分离式数字记录装置的双级时隔记录算法

分离式数字记录装置是一种与外界无连线、也不与外界进行任何形式的无线通讯的记录装置。它主要用于对缓慢变化的被测量 (如西部某地恶劣环境温度 )进行长期自动的数据采集后 ,再取回用微机对其所记数据进行分析。其主要设计要求是简单、便宜、可靠、和存储器一次可记录时间 (从装置存储器第一个单元记录有效数据算起 ,到最后一个单元被占。)长。在文献 [1]中提出并讨论了时隔门限记录法 ,通过对被测量取一适当的门限值并采用一种特别的相对时隔记录方法 ,延长了存储器的可用时间。提出并详细描述了一个称为双级时隔记录法的新算法及其恢复算法 ,利用此方法 ,既可以获得较长的记录时间 ,又可以在一定程度上捕获被测量的一些短时变化。在某些场合这样做是必要的。

编组站解体作业过程溜放钩车时隔控制的分析与研究

本文介绍了在编组站解体作业过程中对溜放钩车进行时隔控制的概念， 分析研究溜放钩车时隔控制的必要性。提出了一种新的溜放钩车时隔控制方式。在理论分析、计算的基础上，对溜放钩车时隔控制新方式的可行性进行了充分论证， 并阐述了溜放钩车新时隔控制方式的实现方法。

时隔票价:与自然节律相匹配的慢旅游

赞同将走马观花式的旅游认作是与慢旅游相对，但在若作深层次的解读，慢旅游应是指与自然节律相匹配的旅游活动。因此，慢旅游的标准应该参照传统农耕社会的节律，同时慢旅游还受旅游者心态、旅游资源性质、交通等影响。时隔即是指当前购票的乘车日，距离最近一次乘车的天数，亦可指行程间变动的时间距离。时隔票价在逻辑上有助于阻止频繁移动的快旅游行为，拓展交通计价体系知识内容，其具有以自我时刻为起点、多周期叠加、强化个人遗产意识等性质。

分离式数字记录装置的两种记录算法

针对一种分离式数字记录装置 ,详细描述并比较了两种数据记录算法 ,且给出了一组典型实验结果。在某些应用场合 ,用方法二可以获得较长的数据记录时间。

浅析高层办公建筑电梯系统选型配置

根据国外标准CIBSE Guide D指导的参考人员密度、5分钟处理能力,候梯时隔等重要性能指标,结合某工程实例详细介绍高层办公建筑电梯系统的选型配置设计及评估方法和步骤,并提出了合理化建议。

负载均匀集群扩充的网络流量分析

PC集群作为科学计算和技术实践的载体已经从幕后走到台前,近几年来成为一种主流趋势。当现有的PC集群已经不能满足需求时,对其扩充后网络性能会出现怎样的影响是本文研究的重点,即利用NS2网络模拟后定性分析网络性能的变化。

Numerical simulation of flow regions in red mud separation thickener's feedwell by analysis of residence-time distribution

The residence-time distribution （RTD） and the compartment model were applied to characterizing the flow regions in red mud separation thickener’s feedwells. Combined with the experimental work, validated mathematical model as well as three-dimensional computational fluid dynamics （CFD） model was established to analyze the flow regions of feedwells on an industrial scale. The concept of RTD, although a well-known method for the characterization of mixing behavior in conventional mixers and reactors, is still a novel measure for the characterization of mixing in feedwells. Numerical simulation results show that the inlet feed rate and the aspect ratio of feedwells are the most critical parameters which affect the RTD of feedwell. Further simulation experiments were then carried out. Under the optimal operation conditions, the volume fraction of dead zone can reduce by10.8% and an increasement of mixing flow volume fraction by 6.5% is also observed. There is an optimum feed inlet rate depending on the feedwell design. The CFD model in conjunction with the RTD analysis then can be used as an effective tool in the design, evaluation and optimization of thickener feedwell in the red mud separation.

