Giant Gating Tunability of Optical Refractive Index in Transition Metal Dichalcogenide Monolayers

We report that the refractive index of transition metal dichacolgenide (TMDC) monolayers, such as MoS2, WS2, and WSe2, can be substantially tuned by > 60% in the imaginary part and > 20% in the real part around exciton resonances using CMOS-compatible electrical gating. This giant tunablility is rooted in the dominance of excitonic effects in the refractive index of the monolayers and the strong susceptibility of the excitons to the influence of injected charge carriers. The tunability mainly results from the effects of injected charge carriers to broaden the spectral width of excitonic interband transitions and to facilitate the interconversion of neutral and charged excitons. The other effects of the injected charge carriers, such as renormalizing bandgap and changing exciton binding energy, only play negligible roles. We also demonstrate that the atomically thin monolayers, when combined with photonic structures, can enable the efficiencies of optical absorption (reflection) tuned from 40% (60%) to 80% (20%) due to the giant tunability of refractive index. This work may pave the way towards the development of field-effect photonics in which the optical functionality can be controlled with CMOS circuits

The combined effect of foreign direct investment on firm productivity

This paper attempts to answer the economic implications of combining inward foreign direct investment (IFDI) and outward foreign direct investment (OFDI) by constructing a panel fixed effects model using Chinese industrial firm-level data for the period 1998–2013. Specifically, we focus on the impact of combining IFDI and OFDI on firm productivity in China. We also introduce interactive terms into the model to explore the direct and indirect mechanisms through which IFDI and OFDI affect productivity growth. The results show that IFDI and OFDI work together to contribute to productivity growth by acting directly on the level of technology, thereby increasing productivity. IFDI intensifies market concentration, which in turn positively moderates the relationship between OFDI and productivity. Furthermore, IFDI moderates the financing constraints of firms, but has a weaker effect; the easing of financing constraints facilitates the positive impact of OFDI on productivity. Absorptive capacity favours IFDI spillover, but OFDI inhibits absorptive capacity improvements. Our in-depth analysis of the mechanism of the combined impact of IFDI and OFDI on productivity reveals the objectives of using this combination, thereby providing theoretical support and policy recommendations for the implementation of this strategy

Knowledge-enhanced Iterative Instruction Generation and Reasoning for Knowledge Base Question Answering

Multi-hop Knowledge Base Question Answering(KBQA) aims to find the answer entity in a knowledge base which is several hops from the topic entity mentioned in the question. Existing Retrieval-based approaches first generate instructions from the question and then use them to guide the multi-hop reasoning on the knowledge graph. As the instructions are fixed during the whole reasoning procedure and the knowledge graph is not considered in instruction generation, the model cannot revise its mistake once it predicts an intermediate entity incorrectly. To handle this, we propose KBIGER(Knowledge Base Iterative Instruction GEnerating and Reasoning), a novel and efficient approach to generate the instructions dynamically with the help of reasoning graph. Instead of generating all the instructions before reasoning, we take the (k-1)-th reasoning graph into consideration to build the k-th instruction. In this way, the model could check the prediction from the graph and generate new instructions to revise the incorrect prediction of intermediate entities. We do experiments on two multi-hop KBQA benchmarks and outperform the existing approaches, becoming the new-state-of-the-art. Further experiments show our method does detect the incorrect prediction of intermediate entities and has the ability to revise such errors.Comment: Accepted by NLPCC 2022(oral

Minimally invasive flapless vs. flapped approach for single implant placement: a 2‐year randomized controlled clinical trial

