Abstract The nucleophilic groups on the side chain of amino acid can attack phosphoryl to form high-coordinated phosphorus intermediate. which was similar to the active sits of the CAMP-enzyme system [1, 2] 相似文献
The high-resolution stress and texture neutron diffractometer HETU at the China Mianyang Research Reactor is dedicated to measuring and analysing the residual stress and texture of engineering materials. The instrument can provide a high instrument resolution and a high neutron flux at the sample position. This article presents the HETU neutron optics design based on Monte Carlo simulation and the first assessment of its experimental performance. The technical parameters of the monochromators, slit system, radial collimators and detector were determined. A double-focusing silicon monochromator with (311) and (400) planes and a highly oriented pyrolytic graphite (HOPG) monochromator with (002) and (004) planes were selected to provide either high instrument resolution or high neutron flux modes. The highest instrument resolution of Δd/d = 1.65 × 10−3 is obtained when using Si(400), while the highest neutron flux at the sample position is 3.0 × 107 n s−1 cm−2 at the wavelength of 2.37 Å reflected by HOPG(004). The HETU diffractometer started operation in early 2022. 相似文献
Although commercial motion-capture systems have been widely used in various applications, the complex setup limits their application scenarios for ordinary consumers. To overcome the drawbacks of wearability, human posture reconstruction based on a few wearable sensors have been actively studied in recent years. In this paper, we propose a deep-learning-based sparse inertial sensor human posture reconstruction method. This method uses bidirectional recurrent neural network (Bi-RNN) to build an a priori model from a large motion dataset to build human motion, thereby the low-dimensional motion measurements are mapped to whole-body posture. To improve the motion reconstruction performance for specific application scenarios, two fundamental problems in the model construction are investigated: training data selection and sparse sensor placement. The problem of deep-learning training data selection is to select independent and identically distributed (IID) data for a certain scenario from the accumulated imbalanced motion dataset with sufficient information. We formulate the data selection into an optimization problem to obtain continuous and IID data segments, which comply with a small reference dataset collected from the target scenario. A two-step heuristic algorithm is proposed to solve the data selection problem. On the other hand, the optimal sensor placement problem is studied to exploit most information from partial observation of human movement. A method for evaluating the motion information amount of any group of wearable inertial sensors based on mutual information is proposed, and a greedy searching method is adopted to obtain the approximate optimal sensor placement of a given sensor number, so that the maximum motion information and minimum redundancy is achieved. Finally, the human posture reconstruction performance is evaluated with different training data and sensor placement selection methods, and experimental results show that the proposed method takes advantages in both posture reconstruction accuracy and model training time. In the 6 sensors configuration, the posture reconstruction errors of our model for walking, running, and playing basketball are 7.25°, 8.84°, and 14.13°, respectively. 相似文献
Summary: The synthesis of magnetic magnetite nanoparticles coated with amphiphilic block copolymers of poly(ethyl methacrylate)‐block‐poly(2‐hydroxyethyl methacrylate) for use as new potential carriers for hydrophobic drug delivery is reported. The results show that a new core‐shell‐corona structural material is obtained with a very narrow molecular weight distribution of the hydrophobic segment (PDI = 1.10). UV‐Vis results show that 37% of progesterone is released from the nanoparticles after 22 h, much slower than free release (99% after 14 h), which demonstrates that the presence of the hydrophobic segment can effectively control the release of hydrophobic drugs.
Synthesis of an amphiphilic block polymer poly(ethyl methacrylate)‐block‐poly(2‐hydroxyethyl methacrylate) on magnetite nanoparticles and their use as potential drug carriers 相似文献
The combined interface boundary condition (CIBC) method has been recently proposed for fluid–structure interaction. The CIBC method employs a Gauss–Seidel-like procedure to transform traditional interface conditions into velocity and traction corrections whose effect is controlled by a dimensional parameter. However, the original CIBC method has to invoke the uncorrected traction when forming the traction correction. This process limits its application to fluid–rigid body interaction. To repair this drawback, a new formulation of the CIBC method has been developed by using a new coupling parameter. The reconstruction is simple and the structural traction is removed completely. Two partitioned subiterative coupling versions of the CIBC method are developed. The first scheme is an implicit strategy while the second one is a semi-implicit strategy. Iterative loops are actualised by the fixed-point algorithm with Aitken accelerator. The obtained results agree with the well-documented data, and some famous flow phenomena have been successfully detected. 相似文献
