TOPOLOGY AND VORTEX STRUCTURES OF A CURVING TURBINE CASCADE WITH TIP CLEARANCE (Ⅱ)- TOPOLOGICAL FLOW PATTERN AND VORTEX STRUCTURE IN THE TRANSVERSE SECTION OF A BLADE CASCADE

By means of ink trace visualization of the flows in conventional straight, positively curved and negatively curved cascades with tip clearance, and measurement of the aerodynamic parameters in transverse section, and by appling topology theory, the topological structures and vortex structure in the transverse section of a blade cascade were analyzed. Compared with conventional straight cascade, blade positive curving eliminates the separation line of the upper passage vortex, and leads the secondary vortex to change from close separation to open separation, while blade negative curving effects merely the positions of singular points and the intensities and scales of vortex.

Flow patterns and their transition characteristics of the air-water two-phase flow in a horizontal pipe with a sudden-changed cross-section area

Flow patterns in upstream and downstream straight tubes of sudden-changed areas in a horizontal straight pipe were experimentally examined. Both sudden-expansion cross-section (SECS) and sudden-contraction cross-section (SCCS) were investigated. The flow pattern maps upstream and downstream were delineated and compared with those in straight tubes with uniform cross-sections. The effects of the SECS and SCCS on flow patterns were discussed and analyzed. Furthermore, flow pattern transition mechanisms resulting in occurrences of different flow patterns were simply discussed and some transition criteria for the flow pattern transitions were deduced by using the non-dimensionlized analysis method.

The influence of selective cutting of mixed Korean pine(Pinus koraiensis Sieb.et Zucc.) and broad-leaf forest on rare species distribution patterns and spatial correlation in Northeast China

This study aimed to demonstrate change in spatial correlation between Korean pine （Pinus koraiensis Sieb. et Zucc.） and three rare species, and change in spatial distribution of four species in response to a range of selective cutting intensities. We sampled three plots of mixed Korean pine and broad-leaf forest in Lushuihe Forestry Bureau of Jilin province, China. Plot 1, a control, was unlogged Korean pine broad-leaf forest. In plots 2 and 3, Korean pine was selectively cut at 15 and 30 % intensity, respectively, in the 1970s. Other species were rarely cut. We used point-pattern analysis to research the spatial distributions of four tree species and quantify spatial correlations between Korean pine and the other three species, Amur linden （Tilia amurensis Rupr.）, Manchurian ash （Fraxinus mandshurica Rupr.）, and Mongolian oak （Quercus mongolica Fisch.） in all three plots. The results of the study show that selective cutting at 15 % intensity did not significantly change either the species spatial patterns or the spatial correlation between Korean pine and broadleaf species. Selective cutting at 30 % intensity slightly affected the growth of Korean pine and valuable species in forest communities, and the effect was considered nondestructive and recoverable.

Expression Pattern and Target Gene of bbu-miR-103-1 in Buffalo(Bubalus bubalis) at Lactation and Non-lactation Periods

[ Objectivel The paper aimed to investigate the expression pattern of bbu-miR-103-1 in buffalo （Bubalus bubalis） at lactation and non-lactation periods, and to predict its target gene and function. [ Method] Expression pattern of bbu-miR-103-1 at lactation and non-lactation periods were detected by qRT-PCR. The precursor expression plasmid of bbu-miR-103-1 was constructed and named LpEZX-pre-miR-103-1. It was packaged and propagated to produce high-titer lenti- virus in 293T cell lines, which could be used to infect buffalo mammary epithelial cells （BMECs） and over express bbu-miR-103-1. The inhibitor of bbu-miR- 103-1 was chemically synthesized and transfected into BMECs to suppress bbu-miR-103-1 at the same time. The relative expression of pantothenate kinase 3 （ PANK3 ） and milk fat metabolism related genes were detected by qRT-PCR. [ Result] The relative expression of bbu-miR-103-1 at lactation period was 5.29 times higher than that at non-lactation period in buffalo （ P 〈 0.01 ）. The LpEZX-pre-miR-103-1 had been successfully constructed and packaged with the infection titer of 3.47×10^6 PFU/mL. Overexpress or suppress of bbu-miR-103-1 extremely down-regulated or up-regulated the expression level of PANK3 in BMECs （ P 〈 0.01 ）. Over expression of bbu-miR-103~l extremely enhanced the expression of Acetyl-CoA carboxylase alpha（ACACA）, Glycerol-3-phosphate acyhransferase 1 mitochon- drial （GPAM）, Diacylglycerol Oacyhransferase l （DGAT1） and Pyrnvate dehydrogenase lipoamide kinase isozyme 4 （PDK4） （P 〈0.01 ）, and also significantly up-regulated the expression of sterol regulatory element binding protein-1 c （SREBPI c）, Adipose differentiation-related protein （ADFP）, Cluster of differentiation 36 （ CD36）, Acetyl-CoA synthetase short-chain subfamily member 1 （ACSS1） （P 〈0.05）. Over expression of bbu-miR-103-1 down-regulated the expression of PANK3, and improved the mRNA level of SREBPlc by feedback regulation, finally promoting the de novo synthesis of fatty acid beginning with ACACA. [ Conclusion] bbu-miR-103-1 plays an important role in enhancing milk fatty acid synthesis, which provides a molecular base for revealing formation and regulatory mechanism of high-level milk fat in buffalo.

