Microwave assisted green chemistry approach of sodium metaborate dihydrate (NaBO2·2H2O) synthesis and use as raw material for sodium borohydride (NaBH4) thermochemical production

In the present study, a novel microwave assisted method has been developed for sodium metaborate dihydrate (NaBO₂·2H₂O) synthesis. Anhydrous NaBO₂, a derivative of borax, is an industrially and technologically important boron compound used as a raw material for the thermochemical production of sodium borohydride (NaBH₄). The effects of different microwave treatment conditions such as microwave power (90, 270 and 360 W) and irradiation time (1, 2, and 5 min) on the synthesis of NaBO₂·2H₂O were examined. After microwave irradiation at 270 W for 1 min, NaBO₂ crystals with 2 molar equivalents of water were formed. Anhydrous NaBO₂ was obtained following incubation at 400 °C for 33 min under calcination conditions. Then the resulting anhydrous NaBO₂ powder was reacted with MgH₂ under 60 bar hydrogen atmosphere at 470 °C, leading to successful production of NaBH₄ with 93% yield.     

Biofilm development during the start-up of a sulfate-reducing down-flow fluidized bed reactor at different COD/SO4(2-) ratios and HRT

In sulfate-reducing reactors, it has been reported that the sulfate removal efficiency increases when the COD/SO4(2-) ratio is increased. The start-up of a down-flow fluidized bed reactor constitutes an important step to establish a microbial community in the biofilm able to survive under the operational bioreactor conditions in order to achieve effective removal of both sulfate and organic matter. In this work the influence of COD/SO4(2-) ratio and HRT in the development of a biofilm during reactor start-up (35 days) was studied. The reactor was inoculated with 1.6 g VSS/L of granular sludge, ground low density polyethylene was used as support material; the feed consisted of mineral medium at pH 5.5 containing 1 g COD/L (acetate:lactate, 70:30) and sodium sulfate. Four experiments were conducted at HRT of 1 or 2 days and COD/SO4(2-) ratio of 0.67 or 2.5. The results obtained indicated that a COD/SO4(2-) ratio of 2.5 and HRT 2 days allowed high sulfate and COD removal (66.1 and 69.8%, respectively), whereas maximum amount of attached biomass (1.9 g SVI/L support) and highest sulfate reducing biofilm activity (10.1 g COD-H2S/g VSS-d) was achieved at HRT of 1 day and at COD/sulfate ratios of 0.67 and 2.5, respectively, which suggests that suspended biomass also played a key role in the performance of the reactors.     

Assessment of the bioavailability of toxic and non-toxic arsenic species in seafood samples

Bioavailability of total arsenic, toxic (arsenite, As(III); and arsenate, As(V)), and non-toxic (monomethylarsonic acid, MA; dimethylarsonic acid, DMA; arsenobetaine, AB; and arsenocholine, AC) arsenic species has been assessed in different raw seafood samples (white fish, cold water fish and molluscs) by using an in vitro model that combines simulated gastric and intestinal digestion/dialysis methods. Correlations between arsenic species bioavailability and seafood nutrient contents (fat and protein) have also been established. Total arsenic content in seafood samples, and dialyzable and non-dialyzable fractions, were analyzed by inductively coupled plasma – mass spectrometry (ICP–MS) after a microwave-assisted acid digestion treatment. The determination of the different arsenic species concentrations in the samples (after an optimised matrix solid phase dispersion (MSPD) approach) and in the dialyzable fraction was done by high performance liquid chromatography (HPLC) coupled to ICP-MS as a selective detector. Accuracy of the procedure (total arsenic determination) was assessed by analyzing DORM-2 and BCR-627 certified reference materials. The accuracy of the in vitro procedure was established through a mass-balance study. After statistical evaluation (95% confidence interval), good accuracy of the whole in vitro process, for total arsenic and for arsenic speciation, was observed. High dialyzability percentages for total arsenic and for arsenic species were found (i.e. from 84.6 ± 1.7% to 106 ± 2.6%). Bioavailability of arsenic exhibits a negative correlation with the fat content of the seafood. However, no correlation was observed between the bioavailable fraction of total arsenic and arsenic species and the protein content of the seafood studied.     

神奇的补充和替代医学

生病，一般人都会以为“吃药“是最为直接、有效的治疗方式。但是，“是药三分毒”，凡是药物，或多或少地都会伤到胃，伤到肝，伤到肾，或者其他组织、器官。更何况，当今的药物滥用，以及传统医药的危险性，已经使得很多人对传统的医学手段和药物治疗产生了防范甚至恐惧心理。     

新闻纸的白度、色度与不透明度

本文通过对目前新闻纸市场上新闻纸的白度、色度和不透明度的调查，结合本厂的实践提出了对新闻纸的ISO白度、CIE白度、L^＊、a^＊、b^＊值和不透明度的合理控制范围。     

