China's building stock estimation and energy intensity analysis

Reliable and objective data regarding building stock is essential for predicting and analyzing energy demand and carbon emission. However, China's building stock data is lacking. This study proposes a set of China building floor space estimation method (CBFSM) based on the improved building stock turnover model. Then it measures China's building stocks by vintage and type from 2000 to 2015, as well as building energy intensity (national level and provincial level) and energy-efficient buildings. Results showed that total building stocks increased significantly, rising from 35.2 billion m2 in 2000 to 63.6 billion m2 in 2015, with the average growth rate 4.0%. The deviations were well below 10% by comparing with China Population Census, which validated the reliability of CBFSM and the results. As for energy intensity, urban dwellings and rural dwellings showed relatively stable and increasing trend respectively. The commercial building energy intensity saw a downward trend during “12th Five Year Plan” period. This indicated the effectiveness of building energy efficiency work for commercial buildings since 2005.38.6 billion m2 residential dwellings and 5.7 billion m2 commercial buildings still need to be retrofitted in future. CBFSM can overcome shortages in previous studies. It can also provide Chinese government with technical support and data evidence to promote the building energy efficiency work

Non-classical non-Gaussian state of a mechanical resonator via selectively incoherent damping in three-mode optomechanical systems

We theoretically propose a scheme for the generation of a non-classical single-mode motional state of a mechanical resonator (MR) in the three-mode optomechanical systems, in which two optical modes of the cavities are linearly coupled to each other and one mechanical mode of the MR is optomechanically coupled to the two optical modes with the same coupling strength simultaneously. One cavity is driven by a coherent laser light. By properly tuning the frequency of the weak driving field, we obtain engineered Liouvillian superoperator via engineering the selective interaction Hamiltonian confined to the Fock subspaces. In this case, the motional state of the MR can be prepared into a non-Gaussian state, which possesses the sub-Poisson statistics although its Wigner function is positive.Comment: 6 pages, 5 figure

Electron Bunch Train Excited Higher-Order Modes in a Superconducting RF Cavity

Higher-order mode (HOM) based intra-cavity beam diagnostics has been proved effectively and conveniently in superconducting radio-frequency (SRF) accelerators. Our recent research shows that the beam harmonics in the bunch train excited HOM spectrum, which have much higher signal-to-noise ratio than the intrinsic HOM peaks, may also be useful for beam diagnostics. In this paper, we will present our study on bunch train excited HOMs, including the theoretic model and recent experiments carried out based on the DC-SRF photoinjector and SRF linac at Peking University.Comment: Supported by National Natural Science Foundation of China (11275014

Influences of S-Wave Velocity to the Seismic Response of Silt Ground

By using of one-dimension equivalent linearzation seismic response analysis method, the study is performed to the different silt grounds. The influences of s-wave velocity uncertainty to the seismic acceleration peak, duration, response spectrum of silt ground are discussed in the paper. Following conclusions will he expected. (1) The relationship between the difference of seismic peak acceleration and the difference of s-wave velocity is in linear distribution approximately. The seismic peak acceleration is changed with the S-wave velocity. The seismic peak acceleration is much effected by the uncertainty of S-wave velocity. (2) The uncertainty of shear wave velocity has little influence on the seismic duration. (3) The long-period seismic response spectrum is much effected by the decreasing of shear wave velocity. Conversely, the moderate-period and short-period seismic response spectrum is much effected by the increasing of shear wave velocity. With the depth of silt layers extended, the seismic response spectrum is greater influenced by the uncertainty of shear wave velocity

Poly[[diaqua­nickel(II)]-μ2-4,4′-bipyridine-κ2 N:N′-μ-p-phenyl­enedioxy­diacetato-κ2 O:O′]

The title coordination polymer, [Ni(C10H8O6)(C10H8N2)(H2O)2]n, was obtained by the hydro­thermal reaction of nickel(II) sulfate, benzene-1,4-dioxy­diacetic acid (p-phenyl­enedioxy­diacetic acid) and 4,4′-bipyridine (4,4′-bpy) in alkaline aqueous solution. Each NiII atom is coordinated by two O atoms from two benzene-1,4-dioxy­diacetate ligands, two N atoms from two 4,4′-bpy ligands and two water mol­ecules, and displays a distorted octa­hedral geometry. The NiII atom and benzene-1,4-dioxy­diacetate and 4,4′-bpy moieties lie on inversion centres. The benzene-1,4-dioxy­diacetate ligands bridge the NiII atoms to form infinite zigzag chains, which are further inter­connected by 4,4′-bpy ligands to form a grid-like layer parallel to the (01) plane. Moreover, there are O—H⋯O hydrogen-bonding inter­actions within the grid-like layer between the coordinated water mol­ecules and the carboxyl­ate O atoms