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Objective: To study the trauma and bone metabolism after internal absorbable screw and metal screw fixation treatment of tibia-fibula fracture. Methods: 78 patients with tibia-fibula fracture who received internal fixation surgery in our hospital between May 2013 and October 2015 were selected and randomly divided into absorbable group and metal group (n=39) who accepted internal absorbable screw fixation and internal metal screw fixation respectively. 3 d after operation, serum was collected to determine the levels of inflammatory factors, pain mediators, stress hormones and bone metabolism indexes. Results: Serum inflammatory mediators procalcitonin (PCT), Resistin, C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), pain mediators substance P (SP), prostaglandin E2 (PGE2) and NPY, stress hormones norepinephrine (NE), epinephrine (E) and cortisol (Cor) as well as bone resorption marker molecules C-terminal telopeptides of type I collagen (CTX-I) and C-terminal telopeptides of type II collagen (CTX-II) levels of absorbable group were significantly lower than those of metal group (P

In order to remove the electromagnetic coupling in IP measurement, previous studies were mostly based on the frequency characteristics of EM coupling. According to the basic EM coupling formulas of electric dipole and by means of Laplace transform and numerical integration, the time course and characteristic of EM coupling are studied in this paper, and the result of research has shown that: (1) the response voltage difference of dipole array shows as a rising slope when rectangular current is turned on and a dropping slope when current is turned off, which both defer the arrival time of EM signal. (2) the middle-grads array response of EM coupling shows as a positive sharp pulse when rectangular current is turned on and a negative sharp pulse when the current is turned off, which defer the arrival time of EM signal too. No matter what kind of array, compared with the on-off time of IP, EM coupling is eventually a short-lived transient phenomenon. EM couplings of all kinds of configurations have dissimilarities as well as similarities. Under the general geoelectric conditions of solid mineral prospecting, the time course of EM coupling does not exceed 10−2 s using middle-grads or dipole array. Utilizing these time characteristics, we are able to distinguish and remove EM coupling from IP data.

It is known that the electromagnetic coupling effect is a disturbance factor in induced-polarization measurements. Based on the different appearances of EM coupling effect and IP effect in measured dual-frequency waveform, a direct decoupling scheme by chop-wave is presented in this paper. The method is able to eliminate EM coupling effect directly during the field data acquisition, and it does not suffer loss of IP information by and large. This paper has mainly discussed several aspects, which include the fundamentals of chop-wave, the distortion of normal dual-frequency wave resulting from chopping wave, chopper of existing pure EM coupling effect and IP effect's loss due to chop-wave. The numerical results show that the scheme reduces and eliminates EM coupling effect markedly and can provide some parameter bases for the development and design on the correlative instrument. Thereby, it is worth generalizing the chop-wave for decoupling scheme in the induced polarization method.

The characteristics of methane hydrate dissociation in the presence of thermal stimulation, chemical injection, and thermal stimulation in conjunction with chemical injection method were investigated by molecular dynamics simulation. The effect of the injection of liquid water (WTR) and 30wt% ethylene glycol (EG) solution at 277K and 340K on methane hydrate dissociation was studied. The results showed the hydrogen bonds between WTR molecules and the water molecules on the hydrate surface were formed，which destroyed the original hydrogen bond balance of the hydrate. Therefore, the clathrate structure of hydrate collapsed, and the hydrate dissociated. The hydrogen bonds was formed obviously between hydroxyl groups of EG molecules and the water molecules on the hydrate surface; this caused the original stable clathrate structure of the hydrate to be destroyed and collapse, and, furthermore, promoted the dissociation of the methane hydrate and the release of methane gas. Compared with the effects of injecting WTR and 30wt% EG solution at 277K and 340K on the dissociation of methane hydrate, the effectivences was found to be: EG(340K)> WTR(340K)>EG(277K)>WTR(277K). The thermal stimulation in conjunction with chemical injection method can more effectively promote the dissociation of hydrate.