Enhancing Translation Validation of Compiler Transformations with Large Language Models

This paper presents a framework that integrates Large Language Models (LLMs) into translation validation, targeting LLVM compiler transformations where formal verification tools fall short. Our framework first utilizes existing formal verification tools for translation validation. In this work, we use Alive2, a well-known tool in LLVM compiler verification, as an example. When formal verification tools are unable to confirm a transformation's soundness, our framework employs fine-tuned LLMs for prediction. It then applies fuzzing to transformations predicted as potentially unsound by the LLMs due to return values or memory inconsistencies, aiming to find counterexamples. In cases where transformations are unsound for other reasons or sound, or if no counterexamples emerge, the framework directly reports these outcomes without further fuzzing. This methodology has shown effectiveness in complex application such as deep-learning accelerator designs, where traditional formal verification tools struggle.Comment: 6 page

Negative to Positive Crossover of Magnetoresistance in Layered WS2 with Ohmic Contact

The discovery of graphene has ignited intensive investigation on two dimensional (2D) materials. Among them, transition metal dichalcogenide (TMDC), a typical representative, attracts much attention due to the excellent performance in field effect transistor (FET) related measurements and applications. Particularly, when TMDC eventually reaches few-layer dimension, a wide range of electronic and optical properties, in striking contrast to bulk samples, are detected. In this Letter, we synthesized single crystalline WS2 nanoflakes by physical vapor deposition (PVD) method and carried out a series of transport measurements of contact resistance and magnetoresistance. Focused ion beam (FIB) technology was applied to deposit Pt electrodes on WS2 flakes. Different from the electron beam lithography (EBL) fabricated electrodes, FIB-deposited leads exhibited ohmic contact, resolving the dilemma of Schottky barrier. Furthermore, a temperature-modulated negative-to-positive transition of magnetoresistance (MR) associated with a crossover of carrier type at similar temperature was demonstrated. Our work offers a pathway to optimize the contact for TMDC and reveals the magnetoresistance characteristics of WS2 flakes, which may stimulate further studies on TMDC and corresponding potential electronic and optoelectronic applications

Alpha-decay half-lives and Q_alpha values of superheavy nuclei

The alpha-decay half-lives of recently synthesized superheavy nuclei (SHN) are investigated based on a unified fission model (UFM) where a new method to calculate the assault frequency of alpha-emission is used. The excellent agreement with the experimental data indicates the UFM is a useful tool to investigate these alpha-decays. It is found that the half-lives become more and more insensitive to the Q_alpha values as the atomic number increases on the whole, which is favorable for us to predict the half-lives of SHN. In addition, a formula is suggested to compute the Q_alpha values for the nuclei with Z > 92 and N > 140 with a good accuracy, according to which the long-lived SHN should be neutron rich. With Q_alpha values from this formula as inputs, we predict the half-lives of isotopes of Z = 117, which may be useful for experimental identication in the future.Comment: 7 pages, 3 figure

Effects of probiotic Clostridium Butyrate on Performance and Immunocompetence and Digestive Function of poultry

The purpose of our research was to study the effects of dietary addition of Clostridium butyricum (CB) on performance, immunocompetence and digestive function of poultry. Using single factor experiment design, 720 one-day-old and healthy AA broilers were divided into 6 groups with 6 replicates in each group and 20 broilers in each replicate. Broilers in control group were fed a basal diet, while broilers of other experimental group were fed the basal diet supplemented with CB 250 mg/kg, 500 mg/kg, 750 mg/kg, 1000 mg/kg and 1250 mg/kg. The results showed as follows: The 1000mg/mg group had the best effect on immunity enhancement, with the thymus index, spleen index and bursa index increased by 18.38 % (P < 0.05), 16.00 % (P < 0.05) and 8.03 % (P > 0.05) in 1–21 days, and 6.45 % (P < 0.05), 12.92 % (P < 0.05) and 13.94 % (P < 0.05) in 22–49 days. The 1000 mg/kg group and 1250 mg/kg group had the best effect on improving the digestive function, with the VH/CD value increased by 27.56 % (P < 0.05) and 29.56 % (P < 0.05) in 1–21 days, and 29.48 % (P < 0.05) and 30.80 % (P < 0.05) in 22–49 days, with the number of harmful bacteria Escherichia coli and Salmonella decreased significantly (P < 0.05). These results indicated that the addition of CB in diets of broiler can improve the production performance, enhance immunity and improve digestive function, and the optimal dosage is 1000 mg/kg

Homogeneous Gold Catalysis: Ligand Design and Reactions of Alkynes

In the past dozen years, great progress has been made in developing highly efficient homogenous gold catalysis. As soft Lewis acids, cationic gold(I) complexes are particularly powerful in terms of activating alkyne/allene towards nucleophilic attack, leading to a variety of synthetically versatile structures. During my research, several synthetic methods have been developed, including: (1) Au-catalyzed ligand-directed anti nucleophilic attack of alkynes; the new ligands I developed enable highly efficient gold-catalyzed nucleophilic addition of acids, anilines and water to the alkynes; and catalyst loadings could be lowered to 10 parts per million; (2) rapid access of chroman-3-ones via gold-catalyzed oxidation of propargyl aryl ethers; this step-economic and efficient transformation was realized by a bulky gold catalyst, Me4tBuXPhosAuNTf2 and bulky electron-deficient pyridine N-oxides derived from Hantzsch esters; (3) Au-catalyzed novel indole synthesis via a key [3,3] sigmatropic rearrangement; 2-alkylindoles were produced with high regioselectivity and efficiency from easily accessed N-arylhydroxylamines under mild conditions; an improved approach involved cooperative dual catalysis of Zn and Au was developed; much broader substrate scope, shorter reaction time and good to excellent yields were achieved

Analysis and Finite Element Approximation of a Coupled, Continuum Pipe-Flow/Darcy Model for Flow in Porous Media with Embedded Conduits

We consider the continuum Darcy/pipe flow model for flows in a porous matrix containing embedded conduits; such coupled flows are present in, e.g., karst aquifers. the mathematical well-posedness of the coupled problem as well as convergence rates of finite element approximation are established in the two-dimensional case. Computational results are also provided. © 2010 Wiley Periodicals, Inc