2×350MW级燃气-蒸汽联合循环发电机机岛预埋件控制

厦门某燃气电厂2×350MW级燃气-蒸汽联合循环发电机组采用SIEMENS公司设计,机岛预留孔洞、预埋件,预埋螺栓繁多;且基础钢筋密集,采用钢筋直径较大,预埋件埋设分布广泛,梁底、梁侧、梁顶、剪力墙侧面、剪力墙顶面均有预埋件分布,钢筋绑扎和预埋件安装冲突严重,施工顺序出现反复交替施工现象(预埋件安装-钢筋绑扎-预埋件安装-钢筋绑扎-预埋件按装)。本文对如何保证预埋件和螺栓的位置准确,介绍了一些成功的经验。

H级燃机电厂低位侧排汽汽轮发电机岛区域布置设计

广州增城燃气冷热电三联供项目是国内率先投运的H级燃气—蒸汽联合循环机组工程。机组采用“1+1”多轴方案,配置低位布置的西门子SGT5-8000H型燃机和低位布置、侧排汽的西门子SST5-5000型汽机。设计院与主机厂进行了深入协作,开发并成功实施了“H级联合循环低位多轴双跨联合主厂房”方案,该方案规避了单纯对称或简单顺列布置的弊端,成为该类型机组新的优化“典型布置”方案。本文对该创新方案实施的难点之一“低位侧排汽汽轮发电机岛区域的布置设计”的特点进行论述。

基于Flexsim的机场行李分拣系统值机岛子系统优化研究

机场行李处理是一项十分复杂的工作。这种特点主要是由行李的数量和种类决定的。从基于Flexsim的机场行李分拣系统值机岛子系统仿真应用效果来看,该系统在运行稳定性、效率等方面存在一定问题。本文从当前我国行李自动分拣系统应用现状入手,对基于Flexsim的机场行李分拣系统值机岛子系统优化进行分析和研究。

一机双岛空冷互联系统改造技术应用

文章主要论述了某热电厂将两台直接空冷机组实现在非采暖季单台机组空冷之间互联运行方式下的改造技术工作。即;一机双岛。当单台机组进入高温夏季时容易使汽轮机背压随之升高,这不仅会使汽轮机理想焓降减少,还会造成在相同蒸汽流量条件下做功减少。所以,采用增大机组排汽冷却面积的方法,可有效降低机组背压的效果。再利用DCS组态软件把所改造的系统连接起来后,实现了自动控制方式和冬、夏季无扰切换的运行模式。这项工程不仅克服了在机组背压升高的情况下容易引起排气装置部分的法兰、螺栓应力增大的安全生产隐患,还解决了单台机组在夏季高煤耗问题。

大型机场旅客进出港通道电气施工技术

大型机场的值机岛、进出港通道是大型机场航站楼工程电气安装最为复杂的区域,其包含建筑、结构、机电、弱电、消防、信息、行李、安检等十几个专业,三十多个子项,其电气施工的好坏决定航站楼能否正常使用。

航班高峰期值机柜台使用合理性研究

随着民航的发展,机场航线及旅客吞吐量不断增加,对机场值机柜台使用合理性分析,能有效避免航班高峰期部分值机岛行李系统过载而其它值机岛利用率低等情况,有利于提高机场资源利用率,保障旅客正常出行。对2017年深圳机场全天航班数据进行统计,从航班数、机型及客座率等因素出发分析各值机岛航班平均人数,结合航站楼旅客到达规律,利用不同时段旅客到达概率作为权值,得出不同时间段内旅客到达分布情况,将同一时间段内旅客人数进行单位时间划分,得到不同时刻旅客到达人数分布,对同一值机岛各时刻到达人数进行整点叠加,依据值机岛行李系统每小时理论设计容量,判断值机岛柜台使用的合理性,为航班高峰期优化机场值机资源提供科学直观的决策依据。

F级燃气轮机联合循环机组的布置方案及造价分析

针对F级燃气轮机联合循环机组,介绍了联合循环机组的布置形式,提出了4种机岛布置方案,得到了不同布置方案的特点并对比了其初期投资,可为联合循环机组布置提供一定参考。

Characteristics of Soil Organic Carbon and Total Nitrogen in Rubber Plantations Soil at Different Age Stages in the Western Region of Hainan Island