经食管超声心动图在室间隔缺损术前的应用价值观察

目的观察经食管超声心动图(TEE)在室间隔缺损(VSD)术前的应用价值。方法选取2013年1月—2016年6月在我院接受TEE实时引导下经胸微创封堵术的VSD患儿103例,所有患儿术前均采用经胸超声心动图(TTE)初步筛选,术前全身麻醉后采用TEE充分评估VSD位置、大小、分流口数量、与主动膜瓣关系、反流程度等指标,并在TEE监测下完成经胸微创VSD封堵术。观察术前TTE和TEE检查结果、手术时间、术后封堵效果。结果 TTE与TEE检测VSD类型比较差异无统计学意义(P>0.05);TEE与TTE检测VSD大小比较差异有统计学意义(P<0.05)。103例患儿中,99例封堵成功,封堵成功的99例患儿TTE与TEE检测VSD大小比较差异有统计学意义(P<0.05)。103例患儿99例1次封堵成功,无封堵器脱落,均未输血,其中72例采用圆形双侧对称封堵器,27例采用偏心型封堵器,腰部直径(5.28±1.27)mm,手术时间均<60 min,平均(38.45±11.56)min,安装封堵器时间(25.32±8.24)min。4例患儿改行体外循环辅助下心内直视修补术。99例患儿封堵术出院前和术后3月采用TTE复查,封堵器正常,室水平未见分流信号;4例心内直视修补术患儿随访,室间隔补片位置未见分流信号。结论 TEE术前充分评估对成功实施经胸微创封堵术治疗VSD具有重要临床价值和指导意义。

Factors affecting headway regularity on bus routes

The common phenomenon of uneven headway in bus service is explored based on the automatic vehicle location （AVL） data of Route 2 in Yichun City of Jiangxi province from 6：00 to 9：00 in the morning. The headway regularity of two stages 6： 00--7：00 and 7： 00--9：00 is comparatively analyzed, and it is found that both the traffic conditions and the passenger demand affect headway regularity. A bus arrival model, which assumes that the dwell time of a bus is linear in headway, is built to probe the effect of scheduled headway, and the model is simulated by Matlab. The simulation results reveal that the departure intervals and fluctuations affect headway regularity. Longer intervals and less fluctuation mean higher regularity of headway. And, the fluctuation has a more obvious influence on headway regularity than the interval. Controlling the fluctuations of scheduled headway can effectively raise the regularity of headway and improve the level of public transport service.

The Course of Time in the Cracking of Earth CrustCaused by Earthquake of Magnitude 8

The world,the continent and the large country at all times have similar distribution of intervals between recurrences of the great earthquakes,depending on the earthquake sequence. lt indicates that how the force source of world scale changes with time and space.

Long-release-interval-first real-time scheduling algorithm and its schedulability test

To fulfill the requirements for hybrid real-time system scheduling, a long-release-interval-first （LRIF） real-time scheduling algorithm is proposed. The algorithm adopts both the fixed priority and the dynamic priority to assign priorities for tasks. By assigning higher priorities to the aperiodic soft real-time jobs with longer release intervals, it guarantees the executions for periodic hard real-time tasks and further probabilistically guarantees the executions for aperiodic soft real-time tasks. The schedulability test approach for the LRIF algorithm is presented. The implementation issues of the LRIF algorithm are also discussed. Simulation result shows that LRIF obtains better schedulable performance than the maximum urgency first （MUF） algorithm, the earliest deadline first （EDF） algorithm and EDF for hybrid tasks. LRIF has great capability to schedule both periodic hard real-time and aperiodic soft real-time tasks.

Cost-benefit analysis of esophageal cancer endoscopic screening in high-risk areas of China

