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海洋工程 2013年第2期31卷 28-34页

作者：肖飞杨和振卢其进张黎邦上海交通大学船舶海洋与建筑工程学院海洋工程国家重点实验室上海200240 mediterranean shipping company kenny HoustonTX77084USA

研究了涡激力作用导致顶张力立管基于双频激励的参量共振机理。随着海洋油气开发走向深水,参量共振成为深海立管设计面临的挑战之一。立管系统一旦发生参量共振,将因应力过大或疲劳损伤而发生破坏,造成油气泄漏从而带来环境污染和重大... 详细信息

研究了涡激力作用导致顶张力立管基于双频激励的参量共振机理。随着海洋油气开发走向深水,参量共振成为深海立管设计面临的挑战之一。立管系统一旦发生参量共振,将因应力过大或疲劳损伤而发生破坏,造成油气泄漏从而带来环境污染和重大经济损失。顶张力立管受涡激力作用产生横向运动,引起轴向张力波动,满足一定条件时,立管将发生参量共振。目前研究多以单频外激励探讨立管的马修不稳定性,而实际激励为多频叠加,因此双频外激励被提出并被应用于对立管参量稳定性的探讨。研究建立了顶张力立管非线性耦合的运动方程,并推导了多频激励马修方程,采用布勃诺夫-伽辽金法求解有阻尼马修方程,对比分析了单频和双频激励对顶张力立管参量稳定性的影响,探讨了双频激励马修方程设计深海顶张力立管参量稳定性的应用。研究表明:涡激致顶张力立管产生轴向应力波动,进而导致立管系统发生参量共振的现象值得设计人员关注;此外,实际工程设计中激励函数的选取,对被研究系统参量稳定性特性以及阻尼特性的预测具有决定性影响。

关键词：涡激力顶张力立管参量共振马修方程双频激励阻尼

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Impact of travel speed on the microstructure and mechanical properties of adjustable-gap bobbin-tool friction stir welded Al–Mg joints

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International Journal of Minerals,Metallurgy and Materials 2021年第4期28卷 710-717页

作者： Dong Wu Wen-ya Li Yan-jun Gao Jun Yang Quan Wen Nektarios Vidakis Achillefs Vairis State Key Laboratory of Solidification Processing Shaanxi Key Laboratory of Friction Travel TechnologiesNorthwestern Polytechnical UniversityXi'an 710072China Capital Aerospace Machinery company Beijing 100076China Department of Mechanical Engineering Hellenic Mediterranean UniversityHeraklionCrete 71004Greece

The butt welds of 4-mm thick 5A06 aluminum alloy plates were produced by adjustable-gap bobbin-tool friction stir travel with travel speeds of 200, 300, and 400 mm/min in this *** microstructure was studied using optical microscopy and electron backscatter diffraction(EBSD).Tensile tests and microhardness measurements were performed to identify the effect of the travel speed on the joint mechanical *** joints were obtained at 200 mm/min while voids were present at different positions of the joints as the travel speed *** EBSD results show that the grain size, high angle grain boundaries, and density of geometrically necessary dislocations in different regions of the joint vary depending on the recovery and recrystallization *** attention was given to the relationship between the local microstructure and mechanical *** measurements show that the average hardness of the stir zone(SZ) was greater than that of the base material, which was only affected slightly by the travel *** tensile strength of the joint decreased with increasing travel speed and the maximal strength efficiency reached 99%.

