Tag: 上海龙凤楼风桑拿


Tradeshows Post Moderate Growth in 2014


first_img “We are optimistic for the performance of the industry overall this year. Economic and job growth should continue to drive expansion in exhibitions,” says Allen Shaw, CEIR economist and chief economist for Global Economic Consulting Associates, Inc. The tradeshow industry continued its steady recovery following the market collapse in the late 2000s, according to the Center for Exhibition Industry Research (CEIR). The CEIR Index, a composite figure that accounts for net square footage (NSF), number of exhibitors, attendance and revenue of all major U.S. tradeshows, was up 1.8 percent last year. While the growth is slightly off the projected 2.0-percent return, it marks the fourth-consecutive year of positive gains. The group is forecasting continued improvement over the next three years, as well. Projections show 2.8-percent growth this year, followed by 2.4- and 2.0-percent gains in 2016 and 2017, respectively. Market-by-market performance varied considerably in 2014. Up 5.2 percent, financial, legal and real estate shows were at the top of the industry, followed by building, construction, home and repair (5.1 percent) and food (4.4 percent). Education (-3.0 percent), machinery and finished business outputs (-1.0 percent) were at the opposite end of the spectrum.last_img read more


Wilmington Public Schools Seeks Per Diem Substitutes


first_imgWILMINGTON, MA – Wilmington Public Schools is seeking substitute teachers at the elementary school, middle school and high school levels, according to a job listing posted on October 1.Substitute teacher rates in Wilmington are as follows:Day to day: $75/day without a DESE license, $85/day with a DESE license45-59 days in the same assignment: $100/day without a DESE license, $110/day with a DESE license60-90 days in the same assignment: $115/day without a DESE license, $125/day with a DESE license91 or more days in the same assignment: $250.84/day (must have a DESE license)The school system is also seeking substitute educational assistants ($60/day), substitute LPNs ($75/day), and substitute nurses ($125/day).View the job posting, which includes further information about the application process, HERE.Got a question? Contact Andrea Armstrong, Human Resources Director, at 978-694-6000 or andrea.armstrong@wpsk12.com.Like Wilmington Apple on Facebook. Follow Wilmington Apple on Twitter. Follow Wilmington Apple on Instagram. Subscribe to Wilmington Apple’s daily email newsletter HERE. Got a comment, question, photo, press release, or news tip? Email wilmingtonapple@gmail.com.Share this:TwitterFacebookLike this:Like Loading… RelatedWilmington Public Schools Hiring Substitute Teachers, Educational Assistants & Nurses For Upcoming School YearIn “Education”Wilmington Public Schools Hiring Substitute Teachers, Educational Assistants & NursesIn “Education”Wilmington Public Schools Hiring Substitute Teachers, Educational Assistants & NursesIn “Education”last_img read more


