常流量法PVC-U普通单立管排水系统通水能力测试研究

介绍了常流量法测试PVC-U普通单立管排水系统的测试结果,总结了测试过程中发现的一些问题,并就下一步应进行的试验提出建议。认为采用常流量法进行排水系统通水能力测试,判定条件可行,重复性好。

进舱前常压高流量吸氧训练对儿童孤独症高压氧治疗依从性及疗效的影响

目的探讨进舱前常压高流量吸氧训练对儿童孤独症高压氧治疗依从性及疗效的影响。方法选择我院及南宁市残疾康复中心2017年1月-2018年12月的儿童孤独症患儿60例。将60例患儿随机分为观察组和对照组各30例,对照组进舱前进行常规宣教后进舱,观察组在常规宣教基础上给予1~3 d常压高流量吸氧适应性训练,患儿适应后进舱。对两组患儿治疗依从性及疗效进行比较。结果观察组患儿的依从性及疗效均优于对照组,差异有统计学意义(P<0.05)。结论进舱前常压高流量吸氧训练能明显提高患儿高压氧治疗的依从性及疗效,值得临床推广应用。

进舱前常压高流量吸氧训练在儿童孤独症高压氧治疗中的应用研究

[目的]观察进舱前常压高流量吸氧训练在儿童孤独症高压氧治疗中的应用效果,总结护理方法。[方法]将60例孤独症患儿随机分为观察组和对照组各30例,对照组进舱前进行常规宣教后进舱,观察组进舱前进行常规宣教,同时给予1~3 d常压高流量吸氧适应训练,患儿适应后进舱。比较两组患儿高压氧治疗的配合情况、不良反应及依从性。[结果]观察组患儿的配合情况及依从性均优于对照组,不良反应发生率低于对照组,差异有统计学意义(P<0.05)。[结论]进舱前进行常压高流量吸氧训练能减少患儿治疗的不良反应,治疗配合情况好,患儿依从性高。

普通铸铁双立管通水能力试验研究

介绍了常流量法测试普通铸铁双立管排水系统的测试结果,研究普通铸铁双立管排水系统的通水能力和气压波动情况,利用排水系统水膜流理论分析通气立管与排水立管连接数量的不同对系统压力波动的影响,得到普通铸铁双立管通水能力的相关结论。

常压高流量氧治疗胎儿阵发性室上性心动过速疗效观察

目的 探讨常压高流量氧治疗胎儿阵发性室上性心动过速（SVT）的疗效.方法 选择经多普勒超声检查诊断为胎儿阵发性SVT孕妇共35例,采用常压高流量氧疗法进行治疗.孕妇在常压环境下戴面罩吸氧,供氧浓度为99.5％,氧流量为10 L/min,吸氧时间为30 min,中间间歇5 min吸空气,每日吸氧1次,10次为1个疗程.每治疗1个疗程复查心脏彩色多普勒超声及外周多普勒检测以评定疗效.结果 35例中18例治疗1个疗程、11例治疗2个疗程SVT消失,3例转为偶发性房性早搏,治疗总有效率91.4％,治愈率82.9％.治疗后胎儿心率、心胸面积比小于治疗前,心脏缩短分数、大脑中动脉搏动指数大于治疗前,差异均有统计学意义（P＜0.01）.结论 缺氧可能是诱发胎儿阵发性室上性心动过速的因素之一,常压高流量氧可有效抑制胎儿阵发性SVT,疗效肯定,无创,安全.

Anomaly detection for network traffic flow

This paper presents a mechanism for detecting flooding-attacks. The simplicity of the mechanism lies in its statelessness and low computation overhead, which makes the detection mechanism itself immune to flooding-attacks. The SYN-flooding, as an instance of flooding-attack, is used to illustrate the anomaly detection mechanism. The mechanism applies an exponentially weighted moving average (EWMA) method to detect the abrupt net flow and applies a symmetry analysis method to detect the anomaly activity of the network flow. Experiment shows that the mechanism has high detection accuracy and low detection latency.

