester.The results showed that the relative density and Shore hardness of the copper-graphite composites increased slightly from 90.04%and 56 HSD to 92.66%and 59 HSD,respectively,when the sintering temperature increased from 700 to 900℃.The copper and graphite phases in the copper-graphite composites were uniformly distributed with a continuous and network-like structure at various sintering temperatures.The interface between the copper and graphite was in good condition,without any obvious cracks or voids.The optimum process for hydrophobic surface construction included etching with a 1 mol/L K_(2)Cr_(2)O_(7)-H_(2)SO_(4)solution for 1 min,and soaking in a 0.09 mol/L cetylbenzene sulfonic acid alcohol solution for 1 h.The contact angle of the copper-graphite composite reached 130°.Hydrophobic treatment was beneficial for reducing the friction coefficient(from 0.18-0.19 to 0.13-0.15)and the wear rate(from 4.1-6.2×10^(-3)to 1.1-2.1×10^(-3)mm^(3)/(N·m)),demonstrating obvious antifriction and wear-resisting properties.The resistivities of the hydrophobic-treated samples increased slightly,from(4-8)×10^(-7)Ω·m to(5-15)×10^(-7)Ω·m,meeting the resistivity requirements of copper-graphite composite pantograph sliders and current receiver sliders in actual working conditions.

Environmental Impact of Flooding in the Main (Smallwood) Reservoir of the Churchill Falls Power Plant, Labrador, Canada . III. Environmental Impact Zones and Direct and Indirect Changes.

The Churchill Falls Hydro Project (called the ‘Upper Churchill Development’) in Labrador [CF(L)Co], was initiated in the late 1960s. At that time, in general, not much attention was paid to the impact of such development on the flooding of vegetation, especially forest stands. Both forested and un-forested terrestrial vegetation types were flooded (244,915 ha creating some 74,075 ha of Islands) in the construction of the Main (Smallwood) Reservoir. The effect of flooding and of the constructions, both above and below the Main Reservoir major dyke system, were the subject of our investigation. This paper, the third in a series, reports on the effect of building the dykes during the early phases of construction with the descriptions of the post flooded conditions below the dykes as related to vegetation. The direct disturbances were excavations, fills, and partial and /or total removal of vegetation cover from fabrication platforms and from gravel and rock extraction sites. No new vegetation cover established in the abandoned quarries and gravel pits. However camp sites and manufacturing platforms were subsequently taken over by Alder growth. The indirect disturbances were the flooding of land areas and the de-watering of sections of the original river and lowering of the water level in some lakes. The results of flooding and the de-watering of some nearby areas are illustrated with aerial photographs and figures showing the environmental impact zones and new shore line development. The flooded trees in large and small pools of stagnant water died suddenly and remain in their original place. New vegetation cover developed on the exposed shore lines of de-watered rivers and lakes.

Managing the Chao Phraya River and Delta in Bangkok, Thailand: Flood Control, Navigation and Land Subsidence Mitigation

Land subsidence as a result of the groundwater withdrawals in the Chao Phraya Delta in Thailand will be studied along with any successful remediation efforts. Most of the deltas of South East Asia are sinking for a variety of reasons. Thailand has national concerns related to land subsidence as a result of sea level rise, climate change, flooding, storm surges, skyscrapers, compaction, and groundwater extraction for rice paddies, shrimp ponds and the drinking water and household needs of approximately 15 million people living on the Chao Phraya Delta. The Chao Phraya River shoreline line is eroding and significant land areas and wetlands are being lost and becoming open water. Urban areas are periodically flooded and require earthen levees or floodwalls. The objective is to assess and mitigate land subsidence as a result of groundwater withdrawals for rice paddies, aquaculture, shrimp ponds, industry, drinking water and household needs of 15 million people living on Chao Phraya Delta in Bangkok. The impact of groundwater extraction and reduced sedimentation on land subsidence in the Chao Phraya Delta will be assessed and mitigation methods recommended. Lessons learned and successful remediation efforts in one Southeast Asia delta may or may not be applicable to other South East Asia deltas. There need to be mitigation methods identified to add sediment to existing Chao Phraya Delta wetlands. River water also needs to be injected deep into the underlying alluvial sediments in the delta. Navigation in the canal systems could be adversely affected by proposed massive Chao Phraya River water injections into the Chao Phraya Delta alluvial sediments underlying Bangkok.

Hybrid Composite Based on Natural Rubber Reinforced with Short Fibers of the Triumfetta cordifolia/Saccharum officinarum L.: Performance Evaluation

This article contributes to the development of the new class of fully biodegradable “green” composites by combining fibers (natural/bio) with biodegradable resin. The vegetable fibers (Triumfetta cordifolia and sugarcane bagasse) treated with NaOH and bleached were incorporated into a natural rubber matrix. The influence of the fiber ratio on the physical properties, tensile strength and surface hardness of the hybrid composites was analyzed. The results show that the addition of fibers in the natural rubber matrix increases the water absorption capacity but gradually reduces it with increasing fiber ratio. The hybrid composites of the NRT50-50B proportions show the best tensile strengths at 20 phr and a shore A hardness of 43.7 at 30 phr. The combination of two fibers has improved the physical and mechanical properties of the hybrid composites which can be used in engineering applications.

