TiO2/BiVO4 Nanowire Heterostructure Photoanodes Based on Type II Band Alignment

Metal oxides that absorb visible light are attractive for use as photoanodes in photoelectrosynthetic cells. However, their performance is often limited by poor charge carrier transport. We show that this problem can be addressed by using separate materials for light absorption and carrier transport. Here, we report a Ta:TiO2|BiVO4 nanowire photoanode, in which BiVO4 acts as a visible light-absorber and Ta:TiO2 acts as a high surface area electron conductor. Electrochemical and spectroscopic measurements provide experimental evidence for the type II band alignment necessary for favorable electron transfer from BiVO4 to TiO2. The host–guest nanowire architecture presented here allows for simultaneously high light absorption and carrier collection efficiency, with an onset of anodic photocurrent near 0.2 V vs RHE, and a photocurrent density of 2.1 mA/cm2 at 1.23 V vs RHE

Efficacy of massage therapy for postprandial distress syndrome : a protocol for systematic review and meta-analysis

BACKGROUND: Postprandial distress syndrome (PDS), characterized by the presence of prevalently meal-related early satiation and fullness, is a highly prevalent condition with major socioeconomic and healthcare impact. To date, there is a lack of pharmacological treatment proven value for PDS. Therefore, an ideal strategy to relieve PDS is urgently needed. In recent years, massage therapy has been increasingly accepted by PDS patients due to its lower costs, fewer unwanted side effects and safety for clinical use. In this systematic review, we aim to evaluate the effectiveness and safety of massage therapy for patients with postprandial distress syndrome. METHODS: We will search the following electronic databases for randomized controlled trials to evaluate the effectiveness and safety of massage therapy in treating postprandial distress syndrome: Wanfang and Pubmed Database, CNKI, CENTRAL, CINAHL, and EMBASE. Each database will be searched from inception to October 2020. The entire process will include study selection, data extraction, risk of bias assessment, and meta-analyses. RESULTS: This proposed study will evaluate the effectiveness and safety of massage therapy for patients with postprandial distress syndrome. The outcomes will include changes in PDS relief and adverse effect. CONCLUSIONS: This proposed systematic review will evaluate the existing evidence on the effectiveness and safety of massage therapy for patients with postprandial distress syndrome. DISSEMINATION AND ETHICS: The results of this review will be disseminated through peer-reviewed publication. Because all of the data used in this systematic review and meta-analysis has been published, this review does not require ethical approval. Furthermore, all data will be analyzed anonymously during the review process. OSF REGISTRATION NUMBER: DOI 10.17605/OSF.IO/9WRX8

Vibrational relaxation dynamics in layered perovskite quantum wells

Organic-inorganic layered perovskites are two-dimensional quantum wells with layers of lead-halide octahedra stacked between organic ligand barriers. The combination of their dielectric confinement and ionic sublattice results in excitonic excitations with substantial binding energies that are strongly coupled to the surrounding soft, polar lattice. However, the ligand environment in layered perovskites can significantly alter their optical properties due to the complex dynamic disorder of soft perovskite lattice. Here, we observe the dynamic disorder through phonon dephasing lifetimes initiated by ultrafast photoexcitation employing high-resolution resonant impulsive stimulated Raman spectroscopy of a variety of ligand substitutions. We demonstrate that vibrational relaxation in layered perovskite formed from flexible alkyl-amines as organic barriers is fast and relatively independent of the lattice temperature. Relaxation in aromatic amine based layered perovskite is slower, though still fast relative to pure inorganic lead bromide lattices, with a rate that is temperature dependent. Using molecular dynamics simulations, we explain the fast rates of relaxation by quantifying the large anharmonic coupling of the optical modes with the ligand layers and rationalize the temperature independence due to their amorphous packing. This work provides a molecular and time-domain depiction of the relaxation of nascent optical excitations and opens opportunities to understand how they couple to the complex layered perovskite lattice, elucidating design principles for optoelectronic devices.Comment: 7 pages, 4 figures, S

