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Diapause is a physiological process in which insects can survive in a natural environment that is not conducive to their survival, which is the result of long-term adaptation to environmental conditions. It provides a great adaptive advantage for insects, allowing insects to survive in unsuitable seasonal environments to synchronize their life cycles with those suitable for growth, development, and reproduction. The process of regulating insect diapause is a complex process interacting with multiple mechanisms. In this chapter, a review is given of the current knowledge of diapause types, environmental inducing factors, sensitive states, and the endogenous molecular mechanism associated with diapause in flies (Diptera). Research regarding both the diapause process and intrinsic mechanism is reviewed.

Oedaleus asiaticus (Bey-Bienko) is an economically devastating locust species found in grassland and pastoral areas of the Inner Mongolia region of northern China. In this study, resistance to three frequently used insecticides (beta-cypermethrin, matrine, and azadirachtin) was investigated in six field populations of O. asiaticus using the leaf-dip bioassay method. The inhibitory effects of synergists and the activities of detoxification enzyme activities in the different populations were determined to explore potential biochemical resistance mechanisms. The results showed that the field populations SB (resistance ratio [RR] = 7.85), ZB (RR = 5.64), and DB (RR = 6.75) had developed low levels of resistance to beta-cypermethrin compared with a susceptible control strain. Both the SB (RR = 5.92) and XC (RR = 6.38) populations had also developed low levels of resistance against matrine, with the other populations remaining susceptible to both beta-cypermethrin and matrine. All field populations were susceptible to azadirachtin. Synergism analysis showed that triphenyl phosphate (TPP) and diethyl-maleate (DEM) increased the toxicity of beta-cypermethrin significantly in the SB population, while the synergistic effects of TPP, piperonyl butoxide (PBO), and DEM on the toxicity of matrine were higher in SB (SR 3.86, 4.18, and 3.07, respectively) than in SS (SR 2.24, 2.86, and 2.29, respectively), but no synergistic effects of TPP, PBO, and DEM on azadirachtin were found. Biochemical assays showed that the activities of carboxylesterases (CarEs) and glutathione-S-transferases (GSTs) were significantly raised in all field populations of O. asiaticus, with a significant positive correlation observed between beta-cypermethrin resistance and CarE activity. The activities of cytochrome P450 monooxygenases (P450) and multi-function oxidases (MFO) were elevated in all six field populations, and P450 activity displayed strong positive correlations with the three insecticides. Our findings suggest that resistance to beta-cypermethrin in O. asiaticus may be mainly attributed to elevated CarE and GST activities, while P450 plays an important role in metabolizing matrine and azadirachtin. Our study provides insights that will help improve insecticide resistance management strategies.

As the backup power supply of power plants and substations, valve-regulated lead-acid (VRLA) batteries are the last safety guarantee for the safe and reliable operation of power systems, and the batteries’ status of health (SOH) directly affects the stability and safety of power system equipment. In recent years, serious safety accidents have often occurred due to aging and failure of VRLA batteries, so it is urgent to accurately evaluate the health status of batteries. Accurate estimation of battery SOH is conducive to real-time monitoring of single-battery health information, providing a reliable guarantee for fault diagnosis and improving the overall life and economic performance of the battery pack. In this paper, first, the floating charging operation characteristics and aging failure mechanism of a VRLA battery are summarized. Then, the definition and estimation methods of battery SOH are reviewed, including an experimental method, model method, data-driven method and fusion method. The advantages and disadvantages of various methods and their application conditions are analyzed. Finally, for a future big data power system backup power application scenario, the existing problems and development prospects of battery health state estimation are summarized and prospected.