OPTIMIZATION ON ANTENNA PATTERN OF SPACEBORNE SAR WITH IMPROVED NSGA-Ⅱ

Optimization of antenna array pattern used in a spaceborne Synthetic Aperture Radar (SAR) system is considered in this study. A robust evolutionary algorithm, Non-dominated Sorting Genetic Algorithms (the improved NSGA-Ⅱ), is applied on a spaceborne SAR antenna pattern design. The system consists of two objective functions with two constraints. Pareto fronts are generated as a result of multi-objective optimization. After being validated by a test problem ZDT4, the algorithms are used to synthesize spaceborne SAR antenna radiation pattern. The good results with low Ambi- guity-to-Signal Ratio (ASR) and high directivity are obtained in the paper.

Antibiotic Prescribing Patterns and Prevalence of Surgical Site Infections in Caesarean Section Deliveries at Two Tertiary Hospitals in Lusaka, Zambia

Introduction: A caesarean section (CS) is one of the most frequently performed obstetric surgeries in the world and its use has increased dramatically in recent years. The number of caesarean section cases worldwide has been increasing each year, and the World Health Organization (WHO) reported an excess of 10% - 15% of CS procedures for all births. However, some women experience surgical site infections (SSIs) after undergoing CS delivery. This study investigated the prescribing patterns of antibiotics in CS deliveries and the prevalence of SSIs at two tertiary hospitals in Lusaka, Zambia. Materials and Methods: A retrospective cross-sectional study was conducted from January 2020 to December 2020 at the Women and Newborn University Teaching Hospital (UTH) and the Levy Mwanawasa University Teaching Hospital, in Lusaka, Zambia. Results: Of a total of 838 women who delivered via CS, more than half were aged between 21 and 25 years (n = 461, 55.0%), 56.3% were from low-cost residential areas, and 57% had emergency CS delivery. The prevalence of SSIs was 6.0%, with the level of education (OR 0.377, 95% CI 0.150 - 0.946), type of caesarean section (OR 6.253, 95% CI 2.833 - 13.803), and oral antibiotics post-caesarean (OR 0.218, 95% CI 0.049 - 0.963). The duration of IV antibiotic treatment significantly predicted SSI (p Conclusion: This study found that the third-generation cephalosporin (cefotaxime) and triple combination therapy (benzylpenicillin, gentamicin, and metronidazole) were the most frequently prescribed antibiotics before and after CS. The level of education, type of CS, oral antibiotics post-CS, facility, and duration of administering IV antibiotics were all predictors of SSIs.

Computer-aided Pattern Design of Multi-bar Warp Knitted Fabrics

To meet the development trend of multi-bar warp knit-ting machine towards high-speed,advanced technologyand computer control and the requirements of variousproducts with small quantity,there are many researcheson the computer-aided pattern design of multi-barwarp knitted fabrics.In terms of the special propertiesof the computer-aided pattern design of multi-barwarp knitted fabrics,the Object Oriented Program(OOP)programming-Object Windows class Library(OWL)programming is selected.According to thecharacters of the OWL programming,various functionsare defined.Pattern design and technical parameters canbe output,which offers a great convenience for the fac-tory.

Study On Pattern Design of Men's Tailored-suit Sleeve

Sleeve pattern design of men’ s tailored - suit is one of the most difficult problems of clothing pattern design. Based on the experimental studies of armhole girth, the difference of armhole width and crown height, crown angle, under sleeve curve’s diagonal line length, crown ease and its distribution rule, this paper mainly deals with the sleeve pattern design of tailored - suit for Chinese men. The influences of these factors are discussed and furthermore, some qualitative, quantifiable conclusions are drawn to design perfect pattern of men’ s tailored - suit sleeve.