[Objective]The aim was to study on the characteristics of soil organic carbon and nitrogen in rubber （Hevea brasiliensis Muell-Arg） plantations at different age stages in the western region of Hainan Island,so as to evaluate the ecological benefits of rubber plantations and provide basic data for studying the effect of tropical land utilization/cover change on the global carbon and nitrogen cycle. [Method]The situs was in Danzhou city,western region of Hainan Island,and the samples were four kinds of rubber plantations soil at different ages and one kind of control check （pepper,Piper nigrum L.） soil. In this research,four quadrats were set up in each sample,and the size of each was 20 cm×20 cm. Four specimens were gathered from four layers of 0-15,15-30,30-45,45-60,and the average of them was the last analysis result of each sample. Soil density was measured by cutting ring method,soil containing and hygroscopic water was detected by oven drying method,soil organic carbon （SOC） was measured by low temperature heated outside potassium dichromate oxidation-colorimetry method,and soil total nitrogen （STN） was detected by semimicro Kjeldahl method. [Result]SOC contents of different layers in rubber plantations soil at different age stages （including the CK pepper soil,the same as below） varied little,and the content of SOC in surface layer （0-15 cm） was higher,while the underlayer （45-60 cm） was lower than the average value; there was significant difference in SOC content among different kinds of soil,and the content was of 6.03-7.78 g/kg,tapping young trees （7 years） CK pepper mature age trees （30 years） prophase of young trees （2 years） tapping trees （16 years）; there was no significant difference in SOC storage among different kinds of soil,and the storage was of 61.33-74.29 t/hm2,mature age trees （30 years） tapping young trees （7 years） prophase of young trees （2 years） CK pepper tapping trees （16 years）; there was significant difference in STN content among rubber plantations soil at different age stages,the content was of 410.86-664.14 mg/kg2,CK pepper tapping young trees （7 years） prophase of young trees （2 years） mature age trees （30 years） tapping trees （16 years）,and STN content of tapping trees （16 years） soil was extremely lowest; there was significant difference in C/N ratio among different kinds of soil,the ratio was of 10.94-14.47,and the ratio of tapping trees （16 years） mature age trees （30 years） tapping young trees （7 years） CK pepper prophase of young trees （2 years）. [Conclusion]There wasn＇t unhealthy effect of rubber trees planted in tropical area on the content and storage of SOC,the content of STN and the ratio of C/N. there was no significant difference between rubber plantations and CK pepper soil,and the effects of rubber plantation on soil carbon-nitrogen was similar to that of other tropical crops （such as pepper）.

Adiponectin as a protective factor in hepatic steatosis

AIM: Obesity and insulin resistance (IR) are closely related to hepatic steatosis (HS), and adiponectin is a hepatic insulin sensitizer that has important effects in liver function. This study aims at investigating the relationship between serum adiponectin concentration and the presence of HS. METHODS: We carried out a cross-sectional study in a check-up unit of a University Hospital in Mexico City. We enrolled 196 subjects, comprising 98 subjects with HS (27 women, 71 men) and 98 controls (37 women and 61 men). Anthropometric, metabolic and biochemical variables were measured in the two groups. Serum adiponectin and leptin concentrations were determined, their association with grade of HS tested, and concentrations, according to quartiles, compared between cases and controls. X2 analysis for linear trends was used to test for a dose-response relationship and logistic regression analysis was conducted to test for a protective effect of adiponectin. RESULTS: The HS subjects were older and more obese than controls, with a central obesity pattern. In the fourth quartile of adiponectin concentrations, HS was less common and severe. In a multivariate model of the fourth quartile of the adiponectin concentrations, we observed a protective effect (OR = 0.17, 95%CI: 0.04-0.67, P= 0.01). In subjects with more severe HS, we observed higher leptin concentrations, and caloric intakes, total fat and iron consumption were higher than in controls. CONCLUSION: The results of the present study suggest that a high serum concentration of adiponectin is associated with a protective effect against HS.

BRCA1 affects global DNA methylation through regulation of DNMT1

Global DNA hypomethylation at CpG islands coupled with local hypermethylation is a hallmark for breast cancer, yet the mechanism underlying this change remains elusive. In this study, we showed that DNMT1, which encodes a methylation maintenance enzyme, is a transcriptional target of BRCA1. BRCA1 binds to the promoter of the DNMT1 gene through a potential OCT1 site and the binding is required for maintaining a transcriptional active configuration of the promoter in both mouse and human cells. We further demonstrated that impaired function of BRCA1 leads to global DNA hypomethylation, loss of genomic imprinting, and an open chromatin configuration in several types of tissues examined in a BRCA1 mutant mouse model at premaligant stages. BRCA1 deficiency is also associated with significantly increased expression levels of several protooncogenes, including c-Fos, Ha-Ras, and c-Myc, with a higher expression in tumors, while premalignant mammary epithelial cells displayed an intermediate state between tumors and controls. In human clinical samples, reduced expression of BRCA1 correlates with decreased levels of DNMT1, and reduced methylation of CpG islands. Thus, BRCA1 prevents global DNA hypomethylation through positively regulating DNMT1 expression, and this provides one of mechanisms for BRCAl-associated breast cancer formation.

