PC cluster computing environment based on LAN and MPI

利用现成PC构建由几十乃至几百台PC组成的廉价、实用且性能优良的并行计算机。实验系统是在由40台PC组成的以太局域网内,建立一个基于TRUBO-LINUX和MPI的集群计算环境,并在此基础上进行并行计算实验和性能测试。实验表明,这种环境适合于那些进程之间通信不频繁的或者通信开销相对于计算开销小得多的中粒度或粗粒度的计算任务。PCs available on hand are used to construct parallel computers consisting of tens or even hundreds PCs, which are cheap, practical but with high performance. The experiment system is a cluster computing environment based on TRUBO-LINUX and MPI, which consistsof 40 PCs connected by an Ethernet LAN. In this environment, experimentsof parallelcomputing and performance testing were made. Experimental results indicatethat this kind of environments are suitable for coarse-grained and medium-grained parallel tasks, of which intercommunications among processes are infrequent or cost much lower compared to computations

掺铒a-Si_xC_(1-x)-H薄膜的发光特性

用等离子体增强化学气相沉积(PECVD) 的方法,以固定的氢气(H2)流量和不同的硅烷(SiH4)和甲烷(CH4)流量比沉积了一系列的氢化非晶SiC(a-SixC1-x-H)膜.用这种宽带隙的a-SixC1-x-H材料作为掺铒的基体材料,通过离子注入的方法得到掺铒的a-SixC1-x-H(a-SixC1-x-H:Er)膜.注入以后的样品经过不同温度的退火.用X射线光电子能谱(XPS)、红外吸收光谱(IR)、拉曼散射谱(Raman)等技术研究不同的SiH4/CH4流量比和退火温度对a-SixC1-x-H:Er发光强度的影响.结果表明,高温退火引起了膜中C的分凝,对铒的发光是不利的.通过低温和室温下铒发光强度的比较,表明这种材料具有较弱的温度猝灭效应

Effects of different restoration ages on plant diversity and community stability of wetlands in the Yellow River Delta

Ecological restoration is an efficient method to reduce the degradation of natural coastal wetlands.Restoration age has important effects on soil chemical properties and plant community characteristics.However,long-term monitoring on the effects of wetland restoration projects and their underlying mechanism is still limited.Here,we examined the effects of different restoration ages (0,3,7,10,and 19 years) of wetlands on soil properties,plant species diversity,and community stability in the Yellow River Delta.The results showed that soil electric conductivity,available phosphorus concentration,and available potassium concentration decreased with increasing restoration age.However,soil available nitrogen concentration increased during the restoration process.Shannon index,Pielou evenness index,and species richness index of plant communities increased continuously with increasing restoration age,while plant diversity indices were mainly driven by the changes in soil electrical conductivity.In addition,restoration age also promoted plant community stability,which was significantly and negatively related to soil electric conductivity,available phosphorus and available potassium,and positively related to available nitrogen concentration.With the proceeding of restoration,soil environment and plant community structure improved continuously.Therefore,restoration projects can stimulate positive succession of community and improve the stability of coastal wetland ecosystems

Design of coaxial intervention catheter robot for Endoscopic Retrograde Cholangio-Pancreatography

Due to the high incidence of biliary and pancreatic diseases, ERCP (Endoscopic Retrograde Cholangio-Pancreatography) is widely used as an effective method for treating biliary and pancreatic diseases. However, the location of biliary and pancreatic diseases is special, and the currently used ERCP surgical instruments are not flexible enough to make the intubation process difficult and cause damage to human tissues. This paper presents a new type of coaxial catheter intervention robot, which is composed of a flexible mechanical arm, a driving mechanism, and a guide wire conveying mechanism. The robot is coaxially transported to the nipple through the duodenoscope, which can provide the doctor with a clear surgical field of vision. The 2-degree-of-freedom flexible manipulator can bend in four directions, so that the direction of the catheter is as consistent as possible with the axis of the cholangiopancreatic duct, thus simplifying insertion Tube process. After the prototype was manufactured, the biliary and pancreatic duct model intervention experiment was carried out. The experiment verified the feasibility of the flexible robot system. The experimental results showed that compared with manual intubation, the efficiency is higher and the operation difficulty is lower

绿色农业新技术集成研究与示范

一、该项目针对农业生产中食品安全和环境污染问题,开展了S-诱抗素、新奥霉素、壳寡糖、棉铃虫病毒杀虫剂与昆虫病原线虫生物制剂、功能性堆肥及其浸提液工业化生产等的试验和示范,立项准确,针对性强,意义重大。 二、项目研究出S-诱抗素等生物制剂及其生产工艺、工厂化技术;研究开发出昆虫病原线虫活体繁殖技术,实现了工厂化生产;研究开发了两种功能性堆肥及浸提液,提出了“功能性堆肥+秸秆生物反应堆+堆肥浸提液+S-诱抗素等生物制剂”健康、安全设施蔬菜生产模式;在宁夏实现了地上、地下,土壤、作物生物制剂联防技术体系,为低耗、高效、安全、健康农产品生产开辟了新途径。 三、在S-诱抗素、新奥霉素高产菌株的生产工艺,昆虫病原线虫活体繁殖工厂化生产方面取得了新突破;在S-诱抗素、新奥霉素、壳寡糖、棉铃虫病毒杀虫剂、功能性堆肥及其浸提液集成应用控制作物病虫害等方面有创新。研究成果达到了国内先进水平,S-诱抗素、新奥霉素高产菌株的生产工艺研究达到国际领先。 四、项目执行期间,在宁夏15个市县建立核心试验基地14个,示范推广点40个,累计推广面积17万亩,新增效益9600万元。获得发明专利4项,实用新型专利1项,制定地方标准5项,专著1部,发表论文19篇(其中SCI收录6篇)。培训农技人员300人次,农民4700多人次

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel