30万吨/年聚丙烯装置预聚合反应器轴流泵节流环改造

对大庆炼化公司30万吨/年聚丙烯装置预聚合反应器轴流泵节流环进行改造,该泵为意大利ENSIVAL-MORET公司生产,设备型号AH1B,设备位号P200。该泵原节流环在运行期间容易在泵轴底部与泵体的间隙处积粉,形成塑料套,造成泵轴功率升高,最终被迫停工清理积粉,通过对节流环结构的改造,能够满足一个周期连续生产。

通过调整HP983中速磨煤机磨辊间隙和空气节流环降低石子煤排放量

为了研究调整HP983中速磨煤机磨辊间隙和空气节流环降低石子煤排放量的策略,提高工厂生产的文明程度。本文通过查阅现有文献,首先阐述了HP983中速磨煤机组成部件及工作原理,其次分析了HP983中速磨煤机的石子煤排放量偏大原因,最后探讨了调整HP983中速磨煤机磨辊间隙和空气节流环降低石子煤排放量的有效策略,旨在提高HP983中速磨煤机运行可靠性、改善环境污染、实现节能减排目标,同时为相关人员提供参考。

大型脱硫循环泵用新型机械密封装置的设计

针对大型脱硫循环泵工作过程中机械密封存在的易出现振动、轴向冲击和干烧等问题,通过设计缓冲垫和节流环等新型结构,研制出一种适合大型脱硫循环泵工况要求和密封腔体特点的新型机械密封装置,并介绍了该新型密封装置的结构设计和主要的技术特点。该新型密封装置已成功应用于大型脱硫循环泵的密封。

尿素一段分解加热器节流结构的设计改进

介绍了尿素一段分解加热器中节流结构常用的两种形式:节流环结构和节流板结构,并对这两种形式的结构、性能、制造、装配及拆卸等方面进行了对比,在分析其结构优缺点的基础上对节流结构进行了改进。改进后的节流结构具有性能可靠、制造方便、节流效果好以及装配、拆卸方便等优点。

大口径喷嘴水射流特性研究

大口径喷嘴常用于远距离冲洗,在高速铁路供电系统带电水冲洗过程中,要平衡冲洗距离长、水柱绝缘电阻小、用水量少三者之间的矛盾。对带电冲洗领域常用的二段形喷嘴进行了研究,提出了在喷嘴内部增加节流环的方式,在不改变喷嘴直径的情况下,可快速调整喷嘴的出口速度、打击力和水柱含水量。通过对喷嘴内外流场进行仿真分析,得到了不同半径的节流环在不同位置时的喷嘴射流特性及相关规律,并发现直径一定的喷嘴对应存在一个节流环半径的极限值,当超出这个极限值后喷嘴的射流特性有明显下降。通过对不同半径的节流环在不同位置时对喷嘴射流特性的影响及规律的研究,为自动化、智能化带电水冲洗过程中喷嘴的优化选型提供了参考。

压缩机无油润滑密封的应用研究

通过计算和试验，确定了填充ＰＴＦＥ材料密封填料环的径向和轴向间隙，并分别采用尼龙、锡青铜和铸铁３种材料设计制造出了阻流环和节流环。经在石油气压缩机上安装试用证明，其密封效果和使用寿命均取得了满意的结果，经济效益亦显著。

两种可调式液力变矩器的性能分析与试验研究

本文在可调导轮叶片和可调节流环两种可调式液力变矩器工作原理的基础上，提出了可调导轮叶片的可调式变矩器的优化设计和特性计算方法，并建立了可调节流环的可调式变矩器的特性计算数学模型。将Ｂ８—Ⅲ型非可调变矩器进行改型设计，试制成可调导轮叶片和可调节流环两种可调式变矩器模型，并对它们进行试验和分析。

Review of Food Safety Supervision for the Wholesale Market of Chinese Agricultural Products

With the continuous improvement of living standards, there is an increasingly concerned about food quality and safety issues. Especially in recent years,food safety incidents, breaking out frequently, have become the focus of people＇s attention, putting forward new demands on the regulation of food safety. This paper reviewed the Food Safety Supervision in China from food safety supervision mode,regulatory system defects and circulation supervision system, and also proposed the future research trends of food safety regulations for the wholesale market of Chinese agricultural products.

