Maximal Quantum Fisher Information in a Mach-Zehnder Interferometer without initial parity

Mach-Zehnder interferometer is a common device in quantum phase estimation and the photon losses in it are an important issue for achieving a high phase accuracy. Here we thoroughly discuss the precision limit of the phase in the Mach-Zehnder interferometer with a coherent state and a superposition of coherent states as input states. By providing a general analytical expression of quantum Fisher information, the phase-matching condition and optimal initial parity are given. Especially, in the photon loss scenario, the sensitivity behaviors are analyzed and specific strategies are provided to restore the phase accuracies for symmetric and asymmetric losses.Comment: 10 pages, 3 figure

Don't Lose Yourself! Empathetic Response Generation via Explicit Self-Other Awareness

As a critical step to achieve human-like chatbots, empathetic response generation has attained increasing interests. Previous attempts are incomplete and not sufficient enough to elicit empathy because they only focus on the initial aspect of empathy to automatically mimic the feelings and thoughts of the user via other-awareness. However, they ignore to maintain and take the own views of the system into account, which is a crucial process to achieve the empathy called self-other awareness. To this end, we propose to generate Empathetic response with explicit Self-Other Awareness (EmpSOA). Specifically, three stages, self-other differentiation, self-other modulation and self-other generation, are devised to clearly maintain, regulate and inject the self-other aware information into the process of empathetic response generation. Both automatic and human evaluations on the benchmark dataset demonstrate the superiority of EmpSOA to generate more empathetic responses

A citation-based review of study on image retrieval

Driven by the development of the information retrieval technologies, image retrieval has been studied for more than several decades. This study centers on revealing the current status and future directions of image retrieval based on reviewing previous related studies. The citation-based analysis was applied to 2243 articles retrieved from Web of Science database. The time series plots of the citation relationships between the retrieved articles reveal a fundamental research article that lay the foundation for the image retrieval field. Co-citation analysis identifies that the existing studies formed two clusters. Each cluster represents one of the two major areas in the field of image retrieval: the text-based image retrieval and the content-based image retrieval. The visualization map shows that the research of content-based image retrieval has received more attention than the area of text-based image retrieval. Relevance feedback was identified as a promising research direction for the future study

DoubleAdapt: A Meta-learning Approach to Incremental Learning for Stock Trend Forecasting

Stock trend forecasting is a fundamental task of quantitative investment where precise predictions of price trends are indispensable. As an online service, stock data continuously arrive over time. It is practical and efficient to incrementally update the forecast model with the latest data which may reveal some new patterns recurring in the future stock market. However, incremental learning for stock trend forecasting still remains under-explored due to the challenge of distribution shifts (a.k.a. concept drifts). With the stock market dynamically evolving, the distribution of future data can slightly or significantly differ from incremental data, hindering the effectiveness of incremental updates. To address this challenge, we propose DoubleAdapt, an end-to-end framework with two adapters, which can effectively adapt the data and the model to mitigate the effects of distribution shifts. Our key insight is to automatically learn how to adapt stock data into a locally stationary distribution in favor of profitable updates. Complemented by data adaptation, we can confidently adapt the model parameters under mitigated distribution shifts. We cast each incremental learning task as a meta-learning task and automatically optimize the adapters for desirable data adaptation and parameter initialization. Experiments on real-world stock datasets demonstrate that DoubleAdapt achieves state-of-the-art predictive performance and shows considerable efficiency.Comment: Accepted by KDD 2023. Code is at https://github.com/SJTU-Quant/qli

Engineering the Surface/Interface Structures of Titanium Dioxide Micro and Nano Architectures towards Environmental and Electrochemical Applications

Titanium dioxide (TiO2) materials have been intensively studied in the past years because of many varied applications. This mini review article focuses on TiO2 micro and nano architectures with the prevalent crystal structures (anatase, rutile, brookite, and TiO2(B)), and summarizes the major advances in the surface and interface engineering and applications in environmental and electrochemical applications. We analyze the advantages of surface/interface engineered TiO2 micro and nano structures, and present the principles and growth mechanisms of TiO2 nanostructures via different strategies, with an emphasis on rational control of the surface and interface structures. We further discuss the applications of TiO2 micro and nano architectures in photocatalysis, lithium/sodium ion batteries, and Li–S batteries. Throughout the discussion, the relationship between the device performance and the surface/interface structures of TiO2 micro and nano structures will be highlighted. Then, we discuss the phase transitions of TiO2 nanostructures and possible strategies of improving the phase stability. The review concludes with a perspective on the current challenges and future research directions

NATURE OF THE LATE CARBONIFEROUS TO TRIASSIC MAGMATISM ALONG THE NORTHERN MARGIN OF THE NORTH CHINA BLOCK: LINK WITH THE EVOLUTION OF THE CENTRAL ASIAN OROGEN

There are two episodes of magmatism along the northern margin of the North China block during the Late Carboniferous to Late Triassic, one at 310–250 Ma (Late Carboniferous to Permian) and the other at 235–210 Ma (Late Triassic). The former group comprises plutonic rocks (gabbro-diorite-monzodioritemonzogranite-granite), mafic to intermediate dykes (diorite to dolerite) and a few felsic volcanics (andesite to dacite).There are two episodes of magmatism along the northern margin of the North China block during the Late Carboniferous to Late Triassic, one at 310–250 Ma (Late Carboniferous to Permian) and the other at 235–210 Ma (Late Triassic). The former group comprises plutonic rocks (gabbro-diorite-monzodioritemonzogranite-granite), mafic to intermediate dykes (diorite to dolerite) and a few felsic volcanics (andesite to dacite)

Mediator complex subunit 19 regulates the proliferation, migration and invasion of human breast cancer cells

Purpose: To investigate the therapeutic implication of mediator complex subunit 19 (Med19) in breast cancer cells. Methods: The mRNA expression of Med19 was assayed using qRT-PCR. Cell viability was determined with 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyl tetrazolium bromide (MTT) assay, while 4′,6-diamidino-2- phenylindole (DAPI) and annexin V/propidium iodide (PI) assays were used for determination of apoptosis. Wound healing and Transwell assays were used for the determination of cell migration and invasion. Western blotting analysis was used for assay of protein expression levels. Results: The results showed that Med19 was significantly (p < 0.05) upregulated in human breast cancer cell lines, relative to normal cells. The up-regulations ranged from 3.7-fold in UACC-2087 cells to 6.4-fold in BT-20 cells. Moreover, Med19 silencing caused significant decrease in the proliferation of BT-20 breast cancer cells (p < 0.05). The inhibition of cell proliferation was due to the induction of apoptosis, as was evident in increased Bax/Bcl-2 ratio. Annexin V/PI staining revealed 6 % apoptosis in si-NC-transfected, and about 13.30 % in si-Med19-transfected BT-20 cells. Wound healing and Transwell assays revealed that the invasion of BT-20 breast cancer cells significantly decreased upon Med19 silencing. Conclusion: Med19 regulates the proliferation, migration and invasion of human breast cancer cells. Thus, Med19 may be beneficial in the treatment of breast cancer