Impact of the Sanya new airport artificial islands project on tidal dynamics of the Hongtang Bay

By establishing a 3-dimensional hydrodynamic model of the Hongtang Bay and the validation tests,tidal currents of the area before and after the construction of the Sanya new airport project,which include two artificial islands built respectively to accommodate the airport and its connected technology park,are simulated.The hydrodynamic impacts of the islands on the Hongtang Bay and surrounding waters were analyzed by comparing flow fields and velocities of tidal currents under the two conditions.

Intrahepatic vascular changes in non-alcoholic fatty liver disease: potential role of insulin-resistance and endothelial dysfunction

Metabolic syndrome is a cluster of several clinical conditions characterized by insulin-resistance and high cardiovascular risk. Non-alcoholic fatty liver disease is the liver expression of the metabolic syndrome, and insulin resistance can be a frequent comorbidity in several chronic liver diseases, in particular hepatitis C virus infection and/or cirrhosis. Several studies have demonstrated that insulin action is not only relevant for glucose control, but also for vascular homeostasis. Insulin regulates nitric oxide production, which mediates to a large degree the vasodilating, antiinflammatory and antithrombotic properties of a healthy endothelium, guaranteeing organ perfusion. The effects of insulin on the liver microvasculature and the effects of IR on sinusoidal endothelial cells have been studied in animal models of non-alcoholic fatty liver disease. The hypotheses derived from these studies and the potential translation of these results into humans are critically discussed in this review.

Chemical and spectroscopic characterization of dissolved humic substances in a mangrove-fringed estuary in the eastern coast of Hainan Island,China

Mangrove-derived dissolved organic matter （DOM） has an important effect on estuarine and coastal area on a large scale. In order to improve the understanding of origin, composition, and fate of DOM in mangrove-fringed estuarine and coastal areas, dissolved humic substances （DHS） were isolated from one mangrove pore-water sample and one near-shore seawater sample downstream the mangrove pore-water site in the eastern coast of Hainan Island, South China. Fulvic acids, humic acids and XAD-4 fractions were obtained from the two water samples by using a two-column array of XAD-g and XAD-4 resins. Chemica~ and spectroscopic methods were used to analyze the features of these DHS. Compared to the mangrove pore-water DHS, the near-shore seawater DHS were found rich in 13C with lower C/N ratios and more aliphatic compounds and carbohydrates, but less aromatic structures and carboxyl groups. As for the three fractions of the two DHS, XAD-4 fractions contain more aliphatics, carbohydrates, carboxyl groups, and enrich in 13C with respect to both fulvic and humic acids. Photo-oxidation transformation and contribution from marine-derived DOM were considered as the main reasons resulted in the difference in compositional features for these DHS in this study.

Expression of microRNA-29b2-c Cluster is Positively Regulated by MyoD in L6 Cells

Objectives To evaluate the expression profile of myoD microRNA-29 （miR-29） family in L6 myoblast differentiated to myotube or L6 myotube treated by glucose and insulin, and to further probe the molecular mechanism of myoD regulating the expression of miR-29 clusters.

Impact of liver diseases on the development of type 2 diabetes mellitus

The prevalence of type 2 diabetes mellitus （T2DM） is higher in patients who have liver diseases such as nonalcoholic fatty liver disease, chronic viral hepatitis, hemochromatosis, alcoholic liver disease and cirrhosis. It is suggested that there is a pathogenic link between the presence of T2DM and the severity of liver injury. However, evidence related to the impact of hepatic inflammation on the development of T2DM has not yet emerged. This article provides an overview of the evidence for an increased prevalence of diabetes in a range of liver diseases, the impact of liver diseases on insulin resistance and 13 cell dysfunction, and the potential mechanisms whereby coexistent liver diseases exacerbate the development of T2DM.

