Literary destination familiarity and inbound tourism: evidence from mainland China

Destination familiarity is an important non-economic determinant of tourists’ destination choice that has not been adequately studied. This study posits a literary dimension to the concept of destination familiarity —that is, the extent to which tourists have gained familiarity with a given destination through literature—and seeks to investigate the impact of this form of familiarity on inbound tourism to Mainland China. Employing the English fiction dataset of the Google Books corpus, the New York Times annotated corpus, and the Time magazine corpus, we construct two types of destination familiarity based on literary texts: affection-based destination familiarity and knowledge-based destination familiarity. The results from dynamic panel estimation (1994–2004) demonstrate that the higher the degree of affection-based destination familiarity with a province in the previous year, the larger the number of inbound tourists the following year. Examining the influence of literature and its consumption on tourism activities sheds light on the dynamics of sustainable tourism development in emerging markets

Structure of photosystem I-LHCI-LHCII from the green alga Chlamydomonas reinhardtii in State 2

Photosystem I (PSI) and II (PSII) balance their light energy distribution absorbed by their light-harvesting complexes (LHCs) through state transition to maintain the maximum photosynthetic performance and to avoid photodamage. In state 2, a part of LHCII moves to PSI, forming a PSI-LHCI-LHCII supercomplex. The green alga Chlamydomonas reinhardtii exhibits state transition to a far larger extent than higher plants. Here we report the cryo-electron microscopy structure of a PSI-LHCI-LHCII supercomplex in state 2 from C. reinhardtii at 3.42 Å resolution. The result reveals that the PSI-LHCI-LHCII of C. reinhardtii binds two LHCII trimers in addition to ten LHCI subunits. The PSI core subunits PsaO and PsaH, which were missed or not well-resolved in previous Cr-PSI-LHCI structures, are observed. The present results reveal the organization and assembly of PSI core subunits, LHCI and LHCII, pigment arrangement, and possible pathways of energy transfer from peripheral antennae to the PSI core

Crystallinity Effects in Sequentially Processed and Blend-Cast Bulk-Heterojunction Polymer/Fullerene Photovoltaics

Although most polymer/fullerene-based solar cells are cast from a blend of the components in solution, it is also possible to sequentially process the polymer and fullerene layers from quasi-orthogonal solvents. Sequential processing (SqP) not only produces photovoltaic devices with efficiencies comparable to the more traditional bulk heterojunction (BHJ) solar cells produced by blend casting (BC) but also offers the advantage that the polymer and fullerene layers can be optimized separately. In this paper, we explore the morphology produced when sequentially processing polymer/fullerene solar cells and compare it to the BC morphology. We find that increasing polymer regioregularity leads to the opposite effect in SqP and BC BHJ solar cells. We start by constructing a series of SqP and BC solar cells using different types of poly(3-hexylthiophene) (P3HT) that vary in regioregulary and polydispersity combined with [6,6]-phenyl-C61-butyric-acid-methyl-ester (PCBM). We use grazing incidence wide-angle X-ray scattering to demonstrate how strongly changes in the P3HT and PCBM crystallinity upon thermal annealing of SqP and BC BHJ films depend on polymer regioregularity. For SqP devices, low regioregularity P3HT films that possess more amorphous regions allow for more PCBM crystallite growth and thus show better photovoltaic device efficiency. On the other hand, highly regioregular P3HT leads to a more favorable morphology and better device efficiency for BC BHJ films. Comparing the photovoltaic performance and structural characterization indicates that the mechanisms controlling morphology in the active layers are fundamentally different for BHJs formed via SqP and BC. Most importantly, we find that nanoscale morphology in both SqP and BC BHJs can be systematically controlled by tuning the amorphous fraction of polymer in the active layer. © 2014 American Chemical Society

Study of Device Physics and Active Layer Morphology in Polymer-Fullerene Based Solar Cells: The Role of Vertical Phase Segregation and Organic/Metal Interface

Organic photovoltaics (OPVs) are flexible, low cost and easily processable, which provides them with a very short energy payback time compared to most PV technologies and makes them strong candidates for industrial mass production. The richness of organic synthesis has afforded a large library of molecular semiconductors, among which the combination of conjugated polymers as electron donors and fullerenes as electron acceptors has been demonstrated to be the best sellers as building blocks of OPV devices. In the past few years, the majority of research focus on OPVs has been devoted to improving their power conversion efficiencies by using new combinations of polymer and fullerene materials. Most devices are based on blend-cast bulk heterojunctions (BHJs), in which a polymer and fullerene are mixed together in a solution that is then used to cast the active layer of the organic solar cell. Because the nm-scale morphology of the film depends on so many of the details of how it is cast, the device performance of blend-cast BHJ solar cells is hypersensitive to the processing kinetics of the active layer. Thus, for any new set of OPV materials, an Edisonian approach involving the fabrication of hundreds of blend-cast devices is needed to find the processing conditions that lead to the optimal morphology and best device performance. In this thesis, I will focus on two main contributions that I have made to help rationally design OPVs.First, our group recently has gone beyond the traditional method of simply blending the donor and acceptor material by developing a new technique to process the active layer of OPVs called sequential processing. This method takes advantage of a pair of quasi-orthogonal solvents to process the two components used in the active layer separately. By studying a series of crystalline polymers with controlled regioregularities and polydispersities, I have found that increasing polymer crystallinity produces the opposite behavior in BHJ solar cells fabricated by sequentially-processing and blend-casting. This suggests that the two processing techniques are complementary and provides guidance on selecting the appropriate processing technique for a given polymer. Second, I have studied the performance and device physics of a new series of controllably tuned fullerene derivatives applied in traditional blend-cast active layers. We obtained a series of carefully designed 1,4-dibenzyl fullerene bisadducts synthesized by our collaborators in Prof. Yves Rubin's group. The fullerenes have methoxy substituents selectively positioned on pendant phenyl rings, which allows us to examine the effect of the subtle molecular changes on both macroscopic solar cell performance and the underlying device physics. Through carrier recombination studies, I have learned that solar cell performance often depends on the material's surface energy and the vertical phase segregation caused by this surface energy in the active layer. The results will allow us to offer new directions on how to select the best device structure with a given new fullerene material. Finally, I have helped to make an interesting discovery during my study of the device physics of as-cast sequentially processed solar cells. I found that the specific type of vertical phase segregation in the as-cast devices gives rise to dark carriers, whose presence can be measured using the charge extraction by linear increasing voltage (CELIV) technique. The dark carriers directly clearly are created by the evaporation of metal electrodes because I found no such carriers when non-metal interfacial layers were inserted between the metal and the organic layer. Through capacitance analysis and transmission electron microscopy studies, we found this n-type doping is caused by metal penetration into the fullerene domain. These findings could have significant impact on determining device performance, explaining device physics and guiding future research directions

