Synthesis of well‐defined star‐shaped poly(ε‐caprolactone)/poly(ethylbene glycol) amphiphilic conetworks by combination of ring opening polymerization and “click” chemistry

Well‐defined star‐shaped hydrophobic poly(ε‐caprolactone) (PCL) and hydrophilic poly(ethylene glycol) (PEG) amphiphilic conetworks (APCNs) have been synthesized via the combination of ring opening polymerization (ROP) and click chemistry. Alkyne‐terminated six arm star‐shaped PCL (6‐s‐PCLx‐C?CH) and azido‐terminated PEG (N₃‐PEG‐N₃) are characterized by ¹H NMR and FT‐IR. The swelling degree of the APCNs is determined both in water and organic solvent. This unique property of the conetworks is dependent on the nanophase separation of hydrophilic and hydrophobic phases. The morphology and thermal behaviors of the APCNs are investigated by SEM and DSC respectively. The biocompatibility is determined by water soluble tetrazolium salt reagents (WST‐1) assay, which shows the new polymer networks had good biocompatibility. Through in vitro release of paclitaxel (PTX) and doxorubicin (DOX), the APCNs is confirmed to be promising drug depot materials for sustained hydrophobic and hydrophilic drugs. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 407–417     

Type II hybrid structures of TiO2 nanorods conjugated with CdS quantum dots: assembly and optical properties

We developed a novel method to assemble TiO₂ nanorods conjugated with CdS quantum dots by L-cysteine molecular linker for type II semiconducting hybrid structure. The XRD patterns indicate that the CdS quantum dots perform the cubic phase structure, and TEM images show that CdS quantum dots are well dispersed on the surfaces of anatase TiO₂ nanorods with little agglomeration. The UV-vis absorption spectra reveal the bandgap alignment in type II configuration between CdS QDs and TiO₂ nanorods.     

The Nonnegative Zero-Norm Minimization Under Generalized Z-Matrix Measurement

In this paper, we consider the zero-norm minimization problem with linear equation and nonnegativity constraints. By introducing the concept of generalized Z-matrix for a rectangular matrix, we show that this zero-norm minimization with such a kind of measurement matrices and nonnegative observations can be exactly solved via the corresponding p-norm minimization with p in the open interval from zero to one. Moreover, the lower bound of sample number for exact recovery is allowed to be the same as the sparsity of the original image or signal by the underlying zero-norm minimization. A practical application in communications is presented, which satisfies the generalized Z-matrix recovery condition.     

A gold-based nanobeacon probe for fluorescence sensing of organophosphorus pesticides

A nanomaterials-based novel molecular beacon has attracted growing attentions in fluorescent assays as many nanomaterials possess excellent quenching efficiency. In this work, a gold-based nanobeacon probe was established to detect organophosphorus pesticides for the first time. The constructed gold-based nanobeacon acted as a signal indicator and could display the decreasing of the intensity in the presence of targets, which competitively bound to single strand DNA. To achieve a high sensitive probe, some parameters including solution pH, temperature and reaction time were investigated and optimized. The gold-based nanobeacon probe assay was proved to be rapid and sensitive to achieve a detection limit of 0.035 μM for isocarbophos, 0.134 μM for profenofos, 0.384 μM for phorate and 2.35 μM for omethoate, respectively. The prepared nanobeacon effectively reduced the background and improved the detection sensitivity and selectivity. The probe is stable, easy to operate and does not need sophisticated instruments. These features makes the probe feasible for screening trace organophosphorus pesticides in real samples.     

Li-ion-conductive Li2TiO3-coated Li[Li0.2Mn0.51Ni0.19Co0.1]O2 for high-performance cathode material in lithium-ion battery

Journal of Solid State Electrochemistry - Li2TiO3 is used as a novel coating material to modify Li(Li0.2Mn0.51Ni0.19Co0.1)O2 electrode to enhance the electrochemical performance of the host...     

Luminescent Ag6Au6 Heterometallic Ethisterone Cluster and Probe for Estrogen Receptor α

A heterometallic cluster [Ag₆Au₆(ethisterone)₁₂] of an unprecedented topology was synthesized and characterized. A sensitive and specific probe for estrogen receptor α (ERα) has been developed for the first time based on the enhancement of the Ag₆Au₆ luminescence.     

3D photon counting imaging at 1550 nm with 1.5-GHz sine-wave-gated InGaAs/InP GAPD

We demonstrated a 3D laser imaging system at 1550 nm with a 1.5-GHz sine-wave gated Geiger-mode InGaAs/InP avalanche photodiode (APD). An optical fiber bundle with 100 individual fiber outputs was implemented at the focal plane of the telescope, providing a 2.5-mrad imaging view. The system used single-pixel near-infrared single-photon detector to measure photons at fiber outputs instead of a photon counting array. The 1.5-GHz gated Geiger-mode InGaAs/InP APD with a timing jitter of 290 ps was operated in quasi-continuous mode with detection efficiency of ∼4.3%. We achieved higher than 6-cm surface-to-surface resolution at single-photon level, showing a potential of low-energy and eye-safe laser imaging system for long-distance measurements.     

熔盐堆空气换热器结构完整性分析

熔盐堆作为第四代核反应堆备选堆型之一,运行温度高,对材料高温性能要求严格;熔盐堆空气换热器作为实验堆关键设备,工作温度高,启停机次数多,长期运行后,材料许用应力松弛下降,应力、应变可能超出允许限值,或发生蠕变疲劳失效。使用Workbench软件,对熔盐堆空气换热器进行力学分析,并对A级使用载荷要求进行结构完整性评定,结果表明:熔盐堆空气换热器满足力学性能要求,其中疲劳损伤占比重较大,高温蠕变损伤也较为显著。