Do leaders matter? : Chinese politics, leadership transition and the 17th Party Congress

The opaque nature of decision making in China has generated considerable interest in the internecine machinations of elite politics. Particularly, but not only, when it comes to issues of leadership transition, considerations of factional formation and conflict come to the fore. This is partly to explain the transition process itself, but also out of concern for how new leaders might change the direction of Chinese policy. This paper suggests that whilst leaders and leadership changes do matter, they matter less than they once did. This is partly a result of the de-ideologicization and increasing diverse nature of elite interests and group formation. But it is also partly a result of the changed nature of China’s political economy; in short, there is less desire and less ability for new leaders to impose a clear paradigm shift

Study on Restoring Force Model of Cold-Formed Thin-Walled Steel Lipped Channel Beam-Columns under Cyclic Load

In order to study the hysteretic behavior and restoring force model of cold-formed thin-walled steel (CFTWS) lipped channel beam-column, a finite element analysis (FEA) model considering the material and geometric nonlinearity and the influence of the initial geometric imperfection under cyclic loading was established by ABAQUS software. Based on the verified FEA model, the hysteretic behavior of CFTWS lipped channel beam-column members with different influencing factors was analyzed by parameterization. The effects of width-to-thickness ratio, axial compression ratio and slenderness ratio on ductility, energy dissipation capacity and stiffness degradation were studied. Based on the results of parameter analysis and the theoretical and regression analysis, the calculation formula of each characteristic point of the trilinear skeleton curve of beam-column member was proposed. Based on the hysteresis curve analysis of beam-column member, the simplified restoring force model (SRFM) of CFTWS lipped channel beam-column was established according to different hysteresis rules for the different buckling modes. The results showed that the SRFM under different buckling modes was in good agreement with the hysteretic curve of FEA, which can better indicate the hysteretic behavior of the member. The proposed SRFM was accurate and applicable, and can provide a fundament for the seismic analysis of the CFTWS lipped channel beam-column

Soil bacterial community shifts driven by restoration time and steppe types in the degraded steppe of Inner Mongolia

Degraded grassland can be restored through management practices such as fencing to protect land from over-grazing. However, little is known about the dynamics of underground microbial communities and their associated ecological function during the restoration process. In this study, we investigated changes in the soil bacterial community composition with varying restoration time in the Leymus chinensis steppe. We also studied the differences in the soil bacterial community composition between a Leymus chinensis steppe and a Stipa grandis steppe at the same restoration time in the Inner Mongolia of China. Results showed that restoration of the degraded steppe through fencing significantly changed the bacterial community composition through the restoration time. The relative abundances of Chlorofiexi and Cyanobacteria decreased significantly with restoration. However, the relative abundances of copiotrophic Proteobacteria and Bacteriodetes increased. Significant changes for many dominant taxa occurred between 7 and 13 years of restoration time in the Leymus chinensis steppe. Shifts in the composition of bacterial communities with fencing and grazing were driven by multiple factors, including soil moisture, pH, nutrients (organic carbon and nitrogen, etc.). Network analysis of soil bacterial community compositions showed that the three largest modules in co-occurrence networks were separated by fencing, grazing and steppe type. This study revealed the successions of underground microbial communities associated with steppe restoration management over time

A 0.18-ns Response Time Digital LDO Regulator with Adaptive PI Controller in 180-nm CMOS

Digital low drop-out regulator (D-LDO) with fast settling time and superior transient response is gaining increasing attention to make up for the deficiency of analog LDO. However, as the traditional digital LDOs regulate the output voltage code at a rate of 1 bit per clock cycle, the transient response speed is limited. In this paper, a multi-bit conversion technique is proposed to improve the transient response speed. The multi-bit conversion technique is achieved by an error detector with adaptive regulation of proportion and integration parameters in the digital controller before pass devices. Besides, a voltage sensor and a time-to-digital converter are employed to convert the output voltage to digital codes. Implemented in a 180-nm CMOS process, the proposed D-LDO features under 36/33 mV of undershoot/overshoot at VOUT = 0.95 V as the load current steps up with 40 mA/1 ns on a 0.5 nF load capacitor. The simulated response time is 0.18-ns, the figure-of-merit of speed FOM1 is 0.65 ps and FOM2 achieves 0.068 pF

Temporal response of soil prokaryotic communities to acidification and alkalization under laboratory conditions