Video-based urban expressway traffic measurement and performance monitoring

This paper presents an urban expressway video surveillance and monitoring system for traffic flow measurement and abnormal performance detection. The proposed flow detection module collects traffic flow statistics in real time by leveraging multi-vehicle tracking information. Based on these online statistics, road operating situations can be easily obtained. Using spatiotemporal trajectories, vehicle motion paths are encoded by hidden Markov models. With path division and parameter matching, abnormal performances containing extra low or high speed driving, illegal stopping and turning are detected in real scenes. The traffic surveillance approach is implemented and evaluated on a DM642 DSP-based embedded platform. Experimental results demonstrate that the proposed system is feasible for the detection of vehicle speed, vehicle counts and road efficiency, and it is effective for the monitoring of the aforementioned anomalies with low computational costs.

3G网络中的CDMA校园网建设

校园网络建设一直是网络建设中的重点和难点。尤其随着3G业务的推广和普及,数据业务给现有网络带来了巨大的冲击。如何在快速发展校园用户的同时更好地应对数据业务,这给网络建设提出了新的考验。文章结合CDMA(码分多址)网络的特点,分析研究校园网建设的特点,结合案例分析提出了校园网建设的一些思路和解决策略。

Approach to Anomaly Traffic Detection in a Local Network

The research intends to solve the problem of the occupation of bandwidth of local network by abnormal traffic which affects normal user's network behaviors.Firstly,a new algorithm in this paper named danger-theory-based abnormal traffic detection was presented.Then an advanced ID3 algorithm was presented to classify the abnormal traffic.Finally a new model of anomaly traffic detection was built upon the two algorithms above and the detection results were integrated with firewall.The firewall limits the bandwidth based on different types of abnormal traffic.Experiments show the outstanding performance of the proposed approach in real-time property,high detection rate,and unsupervised learning.

Complete Space-like Submanifolds with Constant Scalar Curvature in de Sitter Spaces

In this paper,we study the complete space-like submanifold Mn with constant scalar curvature R≤c in the de Sitter space Spn+p(c) and obtain a pinching condition for Mn to be totally umbilical ones.The result generalizes that in [5,Main Theorem] to higher codimension and give a complement for n=2 there.

Decomposition patterns of leaf litter of seven common canopy species in a subtropical forest： dynamics of mineral nutrients

Dynamical patterns of mineral elements during decomposition processes were investigated for seven common canopy species in a subtropical evergreen broad-leaved forest by means of litterbag technique over 2 years. The species studied are representative for the vegetation in the study area and differed significantly in chemical qualities of their litter. No significant relationships were found between decomposition rate （percentage dry mass remaining and decomposition constant k） and initial element cuncentrations.However, there were significant correlations betweeu the percentage of dry mass remaining and the mineral element concentrations in the remaining litter for most cases. The rank of the element mobility in decomposition process was as follows： Na = K 〉 Mg ≥ Ca 〉 N ≥ Mn ≥ Zn ≥ P 〉 Cu 〉〉 Al 〉〉 Fe. Concentrations of K and Na decreased in all species as decomposition proceeded. Calcium and Mg also decreased in concentrntion but with a temporal increase in the initial phase of decomposition, while the concentrations of other elements （Zn, Cu, AL and Fei increased for all species with exception of Mn which revealed a different pattern in different species. In most species, microelements （Cu, Al, and Fe） significantly increased in absolute amounts at the end of the litterbag incubation, which could be ascribed to a lange extent to the mechanism of abiotic fixation to humic substances rather than biological immobilization.

Second Order Parallel Tensors on Quasi-constant Curvature Manifolds

The author establishes in this paper the following results: (1) In a quasiconstant curvature manifold M a parallel tensor of type is constant multiple of the metric tensor. (2) On a quasi_constant curvature manifold there is no nonzero parallel 2_form. Unless the Ricci principal curvature corresponding to the generator of M is equal to zero.

