Spirobifluorene Dimers: Understanding How The Molecular Assemblies Drive The Electronic Properties

Spirobifluorene (SBF) is one of the most important scaffolds used in the design of organic semi-conductors (OSCs) for electronics. In recent years, among all the structures developed for these applications, SBF dimers have been highlighted due to their great potential in thermally activated delayed fluorescence and in phosphorescent organic light-emitting diodes. Attaching two SBF units generate 10 dimers, each possessing its own structural specificity, which in turn drives its electronic properties. These ten SBF dimers are gathered herein. Understanding how the molecular assembly determines the electronic properties has been one of the pillars of organic electronics. This is the goal of this article. As positional isomerism is a key tool to design OSCs, defining the design guidelines for the SBF scaffold appears of interest for the future of this building block. Herein, the importance of the two main parameters involved in the electrochemical and photophysical properties, namely the nature of the phenyl linkages and the steric congestion between the two SBF units is discussed. The combination of these two parameters drives the electronic properties but their respective weight is different as a function of the regioisomer involved or of the property considered (frontier orbitals energy level, absorption, fluorescence, phosphorescence).     

Hydrogen storage capacity and reversibility of Li-decorated B4CN3 monolayer revealed by first-principles calculations

This work explored the feasibility of Li decoration on the B₄CN₃ monolayer for hydrogen (H₂) storage performance using first-principles calculations. The results of density functional theory (DFT) calculations showed that each Li atom decorated on the B₄CN₃ monolayer can physically adsorb four H₂ molecules with an average adsorption energy of ?0.23 eV/H₂, and the corresponding theoretical gravimetric density could reach as high as 12.7 wt%. Moreover, the H₂ desorption behaviors of Li-decorated B₄CN₃ monolayer at temperatures of 100, 200, 300 and 400 K were simulated via molecular dynamics (MD) methods. The results showed that the structure was stable within the prescribed temperature range, and a large amount of H₂ could be released at 300 K, indicative of the reversibility of hydrogen storage. The above findings demonstrate that the Li-decorated B₄CN₃ monolayer can serve as a favorable candidate material for high-capacity reversible hydrogen storage application.     

Combining a new baseboard radiator with a fan coil system for improving heating performance and reduce energy consumption

In the present work, the heating performance of a new system combined with a new modified baseboard radiator and fan coil is investigated. Using longitudinal fins with special geometry and also forced airflow at the end of the system causes that at the lower inlet water temperature compared with the conventional models, higher heat output rate be obtained. The heat output rate of the new modified system is obtained by experimental metrology based on the European Standard No. EN-442. Temperature and velocity distribution in the room space is done by simulation of the modified system in the Flovent software. Computational fluid dynamics (CFD) results are validated against experimental results and there is a good agreement between them. Also, the energy consumption of the system during the winter season is calculated in TRANSYS software. Experimental results show that the heat output rate of a new modified heating system with inlet water temperature in the range of 45–55°C is on average 4.17 times higher compared with the conventional model. CFD simulation also showed that the combined system provides good thermal comfort conditions. Energy consumption of the new system reduced about 13% compared with conventional models.     

Genetic and genomic analysis of age at first insemination in Israeli dairy cattle

We performed a genetic analysis of age at first insemination, including estimation of the heritability and genetic correlations with other economic traits, and the consequences of including this trait in the Israeli selection index. The genetic factors affecting age at first insemination were determined via GWAS. Five data sets were analyzed. Data sets 1, 2, and 3 were used to compute variance components among age at first insemination, first calving age, days from first insemination to calving, and the 9 traits included in the Israel breeding index. Heritabilities for age at first insemination, calving age, and days from first insemination to calving in Israeli Holsteins as computed by REML individual animal model analyses of 273,239 Israeli Holstein cows were 0.072, 0.042, and 0.014. The estimated genetic correlation between the first 2 traits was 0.88. In addition to the fact that heritability of age at first insemination is 1.7 times the heritability for calving, the former trait has the advantage that the number of records is greater, and the records are generated earlier. Absolute values of the genetic and residual correlations between age at first insemination and the 9 traits included in the Israeli index were all less than 0.2. Data set 4 included first insemination dates of 1,181,600 calves born from 1985 through 2018. Genetic evaluations were computed by a single trait animal model. Annual phenotypic and genetic trends for age at first calving for calves born since 1985 were “positive,” that is, economically negative, at 0.320 ± 0.003 and 0.169 ± 0.005 d, respectively. Applying the GCTA-GREML software, 54% of variance in the transmitting ability of 1,585 sires could be explained by considering all 40,498 markers included in the GWAS analysis. The significant markers were mainly associated with milk production genes. The SNP UA-IFASA-8854 on chromosome 11 had the lowest probability value, 1.2 × 10^?24. This marker is located between the genes RETSAT and ELMOD3, both of which are overexpressed in human mammary glands. The gene RETSAT is reported to be essential for lipid accumulation and adipogenesis promotion. Gene enrichment analysis found that genes in the genomic region flanking significant markers are associated with vasopressin receptor activity, which was shown to mediate puberty in humans. If age at first insemination is included in the index with a weighting to account for 9% of the index, reductions of 2.8 and 2.6 d for age at first insemination and first calving age after 10 yr of selection are predicted, as compared with reductions of 1.4 and 1.1 d with the current index. Gains for the other index traits are only marginally affected. We suggest selection on age at first insemination as an alternative to selection for early calving.     

