Upgrade of the MARI spectrometer at ISIS

The MARI direct geometry time-of-flight neutron spectrometer at ISIS has been upgraded with an $m=3$ supermirror guide and new detector electronics. This has resulted in a flux gain of ${\approx}6{\times}$ at $\lambda=1.8$ {\AA}, and improvements on discriminating electrical noise, allowing MARI to continue to deliver a high quality science program well into its fourth decade of life

Bose-Einstein Correlations of Three Charged Pions in Hadronic Z^0 Decays

Bose-Einstein Correlations (BEC) of three identical charged pions were studied in 4 x 10^6 hadronic Z^0 decays recorded with the OPAL detector at LEP. The genuine three-pion correlations, corrected for the Coulomb effect, were separated from the known two-pion correlations by a new subtraction procedure. A significant genuine three-pion BEC enhancement near threshold was observed having an emitter source radius of r_3 = 0.580 +/- 0.004 (stat.) +/- 0.029 (syst.) fm and a strength of \lambda_3 = 0.504 +/- 0.010 (stat.) +/- 0.041 (syst.). The Coulomb correction was found to increase the \lambda_3 value by \~9% and to reduce r_3 by ~6%. The measured \lambda_3 corresponds to a value of 0.707 +/- 0.014 (stat.) +/- 0.078 (syst.) when one takes into account the three-pion sample purity. A relation between the two-pion and the three-pion source parameters is discussed.Comment: 19 pages, LaTeX, 5 eps figures included, accepted by Eur. Phys. J.

Measurement of the Production Rate of Charm Quark Pairs from Gluons in Hadronic Z0Z^{0} Decays

The rate of secondary charm-quark-pair production has been measured in 4.4 million hadronic Z0 decays collected by OPAL. By selecting events with three jets and tagging charmed hadrons in the gluon jet candidate using leptons and charged D* mesons, the average number of secondary charm-quark pairs per hadronic event is found to be (3.20+-0.21+-0.38)x10-2

Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks

无线传感器网络，作为全球未来十大技术之一，集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术，可实时感知、采集、处理、传输网络分布区域内的各种信息数据，在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议，并针对大规模的无线传感器网络设计了一种树状路由协议，它根据节点地址信息来形成路由，从而简化了复杂繁冗的路由表查找和维护，节省了不必要的开销，提高了路由效率，实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR（AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位：工学硕士院系专业：信息科学与技术学院通信工程系_通信与信息系统学号：2332007115216

Search for heavy charged particles and for particles with anomalous charge in e+-e- collisions at LEP

Contains fulltext : 124552.pdf (preprint version ) (Open Access

Measurement of the semileptonic branching fraction of inclusive b baryon decays to Lambda

Contains fulltext : 124911.pdf (preprint version ) (Open Access

AVIATOR: An open international registry to evaluate medical and surgical outcomes of aortic valve insufficiency and ascending aorta aneurysm

Objectives: Current national registries are lacking detailed pathology-driven analysis and long-term patients outcomes. The Heart Valve Society (HVS) aortic valve (AV) repair research network started the Aortic Valve Insufficiency and ascending aorta Aneurysm InternATiOnal Registry (AVIATOR) to evaluate long-term patient outcomes of AV repair and replacement. The purpose of the current report is to describe the AVIATOR initiative and report in a descriptive manner the patients included. Methods: The AV repair research network includes surgeons, cardiologists, and scientists and established an online database compliant with the guidelines for reporting valve-related events. Prospective inclusion started from January 2013. Adult patients (18 years or older) who were operated on between 1995 and 2017 with complete procedural specification of the type of repair/replacement were selected for descriptive analysis. Results: Currently 58 centers from 17 countries include 4896 patients with 89% AV repair (n = 4379) versus 11% AV replacement (n = 517). AV repair was either isolated (28%), or associated with tubular/partial root replacement (22%) or valve-sparing root replacement (49%) with an in-hospital mortality of 0.5%, 1.7%, and 1.2%, respectively. AV replacement was either isolated (24%), associated with tubular/partial root replacement (17%) or root replacement (59%) with an in-hospital mortality of 1%, 2.6%, and 2.0%, respectively. Conclusions: The multicenter surgical AVIATOR registry, by applying uniform definitions, should provide a solid evidence base to evaluate the place of repair versus replacement on the basis of long-term patient outcomes. Obtaining data completeness and adequate representation of all surgery types remain challenging. Toward the near future AVIATOR-medical will start to study natural history, as will AVIATOR-kids, with a focus on pediatric disease

AVIATOR: An open international registry to evaluate medical and surgical outcomes of aortic valve insufficiency and ascending aorta aneurysm

Objectives: Current national registries are lacking detailed pathology-driven analysis and long-term patients outcomes. The Heart Valve Society (HVS) aortic valve (AV) repair research network started the Aortic Valve Insufficiency and ascending aorta Aneurysm InternATiOnal Registry (AVIATOR) to evaluate long-term patient outcomes of AV repair and replacement. The purpose of the current report is to describe the AVIATOR initiative and report in a descriptive manner the patients included. Methods: The AV repair research network includes surgeons, cardiologists, and scientists and established an online database compliant with the guidelines for reporting valve-related events. Prospective inclusion started from January 2013. Adult patients (18 years or older) who were operated on between 1995 and 2017 with complete procedural specification of the type of repair/replacement were selected for descriptive analysis. Results: Currently 58 centers from 17 countries include 4896 patients with 89% AV repair (n = 4379) versus 11% AV replacement (n = 517). AV repair was either isolated (28%), or associated with tubular/partial root replacement (22%) or valve-sparing root replacement (49%) with an in-hospital mortality of 0.5%, 1.7%, and 1.2%, respectively. AV replacement was either isolated (24%), associated with tubular/partial root replacement (17%) or root replacement (59%) with an in-hospital mortality of 1%, 2.6%, and 2.0%, respectively. Conclusions: The multicenter surgical AVIATOR registry, by applying uniform definitions, should provide a solid evidence base to evaluate the place of repair versus replacement on the basis of long-term patient outcomes. Obtaining data completeness and adequate representation of all surgery types remain challenging. Toward the near future AVIATOR-medical will start to study natural history, as will AVIATOR-kids, with a focus on pediatric disease

Aortic Valve Surgery in Nonelderly Patients: Insights Gained From AVIATOR

Aortic valve surgery in non-elderly patients represents a very challenging patient population. The younger the patient is at the point of aortic valve intervention, the longer their anticipated life expectancy will be, with longer exposure to valve-related complications and risk for re-operation. Although the latest international guidelines recommend aortic valve repair in patients with aortic valve insufficiency, what we see in the real world is that the vast majority of these aortic valves are replaced. However, current prosthetic valves has now been shown to lead to significant loss of life expectancy for non-elderly patients up to 50% for patients in their 40s undergoing mechanical aortic valve replacement. Bioprostheses carry an even worse long-term survival, with higher rates of re-intervention. The promise of trans-catheter valve-in-valve technology is accentuating the trend of bioprosthetic implantation in younger patients, without yet the appropriate evidence. In contrast, aortic valve repair has shown excellent outcomes in terms of quality of life, freedom from re-operation and freedom from major adverse valve-related events with similar life expectancy to general population as it is also found for the Ross procedure, the only available living valve substitute. We are at a time when the paradigm of aortic valve surgery needs to change for the better. To better serve our patients, we must acquire high quality real-world evidence from multiple centers globally – this is the vision of the AVIATOR registry and our common responsibility