Scientists go to great lengths to extend superlow friction


first_img Citation: Scientists go to great lengths to extend superlow friction (2015, February 13) retrieved 18 August 2019 from https://phys.org/news/2015-02-scientists-great-lengths-superlow-friction.html Researchers investigated the superlow friction of the chain structures above. They found that superlubricity can theoretically hold for tens of cemtimeters and disappears above a critical chain length, which depends on a material’s intrinsic properties. Credit: Ma, et al. ©2015 American Physical Society In the new study published in Physical Review Letters, researchers Ming Ma, et al., have theoretically investigated the maximum length of a chain of particles that exhibits superlubricity. Their model shows that this critical length depends on the experimental parameters and the material’s properties, especially its stiffness. For very stiff materials, such as carbon nanotubes, the scientists found that superlubricity may hold for up to tens of centimeters, after which it abruptly disappears. “These results indicate an avenue for achieving superlow friction at the macroscale, and can potentially aid in the rational design of superlubric materials for nanomechanical applications,” Michael Urbakh, a professor at Tel Aviv University and one of the study’s lead authors, told Phys.org.As the scientists explain, superlow friction relies on a special arrangement of atoms on a material’s surface. In graphite, for instance, the surface atoms have a bumpy hexagonal arrangement like egg cartons/boxes. In certain orientations, two surfaces of graphite can mesh in such a way that the “bumps” can slide past one other effortlessly, and friction drops to almost zero. In contrast, when the same pieces of graphite are slightly rotated with respect to each other, their surface atoms can no longer easily slide, and the materials exhibit the familiar effects of friction. This kind of change in geometrical configuration can explain the abrupt transition between the frictionless and friction regimes in the researchers’ models. A shorter nanotube, or chain, exhibits superlubricity because its particles are mismatched, or incommensurate, with the underlying substrate atoms. Since the atoms avoid interlocking with each other, the chain easily slides on the surface. But for a longer chain, a mechanical instability triggers lattice matching at the chain’s leading edge. As a result, the particles become in registry, or commensurate, with the atoms in the substrate lattice, and friction suddenly increases.The researchers’ simulations also revealed that the critical chain length forms a sharp boundary between two phases based on interparticle distance: the distance between particles is smaller in the shorter chain than in the longer chain. At exactly the critical length, an abrupt jump in this distance occurs, along with the abrupt jump in friction. By better understanding superlubricity and its limits, the researchers hope to extend the effect to as large a scale as possible. Superlubricity could prove very useful for designing nanoscale systems with low wear and tear, and it could be even more useful if it could be extended to larger scales. “The challenge here is to scale up the size of the sliding objects without losing the perfect egg-box geometry necessary for superlubricity,” said coauthor Andrea Vanossi at the CNR-IOM Democritos National Simulation Center and the International School for Advanced Studies (SISSA), both in Trieste, Italy. “Normally, as the size of the objects grows, defects and imperfections comes into play. Only recently, thanks to the impressive advances in the synthesis techniques, has it been possible to produce defect-free, atomically perfect elongated nanostructures such as carbon nanotubes, graphene nanoribbons, and conjugated polymers. Once it is possible to have two large-scale, geometrically perfect surfaces rub against each other without friction, and to apply this material as a coating to ball bearings and moving machine parts, there will be huge savings ahead in the areas of energy, resource consumption, and maintenance.”The researchers are currently working to expand their approach to understand mechanisms limiting superlow friction between 3D materials. © 2015 Phys.org (Phys.org)—When nanosized pieces of graphite slide against each other, there can be virtually no friction between them. For many years, superlow friction, or “superlubricity,” was known to exist only on the nanoscale. Then in 2012, scientists first demonstrated superlubricity beyond the nanoscale when they discovered the phenomenon in micrometer-sized graphite. Building on this and related research, scientists in a new study have now theoretically shown that superlow friction could extend to lengths of tens of centimeters. More information: Ming Ma, et al. “Critical Length Limiting Superlow Friction.” Physical Review Letters. DOI: 10.1103/PhysRevLett.114.055501center_img Journal information: Physical Review Letters Friction almost vanishes in microscale graphite Explore further This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more