关键词： friction stir welding bobbin-tool aluminum alloy microstructure mechanical properties adjustable-gap

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Physiological traits contributed to the recent increase in yield potential of winter wheat from Henan Province, China

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Journal of Integrative Plant Biology 2014年第5期56卷 492-504页

作者： Bangwei Zhou álvaro Sanz-Sáez Abdelhalim Elazab Tianmin Shen Rut Sánchez-Bragado Jordi Bort Maria Dolors Serret José Luis Araus Unit of Plant Physiology Faculty of Biology University of Barcelona Henan Tianmin Seed company Lankao County Department of Plant Biology University of Illinois Urbana-Champaign

This experiment aims to test the traits responsible for the increase in yield potential of winter wheat released in Henan Province, China. Seven established cultivars released in the last 20 years and three advanced lines were assayed. The results showed that grain yield was positively correlated with harvest index（HI）, kernel number per square meter, and aboveground biomass. In addition, the HI and aboveground biomass showed an increasing trend with the year of ***, we can conclude that bread wheat breeding advances during recent decades in Henan Province, China,have been achieved through an increase in HI, kernel number per square meter, and aboveground biomass. A higher d13C seems also to be involved in these advances, which suggests a progressive improvement in constitutive water use efficiency not associated with a trend towards lower stomatal conductance in the most recent genotypes. However, genetic advance Researchdoes not appear related to changes in photosynthesis rates on area basis when measured in the flag leaf or the spike,but only to a higher, whole‐spike photosynthesis. Results also indirectly support the concept that under potential yield conditions, the spike contributed more than the flag leaf to kernel formation.

关键词： Carbon isotopes grain yield net carbon exchange nitrogen content yield potential

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Application of AVO and Seismic Attributes Techniques for Characterizing Pliocene Sand Reservoirs in Darfeel Field, Eastern mediterranean, Egypt

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International Journal of Geosciences 2022年第10期13卷 973-984页

作者： Islam Hashem Abd El-Naser Helal Amir M. S. Lala Belayim Petroleum company Cairo Egypt Faculty of Science Ain Shams University Cairo Egypt

mediterranean Sea considered as a main hydrocarbon province in Egypt as a huge reservoirs have been discovered till now. Port Fouad marine is a gas and condensate field located in Eastern mediterranean Sea about 30 KM off Egyptian coast, in a water depth of about 30 m. The Concession is operated by PETROBEL on behalf of Petrosaid (Port Said Petroleum company). The field was put on production on April 1996, from the Miocene turbidities sands of Wakar Formation plus Pilocene Kafr EL Sheikh Formation. Darfeel field is located within Port Fouad Concession, seven wells have been drilled till now and producing from Pliocene section (Kafr El Sheikh Formation). Pliocene is the main reservoir in Darfeel field which characterized by turbidities sand stone. The aim of this work is to identify the distribution of turbidities sand and characterize sand reservoirs using AVO (amplitude verses offset) and seismic attributes techniques. The workflow is starting from conventional seismic interpretation, maps (time, depth, and amplitude), depositional environments, and finally structure setting. In addition to use some of unconventional seismic interpretation such as seismic attributes. AVO analysis and attributes had been applied in a temp of differentiate between gas sand reservoirs and non-gas reservoirs. The final result aid to identify the reservoir distribution and characterization of sand reservoirs through the field. So, the use of different seismic techniques is powerful techniques in identifying reservoir distribution.

关键词： AVO Darfeel Field Seismic Attributes Wakar Formation Kafr El Sheikh Formation Turbidities

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Insecticidal Activity of an Indian Botanical Insecticide ULTRA ACT&#174 against the Olive Pest <i>Bactrocera oleae</i>(Diptera: Tephritidae) in Tunisia

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Advances in Chemical Engineering and Science 2020年第1期10卷 69-80页

作者： Imen Blibech Mohieddine Ksantini Manohar Shete Laboratory for Improvement and Protection of the Genetic Resources of the Olive Tree Sousse Tunisia Laboratory for Improvement and Protection of the Genetic Resources of the Olive Tree Sfax Tunisia Certified company M & M Industries Nashik India

