Research on forming quality of poly-wedge pulley spinning

As an important power transmission part, pulleys are widely used in automobile industry, agricultural machinery, pumps and machines. A near-net forming process for six-wedge belt pulleys manufacturing was put forward. For this purpose, the required tooth shape and size can be formed directly by spinning without machining. The whole manufacturing procedures include blanking, drawing and spinning. The spinning procedure includes five processes, performing, drumming, thickening, toothing and finishing. The forming defects occurred during each forming processes of poly-wedge pulley spinning, such as the drumming failure, flanged opening-end, folded side-wall, insufficient bottom size, flashed opening-end, cutting-off bottom, are introduced, and the factors influencing the defects are analyzed. The corresponding preventive measures are put forward

2-Phenyl-1H-1,3,7,8-tetra­azacyclo­penta­[l]phenanthrene

There are two mol­ecules in the asymmetric unit of the title compound, C19H12N4, with dihedral angles of 2.41 (10) and 10.53 (12)° between the fused ring system and the pendant phenyl ring. In the crystal, mol­ecules are linked into chains by N—H⋯N hydrogen bonds and aromatic π–π stacking inter­actions [shortest centroid–centroid distance = 3.6176 (16) Å] complete the structure

Flow Boiling Pressure Drop for R410A and RL32H in Multi-channel Tube

This paper introduced a test facility to conduct both flow boiling and condensation test in a multi-channel tube, including structure designs in test section to maintain good and stable flow regime in multi-channels. It supports flow boiling and condensing testing at the same time. The refrigerant cycle was driven by a gear pump, liquid refrigerant flows from the gear pump, passes through an electrical pre-heater, evaporator and post-heater, then flow through water/glycol bath pre-condenser, condenser and post-condenser. Experimental data for pure R410A, R410A and lubricant RL32H mixture pressure drop in flow boiling is presented and analyzed in this paper. Inlet vapor quality was changing at 0.2, 0.4, 0.6 to 0.8 with 0.2 quality increase along the tube, mass fraction of lubricant was changing from 0%, 1%, 3% to 5%, and mass velocity of the pure and mixture varied from 100 to 700 kg s-1 m-2. The experiments have been conducted for average saturation temperature at 5ºC. Literatures on two phase flow boiling pressure drop for both pure refrigerant and refrigerant mixtures are carefully reviewed, popular published correlations are used in this study to evaluate test data. New two phase flow boiling pressure drop correlations for pure refrigerant and mixtures inside multi-channel tube are proposed. Some published data are used to validate new correlations

Transcriptomic analysis of reproductive damage in the epididymis of male Kunming mice induced by chronic infection of Toxoplasma gondii PRU strain

This work was supported, in part, by grants from the National Key Research and Development Programme of China (2017YFD0501305), National Natural Science Foundation of China (31972707), Major Scientific Research Projects (Characteristic Innovation) of Guangdong Province (2017KTSCX018), the Key Research and Development Programme of Guangdong Province (2019B020218004), the Guangzhou Zoo Project (h2016141), the Natural Science Foundation of Guangdong Province (2019A1515011534, 2016A030313396), and Huizhou Science and Technology Projects (2015B040009001).According to results of a bioinformatics analysis, Gene Ontology (GO) function is divided into three categories: Cellular component, molecular function and biological process. Upon performing GO analysis, we found that some DEGs correlated with an integral part of membrane, protein complex, cell surface, ATP binding, immune system process, signal transduction and metabolic process which are responsible for the epididymal injury. DEGs were mapped to 101 unique KEGG pathways. Pathways such as cytokine-cytokine receptor interaction, glycolysis/gluconeogenesis and apoptosis are closely related to sperm quality. Moreover, Tnfsf10 and spata18 can damage the mitochondria in sperm, which decreases sperm motility and morphology. Conclusions: We sequenced the reproductive system of male mice chronically infected with T. gondii, which provides a new direction for research into male sterility caused by Toxoplasma infection. This work provides valuable information and a comprehensive database for future studies of the interaction between T. gondii infection and the male reproductive system. $a Background: Some researchers have reported that Toxoplasma gondii can cause serious reproductive impairment in male animals. Specifically, T. gondii destroy the quality of sperm in the epididymis, which affects their sexual ability. However, among such studies, none have investigated the male reproductive transcriptome. Therefore, to investigate the relationship between T. gondii and sperm maturation, we infected mice with T. gondii prugniaud (PRU) strain and performed transcriptome sequencing of the epididymis. Results: Compared with the control group, 431 upregulated and 229 downregulated differentially expressed genes (DEGs) were found (P-value < 0.05, false discovery rate (FDR) < 0.05 and l og2 (fold change)

Aqua­(2-hydr­oxy-5-sulfonatobenzoato-κO 1)bis­(2-phenyl-1H-1,3,7,8-tetra­aza­cyclo­penta­[l]phenanthrene-κ2 N 7,N 8)zinc(II)

In the title compound, [Zn(C7H4O6S)(C19H12N4)2(H2O)], the ZnII ion is coordinated by two N,N′-bidentate 2-phenyl-1H-1,3,7,8-tetra­azacyclo­penta­[l]phenanthrene ligands, one O-monodentate 5-sulfosalicylate dianion and a water mol­ecule. This results in a distorted cis-ZnO2N4 octa­hedral coordination geometry for the metal ion. In the crystal, mol­ecules are expanded into a three-dimensional supra­molecular motif via O—H⋯O, O—H⋯N and N—H⋯(O,S) hydrogen bonds. In addition, π–π stacking inter­actions between the aromatic rings of the polycyclic ligands consolidate the sturcture [shortest centroid–centroid distance = 3.501 (2) Å]