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Currently, the reported endoscopic system cannot meet the necessary conditions for real-time and optical-resolution clinical application simultaneously. In this study, by utilizing a high-repetition-rate laser and optimizing the overall structure of the probe, a real-time optical-resolution photoacoustic endoscope was developed, which could image targets in real time while maintaining a relatively constant lateral resolution. The endoscopic system has a best-resolution of 19 μm and a real-time imaging speed of 25 Hz. Experimental results demonstrate that this approach will push the promotion and commercialization of photoacoustic endoscopic imaging in a variety of preclinical and clinical applications.

In order to find a green, low-cost and high-performance modified raw soil method, samples were made from highland barley straw and gravel, which are unique in Qinghai-Tibet Plateau. The failure phenomenon, compressive strength, deformation capacity and load-displacement curve of different samples were studied, and the action mechanism and influence law of compressive strength of modified soil with different admixtures were analyzed and discussed. The test results show that when 0.25% highland barley straw and 20% gravel are mixed, the specimen has a smooth surface without dry shrinkage cracks, and its compressive strength and deformability are increased by 2.1 times and 30% respectively compared with that of plain soil. This content can be used as the best mixture ratio of this modified raw soil method.

According to the confined compression test in Xining area, the variation law of pressure on the collapsible deformation and compress deformation of loess is analyzed. The qualitative and quantitative analysis of the microstructure of loess samples before and after collapsing is carried out by electron microscopy. The relationship between the microstructure of the loess sample and the collapsible deformation is analyzed. The results show that:(1)with the increase of pressure, the deformation and compression of loess collapsing gradually become smaller, the soil is compacted, the strength is increased, the compressibility is weakened, the collapsibility is weakened or no collapsibility; (2) with the increase of pressure, the microscopic image observation of the sample before immersion, the structure of the undisturbed soil sample is relatively loose, the pores and particles are clearly distinguished, and the particle contour is relatively clear. After the sample is immersed in water, the arrangement of the skeleton particles becomes very tight, and the pore shape changes from large become small. As the pressure continues to increase, the microstructure of the sample gradually becomes dense; (3) the pressure increases with the increase of pressure before and after immersion in water. The arrangement gradually became stable, the particle distribution gradually concentrated and the degree of agglomeration became higher, and the proportion of pore area gradually decreased. The macroscopic collapse deformation and compression deformation of the loess before and after water immersion were consistent.

In order to investigate the effects of anisotropy of undisturbed loess on failure strength, dynamic shear modulus and damping ratio under cyclic loading, the dynamic characteristics of undisturbed loess in HaiDong area of Qinghai Province were studied by using the British GDS two-way dynamic triaxial test system. The results show that under the action of equal strain control cyclic load, as the number of cycles increases, the deformation of the sample gradually accumulates, the amplitude of dynamic strain decreases gradually, and the dynamic shear stress decreases. With the increase of dynamic shearing, the strain increases slowly and the strain hardening phenomenon appears. Different sampling angles have an important influence on the failure strength and dynamic shear modulus of undisturbed loess.

With the increase in global temperature, the frozen soil in the Qinghai-Tibet Plateau has been degraded to varying degrees, resulting in frequent road disease in the cold area, causing the bearing capacity of the frozen soil subgrade to be attenuated. In order to study the effects of the elevated temperature on the deviatoric stress and strain of the subgrade soil, the loading rate, dynamic stress amplitude, and frequency were introduced to simulate the working conditions of the highway, which ensure the negative effect of loading rate, dynamic stress amplitude, and frequency on the deviatoric stress. Then, using the orthogonal test method, for the 9 samples make the GDS dynamic triaxial test. The test results showed that the vibration frequency is the major effect factor on the deviatoric stress, deviatoric stress increased with the vibration frequency increased; the strain increased with the loading rate increased.

The variation of strength of fly ash geopolymer under different alkali activator modulus is studied. In this paper, three samples with modulus of alkali initiator 1.0, 2.0, 3.0 were prepared by laboratory test, and the unconfined compressive strength, SEM scanning and XRD analysis were conducted. Results show that the strength of the fly ash geopolymer negative correlation with alkali excitation agent module, with higher modulus alkali excitation agent, the strength of the polymer decreased obviously. From the micro perspective, the lower modulus of the sample of the microstructure appear more dense, gelling material produce more obvious at the same time. From the part of XRD, different modulus of the sample composition are same basically.

Aimed at researching intact loess mechanical properties in Qinghai area, this paper analyses these parameters through consolidated and undrained triaxial tests and SEM tests, and tests results are fitted linearly. The results show the maximum deviatoric stress increases with the increase of confining pressure when loess moisture contents are same. SEM images of loess clearly illustrate the close relative between moisture content and the pore distribution. The relationship between water content and shear strength index c and φ and ratio of pore area is nearly linear. Through using moisture content parameters, loess strength and pore ratio can be deduced by fitting linearly formulation, which has certain reference significance to the local engineering construction.