AIM:To estimate the cost-benefit of endoscopic screening strategies of esophageal cancer(EC)in high-risk areas of China. METHODS:Markov model-based analyses were conducted to compare the net present values(NPVs)and the benefit-cost ratios(BCRs)of 12 EC endoscopic screening strategies.Strategies varied according to the targeted screening age,screening frequencies,and follow-up intervals.Model parameters were collected from population-based studies in China,published literatures,and surveillance data. RESULTS:Compared with non-screening outcomes,all strategies with hypothetical 100 000 subjects saved life years.Among five dominant strategies determined by the incremental cost-effectiveness analysis,screening once at age 50 years incurred the lowest NPV(international dollar-I$55 million)and BCR(2.52).Screening six times between 40-70 years at a 5-year interval[i.e., six times(40)f-strategy]yielded the highest NPV(I$99 million)and BCR(3.06).Compared with six times(40)fstrategy,screening thrice between 40-70 years at a 10-year interval resulted in relatively lower NPV,but the same BCR. CONCLUSION:EC endoscopic screening is cost-beneficial in high-risk areas of China.Policy-makers should consider the cost-benefit,population acceptance,and local economic status when choosing suitable screening strategies.

Stationarity Intervals of Time-Variant Channel in High Speed Railway Scenario

The non-stationary behavior, caused by the train rmverrent, is the rmin factor for the variation of high speed railway channel. To measure the tirce-variant effect, the parameter of stationarity interval, in which the channel keeps constant or has no great change, is adopted based on Zhengzfiou- Xi＇an （Zhengxi） passenger dedicated line measurement with different train speeds. The stationarity interval is calculated through the definition of Local Region of Stationarity （LRS） under three train ve- locities. Furthermore, the time non-stationary characteristic of high speed pared with five standard railway channel is corn- Multiple-Input MultipleOutput （MIMO） channel models, i.e. Spatial Channel Model （SCM）, extended version of SCM （SCME）, Wireless World Initiative New Radio Phase II （WINNERII）, International Mobile Teleconmnications-Advanced （IMT-Advanced） and WiMAX models which contain the high speed moving scenario. The stationarity interval of real channel is 9 ms in 80% of the cases, which is shorter than those of the standard models. Hence the real channel of high speed railway changes more rapidly. The stationarity intervals of standard models are different due to different modeling methods and scenario def- initions. And the compared results are instructive for wireless system design in high speed railway.

Progression of remnant gastric cancer is associated with duration of follow-up following distal gastrectomy

AIM： TO re-evaluate the recent clinicopathological fea- tures of remnant gastric cancer （RGC） and to develop desirable surveillance programs.METHODS： Between 1997 and 2008, 1149 patients underwent gastrectomy for gastric cancer at the Department of Digestive Surgery, Kyoto Prefectural Uni- versity of Medicine, Japan. Of these, 33 patients un- derwent gastrectomy with lymphadenectomy for RGC. Regarding the initial gastric disease, there were 19 patients with benign disease and 14 patients with gas- tric cancer. The hospital records of these patients were reviewed retrospectively. RESULTS： Concerning the initial gastric disease, the RGC group following gastric cancer had a shorter in- terval [P 〈 0.05; gastric cancer vs benign disease： 12 （2-22） vs 30 （4-51） years] and were more frequently reconstructed by Billroth- I procedure than those fol- lowing benign lesions （P 〈 0.001）. Regarding recon- struction, RGC following Billroth-]_l reconstruction showed a longer interval between surgical procedures [P 〈 0.001; Billroth-11 vs Billroth- I ： 32 （5-51） vs 12 （2-36） years] and tumors were more frequently associated with benign disease （P 〈 0.001） than those following Billroth- I reconstruction. In tumor location of RGC, after Billroth- I reconstruction, RGC occurred more fre- quently near the suture line and remnant gastric wall. After Billroth- 1I reconstruction, RGC occurred more fre- quently at the anastomotic site. The duration of follow- up was significantly associated with the stage of RGC （P 〈 0.05）. Patients diagnosed with early stage RGC such as stage Ⅰ-Ⅱ tended to have been followed up almost every second year. CONCLUSION： Meticulous follow-up examination and early detection of RGC might lead to a better prognosis. Based on the initial gastric disease and the procedure of reconstruction, an appropriate follow-up interval and programs might enable early detection of RGC.

