新型内外管差压流量计特性研究

针对现有各种流量计机械结构较复杂、节流方式对流体的扰动大、差压信号稳定性不足的缺点,设计了一种新型内外管差压流量计。运用三维CFD模拟仿真软件对其结构进行优化设计,通过实验验证了内外管差压流量计三维CFD仿真分析结果的可靠性。以内锥流量计作为参照对象,对内外管差压流量计的特性进行了对比分析,对比分析的结果表明,内外管差压流量计较内锥流量计压力损失小、压损比小、差压信号稳定性高。为了得到本装置的其他特性参数,又进行了大量的标定试验,实验结果表明测量精度、量程比等参数均满足技术标准的要求。

新型内外管差压流量计湿气测量模型研究

针对湿气的在线不分离测量,课题组提出了一种新型内外管差压式流量计,针对该流量计在天津大学油、气、水三相流实验装置上进行了测试,实验压力定为0.1 MPa和0.2 MPa,选取了与本实验工况相近的经典湿气测量模型对其虚高值进行了预测,预测结果显示"Bizon模型"预测效果最佳,但直接应用于内外管差压式流量计,测量误差仍不满足要求,因此,将理论分析与数据融合思想结合,进行了内外管差压流量计的湿气新测量模型拟合,建立湿气虚高值与其特性参数之间的非线性关系式。误差分析验证表明,新测量模型平均误差在1.6%以内,且误差波动性较小,比较稳定,能够满足工业生产中湿气的测量要求。

大容量液流、喷射染色机的管差原因剖析

文中对大容量液流、喷射染色机的利与弊进行了剖析。详尽分析了大容量液流、喷射染色机产生管差的原因,从机械设备、坯布准备、挡车操作等方面,提出了防止管差的具体措施。

新型内外管差压流量计特性研究

近年来,我国工业化进程推进趋势下,信息技术逐渐渗透至社会各个领域,在改革生产方式、提高生产效率及质量等方面发挥着十分重要的作用。内外管差压流量计作为其中的一部分,是工业生产中常见的设备之一,而在节能减排号召下,传统设备存在能耗高等弊端,对此本文针对新型设备的性能进行研究,明确其自身具有的节能降耗关键点,以期帮助人们更多的了解新型设备的优势,并积极引进该设备。

硫化车间火灾探测器的选型

介绍火灾探测器的种类以及硫化车间火灾探测器的选型依据。轮胎硫化车间内湿度大且有烟雾 ,环境恶劣 ,根据其火灾过程曲线并综合分析各探测器的特点后指出 :轮胎硫化车间里最适用的是感烟探测器 ,但普通感烟探测器不能正常工作 ,最好采用空气采样式烟雾探测器 ,也可采用空气管差温探测器以提高性能价格比 ,前者比后者价格贵 。

气流染色机的节电技术分析与应用

气流染色机由于利用风机的高速气流循环运动,因此有较高的用电量,而这个耗电量一直是应用企业诟病的地方。通过对风机电能消耗因素的分析,进行设备技术改进,从根本上大幅度降低了气流染色机的耗电,比技术改进前降低了1倍以上,并为染色时的管差控制提供了有利条件,使气流染色机染色一次成功率高、织物适应范围广、节能环保的特点更为突出。

A 2.4GHz CMOS Quadrature Voltage-Controlled Oscillator Based on Symmetrical Spiral Inductors and Differential Diodes

A voltage controlled oscillator (VCO) which can generate 2 4GHz quadrature local oscillating (LO) signals is reported.It combines a LC VCO,realized by on chip symmetrical spiral inductors and differential diodes,and a two stage ring VCO.The principle of this VCO is demonstrated and further the phase noise is discussed in detail.The fabrication of prototype is demonstrated using 0 25μm single poly five metal N well salicide CMOS digital process.The reports show that the novel VCO is can generate quadrature LO signals with a tuning range of more than 300MHz as well as the phase noise--104 33dBc/Hz at 600KHz offset at 2 41GHz (when measuring only one port of differential outputs).In addition,this VCO can work in low power supply voltage and dissipate low power,thus it can be used in many integrated transceivers.