Numerical Hydrodynamics Study Around Turbine Array of Tidal Stream Farm in Zhoushan, China

In recent decades,great efforts have been made to efficiently explore tidal stream energy due to its unique advantages of easy prediction and great potential.China recently launched a national tidal stream farm demonstration project in the waterway between Putuoshan and Hulu Islands in the Zhoushan area.Before deployment of the turbine array,it is necessary to understand the hydrodynamic changes associated with the construction of a turbine array.In this study,we developed a depth-averaged hydrodynamics model that solves the shallow water governing equations to simulate the tidal hydrodynamics around the Zhoushan Archipelago.The simulation results agree with field data in terms of the water elevation and stream velocity.We considered two types of turbine arrays in this study and investigated their impacts on the local hydrodynamics.In general,the stream velocity in the northern and southern areas is reduced due to the power take-off of the turbine array,whereas stream velocity in the western and eastern areas is slightly increased due to the blockage impact of the turbine array.

禹州电厂机炉岛国际招投标评标因素介绍

河南禹州电厂一期工程的锅炉、汽轮发电机及其辅属设备岛利用亚洲开发银行贷款,按照国际竞争性招标方式进行采购。其评标也严格按照招、投标文件进行,在招标文件中明确规定了评标因素,这些因素的确定经国内专家研究和有关部门批准,并得到了贷款机构亚洲开发银行的认可。这些因素都要求各个投标商在投标中提供保证值,作为今后合同谈判及电厂建成后性能考核和不合格罚款的依据。现分别介绍如下。

Effect of soy protein supplementation in patients with chronic hepatitis C:A randomized clinical trial

AIM:To evaluate the effects of soy supplementation on insulin resistance,fatty liver and alanine aminotransferase(ALT) levels in non-diabetic patients with chronic hepatitis C(CHC).METHODS:In a prospective,randomized and singleblinded clinical trial,we compared patients with CHC who had casein as a supplement(n = 80)(control group),with patients who consumed a soy supplement diet(n = 80) [intervention group(IG)].Both groups received 32 g/d of protein for 12 wk.RESULTS:Patients' baseline features showed that 48.1% were overweight,43.7% had abdominal fat accumulation,34.7% had hepatic steatosis and 36.3% had an homeostasis model assessment index of insulin resistance(HOMA-IR) ≥ 3.0.Descriptive analysis showed that protein supplementation diet reduced hepatic steatosis in both groups;however,significant reductions in ALT levels occurred in the soy group.Multiple regression modeling indicated that in the presence of severe fibrosis(F3/F4),g glutamyl transferase elevation and high density lipoprotein(HDL) reduction,the intervention group had 75% less chance of developing hepatic steatosis(OR= 0.25;95% CI:0.06-0.82) and 55% less chance of presenting with an ALT level ≥ 1.5 × the upper limit of normal(ULN)(OR = 0.45,95% CI:0.22-0.89).Soy treatment did not have any effect on insulin resistance(OR = 1.92;95% CI:0.80-4.83),which might be attributed to the fact that the HOMAIR values at baseline in most of our patients were in the normal range.Advanced hepatic fibrosis,an ALT level > 1.5 × ULN and visceral fat were predictors of an HOMA-IR ≥ 3.The IG group had a reduced risk of an ALT level > 1.5 × ULN.An HOMA-IR ≥ 3.0 and HDL < 35 mg/dL were also risk factors for increased ALT.CONCLUSION:Soy supplementation decreased ALT levels and thus may improve liver inflammation in hepatitis C virus(HCV) patients;it also reduced hepatic steatosis in a subgroup of patients but did not change insulin resistance.It should be considered in the nutritional care of HCV patients.

Distribution of Dissolved Inorganic Carbon (DIC) and Its Related Parameters in Seawater of the North Yellow Sea and off the Qingdao Coast in October, 2007

Data on the distribution of dissolved inorganic carbon (DIC) were obtained from two cruises in the North Yellow Sea (NYS) and off the Qingdao Coast (QC) in October, 2007. Carbonate parameters were calculated. The concentrations of DIC are from 1.896-2.229 mmolL-1 in the NYS and from 1.939-2.032 mmolL-1 off the QC. In the southwest of the NYS, DIC in the upper layers decreases from the north of the SP (Shandong Peninsula) shelf to the center of the NYS; whereas in the lower layers DIC increases from the north of the SP shelf to the center of the NYS and South Yellow Sea. In the northeast of the NYS, DIC in all layers in- creases from the YR (Yalu River) estuary to the centre of the NYS. The distribution of DIC in NYS can be used as an indicator of Yellow Sea Cold Water Mass (YSCWM). Air-sea CO2 fluxes were calculated using three models and the results suggest that both the NYS and the QC waters are potential sources of atmospheric CO2 in October.