Brain-Computer Interface Controlled Cyborg: Establishing a Functional Information Transfer Pathway from Human Brain to Cockroach Brain.

An all-chain-wireless brain-to-brain system (BTBS), which enabled motion control of a cyborg cockroach via human brain, was developed in this work. Steady-state visual evoked potential (SSVEP) based brain-computer interface (BCI) was used in this system for recognizing human motion intention and an optimization algorithm was proposed in SSVEP to improve online performance of the BCI. The cyborg cockroach was developed by surgically integrating a portable microstimulator that could generate invasive electrical nerve stimulation. Through Bluetooth communication, specific electrical pulse trains could be triggered from the microstimulator by BCI commands and were sent through the antenna nerve to stimulate the brain of cockroach. Serial experiments were designed and conducted to test overall performance of the BTBS with six human subjects and three cockroaches. The experimental results showed that the online classification accuracy of three-mode BCI increased from 72.86% to 78.56% by 5.70% using the optimization algorithm and the mean response accuracy of the cyborgs using this system reached 89.5%. Moreover, the results also showed that the cyborg could be navigated by the human brain to complete walking along an S-shape track with the success rate of about 20%, suggesting the proposed BTBS established a feasible functional information transfer pathway from the human brain to the cockroach brain

Effect of an AC Magnetic-field on the Dead-zone Range of Inclusions in the Circular Channel of an Induction-heating Tundish

In this paper, the radial electromagnetic force in the horizontal circular channel of an induction-heating tundish is derived. A dimensionless trajectory model of the inclusion is developed and numerically solved to acquire the trajectory of the moving inclusion. When the inclusion is in the lower half of the horizontal circular channel, the direction of the vertical component of the radial electromagnetic pinch force which acts on the inclusion is opposite to the buoyancy. Provided their magnitudes are the same, there is a balanced-position for the inclusions in a circular channel. Therefore, a dead-zone exists near the balanced-position, where the removal time of the inclusion with an AC magnetic-field is longer than without it. Then, the effect of the AC magnetic-field parameters on the range of the dead-zone is identified, which makes it possible to improve the removal efficiency of inclusions. The range of the dead-zone decreases with increasing magnetic-field intensity. When the dimensionless magnetic-field intensity is 56.3, the shielding parameter of 10-15.9 are optimal to decrease the range of the dead-zone

Plots of EEG signals in time domain, frequency domain, and spatial domain.

<p>The first row of the graphs are 40-second EEG signal taken from 4 channels when a subject facing visual stimuli with three different frequencies separately. Relevant spectrum is presented in the second row, and the third row is the power distribution on brain map.</p

Effective Removal Zone of Inclusions in a Horizontal Channel under AC Magnetic Field Imposition

A channel type horizontal induction heating tundish compensates for the heat loss of the molten steel due to Joule loss generated by an A.C. magnetic field. It also exhibits another function of inclusions removal because the A.C. magnetic field generates an electromagnetic pinch force. For the inclusions below the center of the horizontal channel, the direction of the electromagnetic pinch force and the buoyancy force acting on them are opposite. Thus, there is a possibility of the existence of the balanced position where the magnitudes of the electromagnetic pinch force and the buoyancy force are same. Around there the net time average force acting on the inclusions is almost zero, and there is a dead zone where the removal time of the inclusions under the imposed A.C. magnetic field is longer than that without it. In this study, non-dimensional models of the force balance and the inclusion trajectory were established and numerically solved to find out the relationship between the dead zone and the A.C. magnetic field parameters because the dead zone range should be reduced for effective removal of the inclusions. Consequently, the dead zone range decreased with the increase in the magnetic field intensity. Furthermore, the shielding parameter of 5-10 is one of the optimum conditions to reduce the dead zone range under the constant magnetic field condition because the dead zone range has the local and/or global minimum at this parameter

Results acquired in experimental phase II from three groups.

<p>CPT was measured in seconds, LTC, RTC and TC were counted in number, their value were shown on primary axis located in the left edge of above figure; RA from each cyborg, CPC, SR and CA were presented in decimal number in secondary axis located in the right edge of above figure. (Notes: Positive Standard Deviation are presented only.)</p