PurposeThe purpose of this 2‐year randomized controlled clinical trial was to assess the differences in implant survival rates, soft tissue preservation, patient centered outcome and crestal bone changes applying the minimally invasive (MI) flapless approach for single implant placement compared to flapped implant surgery (FS).Materials and methodsSubjects eligible for this study were randomly assigned into two groups: MI or FS. Items of evaluation were the following: implant installation position, soft tissue healing, post‐surgical pain, soft tissue outcome, marginal bone loss (MBL), and implant survival rate.ResultsForty subjects (14 women and 26 men, 20 in MI group and 20 in FS group with a mean of 39 ± 13.2 years old) were included in the study. None of the implants demonstrated dehiscence or loss during the follow‐up. Subjects in MI group showed significantly lower post‐surgical pain and significantly less wound healing index scores at 1‐week follow‐up. The width of keratinized mucosa decreased from a mean of 4.2 ± 1.6 mm pre‐surgically to 3.7 ± 1.1 mm at crown delivery but remained stable at 2‐year follow‐up in MI group. At every appointment in the study, no statistical significant difference of PD and MBL was found between the two groups.ConclusionCompared with FS, single implants placed applying the MI technique in selected subjects showed advantages in improving patient comfort and decreasing post‐implant placement soft tissue reaction. Meanwhile, implants with MI approach have the same level of MBL and high success rates as FS procedure at 2‐year follow‐up. The deduction of keratinized mucosa is very limited and the width of KM remained stable with MI approach at 2‐year follow‐up.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137279/1/clr12875.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137279/2/clr12875_am.pd

Ordered multilayer films of hollow sphere aluminium-doped zinc oxide for photoelectrochemical solar energy conversion

Transparent conducting oxides (TCO's) are integral to many optoelectronic devices used for a range of display and solar energy technologies. Non-planar, 3-dimensional, TCO's offer the opportunity to support thin films of functional materials to increase light absorption, charge extraction, and wavelength-dependent manipulation of light if ordered into photonic structures. In addition increased surface area is also important for applications which rely on interfacial phenomena such as photoelectrochemical solar energy conversion, which is the focus of this investigation. Photoelectrodes have been fabricated from ordered spherical arrays of aluminium doped zinc oxide (AZO) and subsequently coated with photoactive semiconductor (CdS) nanoparticles using simple solution chemical deposition. The spheres of the structured AZO TCO are hollow and access to the internal volume supports loading of CdS as a thin film which results in increased light collection per geometric surface area. Efficient charge collection is observed, without restricting diffusion of electrolyte, allowing photocurrents ca. 20 times greater than a planar analogue

Development and validation of nomograms to predict the survival probability and occurrence of a second primary malignancy of male breast cancer patients: a population-based analysis

BackgroundMale breast cancer (MBC) is rare, which has restricted prospective research among MBC patients. With effective treatments, the prognosis of MBC patients has improved and developing a second primary malignancy (SPM) has become a life-threatening event for MBC survivors. However, few studies have focused on the prognosis of MBC patients and looked into the SPM issue in MBC survivors.MethodWe reviewed MBC patients diagnosed between 1990 and 2016 from the latest Surveillance, Epidemiology, and End Results (SEER) Plus database. Competing risk models and nomograms were conducted for predicting the risk of cancer-specific death and SPM occurrence. C-indexes, calibration curves, ROC curves, and decision curve analysis (DCA) curves were applied for validation.ResultA total of 1,843 MBC patients with complete information were finally enrolled and 60 (3.26%) had developed an SPM. Prostate cancer (40%) was the most common SPM. The median OS of all the enrolled patients was 102.41 months, while the median latency from the initial MBC diagnosis to the subsequent diagnosis of SPM was 67.2 months. The patients who suffered from an SPM shared a longer OS than those patients with only one MBC (p = 0.027). The patients were randomly divided into the development cohort and the validation cohort (at a ratio of 7:3). The Fine and Gray competing risk model was used to identify the risk factors. Two nomograms were constructed and validated to predict the 5-year, 8-year, and 10-year survival probability of MBC patients, both of which had good performance in the C-index, ROC curves, calibration plots, and DCA curves, showing the ideal discrimination capability and predictive value clinically. Furthermore, we, for the first time, constructed a nomogram based on the competing risk model to predict the 5-year, 8-year, and 10-year probability of developing an SPM in MBC survivors, which also showed good discrimination, calibration, and clinical effectiveness.ConclusionWe, for the first time, included treatment information and clinical parameters to construct a nomogram to predict not only the survival probability of MBC patients but also the probability of developing an SPM in MBC survivors, which were helpful in individual risk estimation, patient follow-up, and counseling in MBC patients