Background and Objectives: The rarity of duodenal gastrointestinal stromal tumors (DGIST) led to only limited data being available on their management and prognosis. We retrospectively analyzed the clinicopathological features, surgical treatments, adjuvant therapy, and prognosis of DGIST. Methods: Sixty-one patients were identified at diagnosis of primary DGIST from February 2005 to December 2015. One hundred twenty six patients with small intestinal gastrointestinal stromal tutors (GIST) were selected as control groups. Survival analyses were calculated using the Kaplan-Meier method. Results: Three- and five-year recurrence/metastasis-free survival rates of patients with DGIST were similar to those of patients with small intestinal GIST (p > 0.05 for all). Out of 61 cases with DGIST, 45 patients were treated with Limited Resection (LR). Sixteen patients were treated with Pancreaticoduodenectomy (PD). The 3- and 5-year recurrence/metastasis-free survival rates of the PD group and LR group were of no significant difference (p > 0.05 for all). Univariate analysis indicated that factors including surgical approaches, mitotic count, size, and risk grades were significantly associated with recurrence/metastasis-free survival (log-rank test, p < 0.05). Multivariate analysis demonstrated that the mitotic count was independently correlated with a worse recurrence/metastasis-free survival. Conclusions: Patients with radical resected DGIST had a favourable prognosis, which is similar to that of small intestinal GIST. Both LR and PD were optimal choices for treating DGIST.

Since the three Gorges reservoir Water storage, reservoir water level have about 30m water levels fluctuation every year, different level will lead to the bank slope infiltration lines rise and fall, and influent on the bank slopes stability. The test according to Manzo reservoir laboratory test data and geological survey report, using the finite element software of ANSYS to establish the finite element model. The model put different water level decline speed, different osmotic coefficient and the different infiltration recharge tension cases to analysis separately,the result shows:1) more greater the reductions speed, more steeper the saturation lines luffing, more adverse the slopes stability;2) more smaller the permeability coefficient, more poor the slopes drainage capacity,more steeper the infiltration line, more poor the slopes stability; 3) seepage lines position higher than no infiltration seepage lines position.

In the wireless positioning issue basing on TOA/TDOA, NLOS makes a great impact on the positioning accuracy. This paper presents a particle filtering based improved Chan Algorithm. Considering the case of multiple base stations, in the first step we use Chan algorithm to get the initial location estimation basing on the information provided by the base stations which are divided into subgroups. In the second step, we calculate the contributions of these estimated locations, and then use these contributions in the particle filtering framework to get the MAP of the location. Experimental results show that the improved algorithm can suppress the effect of the NLOS and can get better location estimation than the basic algorithm.

The commercial pure titanium plate was shot vertically by the projectile with a diameter of 7.62mm at impact velocities ranging from 782m/s to 825m/s. The microstructure around the crater of commercial pure titanium plate was analyzed by optical microscopy (OM) and electron backscatter diffraction (EBSD) methods. It was found that different microstructures were observed along the depth of cater. In upper region of the crater, grains were deformed and fragmented. Adiabatic shear bands (ASBs) were observed in the middle of the crater, and some ASBs were bifurcated. At the bottom of the crater, the grains were less deformed, and the deformation twins were formed. The microstructures in the center of adiabatic shear band were mainly consisted of the dynamic recrystallization grains and sub-grains. The microstructure in the transition region was elongated grains along the shear stress distribution.

The microstructures and mechanical properties of the high temperature titanium alloys containing Er, i.e. Ti-6Al-2.5Sn-4Zr-0.3Mo-1Nb-0.35Si-xEr (x=0, 0.1, 0.3wt%), were investigated. Both the grain size and lamellar structure inside grains were significantly refined with the addition of Er in as-cast alloys. Lamellar and duplex microstructures were obtained after forging and heat treatment. Silicide precipitates were generated in the boundary of lamellar α phase after aging treatment. Meanwhile, a few α2 phase were precipitated in the alloys after aging treatment. After 600°C /100h thermal exposure, the α2 phases with a mean size of 7nm and spacing of 10 nm were precipitated homogeneously in α lamellar. The creep properties were significantly improved by the addition of rare earth Er due to the formation of the second phase containing Er, silicide and α2 phase.

A new high-temperature titanium alloy containing erbium was designed and fabricated. The influence of α+β forging process and β forging process on microstructure and mechanical properties of the alloy was studied. The microstructure, mechanical properties and fracture morphologies of the new high-temperature titanium alloy after different forging processes were characterized. The results showed that the forging process significantly affected the microstructure of the alloy. The alloy exhibits nearly equiaxed microstructure and lamellar microstructure after α+β and β forging, respectively. In addition, there were Er-rich phases in both forged alloys. The alloy with nearly equiaxed microstructure acquired a satisfactory comprehensive performance. However, the alloy with lamellar microstructure had higher strength and less plasticity. The tensile fracture of the alloy after α + β forging had more dimples, while cleavage plane was obvious in the alloy after β forging. Owing to the addition of erbium and the formation of Er-rich phases, forged alloys possess excellent strength. The Er-rich phase might be the main reason for the fracture.