Analysis of radionuclide retention in water pools

An analysis is presented of the removal of aerosol particles and gaseous fission products from steam-noncondensable gas mixtures rising through water pools. The pool is divided into a gas injection zone, a bubble rise zone and a pool surface zone. The formulation of the governing conservation equations is relatively general with a quasi-steady one-dimensional formulation for the gas phase, and an unsteady, well stirred, formulation for the liquid phase. An associated computer code for performing the calculations, SUPRA, is described. Results of parametric calculations are given for conditions expected in a BWR severely degraded core accident sequence. Parameters studied include aerosol particle size and distribution, mass fraction of noncondensable gas, gas mass flow rate, quencher submergence depth, and pool water temperature.     

Electronic structure of polythieno[3,4-b]-thiophene-co-benzodithiophene (PTB7) derivatives for organic solar cell applications

Among the new materials currently employed as electron donor element in active layers of organic solar cells (OSCs), PTB7 holds the best results. It has been extensively studied and now there is a search for new derivatives to improve its properties. In this work, a set of 24 polymers derived from polythieno[3,4-b]-thiophene-co-benzodithiophene (PTB7) was studied theoretically, using chemical modifications in the benzodithiophene (BDT) moiety of the PTB7 monomeric units. After evaluations of the electronic and optical properties, including the open circuit voltage and exciton dissociation and recombination conditions, the results indicate that employing chlorine as substituent yields the most promising material for application in active layers together with Phenyl-C₆₁-Butyric-Acid-Methyl-Ester (PCBM) as electron acceptor material.     

PTB乳液特性及其在无机植筋胶中的应用

PTB乳液是一种聚合物砂浆添加剂。在试验的基础上，本文研究了PTB乳液对提高砂浆防水性、防腐性、粘结性、柔韧性的作用，并介绍了PTB乳液在无机植筋胶中的应用。     

PTB乳液对水泥砂浆力学性能和抗侵蚀性能的影响

研究了PTB乳液改性水泥砂浆的力学性能、抗氯盐和抗硫酸盐侵蚀等性能。结果表明,掺入PTB乳液对水泥净浆有缓凝作用,大幅延长了水泥净浆的终凝时间;掺入PTB乳液降低了水泥砂浆的抗压强度,但是降低抗压/抗折强度比改善了水泥砂浆的延性,提高了水泥砂浆的综合力学性能。PTB乳液/水泥为0.22时的PTB乳液水泥砂浆在氯化钠、硫酸镁溶液中浸泡28d后,其抗蚀系数提高。     

Photo-physics of PTB7, PCBM and ICBA based ternary solar cells

Indene-C₆₀bisadduct (ICBA) is one of the rare acceptors which can supersede commonly used phenyl-C71-butyric acid methyl ester (PCBM70) in enhancing the performance of bulk heterojunction (BHJ) solar cells owing to its shallower lowest unoccupied molecular orbital (LUMO) level. However, ICBA tends to decrease the photocurrent for most of the low band-gap polymers synthesized to date. Here we examine the interaction of ICBA with the one of the popular low band-gap polymers poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl) carbonyl] thieno[3,4-b]thiophenediyl]] (PTB7), at femtosecond level, to explore key dynamics governing the operation of BHJ cells involving ICBA. The photo-physics of binary and ternary systems based on PTB7 coupled with PCBM70 and/or ICBA are studied by means of transient absorption spectroscopy (TAS) and electrochemical impedance spectroscopy (EIS) and supported by morphology analysis. Our study suggests that both inefficient charge-separation and poor charge transport of ICBA is responsible for relatively low photocurrent generation.     

Impact of alkyl chain length of 1,n-diiodoalkanes on PC71BM distribution in both bulk and air surface of PTB7:PC71BM film

The impact of alkyl chain length of different additives, such as 1,4-diiodobutane (DIB), 1,6-diiodohexane (DIH), 1,8-diiodooctane (DIO) and 1,10-diiododecane (DID), on the PC₇₁BM distribution in PTB7:PC₇₁BM-based polymer solar cells, is systematically investigated, for the first time. Among these additives, DIO is found to have the optimum alkyl chain length that maximizes the performance of PTB7:PC₇₁BM based polymer solar cells, attaining a power conversion efficiency as high as 8.84%, which is almost four times higher than that without any additives. For DID additives (longer alkyl chain length than DIO), a drop in efficiency to 7.91% was observed. Experimental investigations show that the microstructure of the bulk and the surface layer as well as the surface morphology of the PTB7:PC₇₁BM polymer film can be controlled simultaneously by varying the alkyl chain length of additives. Results also show that the substantial improvement in performance is attributed to the improved 1) phase segregation, 2) PC₇₁BM distribution uniformity in the bulk of the PTB7:PC₇₁BM film, 3) surface smoothness and 4) high PTB7 content at the interface between the active layer and the top electrode.     

PTB乳液水泥砂浆抗渗性能及粘结性能研究

通过试验对PTB乳液水泥砂浆的表面憎水性能、吸水率、抗氯离子渗透、粘结性能等进行了研究。结果表明,掺入PTB乳液能够提高水泥砂浆表面的憎水性能,降低水泥砂浆的吸水率,提高抗氯离子渗透性能;掺入PTB乳液提高了水泥砂浆的拉伸粘结强度和粘结抗折强度。     

国产智能气压测量仪实验室校准方法研究

以国产智能气压测量仪为研究对象，选取国产DYG4和国外PTB系列气压传感器为实验样本，对国产智能气压测量仪的实验室校准方法展开研究；校准方法对校准所用仪器设备、校准项目、校准数据处理原则展开分析，在校准方法研究基础上设计了DYG4自动化校准系统；校准案例中对样本仪器示值误差、回程误差、测量结果重复性进行了测试，并评定了示值误差测量结果的不确定度，DYG4在各校准点不确定度为0.14 hPa，PTB系列为0.12 hPa；实验室比对结果表明，各校准点归一化偏差绝对值均未超过1，证明校准方法合理。     

A highly efficient PTB7-Th polymer donor bulk hetero-junction solar cell with increased open circuit voltage using fullerene acceptor CN-PC70BM

Modified [6,6]-phenyl-C₇₀-butyric acid methyl ester (CN-PC₇₀BM) is employed as an electron acceptor along with poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b; 4,5-b']dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene-)-2-carboxylate-2-6-diyl)] (PTB7-Th) polymer as donor for solution-processed organic solar cells. Inverted device architecture is adopted to fabricate the photovoltaic devices. Using chloronaphthalene as an additive, a high power conversion efficiency (PCE) of 8.2% is achieved with an excellent open circuit voltage (V_oc) of 0.9 V, short-circuit current density (J_sc) of 13.5 mA cm⁻² and fill factor of 0.68 as compared to PCE of 5.4% from the reference solar cell using PC₇₀BM.