Efficacy and Safety of a Continuous Wound Catheter in Open Abdominal Partial Hepatectomy

Objective To investigate the efficacy and safety of continuous local anesthetic wound infiltration following open abdominal partial hepatectomy. Methods We performed a prospective, non-randomized, concurrent and controlled study. Patients undergoing open abdominal partial hepatectomy, according to their willingness, accepted one of the following managements for the postoperative pain： continuous wound catheter （CWC） infiltration, patient-controlled epidural analgesia （PCEA）, patient-controlled intravenous analgesia of morphine （PCIAM）, and patient-controlled intravenous analgesia of sufentanil （PCIAS）. The primary outcome was postoperative visual analogue scale （VAS） scores at rest and on movement. Secondary outcomes included consumption of rescue medication, side effects, and complications associated with postoperative pain management. Results From August 2013 to December 2013, 80 patients were allocated to receive CWC （n=10）, PCEA （n=22）, PCIAM （n=29）, or PCIAS （n=19）. After adjusting for age, sex, body mass index, percentage of resected liver, operation time, and Amsterdam Preoperative Anxiety and Information Scale, there was no significant difference in the VAS scores at rest or on movement between Group CWC and the other groups, namely PCEA, PCIAM, and PCIAS, at 4, 12, 48, and 72 hours postoperatively （all P〉0.05）. The need for rescue medication was not significantly different between Group CWC and the other three groups at 48 and 72 hours postoperatively （all P〉0.05）. There was no significant difference in the incidence of postoperative nausea and vomiting or anal exsufflation time between group CWC and the other three groups （all P〉0.05）. No severe adverse effects associated with continuous wound infiltration were observed during the study period. Conclusions CWC has a comparable analgesic effect compared with traditional analgesia methods at most time points postoperatively. CWC is a safe alternative for the postoperative analgesic management of open liver surgery.

Diversity patterns and phylogenetic structure of vascular plants along elevational gradients in a mountain ecosystem, South Korea

Recently, a phylogenetic diversity and community structure analysis as complementary to species-centric approaches in biodiversity studies provides new insights into the processes of community assembly. In this study, we analyzed species and phylogenetic diversity and community structures for woody and herbaceous plants along two elevational transects on Mt. Baekhwa, South Korea. The species richness and phylogenetic diversity of woody plants showed monotonic declining patterns with increasing elevation along all transects, whereas herbaceous plants showed different patterns, such as no relationship and a reversed unimodal pattern, between the study transects. The main drivers of these patterns were climate and habitat variables for woody and herbaceous plants, respectively. In addition, the phylogenetic community structure primarily showed phylogenetic clustering regulated by deterministic processes, especially environmental filtering, such as climate or habitat factors, along the two transects, although herbaceous plants along a transect depicted phylogenetic randomness as a result of a neutral process. Our findings suggest that deterministic and neutral processes may simultaneously control the community structures along small-scale elevational gradients such as local transects, although the deterministic process may be the predominant type.

Prediction of Pressure Drop of Slurry Flow in Pipeline by Hybrid Support Vector Regression and Genetic Algorithm Model

This paper describes a robust support vector regression （SVR） methodology, which can offer superior performance for important process engineering problems. The method incorporates hybrid support vector regression and genetic algorithm technique （SVR-GA） for efficient tuning of SVR meta-parameters. The algorithm has been applied for prediction of pressure drop of solid liquid slurry flow. A comparison with selected correlations in the lit- erature showed that the developed SVR correlation noticeably improved the prediction of pressure drop over a wide range of operating conditions, physical properties, and pipe diameters.

