Empirical prediction of blast-induced vibration on adjacent tunnels

The blast-induced vibration during excavation by the drilling and blasting method has an important impact on the surrounding buildings/structures and auxiliary equipment. In particular, with the development of tunnel engineering, the impact of blasting vibration on tunnel construction has attracted extensive attention. Based on literature data statistics, this paper first explored the performance of several commonly used empirical equations in predicting the propagation and attenuation characteristics of blasting vibration on adjacent tunnels. Secondly, the relationships between the empirical parameters of the blasting vibration prediction equation and the geological strength index (GSI) of tunnel surrounding rock were discussed, and two new blasting vibration prediction equations based on site rock GSI were established to approximately predict blast-induced vibration on adjacent tunnels. Finally, the application feasibility of the established prediction equation in practical engineering was discussed based on field test data. The research results show that under the condition of multiple groups of data, the prediction performance of various prediction models does not differ significantly. With the increase of the GSI of the surrounding rock mass of the adjacent tunnel, the site coefficients β and k of the blasting vibration prediction equation in predicting PPV (peak particle velocity, resultant velocity) both show a decreasing trend as a whole. The site coefficient k is generally within 3,000. Two new empirical prediction equations of blasting vibration propagation and attenuation on adjacent tunnels under different site conditions were established: Eq. (14) for PPV and Eq. (15) for PPVi (max) (maximum value of the three component velocities; i = x, y, z represent peak component particle velocity). The verification analysis of five sites shows that these two equations have a certain practical application value. Compared with other empirical equations, these two equations do not need regression fitting blasting vibration data, they only used the GSI of the site rock mass, and they are more easy to use in the field when there is a lack of monitoring data

Nadir oxygen delivery is associated with postoperative acute kidney injury in low-weight infants undergoing cardiopulmonary bypass

BackgroundAcute kidney injury (AKI) is common after cardiac surgery with cardiopulmonary bypass (CPB) and is associated with increased mortality and morbidity. Nadir indexed oxygen delivery (DO2i) lower than the critical threshold during CPB is a risk factor for postoperative AKI. The critical DO2i for preventing AKI in children has not been well studied. The study aimed to explore the association between nadir DO2i and postoperative AKI in infant cardiac surgery with CPB.MethodsFrom August 2021 to July 2022, 413 low-weight infants (≤10 kg) undergoing cardiac surgery with CPB were consecutively enrolled in this prospective observational study. Nadir DO2i was calculated during the hypothermia and rewarming phases of CPB, respectively. The association between nadir DO2i and postoperative AKI was investigated in mild hypothermia (32–34°C) and moderate hypothermia (26–32°C).ResultsA total of 142 (38.3%) patients developed postoperative AKI. In patients undergoing mild hypothermia during CPB, nadir DO2i in hypothermia and rewarming phases was independently associated with postoperative AKI. The cutoff values of nadir DO2i during hypothermia and rewarming phases were 258 mL/min/m2 and 281 mL/min/m2, respectively. There was no significant association between nadir DO2i and postoperative AKI in patients undergoing moderate hypothermia during CPB.ConclusionIn low-weight infants undergoing mild hypothermia during CPB, the critical DO2i for preventing AKI was 258 mL/min/m2 in the hypothermia phase and 281 mL/min/m2 for rewarming. Moreover, an individualized critical DO2i threshold should be advocated during CPB

X-shaped hollow α-FeOOH penetration twins and their conversion to α-Fe2O3 nanocrystals bound by high-index facets with enhanced photocatalytic activity

通讯作者地址: Wang, ZCNonspherical hollow nanoparticles (NHNPs) have attracted a great deal of attention in recent years due to their unique properties and many promising applications. However, compared to hollow spheres, the fabrication of NHNPs is generally much more difficult and there are only a few successful examples to date. In this work, X-shaped hollow alpha-FeOOH penetration twins were first synthesized by a facile hydrothermal reaction. X-shaped alpha-Fe2O3 hollow nanostructures with high-index {11 (2) over bar3} facets exposed were further obtained via the topotactic transformation of alpha-FeOOH precursor. To the best of our knowledge, this is the first report on the nanostructures with high-index facets as well as a hollow interior. Owing to the special hollow structure and the high-energy surface, the as-obtained alpha-Fe2O3 nanocrystals show excellent visible-light photocatalytic activity toward the degradation of RhB.State Key Development Program for Basic Research of China 2007CB935603 National Natural Science Foundation of China 5137221

Increasing Cytosine Base Editing Scope and Efficiency With Engineered Cas9-PmCDA1 Fusions and the Modified sgRNA in Rice

