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Thermal insulation design of subsea vertical X-mas tree

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Petroleum Science 2021年第4期18卷 1182-1194页

作者： xin rong Hong-Wu Zhu College of Mechanical and Transportation Engineering China University of PetroleumBeijing102249China

Temperature drop is commonly observed in subsea vertical X-mas trees during *** presence of a huge temperature difference between internal crude oil and external seawater can cause severe equipment degradation of the oil flow channel(e.g.,hydrate precipitation),which can block the oil flow channel and interrupt the production *** most vulnerable parts of a subsea vertical X-mas tree tend to be components with high convective heat transfer rates,such as production modules and short *** proposed an innovative approach for the insulation design of underwater equipment under a shutdown ***,we obtained a heat transfer analysis of the tree under working conditions through computational fluid dynamics to ascertain the initial temperature condition for an unsteadystate ***,we investigated the unsteady heat transfer characteristics of the tree with an insulation layer in the shutdown state and derived the relationships between insulation duration and thickness by data *** used data analysis to identify the relationship between insulation duration and ***,we derived the empirical formula of insulation thickness for underwater equipment given the effect of environmental factors on the heat preservation *** performed the experiment with an oil pipeline,and the results showed that the internal oil of the equipment did not hydrate within 8 h under the shutdown condition with insulation layers.

关键词： Subsea vertical X-mas tree Thermal insulation design Unsteady heat-transfer analysis Computational fluid dynamics

NUMERICAL SIMULATION OF 3-D TURBULENT FLOW IN THE MULTI-INTAKES SUMP OF THE PUMP STATION

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Journal of Hydrodynamics 2007年第1期19卷 42-47页

作者： CHEN Hong-xun SHEN xin-rong Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China

In this article, a numerical model forthree-dimensional turbulent flow in the sump of the pumpstation was presented. A reasonable boundary condition for the flow in the sump with several water intakes at different flowrates was proposed. The finite volume method was employed tosolve the governing equations with the body fitted gridgenerated by the multi-block grid technique. By using theFluent software, the fluid flow in a model sump of the pumpstation was calculated. Compared with the experimental result,the numerical result of the example is fairly good.

关键词： pumping station sump suction pipe turbulentmodel numerical simulation

Osmotic Adjustment of Soil Biocrust Mosses in Response to Desiccation Stress

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Pedosphere 2015年第3期25卷 459-467页

作者： ZHAO xin SHI Yong LIU Yang JIA rong-Liang LI xin-rong Key Laboratory of Stress Physiology and Ecology Shapotou Desert Research and Experiment Station Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences

Biological soil crusts(biocrusts) widely occur in semiarid and arid regions throughout the world and play important roles in many desert ecosystems: protecting soil from wind erosion and detaining nutrient-rich dust and organic carbon. An experiment was conducted in the Shapotou revegetated area of the Tengger Desert, Ningxia Hui Autonomous Region of China to investigate the physiological responses of the dominant biocrust mosses, Bryum argenteum and Didymodon vinealis, to desiccant stress using different osmotic adjustments. B. argenteum and D. vinealis accumulated K+, total soluble sugar, sucrose, trehalose, proline, and glycine betaine during desiccation. The proline content of B. argenteum was about two times higher than that of D. vinealis. The K+and glycine betaine contents in B. argenteum were slightly higher than those in D. vinealis. In contrast, the total soluble sugar, sucrose,and trehalose contents in D. vinealis were about 3 to 5 times higher than those in B. argenteum. With gradual desiccation stress,the Na+content of B. argenteum was low and did not significantly change. On the contrary, the Na+content of D. vinealis sharply increased and reached a very high level of about 10 to 18 times higher than that of B. argenteum, indicating that B. argenteum and D. vinealis gradually adapted to desiccation stress by osmotic substances accumulation to different degrees.