A retrospective observational study on maintenance and complications of totally implantable venous access ports in 563 patients:Prolonged versus short flushing intervals

Objectives:To assess whether the extension of the flushing interval will increase risks of complications associated with totally implantable venous access port(TIVAP)in the off-treatment period.Methods:A retrospective single-center observational study was performed.Patients with a TIVAP in the off-treatment period that underwent regular flushing in our clinic were included.Data concerning patients and their TIVAPs were recorded.Patient baseline characteristics and TIVAP-related complications were analyzed.Continuous variables were analyzed by ANOVA or the Kruskal-Wallis H test.To compare the occurrence of TIVAP-related complications,the chi-square test was used;if needed,Fisher’s exact test was used.Results:Totally 607 patients were reviewed,and 563 patients were finally included.Thirteen complications were recorded,including 11 cases of catheter occlusion(1.95%),one case of port cannula rotation(0.18%),and one case of catheter tip malposition(0.18%).No device-related infection or venous thrombosis was recorded.Among these patients,the average flushing interval was 35.27±13.09 days.Patients were divided into three groups according to the flushing interval:every 28 days or less(Group 1,n=133);every 29-44 days(Group 2,n=350);and every 45 days or more(Group 3,n=80).No significant difference in catheter-related complications was found among the three groups(P>0.05).Conclusions:In the TIVAP off-treatment period,patients without any history of TIVAP-related complications during approximately one year can attempt to prolong the flushing interval to more than 4 weeks;we further suggest that 5-6 weeks may be an appropriate option for these patients.

Analysis of the delayed approach to the management of infected pancreatic necrosis

AIM: To analyze outcomes of delayed single-stage necrosectomy after early conservative management of patients with infected pancreatic necrosis (IPN) associated with severe acute pancreatitis (SAP). METHODS: Between January 1998 and December 2009, data from patients with SAP who developed IPN and were managed by pancreatic necrosectomy were analyzed. RESULTS: Fifty-nine of 61 pancreatic necrosectomies were performed by open surgery and 2 laparoscopically. In 55 patients, single-stage necrosectomy could be performed (90.2%). Patients underwent surgery at a median of 29 d (range 13-46 d) after diagnosis of acute pancreatitis. Sepsis and multiple organ failure accounted for the 9.8% mortality rate. Pancreatic fistulae (50.8%) predominantly accounted for the morbidity. The median hospital stay was 23 d, and the median interval for return to regular activities was 110 d.CONCLUSION: This series supports the concept of delayed single-stage open pancreatic necrosectomy for IPN. Advances in critical care, antibiotics and interventional radiology have played complementary role in improving the outcomes.

Optimal timing of staged percutaneous coronary intervention in ST-segment elevation myocardial infarction patients with multivessel disease

Background Studies have shown that staged percutaneous coronary intervention （PCI） for non-culprit lesions is beneficial for prog- nosis of ST-segment elevation myocardial infarction （STEMI） patients with multivessel disease. However, the optimal timing of staged re- vascularization is still controversial. This study aimed to find the optimal timing of staged revascularization. Methods A total of 428 STEMI patients with multivessel disease who underwent primary PCI and staged PCI were included. According to the time interval between primary and staged PCI, patients were divided into three groups （〈 1 week, 1- weeks, and 2-12 weeks after primary PCI）. The primary endpoint was major adverse cardiovascular events （MACE）, a composite of all-cause death, non-fatal re-infarction, repeat revascularization, and stroke. Cox regression model was used to assess the association between staged PCI timing and risk of MACE. Results During the follow-up, 119 participants had MACEs. There was statistical difference in MACE incidence among the three groups （〈 1 week： 23.0%; 1-2 weeks： 33.0%; 2-12 weeks： 40.0%; P = 0.001）. In the multivariable adjustment model, the timing interval of staged PCI ≤ 1 week and l-2 weeks were both significantly associated with a lower risk of MACE [hazard ratio （HR）： 0.40, 95% confidence intervals （CI）： 0.24-4）.65; HR： 0.54, 95% CI： 0.3 lq3.93, respectively], mainly attributed to a lower risk of repeat revascularization （HR： 0.41, 95% CI： 0.24-0.70; HR： 0.36, 95% CI： 0.18-0.7）, compared with a strategy of 2-12 weeks later of primary PCI. Conclusions The optimal timing of staged PCI for non-culprit vessels should be within two weeks after primary PCI for STEMI patients.