基于跨临界CO2热泵的茶叶生产能源系统负荷削减潜力

乡村产业中的化石能源设备逐渐被电能技术替代，引起了乡村负荷波动增大、部分时段产生集中高负荷的问题。为了解决以上问题，将低品位清洁能源应用至乡村的茶叶生产中，针对烘茶全过程的工艺要求提出了跨临界CO₂热泵烘茶技术；并以某茶叶生产乡村为对象，对其代表台区的全年日用电量及产茶日负荷进行了分析，得出采用CO₂热泵烘茶后其负荷得到大幅度削减，整体可降低至原负荷的39.6%~46.8%，峰值负荷与平时负荷的比值由原本的13.6降至5.4~6.2。跨临界CO₂热泵应用至农产品生产中可有效缓解乡村供电压力。     

Green Measurements for Software Product Based on Sustainability Dimensions

Software is a central component in the modern world and vastly affects the environment’s sustainability. The demand for energy and resource requirements is rising when producing hardware and software units. Literature study reveals that many studies focused on green hardware; however, limited efforts were made in the greenness of software products. Green software products are necessary to solve the issues and problems related to the long-term use of software, especially from a sustainability perspective. Without a proper mechanism for measuring the greenness of a particular software product executed in a specific environment, the mentioned benefits will not be attained. Currently, there are not enough works to address this problem, and the green status of software products is uncertain and unsure. This paper aims to identify the green measurements based on sustainable dimensions in a software product. The second objective is to reveal the relationships between the elements and measurements through empirical study. The study is conducted in two phases. The first phase is the theoretical phase, where the main components, measurements and practices that influence the sustainability of a software product are identified. The second phase is the empirical study that involved 103 respondents in Malaysia investigating current practices of green software in the industrial environment and further identifying the main sustainability dimensions and measurements and their impact on achieving green software products. This study has revealed seven green measurements of software product: Productivity, Usability, Cost Reduction, Employee Support, Energy Efficiency, Resource Efficiency and Tool Support. The relationships are statistically significant, with a significance level of less than 0.01 (p = 0.000). Thus, the hypothesised relationships were all accepted. The contributions of this study revolve around the research perspectives of the measurements to attain a green software product.     

基于案例分析的工程伦理课程实践

案例教学法在我国起步较晚,以培养学生工程伦理实践能力为取向的案例教学逐渐成为重要的教学方法。通过对工程伦理教育发展历史沿革、工程伦理教育存在的问题等阐述,提出构建工程伦理案例分析课程体系的思路、方法、及其意义,旨在推动我国工程伦理课程体系教学理论和实践的发展。     

Two placebo-controlled crossover studies in healthy subjects to evaluate gastric acid neutralization by an alginate–antacid formulation (Gaviscon Double Action)

Objective: To investigate the intragastric acid neutralization activity of a combined alginate-antacid formulation.

Significance: Published studies have investigated the reflux-suppressing alginate component of Gaviscon Double Action (Gaviscon DA; RB, UK) but intragastric acid neutralization activity of the antacid component has not been evaluated in vivo.

Methods: Intragastric pH monitoring, using a custom-made 10-electrode catheter, was evaluated in a two-part exploratory study in healthy subjects; Part I (n?=?6) tested suitability of the catheter using antacid tablets (Rennie; Bayer, Germany); Part II (n?=?12) evaluated gastric acid neutralization activity of Gaviscon DA liquid (20?ml) versus placebo in fasted subjects using a randomized, open-label, crossover design. The primary endpoint was the percentage of time that intragastric pH ≥4 was measured during 30?min post-treatment. A confirmatory study of identical design was subsequently conducted (n?=?20).

Results: Monitoring pH using the multielectrode catheter was a viable approach, directly detecting changes in intragastric pH following a single dose of antacid tablets. In the exploratory study, the percentage of time that pH ≥4 during 30?minutes post-treatment was 46.8% with Gaviscon DA liquid versus 4.7% with placebo (p?=?0.0004). These findings were supported by the confirmatory study, where pH ≥4 was recorded 50.8% of the time with Gaviscon DA versus 3.5% with placebo (p?=?0.0051). In this study, Gaviscon DA was safe and well tolerated.

Conclusions: These studies demonstrate the effective acid neutralizing capacity of Gaviscon DA versus placebo in healthy, fasted subjects. This adds to the evidence base for the combination of alginates and antacids.     

减少手术创伤始终是妇科肿瘤手术快速康复的决定性因素

减少手术创伤始终是快速康复的决定性因素,这一点在目前的加速康复外科研究尤其是复杂手术,如妇科肿瘤手术中尚未得到充分重视。尊重学习曲线、全面规划手术方案、总结失利经验、开展前瞻性研究是解决此问题的主要方案。本文着重讨论妇科肿瘤手术创伤对术后加速康复的影响及可能的改进措施。