In-situ pressure-preserved coring for deep exploration:Insight into the rotation behavior of the valve cover of a pressure controller

In-situ pressure-preserved coring(IPP-Coring)is considered to be the most reliable and efficient method for the identification of the scale of oil and gas resources.During IPP-Coring,because the rotation behavior of the pressure controller valve cover in different medium environments is unclear,interference between the valve cover and inner pipe may occur and negatively affect the IPP-Coring success rate.To address this issue,we conducted a series of indoor experiments employing a high-speed camera to gain greater insights into the valve cover rotation behavior in different medium environments,e.g.,air,water,and simulated drilling fluids.The results indicated that the variation in the valve cover rotation angle in the air and fluid environments can be described by a one-phase exponential decay function with a constant time parameter and by biphasic dose response function,respectively.The rotation behavior in the fluid environments exhibited distinct elastic and gravitational acceleration zones.In the fluid environments,the density clearly impacted the valve cover closing time and rotation behavior,whereas the effect of viscosity was very slight.This can be attributed to the negligible influence of the fluid viscosity on the drag coefficient found in this study;meanwhile,the density can increase the buoyancy and the time period during which the valve cover experienced a high drag coefficient.Considering these results,control schemes for the valve cover rotation behavior during IPP-Coring were proposed for different layers and geological conditions in which the different drilling fluids should be used,e.g.,the use of a high-density valve cover in high-pore pressure layers.

Analysis of the Orbitation and Rotation of Celestial Bodies

We have developed a structure of dynamic knowledge for non-inertial systems, the so-called Theory of Dynamic Interactions (TDI) as a part of non-inertial dynamic knowledge, which incorporates a causal demonstration of phenomena accelerated by rotation, which would complement Classical Mechanics. We believe that the TDI mathematical model that we propose is of great conceptual importance. In addition, we think that it is not only necessary to understand the dynamics of rotating bodies, but also to understand the dynamics of the cosmos, with bodies that orbit and with constantly recurring movements, which make possible systems that have been in dynamic equilibrium for centuries and are not in a process of unlimited expansion. We even believe that this new dynamic theory allows us a better understanding of our universe, and the matter from which it is made.

Undrained response of reconstituted clay to cyclic pure principal stress rotation

A series of monotonic and rotational shearing tests are carried out on reconstituted clay using a hollow cylinder apparatus under undrained condition. In the rotational shearing tests, the principal stress axes rotate cyclically with the magnitudes of the principal stresses keeping constant. The anisotropy of the reconstituted clay is analyzed from the monotonic shearing tests. Obvious pore pressure is induced by the principal stress rotation alone even with shear stress q0=5 k Pa. Strain components also accumulate with increasing the number of cycles and increases suddenly at the onset of failure. The deviatoric shear strain of 7.5% can be taken as the failure criterion for clay subjected to the pure cyclic principal stress rotation. The intermediate principal stress parameter b plays a significant role in the development of pore pressure and strain. Specimens are weakened by cyclic rotational shearing as the shear modulus decreases with increasing the number of cycles, and the shear modulus reduces more quickly with larger b. Clear deviation between the directions of the principal plastic strain increment and the principal stress is observed during pure principal stress rotation. Both the coaxial and non-coaxial plastic mechanisms should be taken into consideration to simulate the deformation behavior of clay under pure principal stress rotation. The mechanism of the soil response to the pure principal stress rotation is discussed based on the experimental observations.

梯度温度下考虑剪切变形影响的弹性约束拱的力学行为

考虑了剪切变形的影响对梯度温度作用下弹性约束圆弧拱的力学行为展开研究,推导了梯度温度作用下工字形截面圆弧拱的有效中心位置,通过能量法推导了弹性约束拱在梯度温度作用下的平面内变形、轴力和弯矩显式表达式,数值讨论了具有不同圆心角和弹性约束的圆弧拱在梯度温度作用下的内力变化情况。结果表明,梯度温度对浅拱的影响较为显著。考虑剪切变形能够使拱的弯矩减小,同时拱的轴力随着弹性约束柔度增大而减小。

Mesencephalic Progenitors Can Differentiate into TH-Positive Neurons and Improve Dysfunction in PD Rats

This study investigated the possibility of using mesencephalic progenitors (MPs) in the treatment of Parkinson's disease (PD). MPs were prepared from E 11 13 rats and proliferated in the serum free medium with basic fibroblast growth factor (bFGF) for 10 days. Cells were then collected and implanted into the striatum only-single grafts, or simultaneously into the substantia nigra (SN) and the striatum-double grafts. Twelve weeks after transplantation, 1,1' dioctadecyl 3,3,3',3' tetramethylindocarbocyanine perchlorate (DiI), a fluorescent dye, was microinjected into the ipsilateral striatum. The results show that double grafted MPs have more potent effects on rotational behavior than single grafted MPs. Injection of the retrograde tracer DiI into the striatum results in fluorescent labeled cells within the intranigral grafts only in double graft subjects. These data suggest that MP transplants not only can improve rotational behavior, but also help to reestablish nigrostriatal connections, so that such transplants may become an efficient way of treating PD.

Asymmetric rotating array beams with free movement and revolution

We introduce a new class of partially coherent asymmetric array beams. When the beam propagates, the spectral density of each lobe and the corresponding degree of coherence have rotating behavior. Especially, not only can array-like lattices revolve arbitrarily, but also they can move freely by controlling transverse plane shifts. Furthermore, we have generated this kind of beam experimentally, and the experimental phenomena are consistent with the numerical simulation results. Such a rotating beam with free movement and revolution may broaden the way for optical applications. More importantly, it inspires further studies in the field of asymmetric coherence gratings and lattices.