Bactrocera oleae is the most economically damaging insect of olive in the mediterranean. As a reliable alternative to synthetic chemical insecticides, botanical pesticides from plant extracts are also considered natural control methods safe for the environment and human health. In practical applications up to date, studies demonstrating toxically effects of biological control agents on the insect have been carried out in organic farming systems based on some industrial microbial formulations. But much less attention has been given to botanical insecticides against B. oleae. Thus, a certified botanical insecticide issue from various plants and approved per Indian and International organic standards was tested against larvae and pupae of the olive pest Bactrocera oleae in the east of Tunisia under laboratory conditions. The experiments were conducted with 3 normal treatments and 1 control. Two techniques were used for larvae and pupae: direct contact using concentration from 0.5;0.750;1 and 1.5 mg/l and fumigation treatment using 2 mg/l conducted in rectangular boxes (25°C - 27°C, 75% - 85% RH and 14:10 LD photo period). For larval stages, LC50 and LC90 values for Ultra-Act were 0.45 and 1.22 mg/L in direct contact and 1.5 - 2 mg/l with fumigation, respectively. For pupal stage, the ID25 and ID50 values were estimated to be 0.71 mg and 1.26 mg respectively corresponding to the inhibition of emergence of 25% and 50% of B. oleae adults from pupa. Our results indicate that sprayed Ultra-Act product has the potential to control the three olive fly instar larvae. Pupal emergency was decreased significantly with fumigation treatment. In conclusion, Ultra-Act is a promising botanical insecticide against B. oleae that could be used as a successful alternative for chemicals in integrated control methods of this pest in Tunisia.

关键词： Olive Insect Pest Bactrocera oleae Indian Botanical Insecticide Ultra-Act In-secticidal Activity Contact Fumigation

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Baseline of the Use of Solar Irrigation Pump in the Niayes Area in Senegal

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Natural Resources 2021年第5期12卷 125-146页

作者： Aminata Sarr Lamine Diop Ibrahima Diatta Yaye Deffa Wane Ansouma Bodian Sidy Mouhamed Seck Luciano Mateos Nicola Lamaddalena Faculty of Agronomic Sciences Aquaculture and Food Technology Gaston Berger University Saint Louis Senegal Irrigated Agriculture Mediterranean Agronomic Institute of Bari (CIHEAM BARI) Bari Italy Interdisciplinary Research Group in Support of Regional Planning and Local Development Gaston Berger University Saint Louis Senegal Faculty of Arts and Humanities Gaston Berger University Saint Louis Senegal Institute for Sustainable Agriculture CSIC Córdoba Spain

Solar irrigation pumps are considered as an alternative to the use of diesel and electric pumps due to the high cost of energy. These pumps are now increasingly used in the Niayes area. Thus, a more in-depth knowledge about the components of a solar pumping system and their characteristics available on the market as well as prices can be beneficial. This study was conducted to have an idea on the baseline of the use of solar irrigation pumps in this area. To perform this study, surveys were conducted among 12 suppliers and 10 service providers located in Dakar, Thies, Louga and Saint-Louis region and among 53 users located in Potou area which is in Louga region. Results show a wide range of pump brands and characteristics. Brands found were Lorentz, LIKOU, SHIMGE, Grundfos, Solar pump, Feili, Difful, JUQIANG, Solar tech, and Asaman. The pumps’ flow rate varies between 2.5 m3/h and 45 m3/h, the pressure ranges from 15 m to 160 m and the power is between 0.072 kW and 10 kW. The price of these pumps varies depending on the brand used and their characteristics. In addition, other materials are available, such as panels with power ranging from 80 W to 330 W and electric cables. The price of these components varies according on the type used. Thus, the investment cost for implementation varies between 640 euros (420,000 CFA) and 25,087 euros (16,455,919 CFA). The cost of installation varies between 76.3 euros (50,000 CFA) and 1219.6 euros (800,000 CFA). Concerning maintenance, it is generally free during the warranty period when the equipment is supplied and installed by the same company. However, the cost of maintenance varies between 152.5 euros and 457.4 euros/year or is estimated at 45.7 euro/maintenance after the warranty years. Investigations conducted among users show that farmers in general do not perform pump maintenance due to a lack of knowledge and financial means. Thus, according to farmers, factors that impact pumps operation are the lo

关键词： Solar Pumping System Irrigation Suppliers Service Providers Users Niayes Area

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