Open millifluidics based on powder-encased channels

Millifluidics, the manipulation of liquid flow in millimeter-sized channels, has been a revolutionary concept in chemical processing and engineering. The solid channels that contain the liquids, though, are not flexible in their design and modification, and prevent contact with the external environment. All-liquid constructs, on the other hand, while flexible and open, are imbedded in a liquid environment. Here, we provide a route to circumvent these limitations by encasing the liquids in a hydrophobic powder in air that jams on the surface, containing and isolating flowing fluids, offering flexibility and adaptability in design, as manifest in the ability to reconfigure, graft, and segment the constructs. Along with the open nature of these powder-contained channels that allow arbitrary connections/disconnections and substance addition/extraction, numerous applications can be opened in the biological, chemical, and material arenas

Ultraquantum magnetoresistance in Kramers Weyl semimetal candidate β\beta-Ag2Se

The topological semimetal $\beta$-Ag2Se features a Kramers Weyl node at the origin in momentum space and a quadruplet of spinless Weyl nodes, which are annihilated by spin-orbit coupling. We show that single crystalline $\beta$-Ag2Se manifests giant Shubnikov-de Haas oscillations in the longitudinal magnetoresistance which stem from a small electron pocket that can be driven beyond the quantum limit by a field less than 9 T. This small electron pocket is a remainder of the spin-orbit annihilatedWeyl nodes and thus encloses a Berry-phase structure. Moreover, we observed a negative longitudinal magnetoresistance when the magnetic field is beyond the quantum limit. Our experimental findings are complemented by thorough theoretical band structure analyses of this Kramers Weyl semimetal candidate, including first-principle calculations and an effective k*p model.Comment: A new version based on arXiv:1502.0232

A large area, high counting rate micromegas-based neutron detector for BNCT

Beam monitoring and evaluation are very important to boron neutron capture therapy (BNCT), and a variety of detectors have been developed for these applications. However, most of the detectors used in BNCT only have a small detection area, leading to the inconvenience of the full-scale 2-D measurement of the beam. Based on micromegas technology, we designed a neutron detector with large detection area and high counting rate. This detector has a detection area of 288 mm multiples 288 mm and can measure thermal, epithermal, and fast neutrons with different detector settings. The BNCT experiments demonstrated that this detector has a very good 2-D imaging performance for the thermal, epithermal, fast neutron and gamma components, a highest counting rate of 94 kHz/channel, and a good linearity response to the beam power. Additionally, the flux fraction of each component can be calculated based on the measurement results. The Am-Be neutron source experiment indicates that this detector has a spatial resolution of approximately 1.4 mm, meeting the requirements of applications in BNCT. It is evident that this micromegas-based neutron detector with a large area and high counting rate capability has great development prospects in BNCT beam monitoring and evaluation applications

Estimates of energy subsidies in China and impact of energy subsidy reform

For a transitional economy such as China, some energy subsidies are reasonable, and sometimes even necessary for achieving social goals. However, with rising energy prices and environmental concerns, we see conflicts emerging between energy subsidies, energy demand/supply fundamentals and climate change considerations. Energy subsidies have important implications for sustainable development through their effects on energy use, efficiency and the choice of fuel source. This paper applies the price-gap approach to estimate China's energy subsidies. Results indicate that China's energy subsidies amounted to CNY 356.73 billion in 2007, equivalent to 1.43% of GDP. Subsidies for oil products consumption are the largest, followed by subsidies for the electricity and coal sectors. Furthermore, a CGE model is used to analyze the economic impacts of energy subsidy reforms. Our findings show that removing energy subsidies will result in a significant fall in energy demand and emissions, but will have negative impacts on macroeconomic variables. We conclude that offsetting policies could be adopted such that certain shares of these subsidies are reallocated to support other sustainable development measures, which could lead to reducing energy intensity and favoring the environment.Price-gap approach Energy subsidies Energy subsidy reform CGE model

Estimates of energy subsidies in China and impact of energy subsidy reform

For a transitional economy such as China, some energy subsidies are reasonable, and sometimes even necessary for achieving social goals. However, with rising energy prices and environmental concerns, we see conflicts emerging between energy subsidies, energy demand/supply fundamentals and climate change considerations. Energy subsidies have important implications for sustainable development through their effects on energy use, efficiency and the choice of fuel source. This paper applies the price-gap approach to estimate China's energy subsidies. Results indicate that China's energy subsidies amounted to CNY 356.73 billion in 2007, equivalent to 1.43% of GDP. Subsidies for oil products consumption are the largest, followed by subsidies for the electricity and coal sectors. Furthermore, a CGE model is used to analyze the economic impacts of energy subsidy reforms. Our findings show that removing energy subsidies will result in a significant fall in energy demand and emissions, but will have negative impacts on macroeconomic variables. We conclude that offsetting policies could be adopted such that certain shares of these subsidies are reallocated to support other sustainable development measures, which could lead to reducing energy intensity and favoring the environment. (C) 2010 Elsevier B.V. All rights reserved

The perverse fossil fuel subsidies in China-The scale and effects

New Huadu Business School Research Fund; China Sustainable Energy Program [G-1203-15828]; Ministry of Education Foundation [10GBJ013, 12YJC790081]; Shanghai "Chen Guang" Program [12CG45]To address the problem of climate change, G-20 government leaders committed to "rationalize and phase-out inefficient fossil fuel subsidies that encourage excessive consumption over the medium term", i.e., removing the perverse subsidies. Considering China's particular circumstances and the purposes of energy subsidies, the perverse fossil fuel subsidies in China mainly concentrated on industries, and gasoline, diesel and natural gas consumption, which are always regressive. Other subsidies, such as those for residential electricity consumption and agriculture, should be kept for the time being. Results indicate that China's perverse fossil fuel subsidies amounted to CNY 509.22 billion in 2008, equivalent to 61.2% of total fossil fuel subsidies and 1.69% of GDP in that year. In addition, reasonable subsidies will not affect energy conservation and emission reduction. Furthermore, CGE (Computable General Equilibrium) model is used to analyze the impacts of energy subsidy reforms. Our finding shows that removing perverse energy subsidies will result in a significant decline in energy demand and CO2 emissions, but will have negative impacts on the macro-economy. Therefore, supporting (or offsetting) policies, like carrying out other cost-benefit and sustainable programs with the revenues saved from subsidy reduction, are needed to alleviate the adverse impacts of removing perverse subsidies. (C) 2014 Elsevier Ltd. All rights reserved