The Connecting Method for the Spiral Blades of Concrete Mixer Truck

For the spiral blade of the concrete mixing tank of concrete mixer truck, in order to satisfy the stirring and discharging performance, the installation angle and helix angle of the blade should be assigned according to their segmentation function. Due to the different helix angles and the installation tilt angles, a junction gap of blade is formed at the joint, resulting in the severe silting of discharge or the uneven agitation. We put forward a more reasonable solution by using the MFG (method of fitting gradient) to solve the gap connection of spiral blades. The MFG that can reduce the discharging residual rate of the mixing material has been verified by experiments and applied to actual mass production. We also make the coupling simulation of Multi-Physics Field based on simulation software 17-STARCCM+® to visually verify the scientificity of design and study the complex stresses distribution inside the actual mixing tank. Finally, we provide an up-to-date reference for the design of spiral logarithmic blade, solving the problem of the gap at the traditional spiral-blade connection

Iron isotope fractionation during skarn Cu-Fe mineralization

Fe isotopes have been applied to the petrogenesis of ore deposits. However, the behavior of iron isotopes in the mineralization of porphyry-skarn deposits is still poorly understood. In this study, we report the Fe isotopes of ore mineral separations (magnetite, pyrite, chalcopyrite and pyrrhotite ) from two different skarn deposits, i.e., the Tonglvshan Cu-Fe skarn deposit developed in an oxidized hydrothermal system and the Anqing Cu skarn deposit developed in a reduced hydro-thermal system. In both deposits, the Fe isotopes of calculated equilibrium fluids are lighter than those of the intrusions responsible for the skarn and porphyry mineralization, corroborating the “light-Fe fluid” hypothesis. Interestingly, chalcopyrite in the oxidized-Tonglvshan skarn deposit has lighter Fe than chalcopyrite in the reduced-Anqing skarn deposit, which is best understood as the result of the prior precipitation of magnetite (heavy Fe) from the ore fluid in the oxidized-Tonglvshan systems and the prior precipitation of pyrrhotite (light Fe) from the ore fluid in the reduced-Anqing system. The δ 56Fe for pyrite shows an inverse correlation with δ 56Fe of magnetite in the Tonglvshan. In both deposits, the Fe isotope fractionation between chalcopyrite and pyrite is offset from equilibrium line at 350℃ and lies between the FeS-chalcopyrite equilibrium line and pyrite-chalcopyrite equilibrium line at 350℃. These observations are consistent with the FeS pathway towards pyrite formation. That is, Fe isotopes fractionation during pyrite formation depends on a path, from the initial FeS-fluid equilibrium towards the pyrite-fluid equilibrium due to the increasing extent of Fe isotopic exchange with fluids. This finding, together with the data from other deposits, allows us to propose that the pathway effect of pyrite formation in the Porphyry-skarn deposit mineralization is the dominant mechanism that controls Fe isotope characteristics

A workflow for turbidite reservoir characterization—a case study of the Macedon member, Northern Carnarvon Basin, NW Australia

Deep-water turbidite systems on passive continental margins are of interest for oil and gas exploration. However, their complexity poses challenges for reservoir characterization. In this study, we proposed a reservoir characterization workflow for the Macedon member turbidite, employing a combination of 90° phase adjustment, geobody extraction, and genetic inversion, based on the abundant well logging and seismic data from the Enfield field, Northern Carnarvon Basin. Our workflow involved seismic sedimentology to determine the morphology of sand bodies and inversion to determine the net reservoir range, resulting in 3D geological attribute modeling. We applied a 90° phase adjustment correlated seismic events and well logging responses. By stratal slice interpretation and geological body extraction, it was revealed the turbidite reservoir distribution. Finally, we achieved net reservoir characterization of the Macedon member through genetic inversion porosity and geostatistical methods. The results showed that the Macedon turbidite reservoir can be divided into the top and base reservoirs. The top reservoir is sheet-like, and the base reservoir is channelized. The average porosity of the former was 24%, while the average porosity of the later is 20%. The top reservoir has better reservoir quality. Furthermore, we discussed sea level changes affect turbidite distribution and reservoir quality. During the Falling Stage Systems Tract (FSST), the long transportation distance led to relatively less sediment supply and a low sand/mud ratio, resulting in confined, channelized, poor quality turbidite reservoir. In contrast, during the Lowstand Systems Tract (LST), unconfined, amalgamated, good quality turbidite sheet reservoirs were formed. The improved workflow based on seismic sedimentology presented in this article proves effective in characterizing complex reservoirs and contributes to the simplified and efficient management of reservoirs

Prevalence of metabolic syndrome among middle-aged and elderly adults in China: current status and temporal trends

Background: Metabolic syndrome (MetS) is a cluster of major risk factors for cardiovascular diseases. We aimed to estimate prevalence and distribution of MetS among middle-aged and elderly adults in China. Methods: The present analysis used data from a national study in 2014–2015. We defined MetS by different definitions, and compared results of the present study and previous nationally representative studies to illustrate possible temporal changes in MetS prevalence. Results: The estimated prevalence of MetS was 18.4% by the ATP III criteria, 34.0% by the revised ATP III criteria, and 26.9% by IDF criteria. The prevalence was higher in women, older adults, those with lower education level, and in economically developed regions. Contrasting with previous national studies, adults in urban areas had a lower rate of MetS than those in rural areas (odds ratio 0.94; 95% CI 0.92−0.97). Rural adults had worse deterioration or less improvement in abdominal obesity, overweight, hypertension, and high fasting plasma glucose, than urban adults, which was particularly striking for women. Conclusion: While measures to prevent and control cardiovascular diseases need to be strengthened in China, rapid increasing risk factors among rural residents and women should be prioritized in making public health policy decisions

Data on prevalence of atrial fibrillation and its association with stroke in low-, middle-, and high-income regions of China

Data presented in this article are supplementary material to our research article entitled " Prevalence of Atrial Fibrillation in Different Socioeconomic Regions of China and Its Association with Stroke: Results from a National Stroke Screening Survey" (Wang et al., 2018) [1]. This data article summarizes previous studies of Atrial Fibrillation (AF) prevalence in China, and estimates the association between AF and stroke in different socioeconomic regions of China through a national survey