Mutation of DNA polymerase p in esophageal carcinoma of different regions

AIM： To observe the variation of DNA polymerase β （polβ） in esophageal carcinoma. METHODS： Thirty specimens containing adjacent normal epithelial tissues were collected from patients in Linzhou region （a high risk area for esophageal squamous carcinoma） and 25 specimens were from a non-high risk area. Total RNA was extracted from the samples and reverse transcription polymerase chain reaction （RT-PCR） was performed. PCR products were cloned and sequenced to investigate the po1β gene with DNASIS and OMIGA. Statistical significance was evaluated using the X^2 test. RESULTS： High-inddence area group： Polβ gene variation was detected in 13 of 30 esophageal carcinoma tissue specimens, and only one variation was found in 30 corresponding adjacent normal tissue specimens. Non high-incidence area group： po1β gene variation was detected in 5 of 25 esophageal carcinoma tissue specimens, and no variation was found in 25 corresponding adjacent normal tissue specimens. The incidence of po1β gene variation observed in the high-incidence area group was significantly higher than in the non-high incidence area group. Two mutation hot spots （454-466 and 648-670 nt） and a 58 bp deletion （177-234 nt） were found. CONCLUSION： Variations of polβ perform different functions between the high-incidence areas and the other areas, and may play a more important role in the high-incidence areas.

Gender differences in the efficacy of cardiovascular rehabilitation in patients after cardiac surgery procedures

Cardiac rehabilitation （CR） programs are well known to improve patients＇ functional status after cardiac surgery and are recommended by current guideline. In fact, they pro- mote not only structured physical exercises but also a complete secondary prevention determining an overall reduction in recurrent cardiac events and an improvement in functional, psychosocial status and survival.

Anti-synchronization in Different Hyperchaotic Systems

Based on active control theory, anti-synchronization between two different hyperchaotic systems is investigated. The sufficient conditions for achieving anti-synchronization of two different hyperchaotic systems are derived. Moreover, numerical simulations are presented for hyperehaotic Lorenz-Chen system, hyperchaotic Lorenz-Lu system, and hyperchaotic Chen Lu system to verify the effectiveness and feasibility of the proposed anti-synchronization scheme.

Analysis of Heat Transfer Performance of Oscillating Heat Pipes Based on a Central Composite Design

Oscillating heat pipes (OHPs) are very promising cooling devices. Their heat transfer performance is af- fected by many factors, and the form of the relationship between the performance and the factors is complex and non-linear. In this paper, the effects of charging ratio, inclination angle, and heat input and their interaction effects on heat transfer performance of a looped copper-water OHP are analyzed. First, suppose that the relationship between the response and the variables approximates a second-order model. And use the central composite design to arrange the ex- periment. Then, the method of least squares is used to estimate the parameters in the second-order model. Finally, multi- variate variance analysis is used to analyze the model. The results show that the assumption is right, that is to say, the re- lationship is well modeled by a second-order function. Among the three main effect variables, the effect of inclination angle is the most significant, but their interaction effects are not significant. In the range of the considered factors, both the optimum charging ratio and the optimum inclination angle increase as the heating water flow rate increases.

A novel adaptive joint power control algorithm with channel estimation in a CDMA cellular system

Joint power control has advantages of multi-user detection and power control; and it can combat the multi-access interference and the near-far problem. A novel adaptive joint power control algorithm with channel estimation in a CDMA cellular system was designed. Simulation results show that the algorithm can control the power not only quickly but also precisely with a time change. The method is useful for increasing system capacity.

Low phase noise millimeter wave monolithic integrated phase locked-loop

A Monolithic integrated phase locked-loop （PLL） with a low phase noise is proposed in this paper. Several techniques are utilized to improve the performance of the PLL which works at the milli- meter-wave band. The on-chip high-Q eoplanar waveguides （CPWs） are utilized in the resonant tank and the differential current amplifier with a resonator is used to realize the VCO. In the output buffer circuit, several stages of cascaded source-followers connect and differential amplifiers are adopted to improve the driving capability of the PLL＇ s output signals. An improved analog multiplier topology is also used in the PD circuit to improve the gain of the PD. The proposed PLL is realized with a 0.2p, m GaAs pseudomorphie high electron mobility transistor （PHEMT） process. At 10 kHz offset from the center frequency, the measured output phase noise of the PLL output is only -88.83dBc/Hz. The circuit exhibits a low root mean sauare （RMS） litter of 1.68Ds.

