Dehydrogenation of Formic Acid by Heterogeneous Catalysts

Formic acid has recently been considered as one of the most promising hydrogen storage materials. The basic concept is briefly discussed and the research progress is detailledly reviewed on the dehydrogenation of aqueous formic acid by heterogeneous catalysts

4-(4-Oxopent-2-en-2-yl­amino)-1,2,4-triazol-1-ium-5-thiol­ate

In the title compound, C8H12N4OS, an intra­molecular N—H⋯O hydrogen bond links the imine N atom to the oxo O atom. In the crystal, mol­ecules are linked by inter­molecular N—H⋯O and N—H⋯S hydrogen bonds, forming a two-dimensional framework

CRaSh: Clustering, Removing, and Sharing Enhance Fine-tuning without Full Large Language Model

Instruction tuning has recently been recognized as an effective way of aligning Large Language Models (LLMs) to enhance their generalization ability across various tasks. However, when tuning publicly accessible, centralized LLMs with private instruction data, privacy concerns are inevitable. While direct transfer of parameterized modules between models is a plausible approach to address this, its implications and effectiveness need further exploration. This paper focuses on Offsite-Tuning (OFT), a representative technique that transfers transformer blocks between centralized LLMs and downstream emulators. Given the limited understanding of the underlying mechanism of OFT, we perform an empirical analysis on LLMs from the perspectives of representation and functional similarity. Interestingly, our findings reveal a unique modular structure within the layers of LLMs that appears to emerge as the model size expands. Simultaneously, we note subtle but potentially significant changes in representation and intermediate predictions across the layers. Inspired by these observations, we propose CRaSh, involving Clustering, Removing, and Sharing, a training-free strategy to derive improved emulators from LLMs. CRaSh significantly boosts performance of OFT with billions of parameters. Furthermore, we investigate the optimal solutions yielded by fine-tuning with and without full model through the lens of loss landscape. Our findings demonstrate a linear connectivity among these optima falling over the same basin, thereby highlighting the effectiveness of CRaSh and OFT. The source code is publicly available at https://github.com/TsinghuaC3I/CRaSh.Comment: Accepted to EMNLP 2023 (Main Conference

Direct fiber vector eigenmode multiplexing transmission seeded by integrated optical vortex emitters

Spatial modes have received substantial attention over the last decades and are used in optical communication applications. In fiber-optic communications, the employed linearly polarized modes and phase vortex modes carrying orbital angular momentum can be synthesized by fiber vector eigenmodes. To improve the transmission capacity and miniaturize the communication system, straightforward fiber vector eigenmode multiplexing and generation of fiber-eigenmode-like polarization vortices (vector vortex modes) using photonic integrated devices are of substantial interest. Here, we propose and demonstrate direct fiber vector eigenmode multiplexing transmission seeded by integrated optical vortex emitters. By exploiting vector vortex modes (radially and azimuthally polarized beams) generated from silicon microring resonators etched with angular gratings, we report data-carrying fiber vector eigenmode multiplexing transmission through a 2-km large-core fiber, showing low-level mode crosstalk and favorable link performance. These demonstrations may open up added capacity scaling opportunities by directly accessing multiple vector eigenmodes in the fiber and provide compact solutions to replace bulky diffractive optical elements for generating various optical vector beams

Combined finite element and multi-body dynamics analysis of effects of hydraulic cylinder movement on ploughshare of horizontally reversible plough

Abstract: Hydraulic Cylinder (HC), one of the key components of Horizontally Reversible Plough (HRP), takes the responsibilities for the commuting soiltillage of HRP. The dynamic behaviors of HC surely affectthe tilling performances of HRP. Based on our previously related work, this paper further addresses the effects of HC movements during tillage on ploughshare, especially at share-point, of HRP. For HC, uniform motion was considered in this study. A combined finite element and multi-body dynamics analysis (MDA) was implemented to assess both tillage kinematics and kinetics of the ploughshare. These numerical predictions were primarily involved in five different HC movement velocities and two actual HRP tilling scenarios, respectively, where loading data due to the HC movements were obtained from an MDA and applied to load a finite element modal of the ploughshare. Our results show that the importance of performing MDA as a preliminary step FEA to obtain an insight into the actual stress and strain variations at the share-point. Our findings demonstrate that the different movements of HC have no adverse effects on the service life of the ploughshare though they result in the maximum stress and strain at the sharepoint during HRP tillage

