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Room-Temperature Sputtered SnO2 as Robust Electron Transport Layer for Air-Stable and Efficient Perovskite Solar Cells on Rigid and Flexible Substrates.
Extraordinary photovoltaic performance and intriguing optoelectronic properties of perovskite solar cells (PSCs) have aroused enormous interest from both academic research and photovoltaic (PV) industry. In order to bring PSC technology from laboratory to market, material stability, device flexibility, and scalability are important issues to address for vast production. Nevertheless, PSCs are still primarily prepared by solution methods which limit film scalability, while high-temperature processing of metal oxide electron transport layer (ETL) makes PSCs costly and incompatible with flexible substrates. Here, we demonstrate rarely-reported room-temperature radio frequency (RF) sputtered SnO2 as a promising ETL with suitable band structure, high transmittance, and excellent stability to replace its solution-processed counterpart. Power conversion efficiencies (PCEs) of 12.82% and 5.88% have been achieved on rigid glass substrate and flexible PEN substrate respectively. The former device retained 93% of its initial PCE after 192-hour exposure in dry air while the latter device maintained over 90% of its initial PCE after 100 consecutive bending cycles. The result is a solid stepping stone toward future PSC all-vapor-deposition fabrication which is being widely used in the PV industry now
Macroeconomic Fluctuations in Emerging Economies: An Unobserved Components Approach
This paper re-examines the impact of demographic factors on the current account balance. To this end, we develop an analytical framework that is more general than the one commonly used in the literature in three aspects. First, it accounts for the facts that the world current account balance must be equal to zero. Second, a bigger economy will have greater impacts on others, but be influenced less by them. Third, a more open economy will have greater impacts on others and at the same time be more readily influenced by them. We then confront two alternative empirical specifications based on both the new and the conventional framework with a panel of data. In contrast to the findings based on the conventional framework, our results with the new framework indicate that population ageing does not appear to have discernible impacts on the current account balance.
Demography, Financial Openness, National Savings and External Balance
This paper examines the impact of demographic factors on saving, investment, and external balances. We derive a number of semi-structural equations from national accounting principle and the principle that external balances for the world as a whole must sum to zero. The resulting equations embody both closed, partially open and completely open economies as special cases, and are arguably more properly specified than those previously used in the literature. We apply these semi-structural equations to a large panel data set. While our findings by and large are in agreement with most of previous studies, our semi-structural equations give much more plausible estimation results for saving and investment than conventional specification.
Does demographic change affect the current account? A reconsideration?
This paper re-examines the impact of demographic factors on the current account balance. To this end, we develop an analytical framework that is more general than the one commonly used in the literature in three aspects. First, it accounts for the facts that the world current account balance must be equal to zero. Second, a bigger economy will have greater impacts on others, but be influenced less by them. Third, a more open economy will have greater impacts on others and at the same time be more readily influenced by them. We then confront two alternative empirical specifications based on both the new and the conventional framework with a panel of data. In contrast to the findings based on the conventional framework, our results with the new framework indicate that population ageing does not appear to have discernible impacts on the current account balance
Does Demographic Change Affect the Current Account? A Reconsideration
This paper re-examines the impact of demographic factors on the current account balance. To this end, we develop an analytical framework that is more general than the one commonly used in the literature in three aspects. First, it accounts for the facts that the world current account balance must be equal to zero. Second, a bigger economy will have greater impacts on others, but be influenced less by them. Third, a more open economy will have greater impacts on others and at the same time be more readily influenced by them. We then confront two alternative empirical specifications based on both the new and the conventional framework with a panel of data. In contrast to the findings based on the conventional framework, our results with the new framework indicate that population ageing does not appear to have discernible impacts on the current account balanc
A Bayesian regression tree approach to identify the effect of nanoparticles' properties on toxicity profiles
We introduce a Bayesian multiple regression tree model to characterize
relationships between physico-chemical properties of nanoparticles and their
in-vitro toxicity over multiple doses and times of exposure. Unlike
conventional models that rely on data summaries, our model solves the low
sample size issue and avoids arbitrary loss of information by combining all
measurements from a general exposure experiment across doses, times of
exposure, and replicates. The proposed technique integrates Bayesian trees for
modeling threshold effects and interactions, and penalized B-splines for dose-
and time-response surface smoothing. The resulting posterior distribution is
sampled by Markov Chain Monte Carlo. This method allows for inference on a
number of quantities of potential interest to substantive nanotoxicology, such
as the importance of physico-chemical properties and their marginal effect on
toxicity. We illustrate the application of our method to the analysis of a
library of 24 nano metal oxides.Comment: Published at http://dx.doi.org/10.1214/14-AOAS797 in the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
The price Asian venture capitalists pay to work in Silicon Valley
They pay higher valuations due to their lower social status rather than social network disadvantages, write Jing Zhang, Poh-Kam Wong and Yuen-Ping H
Investigating the Impact of Institutional Pressures on Information Security Compliance in Organizations
Abstract: The increasing threat to information security has created institutional pressures on organizations to comply with information security policies and standards. This paper presents an empirical study to investigate the impact of institutional pressures (coercive, normative, and mimetic) on information security compliance in organizations. The results show that coercive pressures that are manifested by regulatory agencies, normative pressures that are exerted through social pressures, and mimetic pressures that are manifested by security benefits positively influence information security compliance in public organizations. Furthermore, the results reveal that regulation and security benefits generate pressures on management to strengthen their commitments towards information security compliance in organizations. It is, however, worthwhile to notice that social pressures do not have a significant impact on management commitments towards information security compliance. The implications of this study indicate the criticality of institutional pressures for enhancing information security compliance in public organizations both directly and indirectly
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