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Measures to enforce mandatory civil building energy efficiency codes in China
Mandatory civil building energy efficiency codes strictly govern the energy consumption of new buildings in China. As the promotion of building energy efficiency in China has increased in recent years, compliance with mandatory civil building energy efficiency codes has also improved, increasing from less than 10% in 2000 to nearly 100% in 2012, a remarkable achievement. However, because the promotion of energy efficiency strategies in China has followed a unique pattern, some researchers doubt these statistics. In response to these doubts, this paper summarises and analyses the framework of measures implemented by the Chinese government to enforce mandatory building energy efficiency codes. First, the development and implementation of China's mandatory civil building energy efficiency code system is summarised. Second, the building supervision and inspection systems used to assess energy efficiency are introduced and analysed in detail in order to provide a framework for the development of energy policies in other countries. Third, the assessment and reporting processes used to determine compliance rates are reviewed. Finally, the improvement of compliance rates and its impact on building energy savings in China are discussed. Along with the increase in compliance rates in the construction stage from 71% in 2007 to 100% in 2012, the energy savings of new buildings per increased floor area per year increased from 20.4 kWh/m2 to 28.4 kWh/m2. The supervision and inspection systems reported in this paper are the keys to enforcing building energy efficiency codes
Unselective regrowth of 1.5-μm InGaAsP multiple-quantum-well distributed-feedback buried heterostructure lasers
Unselective regrowth for fabricating 1.5-μm InGaAsP multiple-quantum well (MQW) distributed-feedback (DFB) buried heterostructure (BH) lasers is developed. The experimental results exhibit superior characteristics, such as a low threshold of 8.5mA, high slope efficiency of 0.55mW∕mA, circular-like far-field patterns, the narrow linewidth of 2.5MHz, etc. The high performance of the devices effectively proves the feasibility of the new method to fabricate buried heterostructure lasers
Molecular Dynamics Study of Bamboo-like Carbon Nanotube Nucleation
MD simulations based on an empirical potential energy surface were used to
study the nucleation of bamboo-like carbon nanotubes (BCNTs). The simulations
reveal that inner walls of the bamboo structure start to nucleate at the
junction between the outer nanotube wall and the catalyst particle. In
agreement with experimental results, the simulations show that BCNTs nucleate
at higher dissolved carbon concentrations (i.e., feedstock pressures) than
those where non-bamboolike carbon nanotubes are nucleated
Longitudinal effects of metabolic syndrome on Alzheimer and vascular related brain pathology.
Background/aimsThis study examines the longitudinal effect of metabolic syndrome (MetS) on brain-aging indices among cognitively normal (CN) and amnestic mild cognitive impairment (aMCI) groups [single-domain aMCI (saMCI) and multiple-domain aMCI (maMCI)].MethodsThe study population included 739 participants (CN = 226, saMCI = 275, and maMCI = 238) from the Alzheimer's Disease Neuroimaging Initiative, a clinic-based, multi-center prospective cohort. Confirmatory factor analysis was employed to determine a MetS latent composite score using baseline data of vascular risk factors. We examined the changes of two Alzheimer's disease (AD) biomarkers, namely [(18)F]fluorodeoxyglucose (FDG)-positron emission tomography (PET) regions of interest and medial temporal lobe volume over 5 years. A cerebrovascular aging index, cerebral white matter (cWM) volume, was examined as a comparison.ResultsThe vascular risk was similar in all groups. Applying generalized estimating equation modeling, all brain-aging indices declined significantly over time. Higher MetS scores were associated with a faster decline of cWM in the CN and maMCI groups but with a slower decrement of regional glucose metabolism in FDG-PET in the saMCI and maMCI groups.ConclusionAt the very early stage of cognitive decline, the vascular burden such as MetS may be in parallel with or independent of AD pathology in contributing to cognitive impairment in terms of accelerating the disclosure of AD pathology
Fuzzy control of the dual-stage feeding system consisting of a piezoelectric actuator and a linear motor for electrical discharge machining
Gap width is an important factor that affects material removal rate, surface finish, and machining stability in electrical discharge machining processes. This research is to develop a novel control method for a new hybrid positioning system which consists of a linear motor and a piezoelectric actuator for high-efficiency electrical discharge machining processes. In the new system, the linear motor provides the macro feeding while the piezoelectric actuator feeds the workpiece in micro scale at high frequency. To reduce the delay caused by separate movements of the linear motor and piezoelectric actuator, a new control algorithm was developed to synchronize the movements of the motor and piezoelectric actuator. A fuzzy control system was used to control the feeding process. Piezoelectric actuator position and its speed were selected as the fuzzy inputs, while the fuzzy output was the linear motor speed. Cutting experiments were conducted, and results show that the fuzzy system is more powerful than the conventional algorithm and the new algorithm with constant motor speed. An increase in material removal rate of 1.6 times was achieved using the proposed fuzzy control algorithm
Effect of a Zn impurity on T_c and its implication to pairing symmetry in LaFeAsOF
The effect of non-magnetic Zn impurity on superconductivity in
LaFeZnAsOF system is studied systematically. In the
presence of Zn impurity, the superconducting transition temperature increases
in the under-doped regime, remains unchanged in the optimally doped regime, and
is severely suppressed in the over-doped regime. Our results suggest a switch
of the symmetry of the superconducting order parameters from a -wave to
or -wave states as the charge carrier doping increases in
FeAs-based superconductors.Comment: 4 pages, 4 figures. Format changed and a few revisons mad
Carbon-doped ZnO: A New Class of Room Temperature Dilute Magnetic Semiconductor
We report magnetism in carbon doped ZnO. Our first-principles calculations
based on density functional theory predicted that carbon substitution for
oxygen in ZnO results in a magnetic moment of 1.78 per carbon. The
theoretical prediction was confirmed experimentally. C-doped ZnO films
deposited by pulsed laser deposition with various carbon concentrations showed
ferromagnetism with Curie temperatures higher than 400 K, and the measured
magnetic moment based on the content of carbide in the films (
per carbon) is in agreement with the theoretical prediction. The magnetism is
due to bonding coupling between Zn ions and doped C atoms. Results of
magneto-resistance and abnormal Hall effect show that the doped films are
-type semiconductors with intrinsic ferromagnetism. The carbon doped ZnO
could be a promising room temperature dilute magnetic semiconductor (DMS) and
our work demonstrates possiblity of produing DMS with non-metal doping.Comment: REVtex source with 4 figures in eps forma
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