不同截面形式钢-混组合梁桥面板横向受力性能分析

为研究不同截面形式对钢-混组合梁桥面板横向弯曲效应的影响,以山东九龙东枢纽天桥为背景进行研究。采用有限元软件建立4种截面主梁(波形钢腹板工字梁、波形钢腹板箱梁、平钢板工字梁及混凝土箱梁)精细化模型,对比分析轮载作用数量、轮载横向作用位置对桥面板有效分布宽度的影响,同时对自重、轮载作用以及二者共同作用下的桥面板横向弯矩进行分析,并与《公路钢筋混凝土及预应力混凝土桥涵设计规范》(JTG 3362—2018,简称《桥规》)计算值进行对比。结果表明:双轮载作用下的桥面板有效分布宽度明显大于单轮载作用下的桥面板有效分布宽度,横向设计时应考虑轮载作用数量对桥面板安全设计的影响;钢-混组合梁桥面板有效分布宽度计算时,当轮载作用在横向跨中、支承附近处,采用《桥规》计算,当轮载作用在支承、悬臂板处,建议桥面板有效分布宽度修正系数分别取0.60、1.50;建议波形钢腹板工字梁、波形钢腹板箱梁、平钢板工字梁桥面板弯矩修正系数在轮载作用下分别取0.60、0.60、0.65,在自重、轮载共同作用下分别取0.55、0.55、0.60。

Identification of Socio-Demographic, Behavioral Patterns and Their Relationship with HIV Status among Female Sex Workers

The prevalence of HIV in high risk population is influenced significantly the behavioral and sociodemographic characteristics. However, considering the complexity of behavior among female sex workers, the relationship between a particular behavioral pattern and the HIV status of this “at risk” population assumes significance. Data generated in a community-based cross-sectional study earlier carried out to assess the prevalence estimates, at district level, of HIV status in eight districts of State of Andhra Pradesh, India was used to carry out factor analysis to explore the role of demographic and behavioral pattern and their relationship with the HIV status among female sex workers. Data on 3083 female sex workers in the study revealed that there existed nine patterns among demographic and behavioral characteristics, which explained 62% of the total variation through factor analysis. Further, cluster analysis was performed to identify the groups of individuals having similar characteristics. Two of those clusters had sizeable numbers having similar characteristics. FSWs belonging to cluster 2 had significantly high risk factors compared with Cluster 1. The overall prevalence of HIV was 11.4% (10.6% in cluster 1 and 15.9% in cluster 2) among high risk population. There exists a strong relationship between behavioral patterns and HIV positive.

Lung Function Impairment among Gasoline Attendants: A Cross-Sectional Study

Background: Occupational health is an important consideration, especially for people that work in an environment with pollutants. Gasoline attendants are individuals that work in filling stations. They are constantly exposed to gasoline fumes and automobile engine products from vehicle exhaust. This increases the risk of acute and chronic respiratory diseases and carcinogenesis among them. The risk of health complications tends to increase with the duration of exposure. The study aimed to determine the proportion of gasoline attendants with lung function impairment. Methods and Materials: Two hundred and eight eligible participants were recruited for this study. A cross-sectional analytical study was carried out in Esan West local government area of Edo state, Nigeria. The study was carried out for a period of six months from December 2015 to May 2016. A questionnaire was used to obtain information on demographic characteristics, work history, mode of exposure and duration of exposure to petrol fumes. Lung function was assessed using a DTspiro spirometer (Model POP 10. Serial no 110843-005);also the anthropometric parameters of the respondent were measured. Statistical analysis was done using IBM SPSS version 20.0. Frequency and percentages were used to present categorical data. The mean and standard deviation of continuous variables were calculated and compared using the student’s t-test. The criteria of significant association were assumed for a p-value less than 0.05. Results: A total of one hundred and forty petrol pump attendants and one hundred and forty controls participated in this study. The mean age for petrol pump attendants was 24 ± 3.1 years and 23 ± 2.8 years for the control group. There were no significant differences in the gender distribution and anthropometric parameters as observed in this study. The lung impairment pattern observed in this study was obstructive in twelve (8.6%) gasoline pump attendants and restrictive pattern in thirty-nine (27.9%) gasoline pump attendants, while only four (2.9%) had an obstructive pattern and twelve (8.6%) had a restrictive pattern of lung impairment among the control group. This implies that a restrictive pattern was predominant. This study also observed that there was an increase in the number of gasoline pump attendants with declined lung function compared to the control group. Conclusion: Restrictive pattern of lung impairment was more predominant than the obstructive pattern among gasoline pump attendants. As a result, public health interventions should be instituted among these individuals, especially in developing countries.

