A Laser Irradiation Method for Controlling Pieris rapae Larvae

At present, chemical pesticides remain the main approach for controlling Pieris rapae (L.) (Lepidoptera: Pieridae). This research proposes a novel laser irradiation method for managing P. rapae larvae as an alternative to chemical control. The effectiveness of controlling larvae and the influencing factors of lasers were studied to estimate optimal parameter combinations. Tests using the antifeedant effect and mortality of the larvae as dependent variables showed that the laser power, irradiation area, laser opening time and irradiation position were positively correlated with the P. rapae controlling effect. The optimal parameters for each factor were the following: laser power, 7.5 W; irradiation area, 6.189 mm2; laser opening time, 1.177 s; and irradiation position, middle of the abdomen. Based on these observations, a validation experiment was performed using the optimal combination of parameters, and the results showed that the antifeedant percentage of P. rapae larvae within 24 h posttreatment was 98.49%, whereas the mortality rate was 100%. The optimal parameter combination identified in the study was suitable for P. rapae larvae from the first- to fifth-instar stages, and a more effective controlling effect was observed with the younger larvae. These results can provide a theoretical basis for future pest control using laser pest-killing robots.

Characteristics of coal-measure source rock and its controlling effect on gas-water distribution of tight sandstone of He8 Member in Sulige Gas Province, Ordos Basin

Characteristics of complex gas-water distribution affect the efficient exploration of tight gas. The paper aims at tight sandstone gas-water distribution characteristics of He8 Member in Sulige Gas Province (SGP), describes thickness and TOC of source rocks from Benxi Formation in Carboniferous to the Second Member of Shanxi Formation in Permain, evaluates its hydrocarbon generation potential, discusses its controlling effect on tight sandstone gas-water distribution, and determines the threshold values of Ro and HGI of commercial gas flow wells. Research shows that the coal-measure source rock has the characteristics of extensive and superimposition. The coal seam and dark mudstone is the lithology of source rock, and its Ro is chiefly distributed 1.2% ∼ 2.1% in the stage of high mature thermal evolution, which is mainly type III kerogen. Among them, the thickness of coal seam is mainly ranged from 5 ∼ 15 m with an average of 9.32 m, and its average TOC is 64.08% and the distribution of HGI is (1∼36) ×108 m3/km2. No.8 and No.5 coal seams are relatively stable. The extent of thickness of dark mudstone is mainly between 10m and 30m with an average of 21.2m, and its average TOC is 2.11%, HGI is between (0.2∼10)×108m3/km2. Gas reservoir of He8 Member is tight sandstone lenticular reservoirs with the large-area quasi-continuous distribution. When the gas testing production is less than 1 × 104m3/d, the controlling effect of Ro and HGI are relatively obvious, and its controlling effect is obviously weakened with the increase of gas production. When Ro is more than 1.6%-1.7%, or HGI is larger than 15 × 108m3/km2, the decreasing trend of water/gas ratio is evident, especially in commercial gas flow wells (including high producing gas flow wells). In comparison, the controlling effect of HGI is stronger than Ro. 1.33% and 8 × 108 m3/km2 are the threshold values of Ro and HGI for commercial gas flow wells, respectively.

Mechanism and Classification of Coal and Gas Outbursts in China

Coal and gas outburst is a kind of complex dynamic disaster with short duration and strong explosiveness, and the modes and strength of the outburst are determined by the in situ stress, gas pressure, and physical and mechanical properties of the coal mass. In this paper, the status quo of research on the mechanism of coal and gas outburst in China is described from three aspects: the controlling effect of single factor, the controlling effect of multi-factor, and new understandings of the outburst mechanism in recent years. Firstly, controlling factors of coal and gas outburst are classified for an in-depth analysis of the main factors of the same type of disasters, and the research progress and new understandings of the mechanism of coal and gas outburst are systematically sorted out. Secondly, the influencing factors of the strength coal mass are analyzed, and the related issues of coal mass strength on coal and gas outburst disaster mechanism are discussed. The results show that the stages of incubation, occurrence, development, and stop on coal and gas outburst are affected by the coupling effects of in situ stress field, gas pressure field, and seepage field, and the coal strength becomes an important factor affecting outburst strength under the same in situ stress and gas pressure. Therefore, the scientific and reasonable improvement methods of such similar simulation experiment devices are proposed according to the existing experimental methods and devices, which is of great significance to provide ideas for the continuous transferring to deep mining and preventing coal and gas outburst in China in the future.

“Effectiveness Of Cfg Pile-Slab Shape On Smooth Soil For Supporting Excessive-Pace Railway Embankment”

Reducing the settlements of smooth foundation efficiently is a crucial problem of excessive-pace railway creation in China. The new CFG pile-slab structure composite foundation is a floor remedy method that is carried out on CFG pile basis and pile-slab structure composite basis. Based on the revel in of constructing Beijing-Shanghai excessive-pace railway in China, the settlement-controlling effect, the settlement distribution legal guidelines and 3 key influence elements for structural shape of latest CFG pile-slab structural foundation are studied by the use of physical model exams and numerical simulations. The research results on this look at imply that the piles and soil bearing capacities of the new CFG pile-slab shape can be positioned into complete play due to the “load dispensing” function of slabs. The settlement decreasing effect of the new CFG pile-slab shape is first rate and can meet the requirements of high-pace railway creation. The affected location of engineering load has a depth over 18.Seventy five m and horizontal period of 7.Five m nearing the embankment slope toe. The parametric observe presents the optimalizing structural form for high-quality agreement-controlling effect. The bodily version test results display precise concordance with the numerical simulation effects. The mixture of bodily version assessments and numerical simulations justifies the usage of this version in geotechnical engineering practices.