Biologist suggests carbon monoxide as an energy source for microbes on Mars


first_img This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. In order for life to have existed on Mars (or if it still does in a place we have not found yet) it would have to have an energy source of some kind. Prior research has suggested such a source might be nitrogen, the same energy source for most plants here on Earth—a recent report by researchers studying data from Curiosity rover, describes nitrates found in the soil. In this new effort, King takes a different approach, he believes that carbon monoxide may hold the key to life on Mars.King took soil samples from three places here on Earth that have very dry climates and very salty soil, the Atacama desert in Chili, the Bonneville Salt Flats in Utah and a part of the big island in Hawaii. In studying the samples, he found that the soil did indeed pull carbon monoxide out of the air and held onto it. He suggests the same process could occur on Mars, as its atmosphere has more carbon monoxide in it than does ours. He goes further to suggest that the mysterious, recurring slope lineae—dark streaks that change color seasonally on Mars, might be due to carbon monoxide being pulled into the soil. He believes that carbon monoxide could represent the missing piece in the search for life on Mars: the energy source. As evidence of the possibility, he points out two microbes (Halorubrum str. BV1 and Alkalilimnicola ehrlichii MLHE-1) that live on Earth that use carbon monoxide as an energy source, one of which has also been shown able to tolerate salt concentrations that are similar to those found in Martian soil.Unfortunately, there is no mechanism for testing King’s ideas, neither of the rovers on Mars has the equipment needed for that kind of test. He will have to wait until 2021, when NASA plans to send a probe to the Red planet that is capable of detecting microbes in the soil. Explore further Valles Marineris, Mars. Credit: NASA (Phys.org)—Gary King, a biologist at Louisiana State University has put forth the idea that if life did exist on Mars, it very possibly could have survived by using carbon monoxide. In his paper published in Proceedings of the National Academy of Sciences, he discusses his study of microbes in soil samples collected here on Earth that are able to pull in carbon monoxide and why it might relate to life on Mars. Journal information: Proceedings of the National Academy of Sciencescenter_img More information: Carbon monoxide as a metabolic energy source for extremely halophilic microbes: Implications for microbial activity in Mars regolith, Gary M. King, PNAS, DOI: 10.1073/pnas.1424989112AbstractCarbon monoxide occurs at relatively high concentrations (≥800 parts per million) in Mars’ atmosphere, where it represents a potentially significant energy source that could fuel metabolism by a localized putative surface or near-surface microbiota. However, the plausibility of CO oxidation under conditions relevant for Mars in its past or at present has not been evaluated. Results from diverse terrestrial brines and saline soils provide the first documentation, to our knowledge, of active CO uptake at water potentials (−41 MPa to −117 MPa) that might occur in putative brines at recurrent slope lineae (RSL) on Mars. Results from two extremely halophilic isolates complement the field observations. Halorubrum str. BV1, isolated from the Bonneville Salt Flats, Utah (to our knowledge, the first documented extremely halophilic CO-oxidizing member of the Euryarchaeota), consumed CO in a salt-saturated medium with a water potential of −39.6 MPa; activity was reduced by only 28% relative to activity at its optimum water potential of −11 MPa. A proteobacterial isolate from hypersaline Mono Lake, California, Alkalilimnicola ehrlichii MLHE-1, also oxidized CO at low water potentials (−19 MPa), at temperatures within ranges reported for RSL, and under oxic, suboxic (0.2% oxygen), and anoxic conditions (oxygen-free with nitrate). MLHE-1 was unaffected by magnesium perchlorate or low atmospheric pressure (10 mbar). These results collectively establish the potential for microbial CO oxidation under conditions that might obtain at local scales (e.g., RSL) on contemporary Mars and at larger spatial scales earlier in Mars’ history. Citation: Biologist suggests carbon monoxide as an energy source for microbes on Mars (2015, March 24) retrieved 18 August 2019 from https://phys.org/news/2015-03-biologist-carbon-monoxide-energy-source.html Video: What makes carbon monoxide so deadly? © 2015 Phys.orglast_img read more