Baichuan 2: Open Large-scale Language Models

Large language models (LLMs) have demonstrated remarkable performance on a variety of natural language tasks based on just a few examples of natural language instructions, reducing the need for extensive feature engineering. However, most powerful LLMs are closed-source or limited in their capability for languages other than English. In this technical report, we present Baichuan 2, a series of large-scale multilingual language models containing 7 billion and 13 billion parameters, trained from scratch, on 2.6 trillion tokens. Baichuan 2 matches or outperforms other open-source models of similar size on public benchmarks like MMLU, CMMLU, GSM8K, and HumanEval. Furthermore, Baichuan 2 excels in vertical domains such as medicine and law. We will release all pre-training model checkpoints to benefit the research community in better understanding the training dynamics of Baichuan 2.Comment: Baichuan 2 technical report. Github: https://github.com/baichuan-inc/Baichuan

Prediction and Optimization of Blasting-Induced Ground Vibration in Open-Pit Mines Using Intelligent Algorithms

Prediction and parameter optimization are effective methods for mine personnel to control blast-induced ground vibration. However, the challenge of effective prediction and optimization lies in the multi-factor and multi-effect nature of open-pit blasting. This study proposes a hybrid intelligent model to predict ground vibrations using a least-squares support vector machine (LSSVM) optimized by a particle swarm algorithm (PSO). Meanwhile, multi-objective particle swarm optimization (MOPSO) was used to optimize the blast design parameters by considering the vibration of particular areas and the bulk rate of blast fragmentation. To compare the prediction performance of PSO-LSSVM, a genetic-algorithm-optimized BP neural network (GA-BP), unoptimized LSSVM, and BP were used, by applying the same database. In addition, the root-mean-squared error (RMSE), the mean absolute error (MAE), and the correlation coefficient (r) were regarded as the evaluation indicators. Furthermore, the optimization results of the blasting parameters were obtained by quoting the established vibration prediction model and bulk rate proxy model in MOPSO and verified by field tests. The results indicated that the PSO-LSSVM model provided the highest efficiency in predicting vibrations with an RMSE of 1.954, MAE of 1.717, and r of 0.965. Furthermore, the blasting vibration can be controlled by using the two-objective optimization model to obtain the best blasting parameters. Consequently, this study can provide more specific recommendations for vibration hazard control

Path-dependent game options: A lookback case

The game option, which is also known as Israel option, is an American option with callable features. The option holder can exercise the option at any time up to maturity. This article studies the pricing behaviors of the path-dependent game option where the payoff of the option depends on the maximum or minimum asset price over the life of the option (i.e., the game option with the lookback feature). We obtain the explicit pricing formula for the perpetual case and provide the integral expression of pricing formula under the finite horizon case. In addition, we derive optimal exercise strategies and continuation regions of options in both floating and fixed strike cases

Issues in Polycrystalline Diamond Compact Cutter-Rock Interaction From a Metal Machining Point of View-Part I: Temperature, Stresses, and Forces

This paper provides a comprehensive review of the literature that deals with issues surrounding the polycrystalline diamond compact (PDC) cutter-rock interface during rock cutting/drilling processes. The paper is separated into two parts addressing eight significant issues: Part I deals with fundamental issues associated with temperature/stress distribution and loading force prediction, while Part II focuses on issues related to PDC cutter/bit performance, wear and other failure phenomena, rock removal mechanism and cutting theory, rock properties, and numerical modeling of cutter-rock interaction. Experimental, analytical, and numerical methods are included into the investigation of the abovementioned eight issues. Relevant concepts from metal cutting, micromachining, and other machining processes are also introduced to provide important insights and draw parallels between these interrelated fields

CO2 emission from container glass in China, and emission reduction strategy analysis

Glass is one of the materials most extensively used for packaging. Its manufacturing process is typically energy intensive, with a large quantity of CO2 emissions. In this study, the material and energy consumptioninventory of the manufacturing stage were quantified and CO2 emissions from the glass manufacturing process were calculated. When fuel oil, coal or natural gas is used as the major energy source in the production system, it produces CO2 emissions of 1.2798, 0.6250 and 0.4498 t/t, respectively. CO2 emissions from fossil fuel combustion account for 67.79% of the total emissions and a huge potential exists for emission reduction. Due to differences in energy structure, current research results cannot represent the emissions in China; therefore, six scenarios were created to explore the CO2 emission reduction potential of the glass industry with different energy structures, and six scenarios were created to explore the cost from the adjustment of the energy structure. According to the analysis of the glass furnace, the effective heat accounts for 35.31%, so the basic approach for energy saving and emission reduction is to enhance the effective heat quantity of the glass furnace. Also, energy and virgin feedstock savings were calculated for 1 t of glass container production with different recycling levels