Efficient and Stable Thin-Film Luminescent Solar Concentrators Enabled by Near-Infrared Emission Perovskite Nanocrystals

A novel triphenylphosphine (TPP) treatment strategy was developed to prepare the near-infrared emission CsPbI₃ nanocrystal (NC)-polymer composite thin-film luminescent solar concentrators (LSCs) featuring high absolute photoluminescence quantum yield (PLQY), low reabsorption, and high stability. The PL emission of the LSCs is centered at about 700 nm with 99.4±0.4 % PLQY and narrow full width at half maximum (FWHM) of 75 meV (30 nm). Compared with LSCs prepared with classic CsPbI₃ NCs, the stability of the LSCs after TPP treatments has been greatly improved, even after long-term (30 days) immersion in water and strong mercury-lamp irradiation (50 mW cm⁻²). Owing to the presence of lone-pair electrons on the phosphorus atom, TPP is also used as a photoinitiator, with higher efficiency than other common photoinitiators. Large-area (ca. 75 cm²) infrared LSCs were achieved with a high optical conversion efficiency of 3.1 % at a geometric factor of 10.     

Analysis of Vinyl Chloride in Vapor Phase of Mainstream Cigarette Smoke by GC–MS Under ISO and Health Canada Intensive Machine Smoking Regimens

Vinyl chloride (VC) in the vapor phase of mainstream cigarette smoke was determined under both International Organization for Standardization (ISO) and Health Canada intensive (HCI) machine smoking regimens, which was suspected to be carcinogenic compound. VC was collected by passing the mainstream cigarette smoke through a Cambridge Filter Pad (CFP) into cryogenic traps containing methanol. The impinger solutions were fortified with VC-d ₃ and analyzed by GC–MS. Limits of detection for vinyl chloride was 0.9 ng mL⁻¹ with the recovery in the range of 93.2–98.4 %. Moreover, the intra-day and inter-day precision was 7.39 and 9.77 %, respectively. Under HCI machine smoking regimen, the vinyl chloride yields in vapor phase of mainstream cigarette smoke were much higher and the average increase was greater than 100 % compared with those under ISO smoking condition.

     

pH-Triggered controlled drug release from mesoporous silica nanoparticles via intracelluar dissolution of ZnO nanolids

Acid-decomposable, luminescent ZnO quantum dots (QDs) have been employed to seal the nanopores of mesoporous silica nanoparticles (MSNs) in order to inhibit premature drug (doxorubicin) release. After internalization into HeLa cells, the ZnO QD lids are rapidly dissolved in the acidic intracellular compartments, and as a result, the loaded drug is released into the cytosol from the MSNs. The ZnO QDs behave as a dual-purpose entity that not only acts as a lid but also has a synergistic antitumor effect on cancer cells. We anticipate that these nanoparticles may prove to be a significant step toward the development of a pH-sensitive drug delivery system that minimizes drug toxicity.     

Robust direction-of-arrival estimation method with high accuracy for single vector sensor

The phase errors among the components of a single acoustic vector sensor cause the direction-of-arrival(DOA) estimation error of the existing methods.In order to address this issue,a DOA estimation method is proposed,which is robust to the phase errors.The proposed method first utilizes the Hadamard product of the principal eigenvector of the covariance matrix of the received signal by the single vector sensor and its conjugate vector to construct the spatial spectrum in order to estimate the DOA of the underwater target.Since the Hadamard product eliminates the phase errors,this estimation is independent of the phase errors.However,it is ambiguous.Afterwards,the phase-error estimate is explored to eliminate the ambiguity and get the correct DOA estimate.The proposed method performs independently of the phase errors and obtains high accuracy.The simulation results and the experimental result demonstrate the proposed method is robust to the phase errors.Furthermore,in the presence of the phase errors,it performs better than the average acoustic intensity method,the CAPON method,and the MUSIC method,in terms of estimation accuracy.In addition,the simulation results indicate that the estimation accuracy of the proposed method approaches to the Cramer-Rao bound(CRB).     