ANALYSES OF THE ANNUAL FREQUENCY ANOMALIES OF TYPHOONS AND HURRICANES IN 1998

In 1998, the annual frequency of typhoon (including tropical storms) genesis created a minimum value — 14, far lower than the minimum of 20 in 1950 over North-West Pacific, while in the Atlantic Ocean, the annual frequency of hurricanes (including the tropical storm) created a maximum value — 14, far higher than the average number — 9.2. In this paper, an analysis on the relationship between the generation of Typhoon, Hurricane and the Cross-Equatorial Flow was done by using the NCEP/NCAR reanalysis data for 1979 – 1995. It is pointed out that the anomalies of the CEF over the Pacific and Atlantic Ocean is the main cause for the 1998 annual frequency anomalies of Typhoon and Hurricane, respectively.

Kinetics of acid-oxygen leaching of low-sulfur Ni-Cu matte at atmospheric pressure

The leaching of low-sulfur Ni-Cu matte in acid-oxygen(CuSO4-H2SO4-O2)solution at atmospheric pressure was researched.This matte was obtained from high grade Ni-Cu matte by magnetic separation,which mainly contained Ni-Cu alloy and a small quantity of sulfides.The effects of temperature,agitation speed,oxygen flow rate,particle size,acid concentration and concentration of copper ion were studied.It is found that the matte particles are leached by shrinking core mechanism and the leaching process is electrochemically controlled.In a temperature range of 30-60℃,the surface reaction is rate-limiting step,with an apparent activation energy of 41.9 kJ/mol.But at higher temperature(70-85℃),the rate process is controlled by diffusion through the product layer,with an apparent activation energy of 7.3 kJ/mol.

Traffic An o ma ly De te ctio n in Backbone Networks Using C la s s ifica tio n o f M u Itid ime n s io n a I Time Series of Entropy

Detecting traffic anomalies is essential for diagnosing attacks. HighSp eed Backbone Net works （HSBN） require Traffic Anomaly Detection Systems （TADS） which are accurate （high detec tion and low false positive rates） and efficient. The proposed approach utilizes entropy as traffic distributions metric over some traffic dimensions. An efficient algorithm, having low computational and space complexity, is used to estimate entro py. Entropy values over all dimensions are

Preliminary Study on the Dynamic Variations of the Surface Thermal Flux before and after the M_S5.7 Earthquake of 2005 in Jiujiang City,Jiangxi Province

The temporal and spatial variations of surface latent heat flux(SLHF)and diagnostic air temperature at 2m before and after the M_S5.7 earthquake occurring on November 26,2005 in the area between Ruichang City and Jiujiang City,Jiangxi Province are summarized in this paper.It is found that before the earthquake significant SLHF anomalies and air temperature anomalies occurred in the epicentral area and its vicinity.The air temperature anomalies appeared from the 2nd to the 13th of November,2005 and were concentrated at the epicentral area and in its southern part.Then two days later,that is,from the 4th to the 15th of November 2005,significant SLHF anomalies occurred in the epicentral area and to its northern area where many lakes are distributed along the active faults.During the anomalous period,the SLHF and air temperature at 2m exceeded the sum of average daily value over 26 years and 1.5 times of its mean square deviation.Both anomalies had maintained for 12 days with a peculiar distribution related to the tectonic active zone.It is considered that both of air temperature anomalies and SLHF anomalies are correlated to the movement of thermal flux from underground prior to earthquake.SLHF anomalies occurred over wide regions covered with abundant water,whereas air temperature anomalies occurred over land.