New programming video courses for March 2019


first_imgIt’s not always easy to know what to learn next if you’re a programmer. Industry shifts can be subtle but they can sometimes be dramatic, making it incredibly important to stay on top of what’s happening both in your field and beyond. No one person can make that decision for you. All the thought leadership and mentorship in the world isn’t going to be able to tell you what’s right for you when it comes to your career. But this list of videos, released last month, might give you a helping hand as to where to go next when it comes to your learning… New data science and artificial intelligence video courses for March Apache Spark is carving out a big presence as the go-to software for big data. Two videos from February focus on Spark – Distributed Deep Learning with Apache Spark and Apache Spark in 7 Days. If you’re new to Spark and want a crash course on the tool, then clearly, our video aims to get you up and running quickly. However, Distributed Deep Learning with Apache Spark offers a deeper exploration that shows you how to develop end to end deep learning pipelines that can leverage the full potential of cutting edge deep learning techniques. While we’re on the subject of machine learning, other choice video courses for March include TensorFlow 2.0 New Features (we’ve been eagerly awaiting it and it finally looks like we can see what it will be like), Hands On Machine Learning with JavaScript (yes, you can now do machine learning in the browser), and a handful of interesting videos on artificial intelligence and finance: AI for Finance Machine Learning for Algorithmic Trading Bots with Python Hands on Python for Finance Elsewhere, a number of data visualization video courses prove that communicating and presenting data remains an urgent challenge for those in the data space. Tableau remains one of the definitive tools – you can learn the latest version with Tableau 2019.1 for Data Scientists and Data Visualization Recipes with Python and Matplotlib 3. New app and web development video courses for March 2019 There are a wealth of video courses for web and app developers to choose from this month. True, Hands-on Machine Learning for JavaScript is well worth a look, but moving past the machine learning hype, there are a number of video courses that take a practical look at popular tools and new approaches to app and web development. Angular’s death has been greatly exaggerated – it remains a pillar of the JavaScript world. While the project’s versioning has arguably been lacking some clarity, if you want to get up to speed with where the framework is today, try Angular 7: A Practical Guide. It’s a video that does exactly what it says on the proverbial tin – it shows off Angular 7 and demonstrates how to start using it in web projects. We’ve also been seeing some uptake of Angular by ASP.NET developers, as it offers a nice complement to the Microsoft framework on the front end side. Our latest video on the combination, Hands-on Web Development with ASP.NET Core and Angular, is another practical look at an effective and increasingly popular approach to full-stack development. Other picks for March include Building Mobile Apps with Ionic 4, a video that brings you right up to date with the recent update that launched in January (interestingly, the project is now backed by web components, not Angular), and a couple of Redux videos – Mastering Redux and Redux Recipes. Redux is still relatively new. Essentially, it’s a JavaScript library that helps you manage application state – because it can be used with a range of different frameworks and libraries, including both Angular and React, it’s likely to go from strength to strength in 2019. Infrastructure, admin and security video courses for March 2019 Node.js is becoming an important library for infrastructure and DevOps engineers. As we move to a cloud native world, it’s a great tool for developing lightweight and modular services. That’s why we’re picking Learn Serverless App Development with Node.js and Azure Functions as one of our top videos for this month. Azure has been growing at a rapid rate over the last 12 months, and while it’s still some way behind AWS, Microsoft’s focus on developer experience is making Azure an increasingly popular platform with developers. For Node developers, this video is a great place to begin – it’s also useful for anyone who simply wants to find out what serverless development actually feels like. Read next: Serverless computing wars: AWS Lambda vs. Azure Functions A partner to this, for anyone beginning Node, is the new Node.js Design Patterns video. In particular, if Node.js is an important tool in your architecture, following design patterns is a robust method of ensuring reliability and resilience. Elsewhere, we have Modern DevOps in Practice, cutting through the consultancy-speak to give you useful and applicable guidance on how to use DevOps thinking in your workflows and processes, and DevOps with Azure, another video that again demonstrates just how impressive Azure is. For those not Azure-inclined, there’s AWS Certified Developer Associate – A Practical Guide, a video that takes you through everything you need to know to pass the AWS Developer Associate exam. There’s also a completely cloud-agnostic video course in the form of Creating a Continuous Deployment Pipeline for Cloud Platforms that’s essential for infrastructure and operations engineers getting to grips with cloud native development. Learn a new programming language with these new video courses for March Finally, there are a number of new video courses that can help you get to grips with a new programming language. So, perfect if you’ve been putting off your new year’s resolution to learn a new language… Java 11 in 7 Days is a new video that brings you bang up to date with everything in the latest version of Java, while Hands-on Functional Programming with Java will help you rethink and reevaluate the way you use Java. Together, the two videos are a great way for Java developers to kick start their learning and update their skill set.last_img read more