Base editors that do not require double-stranded DNA cleavage or homology-directed repair enable higher efficiency and cleaner substitution of targeted single nucleotides in genomic DNA than conventional approaches. However, their broad applications are limited within the editing window of several base pairs from the canonical NGG protospacer adjacent motif (PAM) sequence. In this study, we fused the D10A nickase of several Streptococcus pyogenes Cas9 (SpCas9) variants with Petromyzon marinus cytidine deaminase 1 (PmCDA1) and uracil DNA glycosylase inhibitor (UGI) and developed two new effective PmCDA1-based cytosine base editors (pBEs), SpCas9 nickase (SpCas9n)-pBE and VQR nickase (VQRn)-pBE, which expanded the scope of genome targeting for cytosine-to-thymine (C-to-T) substitutions in rice. Four of six and 12 of 18 target sites selected randomly in SpCas9n-pBE and VQRn-pBE, respectively were base edited with frequencies of 4–90% in T0 plants. The effective deaminase window typically spanned positions 1–7 within the protospacer and the single target C showed the maximum C-to-T frequency at or near position 3, counting the end distal to PAM as position 1. In addition, the modified single guide RNA (sgRNA) improved the base editing efficiencies of VQRn-pBE with 1.3- to 7.6-fold increases compared with the native sgRNA, and targets that could not be mutated using the native sgRNA were edited successfully using the modified sgRNA. These newly developed base editors can be used to realize C-to-T substitutions and may become powerful tools for both basic scientific research and crop breeding in rice

Hematite concave nanocubes and their superior catalytic activity for low temperature CO oxidation

Hematite (α-Fe2O3) concave nanocubes bound by high-index {1344} and {1238} facets were synthesized and their catalytic activity for CO oxidation were also investigated. ? 2014 the Partner Organisations

INSEGNARE LA LINGUA ITALIANA NELLA REPUBBLICA POPOLARE CINESE: CASE STUDY DEL DIPARTIMENTO DI ITALIANO DELLA BEIJING FOREIGN STUDIES UNIVERSITY TRA IL 1962 E IL 2022

Il presente articolo illustra la storia dell’insegnamento della lingua italiana nella Repubblica Popolare Cinese, con particolare riferimento alle testimonianze raccolte dal 1962 al 2022 nel Dipartimento di italiano della Beijing Foreign Studies University, una delle prime università cinesi ad insegnare la lingua e la letteratura italiana. Utilizzando le fonti archivistiche dell’Ateneo e le fonti orali dei testimoni, l’autrice ricostruisce la storia del sopracitato Dipartimento in tre fasi, in stretto contatto con l’ambiente cinese e con il contesto del rapporto tra Italia e Cina, sottolineando in ogni fase gli aspetti connessi alle condizioni di ammissione degli studenti, della qualificazione dei docenti, dei lavori lessicografici, dei materiali didattici e delle metodologie glottodidattiche.   Teaching Italian language in the people’s republic of China: a case study at the department of Italian at Beijing foreign studies university between 1962 and 2022 This paper illustrates the history of Italian language teaching in the People’s Republic of China, with particular reference to evidence gathered from 1962 to 2022 at the Department of Italian at Beijing Foreign Studies University, one of the first Chinese universities to teach Italian language and literature. Using the archival sources of the University and the oral sources of witnesses, the author reconstructs the history of the aforementioned Department in three phases, in close contact with the Chinese environment and within the context of the relationship between Italy and China, emphasizing in each phase the aspects related to the conditions for the admission of students, the qualification of teachers, lexicographic works, teaching materials and language teaching methodologies

Research on Interactive Soundscape Design for Urban Landscape

This paper intends to discuss the concept and design elements and methods of the interactive soundscape for urban landscape through the analysis on the influence relationship of components of a soundscape for urban landscape. With the analysis on the composition of the acoustic environment for urban landscape as the starting point, it finds out the implicit relationship of components of the acoustic environment, introduces the concept of interactive design, proposes the concept and components of the interactive soundscape for urban landscape and discusses its design methods and specific process with the case simulation method, taking the soundscape design of landscape nodes in Zhongshan Park, Qingdao as an example

Point‐convolution‐based human skeletal pose estimation on millimetre wave frequency modulated continuous wave multiple‐input multiple‐output radar

Abstract Compared with traditional approaches that used vision sensors which can provide a high‐resolution representation of targets, millimetre‐wave radar is robust to scene lighting and weather conditions, and has more applications. Current methods of human skeletal pose estimation can reconstruct targets, but they lose the spatial information or don't take the density of point cloud into consideration. We propose a skeletal pose estimation method that combines point convolution to extract features from the point cloud. By extracting the local information and density of each point in the point cloud of the target, the spatial location and structure information of the target can be obtained, and the accuracy of the pose estimation is increased. The extraction of point cloud features is based on point‐by‐point convolution, that is, different weights are applied to different features of each point, which also increases the nonlinear expression ability of the model. Experiments show that the proposed approach is effective. We offer more distinct skeletal joints and a lower mean absolute error, average localisation errors of 6.1 cm in X, 3.5 cm in Y and 3.3 cm in Z, respectively

Rational Construction of a Mitochondria-Targeted Reversible Fluorescent Probe with Intramolecular FRET for Ratiometric Monitoring Sulfur Dioxide and Formaldehyde

Sulfur dioxide (SO2) and formaldehyde (FA) are important species that maintain redox homeostasis in life and are closely related to many physiological and pathological processes. Therefore, it is of great significance to realize the reversible monitoring of them at the intracellular level. Here, we synthesized a reversible ratiometric fluorescent probe through a reasonable design, which can sensitively monitor SO2 derivatives and FA, and the detection limit can reach 0.16 μM. The probe can specifically target mitochondria and successfully monitor the fluctuations of SO2 and FA in living cells. It also works well in the detection of SO2 and FA in zebrafish. This high-performance probe is expected to find broad in vitro and in vivo applications