The Legend of Sleepy Hollow

Part Ⅰ On the Eastern shore of the Hudson River there was a little valley, among high hills, which was one of the quietest places in the whole world. This little valley had long been known by the name of SIeepy Hollow. Many strange stories about ghosts were told and retold in the village situated there.

Spotlights(2015. 06-07)

JUNE,2015China Eyes Better Public Service,Stability at Rural Community China is pushing for greater stability and better public services at the country’s vast rural regions in a bid to shore up lagging civil service and advance urban-rural integration.In a guidance document on advancing rural community establishment co-issued by the general offices of the Communist Party of China Central Committee and the State Council,

碎片之路

'由于塑料的出现,海玻璃--被沙砾和海水冲刷得亮晶晶的古老玻璃瓶的碎片越来越稀有了.'马莉-贝丝·波克(北美海玻璃协会会长)说,'海玻璃是很久以前落在海里的玻璃碎片经过海水和泥沙的冲刷而形成的.……

Spatial distribution and structure of benthic polychaete communities of Essaouira intertidal rocky shores(Atlantic coast of Morocco)

Polychaetes are one of the most important groups ofmacrobenthic organisms in coastal and marine environments,in terms of diversity and abundance,and play an important role in the functioning of ecosystem.This study aims to describe the structure and spatial distribution ofpolychaete communities along Essaouira's rocky shoreline(Atlantic coast of Morocco)in relation to the major environmental variables such as granulometry,salinity,temperature,pH,and intertidal range.Twelve sites from these intertidal rocky shores were sampled using a quadrat method during the summer 2016.A total of 4435 individuals belonging to 34 taxa were recorded.Among the families,Sabellaridae(24%)and Nereididae(23%)were ranked first in terms of abundance of individuals.Sabellaria alveolata(24%)and Perinereis cultrifera(13%)were the dominant species.Diversity(H')values varied from 2.28 to 3.95.Pielou's index(J')varied between 0.62 and 0.89.This was essentially due to the low dominance of few species.Cluster analysis was used to characterise Essaouira's rocky shores on the basis of benthic polychaete communities.SIMPER analysis confirmed the presence of three distinct communities.According to canonical correspondence analysis,the structure and distribution of faunal assemblages of benthic polychaetes was mainly related to topographical complexity,water temperature,hydrodynamic conditions and upwelling.We conclude that these rocky shores show typically high benthic polychaete diversity compared to the taxonomic list of other rocky coasts.In addition,these results constitute a baseline data for the development of a sustainable network for long-term monitoring of benthic polychaete community changes due to ecological factor influences and anthropogenic activity impacts.

BIOGEOGRAPHY AND PHYLOGENY OF THE SEA-SKATER HALOBATES

Members of the genus Halobates are the only insects to be found in the open oceans .generally roughly between latitudes 40°N and 40°S . Of the 40 - odd species , only five (Halobates means. H- sericeus. H. germanus. H . sobrinus and H. splendens tare pelagic 】 the others being found in near - shore habitats . often endemic to islands or island groups. H. means is the only cosmopolitan species, being found in the Atlantic . Pacific and Indian Oceans . All five species are found in the Pacific Ocean but only two , Halobates means and Halobates germanus. occur also in the Indian Ocean .Their ranges of distribution are probably limited by physical as well as historical factors .Halobates probably originated from a near - shore brackish - water ancestor in the Indo - Malaysian region . This is the area where the majority of the near - shore sea - skater species are found ;it is also where related brackish - water genera (Asclepios , etc . )occur . There are indications that the open - ocean H alobates

MORPHOLOGY, SEDIMENTARY BEDFORMS AND SAND TRANSPORT ACROSS A RIDGE-AND-RUNNEL BEACH UNDER THE ACTION OF SUMMER WAVES

As part of a collaborative study between the 3rd Institute of Oceanography, Xiamen, and the U-K. Universities of East Anglia and St. Andrews, a 4-day experiment was conducted on a ridge- and -runnel beach of north Norfolk on the North Sea coast- Detailed surveys were made of every low water of an area 10m by 30m and electromagnetic current meters were used to measure wave- induced currents over the ridge and in the runnel- The locations of bedform fields were noted, fluorescent sand was used to follow the sand movement and, at the end of the experiment, lacquer peels were taken of the top 0-2 m of a vertical section through the ridge- and- runnel-During the 4 days 0-75 m3 of sand per metre width of beach accreted in the runnel and a similar volume was eroded from the upper foreshore. The dominant shoreward transport, identified qualitatively by the movement of the fluorescent sand, suggests the ridge- and- runnel system migrated shorewards up the general beach slope of 1 by 2 - 3 m. The wave orbital

Lake Shore低温传感器应用研究

Lake Shore低温传感器是由美国Lake Shore公司生产,类型多,应用广,其可靠性以及测量精确度等都比较高,具有较突出的温度测量应用优势。本文以该公司DT 670低温传感器为例,从该低温传感器的测温原理以及特征、封装校准、安装等方面,对其在实际温度测量中的应用进行研究和分析。