Study on Negative Impact of Harmonic Components on Sensitive Electric Equipment

Distribution systems operators are often confronted with declined power quality, which can cause substantial economical losses. The problem analyzed in paper concerns thyristor controlled direct current motor used for ski-lift in ski resort as a source of disturbances with negative impact on sensitive electric equipment, which is then unable to operate correctly. To solve mentioned problems, series of measurements of voltage quality parameters were carried out according to the respective valid standards. Crucial power quality parameters necessary for parallel power active filter design were then analyzed. Power active filter compensates power factor and filters characteristic current harmonics. After power active filter was put into operation, power quality problems were eliminated. Payback period is estimated up to four years.

104例颅内动脉瘤和脑血管畸形患者氧治疗方案探讨

目的对颅内动脉瘤和脑血管畸形患者氧治疗方案的治疗效果及安全性进行探讨。方法对41例颅内动脉瘤、63例各类脑血管畸形共104例患者采用不同的氧治疗方案。其中25例颅内动脉瘤和脑血管畸形未经手术或血管内治疗的患者，因其本人或家属拒绝高压氧（hyperbaricoxygen，HBO）治疗给予舱外高流量常压氧（normalpressnreoxygen，NPO）治疗。79例采用渐进式HBO治疗：治疗从NPO开始，HBO选择从压力较低开始逐渐升高，加、减压速率相对缓慢的治疗方案（加、减压速率3～4kPa／min，治疗压力0．175MPa，稳压吸氧60rain）。全部患者同时进行生命体征和心电监测分析，疗效评定和治疗安全评定。结果HBO和舱外NPO治疗的有效率分别为97．5％和40．0％，HBO疗效优于NPO，差异有统计学意义（P〈0．05）。生命体征和心电监测分析显示，HBO治疗后心率减慢，吸氧结束时为（83．63±15．80）／min，与NPO比较差异有统计学意义（P〈0．05）。2种治疗方案脉搏氧饱和度均升高，差异无统计学意义。HBO治疗时收缩压、舒张压较加压前均升高（P〈0．01），NPO治疗时变化不大，两者比较差异有统计学意义（P〈0．01）。HBO治疗时，呼吸频率在加压阶段[（22．02±3．15）次]加快，与进舱前[（18．63±4．02）次]比较差异有统计学意义（P〈0．01）；HBO治疗结束后[（19．20±4．01）次]下降，但与进舱前比较差异无统计学意义。104例患者治疗期间无明显不良反应发生。结论脑动脉瘤和脑血管畸形患者接受HBO治疗或NPO治疗均有效，但HBO治疗可引起患者血压、心率波动，必须根据患者具体病情选择不同的治疗方案，确保治疗安全。

鲇鱼山水库迎新水电站技术改造

迎新水电站是信阳市鲇鱼山水库管理局所属的二级电站,属渠道式电站,筹建于1981年,1984年投入运行,装机2台,干渠跌水处正常落差15.71m,设计正常流量18.5m％,加大流量21.2m3/s,电站建于干渠的跌水处,水轮机型号CD661-LH-120,配发电机型号TSL215/21-14,单机出力800kW,总容量共13.8m％,约占干渠设计正常流量的74％。

Unsteady Flow Characteristic of Low-Specific-Speed Centrifugal Pump under Different Flow-Rate Conditions

To investigate the unsteady flow characteristics in centrifugal pump, the flow field in a low-specific-speed centri- fugal pump with complex impeller is numerically simulated under different conditions. The RNG r-e turbulence model and sliding mesh are adopted during the process of computation. The results show that the interaction be- tween impeller and volute results in the unstable flow of the fluid, which causes the uneven distribution of pres- sure fluctuations around the circumference of volute. Besides the main frequency and its multiple frequency of pressure fluctuations in the centrifugal pump, the frequency caused by the long blades of complex impeller also plays a dominant role in the low-frequency areas. Furthermore, there exists biggish fluctuation phenomenon near the tongue. The composition of static pressure fluctuations frequency on the volute wall and blade outlet is similar except that the fluctuation amplitude near the volute wall reduces. In general, the different flow rates mainly have influence on the amplitude of fluctuation frequency in the pump, while have little effect on the frequency compo- sition.