Effect of Root Architecture on Structural Stability and Erodibility of Topsoils during Concentrated Flow in Hilly Loess Plateau

Traditional vegetation techniques for the control of concentrated flow erosion are widely recognized, whereas only a few studies have experimentally investigated the impacts of belowground roots on the erodibility of topsoils in semi-arid areas. To quantify the effects of root architectures on soil erodibility and its relevant structural properties, simulated flow experiments were conducted at six-week intervals from 18 July to 20 October in 2012 in the hilly Loess Plateau. Five treatments were: 1) bare(control), 2) purple alfalfa(Medicago sativa), representing tap roots(T), 3) switchgrass(Panicum virgatum), representing fibrous roots(F), 4) purple alfalfa and switchgrass, representing both tap and fibrous roots(T + F), and 5) natural recovery(N). For each treatment, soil structural properties and root characteristics were measured at an interval of six weeks. Soil anti-scouribility was calculated. Results showed that grass planting slightly reduced soil bulk density, but increased soil aggregate content by 19.1%, 10.6%, 28.5%, and 41.2% in the treatments T, F, T + F, and N, respectively. Soil shear strength(cohesion and angle of internal friction(φ)) significantly increased after the grass was planted. As roots grew, soil cohesion increased by 115.2%–135.5%, while soil disintegration rate decreased by 39.0%–58.1% in the 21 th week compared with the recorded value in the 9th week. Meanwhile, root density and root surface area density increased by 64.0%–104.7% and 75.9%–157.1%, respectively. No significant differences in soil anti-scouribility were observed between the treatments of T and F or of T + F and N, but the treatments of T + F and N performed more effectively than T or F treatment alone in retarding concentrated flow. Soil aggregation and root surface-area density explained the observed soil anti-scouribility during concentrated flow well for the different treatments. This result proved that the restoration of natural vegetation might be the most appropriate strategy in soil reinforcement in the hilly Loess Plateau.

Influences of different time intervals between loop electrosurgical excision and abdominal hysterectomy or radical hysterectomy on postoperative complications: a retrospective analysis

Objective： To study the influences of different time intervals between loop electrosurgical excision （LEEP） and abdominal hysterectomy or radical hysterectomy on postoperative complications. Methods： Sixty-eight patients, who received subsequent abdominal hysterectomy or radical hysterectomy after LEEP due to C1N III and cervical cancer （IA1, IA2 and IB1）, were included in the present study. The hospital and clinic records of these patients were reviewed. The patients were divided into three groups according to the time intervals between LEEP and hysterectomy or radical hysterectomy： group l（within 48 h）, group 2 （between 48 h to 6 weeks）, and group 3（〉 6 weeks ）.Results： General characteristics of patients, including the mean age, delivery history, BMI, menopausal status, clinical stage and HPV infection, were comparable between patients of different groups. There were no significant differences in the mean transfusion amount, posthysterectomy hospital stay or operation time between different groups. The frequencies and spectrum of complications were not significantly affected by the time interval between LEEP and hysterectomy or radical hysterectomy. Conclusion： It is concluded that whenever the LEEP is done, the operation including hysterectomy or radical hysterectomy can be conducted at any time as it is necessary for the patients.

Rules for confidence intervals of permeability coefficients for water flow in over-broken rock mass

Based on the steady-state seepage method, we used the Mechanical Testing and Simulation 815.02 System and a self-designed seepage instrument for over-broken stone to measure seepage properties of water flows in three types of crushed rock samples. Three methods of confidence interval in describing permeability coefficients are presented: the secure interval, the calculated interval and the systemic interval. The lower bound of the secure interval can be applied to water-inrush and the upper bound can solve the problem of connectivity. For the calculated interval, as the axial pressure increases, the length of confidence interval is shortened and the upper and lower bounds are reduced. For the systemic interval, the length of its confidence interval, as well as the upper and lower bounds, clearly vary under low axial pressure but are fairly similar under high axial pressure. These three methods provide useful information and references for analyzing the permeability coefficient of over-broken rock.