Lung Function Impairment among Gasoline Attendants: A Cross-Sectional Study

Background: Occupational health is an important consideration, especially for people that work in an environment with pollutants. Gasoline attendants are individuals that work in filling stations. They are constantly exposed to gasoline fumes and automobile engine products from vehicle exhaust. This increases the risk of acute and chronic respiratory diseases and carcinogenesis among them. The risk of health complications tends to increase with the duration of exposure. The study aimed to determine the proportion of gasoline attendants with lung function impairment. Methods and Materials: Two hundred and eight eligible participants were recruited for this study. A cross-sectional analytical study was carried out in Esan West local government area of Edo state, Nigeria. The study was carried out for a period of six months from December 2015 to May 2016. A questionnaire was used to obtain information on demographic characteristics, work history, mode of exposure and duration of exposure to petrol fumes. Lung function was assessed using a DTspiro spirometer (Model POP 10. Serial no 110843-005);also the anthropometric parameters of the respondent were measured. Statistical analysis was done using IBM SPSS version 20.0. Frequency and percentages were used to present categorical data. The mean and standard deviation of continuous variables were calculated and compared using the student’s t-test. The criteria of significant association were assumed for a p-value less than 0.05. Results: A total of one hundred and forty petrol pump attendants and one hundred and forty controls participated in this study. The mean age for petrol pump attendants was 24 ± 3.1 years and 23 ± 2.8 years for the control group. There were no significant differences in the gender distribution and anthropometric parameters as observed in this study. The lung impairment pattern observed in this study was obstructive in twelve (8.6%) gasoline pump attendants and restrictive pattern in thirty-nine (27.9%) gasoline pump attendants, while only four (2.9%) had an obstructive pattern and twelve (8.6%) had a restrictive pattern of lung impairment among the control group. This implies that a restrictive pattern was predominant. This study also observed that there was an increase in the number of gasoline pump attendants with declined lung function compared to the control group. Conclusion: Restrictive pattern of lung impairment was more predominant than the obstructive pattern among gasoline pump attendants. As a result, public health interventions should be instituted among these individuals, especially in developing countries.

铜街-曼家寨矿段矽卡岩含矿性研究

铜街-曼家寨矿段位于文山老君山花岗岩体南西端的都龙锡锌矿带,矿段内赋存由加里东期志留纪花岗岩的侵入产生的热变质作用形成的干矽卡岩及经过燕山期花岗岩侵入产生的接触交代变质作用形成的湿矽卡岩。文章对铜街-曼家寨矿段矽卡岩进行了科学实验,并对其元素富集规律、品位变化特征行了研究总结。

2000-2011年三峡库区重庆段植被覆盖景观格局变化

基于遥感数据 M ODIS NDVI ，利用像元二分模型定量估算了三峡库区重庆段不同时期（2000－2003年，2004－2007年，2008－2011年）植被覆盖度的变化。将植被覆盖度划分为4个等级：I级（0％～40％）、II级（40％～60％）、III级（60％～80％）、IV级（80％～100％），结合景观生态学理论分析了植被覆盖景观格局随时间的动态变化。结果表明：2000－2011年，III ，IV级所占面积比例之和达到90％以上，是研究区植被覆盖景观的基质。植被覆盖变化的总体趋势为低覆盖度类型向高覆盖度类型转变，整体呈现正向演替的良性发展。近12年来，研究区内植被覆盖景观中各斑块类型在优势度、破碎度、形状、连通性等方面变化差异明显。整体植被覆盖景观格局的镶嵌程度增加，形状趋于复杂，多样性和异质性不断增强，对植被覆盖景观格局起支配作用的优势斑块类型由III级逐渐转变为IV级，各斑块类型在空间上的分布趋向均衡化，结构趋于复杂化，其中III ，IV级特征的变化对植被覆盖景观格局动态起决定性作用。三峡库区植被覆盖景观格局积极变化的主要原因极有可能是近年来由政府主导开展的生态建设和生态恢复。