关键词： biological soil crusts Bryum argenteum compatible solute Didymodon vinealis drought stress

Spaces with σ-point-discrete N_0-weak bases

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Applied Mathematics(A Journal of Chinese Universities) 2013年第1期28卷 116-126页

作者： SHEN rong-xin LIN Shou Department of Mathematics Taizhou Teachers' College Department of Mathematics Nanjing University Department of Mathematics Ningde Normal University

It is discussed in this paper the spaces with σ-point-discrete N_0-weak bases. The main results are：（1） A space X has a σ-compact-finite N_0-weak base if and only if X is a k-space with a σ-point-discrete N_0-weak base; （2） Under （CH）, every separable space with a σ-point-discrete N_0-weak base has a countable N_0-weak base.

关键词： N_0-weak base σ-point-discrete network σ-compact-finite network separable space.

Three-dimensional Pyrenyl Graphdiyne Supported Pd Nanoparticle as an Efficient and Easily Recyclable Catalyst for Reduction of 4-Nitrophenol

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Chemical Research in Chinese Universities 2021年第6期37卷 1296-1300页

作者： rong xin LU Xiuli LU Tongbu Institute for New Energy Materials& Low Carbon TechnologiesSchool of Materials Science and EngineeringTianjin University of TechnologyTianjin300384P.R.China

The fabrication of highly active and easily recyclable Pd-based catalyst is meaningful for their practical ***,a Pd-based dip-catalyst(Pd@Pyr-GDY)is fabricated on graphdiyne(Pyr-GDY)grown on copper foam,and applied in the reduction of ***,the as-formed Pd@Pyr-GDY shows good catalytic performance toward the reduction of 4-nitrophenol(4-NP)to 4-aminophenol(4-AP)by NaBH4 with a rate constant k value of 3.84 min^(−1),which is 12-fold higher than that of the commercial Pd/*** importantly,Pd@Pyr-GDY could be easily and rapidly recovery from the reaction medium and no distinct inactivation was found after six cycles of the *** work presents an easy way to design an efficient and easily recyclable Pd-based catalyst for practical use.

关键词： Pd-based catalyst Dip-catalyst Reduction of 4-nitrophenol Recycling

A note on self-normalized Dickey-Fuller test for unit root in autoregressive time series with GARCH errors

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Applied Mathematics(A Journal of Chinese Universities) 2008年第2期23卷 197-201页

作者： YANG Xiao-rong ZHANG Li-xin Dept. of Math. Zhejiang Univ. Hangzhou 310027 China

In this article, the unit root test for AR（p） model with GARCH errors is considered. The Dickey-Fuller test statistics are rewritten in the form of self-normalized sums, and the asymptotic distribution of the test s... 详细信息

关键词： unit root AR (p)-GARCH (1,1) self-normalized Dickey-Fuller test statistic.

FINITE ELEMENT NUMERICAL SIMULATION FOR THE HYDRODYNAMIC FIELD EVOLUTION OF GEOTHERMAL WATER IN THE NANWENQUAN ANTICLINE IN CHONGQING IN CHINA

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Journal of Hydrodynamics 2006年第4期18卷 443-448页

作者： LUO Yun-ju LIU Dong-yan LIU xin-rong College of Civil Engineering Chongqing University Chongqing 400045 China

The Nanwenquan （South Hot Spring） and Xiao quan （Small Hot Spring） in the Nanwenquan anticline are well-known attraction for their geothermal water, but currently, the two natural hot springs have hot flow naturally. In order to protect the geothermal water resource, the evolution of hydrodynamic field must be researched for the causation of the hydrodynamic field destroyed. The finite element numerical simulation was adopted and quantitative study on the geothermal water hydrodynamic field. The finite element model was set up to simulate the research sites, the simulated water level was compared with the actual water level, the feasibility of this model was proved when the simulated water level is approximate to actual one, and an applicable finite element model was obtained. The finite element model was used to simulate the evolution of the hydrodynamic field. This paper supplies a basis to exploit adequately and protect effectively the geothermal water resource, at the same time it is proved feasible in practice to apply finite element numerical simulation to quantitative study of the geothermal water.