柴油加氢装置新氢压缩机填料改进

介绍了柴油加氢装置新氢压缩机的填料结构及工作原理,并针对该机组二级主填料出现的故障,从装配和运行工况两方面进行原因分析,对填料减压环的材质进行了改进,效果明显,确保了机组填料的长周期运行。

橡胶制品的低成本挤出

橡胶型材挤出中的不少工序要求胶料在抽真空挤出机中脱气。由于抽真空挤出机的螺杆、模具及节流环不够平衡,挤出量往往达不到最佳水平。DeSO系统允许在不更换螺杆的情况下调整节流环,从而使得生产效率大幅度提高。在一般情况下挤出多种型材,需预备多根螺杆,而DeSO系统仅用一根螺杆即可进行多种型材的挤出。文中介绍了这项技术的最新发展动向。

防混阀的选型和建议

本文介绍了防混阀的种类、原理、结构,防混阀的选择、接线方式,如何安装、使用,防混阀的优势以及应用的场合,并且提出了使用中需要注意的问题和改进建议。使用防混阀可以最大限度地减少了清洗的死角,可以使两种不同的产品或流体流过同一阀门时不会交叉,一个双座阀可替代两个或三个单座阀的工作,节省了空间和安装成本。

销钉复合冷喂料排气挤出机螺杆设计

概述利用销钉机筒的炼胶机理来设计排气挤出机的螺杆，同时在螺杆中段、排气口前增加了节流环，以达到排气挤出机喂料段、第一计量段、排气段和第二计量段的产量平衡，以提高排气效率和产品质量。

THREE-DIMENSIONAL BAROCLINIC NUMERICAL SIMULATION OF THE SOUTH CHINA SEA CIRCULATION'S SEASONAL CHARACTERISTICS II. MIDDLE AND DEEP CIRCULATION

A three-dimensional baroclinic shelf sea model’s numerical simulation of the South China Sea (SCS) middle and deep layer circulation structure showed that: 1. In the SCS middle and deep layer, a southward boundary current exists along the east shore of the Indo-China Peninsula all year long. A cyclonic eddy (gyre) is formed by the current in the above sea areas except in the middle layer in spring, when an anticyclonic eddy exists on the eastern side of the current. In the deep layer, a large-scale anticyclonic eddy often exists in the sea areas between the Zhongsha Islands and west shore of southern Luzon Island. 2. In the middle layer in summer and autumn, and in the deep layer in autumn and winter, there is an anticyclonic eddy (gyre) in the northeastern SCS, while in the middle layer in winter and spring, and in the deep layer in spring and summer, there is a cyclonic one. 3. In the middle layer, there is a weak northeastward current in the Nansha Trough in spring and summer, while in autumn and winter it evolves into an anticyclonic eddy (gyre), which then spreads westward to the whole western Nansha Islands sea areas.

An Enhanced Hadoop Heartbeat Mechanism for MapReduce Task Scheduler Using Dynamic Calibration

MapReduce is a popular program- ming model for processing large-scale datasets in a distributed environment and is a funda- mental component of current cloud comput- ing and big data applications. In this paper, a heartbeat mechanism for MapReduce Task Scheduler using Dynamic Calibration （HMTS- DC） is proposed to address the unbalanced node computation capacity problem in a het- erogeneous MapReduce environment. HMTS- DC uses two mechanisms to dynamically adapt and balance tasks assigned to each com- pute node： 1） using heartbeat to dynamically estimate the capacity of the compute nodes, and 2） using data locality of replicated data blocks to reduce data transfer between nodes. With the first mechanism, based on the heart- beats received during the early state of the job, the task scheduler can dynamically estimate the computational capacity of each node. Us- ing the second mechanism, unprocessed Tasks local to each compute node are reassigned and reserved to allow nodes with greater capacities to reserve more local tasks than their weaker counterparts. Experimental results show that HMTS-DC performs better than Hadoop and Dynamic Data Placement Strategy （DDP） in a dynamic environment. Furthermore, an en- hanced HMTS-DC （EHMTS-DC） is proposed bv incorporatin historical data. In contrastto the ＂slow start＂ property of HMTS-DC, EHMTS-DC relies on the historical computation capacity of the slave machines. The experimental results show that EHMTS-DC outperforms HMTS-DC in a dynamic environment.

Typical Surface Seasonal Circulation in the Indian Ocean Derived from Argos Floats

This study investigates the surface circulation in the Indian Ocean using Argos float data over the period 1979-2011.The Argos observations manifest some new phenomena.The climatological annual mean circulation shows that the surface current becomes much stronger after turning around in shore in the western Indian Ocean.In the tropical Indian Ocean,the Great Whirl(GW) to the east of Somalia develops quickly in spring(April-May) as the monsoon reverses to move northward,becoming strongest in summer(June-September) and disappearing in autumn(October-November).The west end of the Agulhas retroflection can reach 18°E,and it exhibits a seasonal variation.At approximately 90°E,the Agulhas Return Current combines with the eastward South Atlantic Current and finally joins the Antarctic Circumpolar Current.