The collapsible loess in Xining area was tested by confined compression test to analyze collapsible and compression deformation of the loess. The researchers used electron microscopy to qualitatively analyze the microstructure of the loess samples before and after collapse. A comprehensive analysis of the relationship between the microstructure of the loess sample and the collapse deformation. The results show that: (1)with the increase of depth, the amount of collapse deformation and compression under the same pressure gradually become smaller, the soil is compacted, the strength is increased, and the compressibility and collapsibility are weakened; (2) due to the influence of loess stress history on its structure and collapsibility, with the increase of depth, the 6m loess exhibits less collapsible deformation and compressive deformation than the 3m loess; (3)with the increase of depth before and after immersion, the arrangement of pores tends to be stable, the particle distribution is gradually concentrated, the degree of agglomeration becomes higher, and the proportion of pore area gradually decreases. The collapsible deformation and compression deformation of loess before and after water immersion are consistent with the microstructure changes.

In this paper, the survival status of the sumatran rhinoceros was studied, the ecological game of the sumatran rhinoceros was put forward according to the critically endangered status, the differential dynamical system model of the sumatran rhinoceros and food was established, and the relationship between the parameters in the model and the land and environmental conditions was discussed. According to the value range of the four indicators, the ecological environment was divided into three conditions of food abundance, food shortage and critical state, so as to obtain the impact and requirements of the sumatran rhinoceros on the ecological environment. The results show that the sumatran rhinoceros lives in cycles under different land area conditions. Analysis from the perspective of the evolution of the ecological environment, the sumatran rhinoceros and food together form an ecological system, the abundant of food can cause sumatran rhinoceros populations, the number of the sumatran rhinoceros too much then can reduce the quantity of food, after reducing the number of the sumatran rhinoceros and will cause the increase in the number of food, this phenomenon is called ecological cycle, namely three environmental situation circulation phenomenon over time. Finally, according to the differential equation, migration is one of the ways that the sumatran rhino can continue to survive when the ecological environment changes.

The subgrade saline soil in a certain area of western Qinghai province was studied, based on the British GDS dynamic triaxial test system, the dynamic triaxial test under laboratory test was carried out to study variation dynamic stress-strain and dynamic shear modulus under the different temperature, frequency and confining pressure. The test results show that the dynamic stress-strain relationship is significantly affected by temperature change under cyclic dynamic load, followed by frequency and confining pressure. Under the same strain amplitude, the lower the temperature, the larger the dynamic shear modulus. When frequency and confining pressure increase, dynamic shear modulus also increases. Whereas, the influence of confining pressure on the dynamic shear modulus is more obvious, and the backbone curve development trend is steeper. Both maximum dynamic shear modulus and final shear stress amplitude increase with the frequency increases when temperature and confining pressure remain unchanged. Meantime, the maximum dynamic shear modulus curve is a convex shape, and the final shear stress amplitude curve is a convex shape at positive temperature,while which a concave shape at negative temperature. At constant frequency and confining pressure, the maximum dynamic shear modulus and final shear stress amplitude increase with the decrease of temperature. Curves of change trend are slower above 0°C, and steeper below 0°C.

In view of the high cost of the existing grouting materials, and at the same time the industrial production of a large number of fly ash, slag and other industrial waste can’t be effectively used. In this paper, the properties of fly ash slag cement with different ratios were studied through laboratory tests. Results show that the cement content in given conditions, with the increase of dosage of fly ash, initial setting and final setting time of cement paste with slow growth, the fluidity is growing, but the stone rate has obvious drop, on the compressive strength, the higher the slag content, is the early compressive strength, the greater the and the higher the dosage of fly ash, the late strength of cement paste were higher. This kind of grouting material has good working performance, can guarantee the project construction needs at the same time save cost, protect the environment.

In this paper, Tafel polarization technique is used to study the corrosion behavior of A3 steel basic magnesium sulfate, and then analyzing the ratio of raw materials cement, nitrites rust inhibitor and wet-dry cycle of basic magnesium sulfate corrosion of reinforced influence, and the steel corrosion behavior of basic magnesium sulfate compared with magnesium oxychloride cement and Portland cement. The results show that: the higher MgO/MgSO4 mole ratio will reduce the corrosion rate of steel; Too high and too low H2O/MgSO4 mole ratio may speed up the reinforcement corrosion effect; Adding a small amount of nitrite rust and corrosion inhibitor, not only can obviously reduce the alkali type magnesium sulfate in the early hydration of cement steel bar corrosion rate, but also can significantly reduce dry-wet circulation under the action of alkali type magnesium sulfate cement corrosion of reinforcement effect. Basic magnesium sulfate cement has excellent ability to protect reinforced, its long-term corrosion of reinforcement effect and was equal to that of Portland cement. Basic magnesium sulfate corrosion of reinforced is far below the level in the MOC in the case.