关键词： Nanwenquan anticline the geothermal water hydrodynamic field finite element numerical simulation water level

Cultivable Microfungal Communities Inhabiting Biological Soil Crusts in the Tengger Desert, China

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Pedosphere 2015年第3期25卷 351-363页

作者： Isabella GRISHKAN JIA rong-Liang Giora J.KIDRON LI xin-rong Institute of Evolution University of Haifa Shapotou Desert Research and Experiment Station Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences Institute of Earth Sciences The Hebrew University of JerusalemGivat Ram Campus

Biological soil crusts are essential components of arid ecosystems. We examined the variations in microfungal communities inhabiting different biological crust types in the vicinity of the Shapotou Research Station in the Tengger Desert, China. A total of 134 species from 66 genera were isolated using the soil dilution plate method. The mycobiota of the crusts from the Tengger Desert, similar to that of the Negev Desert in Israel, was dominated by melanin-containing species with large multicellular spores. Abundance of these xeric species increased spatially with increasing xeric conditions from moss-dominated to cyanobacterial crusts. Density of microfungal isolates displayed the opposite trend and was positively correlated with chlorophyll content, indicating the possible significant influence of organic matter content and wetness duration on fungal biomass. Within a chronosequence of the localities of different periods after sand stabilization with revegetation, little variations were revealed in species composition and isolate density of the crust microfungal communities, while a tendency towards a decrease in the community diversity level with the crust age was noted Microfungal communities from stabilized localities differed from those of the natural localities in abundance of the dominant and some frequent species, and in the fluctuations of diversity characteristics between the cyanobacterial and moss-dominated crusts. The variations in mycobiotie parameters in the soil crusts of the Tengger Desert were apparently associated with the topographically induced variations in abiotic conditions, while the differences in microfungal community of soil crusts between the Tengger and Negev deserts, such as the significantly higher abundance of thermotolerant species in the crusts of the Tengger Deserts, were caused by the principal differences in their precipitation regimes, associated with different rainy seasons, winter and summer in the Negev and Tengger deserts,

关键词： chlorophyll content community structure fungal diversity precipitation regimes revegetation sand stabilization wetness duration

Reconstruction of complex orbital fracture with titanium implants

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International Journal of Ophthalmology(English edition) 2012年第4期5卷 488-492页

作者： Wen-Shu Yi, xin-rong Ou Department of Ophthalmology Xiangya Hospital Central South University Changsha 410008 Hunan Province China Department of Neurologic Xiangya Hospital Central South University Changsha 410008 Hunan Province China Department of Oral and Maxillofacial Xiangya Hospital Central South University Changsha 410008 Hunan Province China

AIM: To evaluate the effectiveness and safety of complex orbital fracture reconstruction with titanium implants. METHODS: A retrospective review of 46 patients treated with complex orbital fractures reconstruction using titanium implants from January 2005 to December 2008 was conducted. The following data were recorded: age, gender, mechanism of injury, preoperative and postoperative orbital CT, visual acuity, diplopia, ocular motility and Hertel exophthalmometer. RESULTS: The most common cause was motor vehicle accident (47.8%), followed by industrial injury (30.4%). All patients had improved appearance after operation and CT scan at one week after operation showed the fracture defects of orbit and neighboring areas had been reconstructed. Forty-six cases had various degrees of enophthalmos before operation. Among them, 32 cases were completely corrected, 11 cases improved obviously and 3 cases had no improvement after operation. Thirty-six patients with visual acuity =20/60 revealed diplopia of various degrees, including 26 patients had diplopia in right ahead and/or reading positions. At the sixth month after operation, diplopia disappeared in five patients, 7 patients still had diplopia in right ahead and/or reading positions, 14 patients had diplopia in positions rather than right ahead and reading positions (20 degrees). All patients had various degrees of ocular motility disorders before operation. At the sixth month after operation, eyeball movement disorder disappeared in 9 patients, 31 patients showed improvement and 6 patients had no improvement. Complications of implant infection, rejection and displacement were not reported after operation. CONCLUSION: The application of titanium implants in the repair of complex orbital fractures greatly improves the appearance and functional results, which is a favorable material for plastic surgery of complex orbital fracture.

关键词： complex orbital fractures titanium reconstruction