复杂电磁环境辐射-散射耦合场快速预估方法

针对复杂电磁环境中目标散射体和干扰辐射源同时存在,影响目标回波散射场的问题,提出了一种基于辐射源方向图和极化散射矩阵数据的耦合场快速预估方法。利用可提前独立获取和加载的辐射源方向图及目标各个方向的散射数据,实现了辐射-散射耦合场景下空间总电磁场的近实时快速预估。仿真计算了辐射源与散射体不同距离和相对强度下场景的总电场变化情况,验证了辐射-散射耦合效应对目标回波场存在显著影响。无需使用电磁计算方法对场景进行重新计算,满足复杂电磁环境内场仿真试验对实时提供数据的需求,具有工程应用价值。

CD99核旁点状阳性:诊断胰腺实性-假乳头状肿瘤的一种独特的染色模式

Guo Y,Yuan F,Deng H,et al.Paranuclear dot-like immu-nostaining for CD99：a unique staining pattern for diagnosingsolid-pseudopapillary neoplasm of the pancreas.Am J SurgPathol,2011,35（6）：799-806.胰腺实性-假乳头状肿瘤是一种组织发生尚未确定的罕见肿瘤,特征性的表现为假乳头状结构伴囊性和实性生长方式。

CD99核旁逗点状阳性:一种诊断胰腺实性-假乳头状肿瘤的独特的染色模式

Guo Y,Yuan F,Deng H,et al.Paranuclear dot-like immu-nostaining for CD99：A unique staining pattern for diagnosingsolid-pseudopapillary neoplasm of the pancreas.Am J SurgPathol,2011,35：799-806.胰腺实性-假乳头状肿瘤（SPN）,又名乳头状囊性肿瘤。

Push-over分析方法在异形柱结构中的应用

Push-over分析方法近年来在地震工程界引起广泛兴趣,我国新的抗震设计规范已将这种方法作为大震作用下结构弹塑性分析的一种方法。影响Push-over分析结果的准确性有许多因素,其中对结构施加的侧向加载模式至关重要。采用不同的侧向加载模式对一座12层不规则异形柱结构进行Push-over分析,并将分析结果与非线性时程分析的结果进行比较,由此给出该异形柱结构Push-over分析加载模式选取的建议。

Experimental investigation on the failure mechanism of a rock landslide controlled by a steep-gentle discontinuity pair

A type of rock landslide is very common in practical engineering, whose stability is mainly controlled by the rock bridge between the steep tensile crack at the crest and the low-inclination weak discontinuities at the toe(namely, ligament is the term for the locking section in the slope). To obtain a deeper understanding into the failure process of this kind of landslide, twenty-four physical slope models containing a steep-gentle discontinuity pair(a steep crack in the upper part and a low-inclination discontinuity in the lower part) were tested by applying vertical loads at the crests. The results indicate that the inclination angle of the ligament(θ) has great influence on the failure and stability of this type of rock slope. With the change of θ, three failure patterns(five subtypes) concerning the tested slopes can be observed, i.e., tensile failure of the ligament(Type 1), tension-shear failure of the ligament(Type 2) and two-stage failure of the main body(Type 3). The failure process of each failure mode presents five stages in terms of crack development, vertical load, horizontal/vertical displacements and strains in the ligaments. The specific range of the ligament angle between different failure patterns is summarized. The discussion on the failure resistances and ductility of different failure patterns, and the guiding significances of the experimental findings to the stability evaluation and the reinforcement were conducted.

黄河大堤内外农村居民点空间格局演变特征及差异分析--以河南段为例

为探寻黄河下游生态薄弱河段大堤内外居民点空间格局演变特征及差异,基于2009—2019年高分辨率遥感影像,运用空间韵律测度、GIS空间分析等方法对研究区居民点空间格局特征变化进行分析。结果表明,在空间分布变化方面,大堤内外农村居民点均分布更加集中和密集,堤内聚集态势更强,居民点发展方向相反。核密度高值区域变化不明显,中低值区域变化显著;在规模特征变化方面,研究区居民点总量减少,总体规模偏小。堤外居民点规模明显高于堤内,但堤内居民点扩张面积却超过堤外,居民点个数变化受不同因素影响,小规模居民点扩张明显。热点区沿黄河大堤呈糖葫芦形间断分布,热点区和冷点区均减少;在形态变化方面,堤内外居民点形态均朝规则方向发展,堤内外均保持着较好的连通度。堤外破碎化程度高于堤内,并且在10年后该态势保持不变。结合近10年来滩区和堤外居民点空间格局变化特征,提出堤内外差别化居民点空间管控和整治,为黄河滩区生态保护和高质量发展背景下的农村居民点迁建工程、滩区脱贫攻坚提供参考。