ASSESSMENT OF CONSEQUENCES OF SEDIMENT DEFICIT ON A GRAVEL RIVER BED DOWNSTREAM OF DAMS IN RESTORATION PERSPECTIVES: APPLICATION OF A MULTICRITERIA,HIERARCHICAL AND SPATIALLY EXPLICIT DIAGNOSIS

As regards river restoration, it is fundamental to better link human pressures and environmental responses and to take into consideration not only target species or habitat but diverse ecological elements. This permits to assess sustainable restoration plan, especially concerning sediment augmentation below dams. The use of a hierarchical multicriteria approach on the Ain River permits us to assess a diagnosis of sediment deficit impact integrating several morphological (channel shifting, river bed degradation and river bed coarsening) and ecological components (Riparian and floodplain lake and fish communities). Our diagnosis also integrates a temporal and spatial approach better to link human pressures and environmental responses and to identify the dam effects amongst other drivers (e.g. grazing decline and channel regulation). The results confirm causality links between sediment deficit and slight channel bed degradation (0.01 m.year^?1) or channel bed paving and thus highlight the impact of the dam on the drying of the riparian forest and on former channel community. However, the relationship between incision and reduction in active channel lateral mobility is more difficult to establish. The role of sediment deficit in the current variability of the riparian regeneration capacity and, thereby, landscape diversity along the lower valley remains unclear. This study also confirms the relevance of using different ecological indicators, notably because all components present different adjustment time scales, whereas some of them are more sensitive to other impacts. Copyright © 2013 John Wiley & Sons, Ltd.     

A Bipolar Host Material Containing Triphenylamine and Diphenylphosphoryl‐Substituted Fluorene Units for Highly Efficient Blue Electrophosphorescence

Highly efficient blue electrophosphorescent organic light‐emitting diodes incorporating a bipolar host, 2,7‐bis(diphenylphosphoryl)‐9‐[4‐(N,N‐diphenylamino)phenyl]‐9‐phenylfluorene (POAPF), doped with a conventional blue triplet emitter, iridium(III) bis[(4,6‐difluoro‐phenyl)pyridinato‐N,C^2´]picolinate (FIrpic) are fabricated. The molecular architecture of POAPF features an electron‐donating (p‐type) triphenylamine group and an electron‐accepting (n‐type) 2,7‐bis(diphenyl‐phosphoryl)fluorene segment linked through the sp³‐hybridized C9 position of the fluorene unit. The lack of conjugation between these p‐ and n‐type groups endows POAPF with a triplet energy gap (E_T) of 2.75 eV, which is sufficiently high to confine the triplet excitons on the blue‐emitting guest. In addition, the built‐in bipolar functionality facilitates both electron and hole injection. As a result, a POAPF‐based device doped with 7 wt% FIrpic exhibits a very low turn‐on voltage (2.5 V) and high electroluminescence efficiencies (20.6% and 36.7 lm W^?1). Even at the practical brightnesses of 100 and 1000 cd m^?2, the efficiencies remain high (20.2%/33.8 lm W^?1 and 18.8%/24.3 lm W^?1, respectively), making POAPF a promising material for use in low‐power‐consumption devices for next‐generation flat‐panel displays and light sources.     

Pressure Effect on Superconductivity and Magnetism in α-FeSe x

In this paper, the pressure effect on superconductivity and magnetism has been investigated in FeSe _x (x=0.80,0.88). The magnetization curves display anomaly at T _s1∼106 K and T _s2∼78 K except for the superconducting diamagnetic transition around T _c ∼8 K. The magnetic anomaly at T _s1 and T _s2 can be related to a ferromagnetic and an antiferromagnetic phase transition, respectively, as revealed by specific heat measurements. The application of pressure not only raises T _c , but also increases both T _s1 and T _s2.      

Synthesis of flower-like sns2 nanostructured microspheres using PEG 200 as solvent

The flower-like tin disulphide (SnS₂) microspheres have been synthesised by a facile solution-based route using polyethylene glycol 200 as the solvent and template. The products are characterised by X-ray diffraction, transmission electron microscopy and scanning electron microscopy. Experimental results show that the flower-like SnS₂ microspheres with diameters around 2-5--m are made of many interleaving petal-like nanostructures. These nanopetals are 1-3--m in side length and less than 60-nm in thickness. The influences of solvent and sulphur source on the morphology of SnS₂ nanostructures have also been investigated. The possible growth mechanism is discussed. Furthermore, the room-temperature Raman spectrum of the flower-like SnS₂ microspheres is also studied.     

A/O-混凝工艺处理氰酚废水的研究

采用后继混凝沉淀的A/O工艺对含酚、氰的焦化废水进行了处理,运行结果表明:废水中酚质量浓度从287～681 mg/L降至1.0 mg/L以下,氰化物质量浓度从0.72～11.4 mg/L降至0.5 mg/L以下,完全达到了<污水综合排放标准>(GB 8978-1996)的二级排放标准;COD_(Cr)从3 879～6 378 mg/L降至116.1～184.2 mg/L.氨氮从145.6～200 mg/L降至11.64～25.26 mg/L.大多数时间达到排放标准.