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This paper investigated the impact of different b-value acquisition ranges (from 0 to 2 500 s/mm2) on the quantitative parameter calculation of six body diffusion models, including mono-exponential (Mono), diffusion kurtosis imaging (DKI), intravoxel incoherent motion (IVIM), stretch exponential model (SEM), fractional-order calculus model (FROC), and continuous time random walk model (CTRW). The influence of different b-value acquisition ranges on parameter calculation was evaluated through correlation between diffusion model parameters, t-test, and the ability to differentiate benign and malignant prostate lesions. The results showed that compared with that of the reference sampling scheme (0~2 500 s/mm2), the difference of the mean value of region of interest (ROI) with the same diffusion parameters gradually increases as the maximum b-value decreases, but the correlation decreases only slightly, and the ability to differentiate between benign and malignant prostate lesions remains at a similar level. Based on the experimental results, a b-value range of 0~1 500 s/mm2 is recommended for clinical practice, because this scheme takes collection efficiency into account, the correlation of more than half of its parameters with those of the reference sampling scheme is not less than 0.98, and the difference in the values of area under the curve (AUC) between benign and malignant differentiation is less than 0.01. In addition, the sensitivity of different diffusion models to the b-value scheme varies, with the parameters of SEM and CTRW models being relatively less affected by the b-value range.

Objective Optimize the latex perfusion technique and apply it to the construction of a murine craniofacial venous vascular model. Methods A total of nine 8-week-old male C57BL/6 mice weighing (25.0±1.3) g were randomly divided into three groups: 60% latex physiological saline group, 60% latex heparin group, and 30% latex heparin group. After completion of the perfusion, the specimens were immersed in 4 °C formalin fixative for 24 h, followed by dissection, observation, and measurement of the extracranial blood vessel diameters.Results After 200 μL latex perfusion solution was injected into the external jugular vein, the supraorbital vein, infraorbital vein, temporal vein, retrofacial vein, masseter vein and external jugular vein were perfused in each group.After comparing the perfusion degree of the distal branches of blood vessels, sublingual vein and tip venule, it was found that the 30% latex heparin group had the best perfusion effect, followed by the 60% latex heparin group, and the 60% latex saline group had the worst perfusion effect. Conclusion The optimized latex perfusion technique can effectively infuse the veins in the head and face of mice, and this technique can provide a good reference for the study of the direction and morphology of facial veins in mice.

To explore the effect of low load strengthening on the fatigue life of parts under random load, the automobile stabilizer bar is taken as an example, and the collected random load signal is extrapolated to the whole life cycle by peak over threshold extrapolation method. Based on the extrapolated load signal, the distribution characteristics of its mean and amplitude are analyzed, and the two-dimensional joint probability distribution is established. According to the characteristic that the stabilizer bar is continuously subjected to complex random loads, the influence of mean and amplitude is considered to compile the two-dimensional load spectrum, and the low load strengthening theory is introduced. The life prediction based on linear fatigue cumulative damage theory（Miner rule） and low load strengthening theory is compared with the test results to verify the effectiveness and accuracy of life prediction based on low load strengthening under random load.

【Background】 Lime concretion black soil is widely distributed in central China including Henan and Anhui provinces. Apart from its low fertility, it is also hard and less porous for roots to penetrate. These combine to hinder crop growth and comprise crop yield. Traditional remediation methods including deep tillage to loosen the soil are effective but are tedious and laborious. As an alternative, soil conditioners have been increasingly used over the past years to improve the properties of the black soil to sustain its productivity. 【Objective】 The objective of this paper is to compare the effectiveness of different soil conditioners in improving soil properties and the consequence for crop growth and yield. 【Method】 We took summer maize as an example and the soil was plowed using conventional tillage after maize harvest but before winter wheat was drilled. There were three treatments: rotary tillage + application of root promoter (RT+RP), rotary tillage + application of soil remediating agent (RT+RA), rotary tillage + soil improvement agent (RT+SI). Traditional deep tillage was taken as the control (CK). In each treatment, we measured the changes in soil properties and fertility, enzyme activity, as we as the resistance of the maize against lodging and the eventual yield. 【Result】 Compared to CK, all treatments increased soil water content and reduced soil bulk density although the change varied with treatments; they also boosted the activity of soil enzymes including urease, sucrase and neutral phosphatase, and improved the contents of available P, ammonium N and nitrate N in the soils, as well as plant height and stem diameter. All improvements and increases were at significant level (p