A submerged structure leakage optical fiber positioning and orienting system without a heat source, comprising a plurality of seepage monitoring devices connected via rotation supports; the seepage monitoring device comprises first seepage monitoring units symmetrically arranged at the front and back and second seepage monitoring units symmetrically arranged at the left and right; seepage measurement optical fibers (118) are arranged in the first seepage monitoring units and the second seepage monitoring units to monitor leakage of a submerged structure. Also disclosed is a monitoring method for the optical fiber positioning and orienting system without a heat source for submerged structure leakage. The monitoring method compares a standard optical fiber (108) and the seepage measurement optical fiber (118) to obtain the position and orientation of water seepage through flexibly arranging the seepage monitoring devices in the submerged structure; in addition, the monitoring method is easy to operate, and can acquire an accurate result.
SiO2-coated graphene was prepared by chemical liquid deposition method by using tetraethyl orthosilicate (TEOS), and then SiO2 particles were successfully coated on the graphene surface. A new kind of stable water-based graphene nanofluid was further prepared using the functionalized nanomaterial (graphene/SiO2). The effect of SiO2-coated modification on the stability and thermal conductivity of water-based graphene nanofluid was examined. The results showed that SiO2-coated modification significantly improved the hydrophilicity of graphene, as well as the stability and thermal conductivity of water-based graphene nanofluid. SiO2-coating can improve thermal conductivity better than surfactants for preparing water-based graphene nanofluid. (C) 2014 Elsevier B.V. All rights reserved.
Treatment of chronic neurodegenerative diseases such as multiple sclerosis (MS) remains a major challenge. Here we genetically engineer neural stem cells (NSCs) to produce a triply therapeutic cocktail comprising IL-10, NT-3, and LINGO-l-Fc, thus simultaneously targeting all mechanisms underlie chronicity of MS in the central nervous system (CNS): persistent inflammation, loss of trophic support for oligodendrocytes and neurons, and accumulation of neuroregeneration inhibitors. After transplantation, NSCs migrated into the CNS inflamed foci and delivered these therapeutic molecules in situ. NSCs transduced with one, two, or none of these molecules had no or limited effect when injected at the chronic stage of experimental autoimmune encephalomyelitis; cocktail -producing NSCs, in contrast, mediated the most effective recovery through inducing M2 macrophages/microglia, reducing astrogliosis, and promoting axonal integrity and endogenous oligodendrocyte/neuron differentiation. These engineered NSCs simultaneously target major mechanisms underlying chronicity of MS and EAE, thus representing a novel and potentially effective therapy for the chronic stage of MS, for which there is currently no treatment available.
In this paper, a small scale solar humidification-dehumidification (HDH) experimental setup based on a new kind of solar air heater with all-glass evacuated tubes is designed and tested. Firstly, a new kind of solar air heater with evacuated tubes is designed and tested for the solar HDH desalination process. The test results of solar air heater show that the cut length of efficiency and overall heat loss coefficient is 0.47 and 1.60 respectively, while air flow rate is 140 m(3)/h. Secondly, the humidifier and dehumidifier are designed and optimized by the mathematical design methods. Finally, a desalination pilot plant is designed and built. And then, operation characteristics are tested and analyzed. Test results show that different inlet sprayed water temperature in the pad humidifier from 9 degrees C to 27 degrees C can effectively improve relative humidity of outlet moist air from 89% to 97% and the outlet air temperature from 35 degrees C to 42 degrees C. The results are valuable in the pursuit of the optimal design for a 1000 L/day solar HDH desalination system with the new kind of solar air heater. (C) 2014 Elsevier B.V. All rights reserved.
A III-nitride semiconductor light emitting device incorporating n-type III-nitride cladding layers, indium containing III-nitride light emitting region, and p-type III-nitride cladding layers. The light emitting region is sandwiched between n- and p-type III-nitride cladding layers and includes multiple sets of multi-quantum-wells (MQWs). The first MQW set formed on the n-type cladding layer comprises relatively lower indium concentration. The second MQW set comprising relatively moderate indium concentration. The third MQW set adjacent to the p-type cladding layer incorporating relatively highest indium concentration of the three MQW sets and is capable of emitting amber-to-red light. The first two MQW sets are utilized as pre-strain layers. Between the MQW sets, intermediate strain compensation layers (ISCLs) are added. The combination of the first two MQW sets and ISCLs prevent phase separation and enhance indium uptake in the third MQW set. The third MQW set, as a result, retains sufficiently high indium concentration to emit amber-to-red light of high output power without any phase separation associated problems.
Li, Xing
Xiao, Dongdong
Zheng, Hao
Wei, Xianlong
Wang, Xiaoye
Gu, Lin
Hu, Yong-Sheng
Yang, Tao
Chen, Qing
Highlights • Lithiation/delithiation of InAs NWs are studied for the first time by in-situ TEM. • An ultrafast lithiation speed of 275 nm/s is observed in InAs NWs. • InAs NWs exhibit a small volume expansion and reversible lithiation/delithiation. • The lithiation products were determined by TEM and chemical equations are proposed. Abstract The electrochemical lithiation/delithiation processes of InAs nanowires (NWs) are studied by in-situ transmission electron microscopy. Our results indicate that InAs NWs have a fast lithiation speed of 275 nm/s and a high lithium ion (Li-ion) diffusion coefficient of 2.49×10−8 cm2/s at room temperature. Upon lithiation, the Li-ion insertion firstly results in severe lattice distortions of InAs NWs, and the formation of Li3As and LixIn through the conversion and alloying processes take place on further lithiation. A small volume expansion of 157% is observed in full lithiation and is attributed to the naturally formed surface oxide layer. During the delithiation process, volume contraction and the dealloying of LixIn take place. Induced by the alloying and dealloying of LixIn, the dark and bright strips along the basal plane of InAs NWs appear and disappear alternately during the lithiation–delithiation cycling. Our results provide important insights into the lithiation/delithiation mechanism of III–V group nanomaterials and are envisaged to be helpful for designing lithium ion battery anode materials with fast lithiation speed, small volume expansion and reversible lithiation/delithiation processes. Graphical abstract