Efficient and Stable Thin‐Film Luminescent Solar Concentrators Enabled by Near‐Infrared Emission Perovskite Nanocrystals

A novel triphenylphosphine (TPP) treatment strategy was developed to prepare the near‐infrared emission CsPbI₃ nanocrystal (NC)‐polymer composite thin‐film luminescent solar concentrators (LSCs) featuring high absolute photoluminescence quantum yield (PLQY), low reabsorption, and high stability. The PL emission of the LSCs is centered at about 700 nm with 99.4±0.4 % PLQY and narrow full width at half maximum (FWHM) of 75 meV (30 nm). Compared with LSCs prepared with classic CsPbI₃ NCs, the stability of the LSCs after TPP treatments has been greatly improved, even after long‐term (30 days) immersion in water and strong mercury‐lamp irradiation (50 mW cm^?2). Owing to the presence of lone‐pair electrons on the phosphorus atom, TPP is also used as a photoinitiator, with higher efficiency than other common photoinitiators. Large‐area (ca. 75 cm²) infrared LSCs were achieved with a high optical conversion efficiency of 3.1 % at a geometric factor of 10.     

Picosecond laser ablation of high-quality micro-grooves on CIGS (CuIn(1-x)Ga2Se x ) thin films

ABSTRACT

This paper presents a study of the effects of ablation direction, beam profile and outer environment on the width and morphology of micro-grooves ablated by a 10-ps, 532-nm laser with a changing range of fluences and scan speeds on 600?nm-thick CIGS (CuIn_(1-x)Ga₂Se _x ) thin films. Experiments show that rear-side ablation by picosecond laser with a flat top beam in water environment yields a larger groove width than normal front-side ablation with a Gaussian beam in air, which is attributed to different material removal mechanisms, uniform energy distribution and the refraction of laser in water. The heat-affected zone and irregular edges induced by the tearing effect are the main defects of groove morphology associated with front- and rear-side ablation processes, respectively. Our studies indicate that flat top beam ablation, in general, inhibits the over-ablation in the central region, thereby improving the uniformity of grooves, though it does not eliminate the heat-affected zone and irregularity of two edges. The straightness of groove edges is further improved with the flat top beam ablation carried out in a water environment, resulting from the action of the shock wave in water. Hence, the nearly perfect micro-grooves can be fabricated with rear-side flat top beam ablation under water, which are characterized by steep sidewalls, straight edges and intact glass substrate without cracks.     

Analysis of Vinyl Chloride in Vapor Phase of Mainstream Cigarette Smoke by GC–MS Under ISO and Health Canada Intensive Machine Smoking Regimens

Vinyl chloride (VC) in the vapor phase of mainstream cigarette smoke was determined under both International Organization for Standardization (ISO) and Health Canada intensive (HCI) machine smoking regimens, which was suspected to be carcinogenic compound. VC was collected by passing the mainstream cigarette smoke through a Cambridge Filter Pad (CFP) into cryogenic traps containing methanol. The impinger solutions were fortified with VC-d ₃ and analyzed by GC–MS. Limits of detection for vinyl chloride was 0.9 ng mL^?1 with the recovery in the range of 93.2–98.4 %. Moreover, the intra-day and inter-day precision was 7.39 and 9.77 %, respectively. Under HCI machine smoking regimen, the vinyl chloride yields in vapor phase of mainstream cigarette smoke were much higher and the average increase was greater than 100 % compared with those under ISO smoking condition.     

P507萃取纯化V(Ⅳ)制备草酸氧钒及其物化性能

从钒渣钠化焙烧后的含钒浸液中, 采用2-乙基己基磷酸单-2-乙基己酯(P507)萃取-草酸反萃取-蒸发结晶新工艺制备了草酸氧钒, 优化了草酸反萃取工艺的条件. 研究结果表明, 采用2.0 mol/L草酸溶液, 在水相与有机相体积比V(A):V(O)为1:5时, 于50 ℃下经过三级(理论)反萃取, 钒的反萃取率可达到99.98%, 反萃取液中VOC₂O₄浓度可达290.0 g/L以上. 负载的反萃取液经膜过滤除去残留有机物后, 再经蒸发结晶得到草酸氧钒. 采用X射线衍射、 X射线能谱、 热场发射扫描电子显微镜及同步热分析等手段表征了草酸氧钒的物化性能, 结果表明, 草酸氧钒的结构为VOC₂O₄·2H₂O, 粒度分布均匀, 结晶度高.