Under the ground mode of generator stator neutral point resistance shunt reactor, the existing grounding protection research cannot satisfy the requirements for development of application. Therefore, a protection method based on phase voltage variation characteristics of generator stator ground fault is proposed in this paper. This method uses the voltage magnitude of the faulted phase and the non-faulted phase before and after the stator ground fault to determine the ground fault phase. And in this method, the position of fault point and the value of transition resistance are obtained by calculating the voltage difference of each phase. In this paper, a simulation model is built to prove that this method can effectively identify the stator ground fault phase, determine the fault location and obtain the transition resistance value. Therefore, this method has great practical value.

Understanding future trajectory of urban residential building carbon emissions (URBCE) is essential to seeking effective carbon-abatement pathways to combat climate change. However, future evolutionary trajectory, possible emission peaks and peaking times in this sector are still unclear. This study innovatively develops an integrated dynamic simulation model by embedding a bottom-up building end-use energy model into the system dynamics model. Based on this, scenario analysis approach is combined with Monte Carlo simulation method to explore the possible emission peaks and peaking times considering the uncertainties of impact factors. We apply the integrated SD-LEAP model to Chongqing, a typical city in China's hot-summer and cold-winter zone. Results show that URBCE will probably peak at 22.8 (±8.0) Mt CO2 in 2042 (±3.4)—well beyond China's 2030 target. Different building end-uses present substantial disparities. The contribution of combined heating and cooling to URBCE mitigation will be over 60% between business-as-usual and low-carbon scenarios. Dynamic sensitivity analysis reveals that per capita gross domestic product, carbon emission factor, and residential floor space per capita can boost emission peaks and peaking time. This study can not only boost the theory and model development for carbon emission prediction, but also assist governments to set effective carbon-reduction targets and policies.

Generator insulation faults account for a high proportion of generator faults. It is difficult to meet the requirements of fast and accurate real-time monitoring of generator stator insulation state. In this paper, the on-line monitoring method of generator stator winding insulation state based on resonance measurement is proposed. By injecting zero-sequence current with constant amplitude and frequency variation into arc suppression coil, the phase angle difference between zero-sequence voltage of stator winding neutral point and injection current is monitored in real time, the resonance frequency of zero-sequence circuit is searched, the capacitance current and leakage resistance current of generator to ground are calculated, and the insulation state of generator stator winding is measured online. Considering the influence of damping resistance and excitation branch of voltage transformer, the accuracy of on-line insulation monitoring is improved. Through PSCAD/EMTDC simulation analysis, the method is not affected by arc suppression coil damping resistance and generator operation mode, which can effectively overcome the interference of excitation branch of voltage transformer to measurement, and meet the requirement of accurate on-line real-time monitoring of generator stator windings. It has certain engineering application value.

Aiming at the problem that the mixed use of overhead lines and cables causes serious refraction and attenuation of the traveling wave signal in propagation, which makes the traditional traveling wave sensor unable to adapt to the weak signal identification and recording requirements. A wideband sensor for detecting transient current signal of power system is developed. The detection principle of the anisotropic magnetoresistive sensor is analyzed, and the tiny signal precision differential amplifier circuit is designed. Based on the actual situation of the power system, a corresponding test environment was built to conduct transient current transfer tests. The experimental results show that the sensor has a high linearity in the 0-5MHz bandwidth, and is suitable for the extraction of various transient signals, especially in the power system traveling wave protection has high application value.

In contrast to conventional block-based discrete cosine transform (DCT) coders, video coding based on wavelet is free from block-artifacts, and has a multi-resolution scalability, which is a strongly desired property for many multimedia video applications. In this paper, a simple wavelet-based video coding system and a new indicator are proposed to evaluate the performance of wavelet in the video coding system, and the composite performance of wavelet compression system is described through four indicators from different aspects. The possibility is analyzed in the video processing system which used wavelet technology, and we provide a selection principle of wavelet functions. Moreover, the research highlights the relationship between the data processed by the different wavelet functions and the quantization steps, and a new concept of sensitivity coefficients are proposed, that explained the characteristics of video applications which use wavelet transform. The specific performance of various wavelets is got through a large number of experiments. Finally, a selection principle of wavelet functions in video processing systems is given.