Soil pH plays an important role in shaping the structure and diversity of prokaryotic community. Altered pH regimes may change prokaryotic community composition by selecting species or groups with different ecological strategies to optimize their fitness. However, it remains unresolved whether prokaryotic communities exhibit deterministic (phylogenetically conserved) or stochastic (phylogenetically overdispersed) responses to pH. In this study we investigated the responses of greenhouse gas emissions and prokaryotic community structure to pH using three-month incubation experiments by adjusting an artificial pH gradient from 4.5 to 8.5. We found decreasing OTUs richness after three months of incubation. Phylogenetic clustering of the prokaryotic community was observed at earlier incubation times whereas greater phylogenetic distance of the prokaryotic community was found at later incubation time. Our results evidenced differential responses of various soil bacterial taxa to the changes in pH. Relative abundances of bacterial phyla and classes of main ecological groups of soil prokaryotes, oligotrophs and copiotrophs, changed significantly along an artificial pH gradient at various incubation times. Relative abundance of Acidobacteria significantly increased with pH at the start of experiment, while opposite trend was observed after 90 days of incubation. In contrast, the relative abundance of Bacteroidetes showed opposite response as Acidobacteria to elevated pH gradient during various incubation time. Methane emissions increased with pH as well as with incubation time, but carbon dioxide and nitrous oxide only increased with incubation time

One-way acoustic beam splitting in spatial four-waveguide couplers designed by adiabatic passage

In this work, we introduce quantum-mechanical adiabatic passage into the design of spatial acoustic four-waveguide (WG) couplers. Thanks to the agreement in form between the Schrödinger equation in quantum mechanics and the coupled-mode equation of classical wave, the behavior of propagating wave in coupled WGs is capable of mapping to quantum states driven by external fields. By coupling the input and output WGs with a mediator WG in space, an apparent beam splitting is realized and the ratio of intensity can be customized arbitrarily by altering the space-dependent coupling strengths. Moreover, a one-way propagation feature is exhibited in the spatial coupler when an appropriate loss is introduced in the mediator WG owing to the existence of dark state. This work builds a bridge between quantum adiabatic technology and acoustic beam splitter, which may have potential applications in acoustic communication, filtering and detection

Functional and phylogenetic response of soil prokaryotic community under an artificial moisture gradient

Moisture is recognized as a key factor shaping the structure of soil microbial community and its function in soil ecosystem. However, the temporal response patterns of soil microbes under various moisture regimes remain poorly understood. Therefore, the main objective of our study was to reveal how moisture regulates prokaryotic community structure, diversity, phylogenetic structure and finally how moisture regulates greenhouse gas emissions, as an indicator of microbial community function. We monitored prokaryotic community in soil incubated under an artificial moisture gradient for three months. We observed robust effects of both moisture gradient and incubation time on increased greenhouse gas emissions (methane, carbon dioxide and nitrous oxide). Furthermore, the moisture gradient as well as the incubation time exerted significant effects on species turnover of the soil prokaryotic community. In contrast, the artificial moisture gradient did not show any significant effects on prokaryotic alpha diversity. Alpha diversity of the soil prokaryotic community decreased significantly with incubation time. Different community assembly patterns were observed (based on both the mean nearest relatedness index (NRI) and nearest taxon index (NTI)). The mean NRI exhibited the dominance of stochastic factors, while the NTI indicated the dominance of deterministic factors. The prokaryotic communities in soils with less moisture tended to be controlled by stochastic factors, while prokaryotes in soils with higher moisture (60%) were controlled by deterministic factors. Relative abundances of oligotrophs and copiotrophs did not change significantly along the artificial moisture gradient, while the relative abundances of some prokaryotic taxa did vary significantly along the artificial moisture gradient

Variation of Fertility and Phenological Synchronization in Cunninghamia lanceolata Seed Orchard: Implications for Seed Production

Reproductive synchronicity between parents influences the seed production and quality in seed orchards. Our objective was to determine clonal variation in fertility and phenological synchronization, as well as their effect on seed production, in a Chinese fir (Cunninghamia lanceolata) open-pollinated seed orchard. Significant variation of female fertility and male phenological synchronization occurred in the clones. The flowering of the male was 2 days earlier than the female. The gamete contribution of female and male were unbalanced between clones (the phenological synchronization indexes (POij) were 0.000–0.585 (as female) vs. 0.000–0.385 (as male)). In general, the average POij value of as a male was lower than as a female, but the number of male flowers were significantly higher than female, indicating that the management of female flowers should be enhanced. The average POij of self-pollination was 0.298, higher than cross-pollination (0.236), indicating that there was a larger probability to selfing in the orchard. The middle phenological type possessed higher phenological synchronization indexes than early and late phenological type. Genetic control was stronger for number of female flowers (H2 = 0.277) than for male and female initial stages and flower duration (H2 = 0.193–0.239). We found a positive correlation between POij and TSW (r = 0.756), SOsc (r = 0.612), and Cp (r = 0.337), suggesting the phenological synchronization determined the seed quality and yield. Comprehensively, this study provided fertility and phenology information for management of a Chinese fir seed orchard, as well as a reference for the establishment of advanced seed orchards of conifer trees