Wave Effect on the Ocean Circulations Through Mass Transport and Wave-Induced Pumping

The wave Coriolis-Stokes-Force-modified ocean momentum equations are reviewed in this paper and the wave Stokes transport is pointed out to be part of the ocean circulations. Using the European Centre for Medium-Range Weather Forecasts 40-year reanalysis data(ERA-40 data) and the Simple Ocean Data Assimilation(SODA) version 2.2.4 data, the magnitude of this transport is compared with that of wind-driven Sverdrup transport and a 5-to-10-precent contribution by the wave Stokes transport is found. Both transports are stronger in boreal winter than in summers. The wave effect can be either contribution or cancellation in different seasons. Examination with Kuroshio transport verifies similar seasonal variations. The clarification of the efficient wave boundary condition helps to understand the role of waves in mass transport. It acts as surface wind stress and can be functional down to the bottom of the ageostrophic layer. The pumping velocities resulting from wave-induced stress are zonally distributed and are significant in relatively high latitudes. Further work will focus on the model performance of the wave-stress-changed-boundary and the role of swells in the eastern part of the oceans.

The Seasonal Variations of the Climatic Circulation of the Black Sea along the Axis of Divergence Zone

The spatial position, seasonal variability and intensity of the main flow and the cyclonic circulation of the Black Sea waters along the axis of the divergence were identified. Corresponding calculations were done with using of the dynamic method and based on the climate data set of temperature and salinity for the surface and intermediate layers of the Black Sea. The important role of spring floods on the rivers of the northern-western Black Sea in the development of the water circulation features was shown because this river＇s water and main Black Sea current interact with the periphery of the western and eastern cyclonic circulation. This process is dominated at the western part sea surface cyclone： in spring and at eastern, in summer and autumn. The flow rate and nature of seasonal migration cyclonic centers were estimated. The results of research are based on a relatively large scale （40＇ latitude and 60＇ longitude） averaging and we have identified the main area of water divergence. Small, localized areas of convergence and divergence of flow that are presented in the Black Sea were not included into the scope of our research.

Preliminary evaluation of MJO simulation in GAMIL3(Grid-point atmospheric model of IAP LASG)

This study evaluates the performance of the Grid-point Atmospheric Model of IAP LASG,version 3(GAMIL3),in simulating the Madden–Julian Oscillation(MJO),based on the CMIP6(phase 6 of the Coupled Model Intercomparison Project)AMIP(Atmospheric Model Intercomparison Project)simulation.Results show that GAMIL3 reasonably captures the main features of the MJO,such as the eastward-propagating signal in the MJO frequency band,the symmetric and asymmetric structures of the MJO,several convectively coupled equatorial waves,and the MJO life cycle.However,GAMIL3 underestimates the MJO amplitude,especially for outgoing longwave radiation,as do most CMIP5 models,and simulates slow eastward propagation.

MJO potential predictability and predictive skill in IAP AGCM 4.1

A 30-year hindcast was performed using version 4.1 of the IAP AGCM（IAP AGCM4.1）, and its potential predictability of the MJO was then evaluated. The results showed that the potential predictability of the MJO is 13 and 24 days, evaluated using the signal-to-error ratio method based on a single member and the ensemble mean, respectively. However, the MJO prediction skill is only9 and 10 days using the two methods mentioned above. It was further found that the potential predictability and prediction skill depend on the MJO amplitude in the initial conditions. Prediction initiated from conditions with a strong MJO amplitude tends to be more skillful. Together with the results of other measures, the current MJO prediction ability of IAP AGCM4.1 is around 10 days, which is much lower than other climate prediction systems. Furthermore, the smaller difference between the MJO predictability and prediction skill evaluated by a single member and the ensemble mean methods could be ascribed to the relatively smaller size of the ensemble member of the model.Therefore, considerable effort should be made to improve MJO prediction in IAP AGCM4.1 through application of a reasonable model initialization and ensemble forecast strategy.

Simulation of the western North Pacific subtropical high in El Ni?o decaying summers by CMIP5 AGCMs

The performances of CMIP5 atmospheric general circulation models （AGCMs） in simulating the western North Pacific subtropical high （WNPSH） in El Nino decaying summers are examined in this study. Results show that most models can reproduce the spatial pattern of both climatological and anomalous circulation associated with the WNPSH in El Nino decaying summers. Most CMIP5 AGCMs can capture the westward shift of the WNPSH in El Nino decaying summers compared with the climatological location. With respect to the sub-seasonal variation of the WNPSH, the performances of these AGCMs in reproducing the northward jump of the WNPSH are better than simulating the eastward retreat of the WNPSH from July to August. Twenty-one out of twenty-two （20 out of 22） models can reasonably reproduce the northward jump of the WNPSH in El Nino decaying summers （climatology）, while only 7 out of 22 （8 out of 22） AGCMs can reasonably reproduce the eastward retreat of the WNPSH in El Nino decaying summers （climatology）. In addition, there is a close connection between the climatological WNPSH location bias and that in El Nino decaying summers.