Characteristics of Multipath Effects in GPS Dynamic Deformation Monitoring

ABSTRACT The multipath has long been considered a major error source in GPS applications .The characteristics 0f the GPS signal multipath effects are analyzed. based on which an experiment that considers the characteristics of dynamic deformation monitoring has been carried out. The solution results of observation data in two successive days are processed by a method,which combines the wavelet filtering and the differential correction betweentwo successive days. The research demonstrates that the multipath errors have stronger repeatability on successive days;after significantly mitigating the influence of multipath effects,the accuracy of three-dimensional positioning for GPS dynamic deformation monitoring can attain the mm level,an obvious accuracy improving particularly invertical component.The characteristics of GPS signal multipath,th eexperimental scheme and the qualitative and quantitative analysis of results are detailed.

Confining Potential Mode in Baryons Spectrum

Based on the flux tube model, the effects of the confining potentials of different configurations, namely the △-type and the Y-type, on the spectra of baryons are studied on SUSF（6） basis. The baryon spectra are obtained in a unified manner. Our result shows that by employing either the △-mode or the Y-mode confining potential, one can achieve reasonable baryon spectra. The △-mode may be mostly effective for the short- and medium-distances, while the Y-mode may offer more contributions to the spectra for long-distances. Although the binding energies in baryon spectra may deviate by a few to several tens MeV for different modes, it is hard to determine either one to be dominant by simply evaluating the baryon spectra. One may need to invoke the baryon decay process to make further judgement.

SCISSORS DIFFERENCE AND ITS IMPACTS ON ECONOMIC VALUE OF CULTIVATED LAND IN CHINA

The problem of price scissors difference between industrial products and agricultural products is one of the important problems in China. It impacts not only the living standard improvement of farmers but also the economic value of cultivated land, furthermore results in the direct and indirect loss of cultivated land resources. China＇s cultivated land area has decreased dramatically in recent years. An important reason for the decrease is the relatively low cost of cultivated land occupancy, which results from the distortion of economic value of cultivated land due to the existence of scissors difference. This study firstly analyzed the dynamic change of scissors difference and calculated the absolute and relative magnitude of scissors difference from 1997 to 2002, then computed the economic value of cultivated land before and after scissors difference adjustment in 2002, and finally discussed the inverted scissors difference. Results suggest that the scissors difference has a remarkable impact on the economic value of cultivated land, and the adjustment of scissors difference even inverted scissors difference to the economic value of cultivated land is indisoensable.

Oligomicroarray-based primary study of gene expression profile changes in Barrett’s esophagus

Objective: To analyze the differential expression genes (DEGs) between Barrett’s esophagus (BE) and normal esophagus mucosa and explore the target genes related to the development and progression of BE. Methods: The total RNAs of matched BE and normal esophagus mucosa of BE patients were isolated using one step Trizol method. Matched RNAs were qualified using 10 g/L agarose gel electrophoresis. cRNAs were synthesized, fluorescence labeled and purified after total RNAs were purified. The RNAs of BE and normal esophagus mucosa were hybridized with Agilent oligomicroarray (30 968 probes). The fluorescence intensity features were detected by Agilent scanner and quantified by feature extraction software. Results: (1) The total RNA, reverse transcription product and fluorescence labeled cRNA were all of high quality; (2) There were 142 up-regulated genes and 284 down-regulated genes among 2-fold DEGs. Conclusion: Microarray-based studies are feasible in endoscopically obtained tissues. Many BE-associated genes are screened by the high-throughput gene chip. The development and progression of BE is a complicated process involving multiple genes and multiple procedures, and functional study of these genes may help to identify the key genes or pathways involved in the pathogenesis and development of BE.