Subgrade is an important component of pavement structure system, and subgrade resilience modulus is an important mechanical parameter to characterize the deformation resistance of subgrade and pavement structure design. Through FWD bending detection of different pavement structures of solid engineering, this paper studies the state distribution of compressive stress on the top surface of subgrade soil under the action of FWD load (Subgrade top and improve soil bottom) was studied in this paper. Reverse calculation of subgrade modulus under different working conditions was conducted. The relationship between subgrade top compressive stress and reverse calculation modulus and the reasonable range of calculation correction coefficient of test data of different structural test roads were analyzed. The results show that the soil subgrade model exhibits nonlinear characteristics, and the modulus of the subgrade increases with the distance of the sensor from the load center. With the increase of structural layer on subgrade, the inverse modulus of subgrade increases. The basic modulus of soil with different structures has the same change trend with the seasons, the basic modulus of soil increases in autumn and winter and decreases in spring and summer. The compressive stress generated by FWD at the top of subgrade decreases. The modulus correction coefficient of subgrade decreases with the increase of structural layer thickness, and C = 0.5493λ + 0.4556 is constructed, which proves that the model is suitable for any pavement structure.
Antagonistic chemicals were purified from liquid culture of strain Pst10 of Penicillium striatisporum by ethyl acetate extraction,thin layer chromatography(TLC),silica column chromatography and high performance liquid chromatography(HPLC) in turn.Two purified fractions were analyzed and identified by1H NMR and13C NMR,followed by checking corresponding database.Biological activity of purified chemicals to different microorganisms was examined by means of liquid drop culture and microscope observation.Two purified fractions(Fraction 1 and Fraction 4) were all identified as mixture of Calbistrin B and Calbistrin A.Calbistrin B was the main chemical of Fraction 1,and Calbistrin A was the dominant of Fraction 4.The minimal inhibitory concentration(MIC) of Calbistrin B to zoospores germination of Phytophthora capsici was 1.25 μg / ml.The biological activity of Calbistrin B showed obviously selective difference to tested microorganisms.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)
'/%3e%3cuse xlink:href='%23a' transform='rotate(144 450 300)'/%3e%3cuse xlink:href='%23a' transform='rotate(216 450 300)'/%3e%3cuse xlink:href='%23a' transform='rotate(288 450 300)'/%3e%3c/svg%3e)