Lead contamination alters enzyme activities and microbial composition in the rhizosphere soil of the hyperaccumulator Pogonatherum crinitum

Pogonatherum crinitum is a promising lead (Pb) hyperaccumulator; however, the effects of Pb contamination on P. crinitum rhizosphere soil enzymatic activities and microbial composition remain largely unexplored. Thus, an indoor experiment was conducted by cultivating P. crinitum seedlings and exposing them to four Pb concentrations (0, 1,000, 2000 and 3000 mg/kg Pb). Protease, urease, acid phosphatase and invertase activities were determined using standard methods while soil bacterial composition was determined by 16 S rDNA sequencing. The results showed that rhizosphere soil acid phosphatase activity significantly increased with increasing Pb concentration, while urease activity was significantly greater in rhizosphere soil contaminated with 1000 and 2000 mg/kg than in the control. There was a clear shift in bacterial composition during phytoremediation by P. crinitum. Compared to the control, Bacteroidetes was more abundant in all Pb-contaminated soils, Actinobacteria was more abundant in 1000 mg/kg Pb-treated soil, and Firmicutes was more abundant in 3000 mg/kg Pb-treated soil. Positive correlations were observed between dominant bacterial phyla and soil enzyme activities. Metabolic pathways, such as ABC transporter, quinine reductase, and ATP-binding protein were significantly increased in rhizosphere soil bacteria with Pb contamination. In conclusion, Pb contamination differentially influenced the activities of rhizosphere soil enzymes, specifically increasing acid phosphatase and urease activities, and alters the dominance of soil bacteria through up-regulation of genes related to some metabolic pathways. The strong correlations between dominant bacterial phyla and enzymatic activities suggest synergetic effects on the growth of P. crinitum during Pb contamination

Correlation of 3'-phosphoadenosine-5'-phosphosulfate synthase 1 (PAPSS1) expression with clinical parameters and prognosis in esophageal squamous cell carcinoma

Background. In recent years, 3'- phosphoadenosine-5'-phosphosulfate synthase 1 (PAPSS1) has been found to be highly expressed in some cancers and significantly associated with prognosis. Nevertheless, the role of PAPSS1 in esophageal squamous cell carcinoma (ESCC) is poorly understood. Methods. In this study, PAPSS1 expression in ESCC samples was researched through real-time quantitative polymerase chain reaction (qPCR), immunohistochemistry (IHC), and western blot (WB) techniques. siRNA technology was then used to inhibit PAPSS1 expression in ESCC cells, and cytologic tests were conducted to research gene affection on cell apoptosis, proliferation, and migration. Then, the expression of Bcl2, Ki67, and Snail was detected using qPCR and WB tests. These experimental data were analyzed by GraphPad software, where the P-value <0.05 was statistically significant. Results. The results showed that PAPSS1 expression level in ESCC tissues was higher than in the adjacent tissues. The data also showed that PAPSS1 was significantly correlated with N stage, and that the patients with high expressions had longer survival time. After transfection for 48 hours, the cell apoptosis rate of siRNA-PAPSS1 transfected groups decreased significantly, whereas the cell proliferation rate and migration ability increased relative to the control. At the same time, the expression levels of Bcl2, Ki67 and Snail were all upregulated by siRNA-PAPSS1. PAPSS1, however, was suppressed. Conclusions. PAPSS1 may be an ESCC suppressor gene, and its specific molecular mechanism in ESCC needs to be further studied