The Party, the Oil Companies, and Energy Security: Who Determines Chinese Policy?

China is today the third largest importer of crude oil in the world. Since 1993 when the country’s consumption of oil first exceeded the capacity of its domestic production, China has become a net importer and has witnessed a growing appetite for oil during the past decade. Energy security has been given enormous emphasis in the country’s foreign policy making, and is believed to be one of the most important components of China’s foreign policy in the 21st century. While enough ink has been spilled on the assessment of what China’s energy security policy looks like, few scholarly inquiries have been made into the domestic sources of China’s energy security policy. The purpose of this article is to reevaluate such a policy by identifying the different domestic stakeholders and analyzing how the potential divergence between the state and the oil companies influences the final policy outcome

Decentralized aircraft landing scheduling at single runway non-controlled airports

The existing air transportation system is approaching a bottleneck because its dominant huband- spoke model results in a concentration of a large percentage of the air traffic at a few hub airports. Advanced technologies are greatly needed to enhance the transportation capabilities of the small airports in the U.S.A., and distribute the high volume of air traffic at the hub airports to those small airports, which are mostly non-controlled airports. Currently, two major focus areas of research are being pursued to achieve this objective. One focus concentrates on the development of tools to improve operations in the current Air Traffic Management system. A more long-term research effort focuses on the development of decentralized Air Traffic Management techniques. This dissertation takes the latter approach and seeks to analyze the degree of decentralization for scheduling aircraft landings in the dynamic operational environment at single runway noncontrolled airports. Moreover, it explores the feasibility and capability of scheduling aircraft landings within uninterrupted free-flight environment in which there is no existence of Air Traffic Control (ATC). First, it addresses the approach of developing static optimization algorithms for scheduling aircraft landings and, thus, analyzes the capability of automated aircraft landing scheduling at single runway non-controlled airports. Then, it provides detailed description of the implementation of a distributed Air Traffic Management (ATM) system that achieves decentralized aircraft landing scheduling with acceptable performance whereas a solution to the distributed coordination issues is presented. Finally real-time Monte Carlo flight simulations of multi-aircraft landing scenarios are conducted to evaluate the static and dynamic performance of the aircraft landing scheduling algorithms and operation concepts introduced. Results presented in the dissertation demonstrate that decentralized aircraft landing scheduling at single runway non-controlled airports can be achieved. It is shown from the flight simulations that reasonable performance of decentralized aircraft landing scheduling is achieved with successful integration of publisher/subscriber communication scheme and aircraft landing scheduling model. The extension from the non-controlled airport application to controlled airport case is expected with suitable amendment, where the reliance on centralized air traffic management can be reduced gradually in favor of a decentralized management to provide more airspace capacity, flight flexibility, and increase operation robustness

Relationships Between Key Dryland Ecosystem Services: A Case Study in Ordos, China

Dryland ecosystem services (ESs) have been severely harmed by global environmental changes and increased human activities. To improve ESs, it is necessary to understand how they interact in drylands. In this study, we selected Ordos dryland, which is situated in northern China, as the study area to assess its four key ESs—food supply (FS), carbon storage (CS), water yield (WY), and habitat quality (HQ)—and to identify the hotspots of multiple ES supply. Furthermore, we studied the constraint effects between ESs in Ordos in 2000, 2010, and 2020 and used a spatial trade-off model to map the trade-off and synergy areas of ESs from 2000 to 2010 and from 2010 to 2020. The results indicated that all four ESs in Ordos increased significantly over the study period. The hotspots for the supply of multiple ESs also increased in areal extent during this period, and the state of the regional ecological environment continued to improve. The constraint effect between ESs showed that as the CS increased, its constraint effect on WY and FS decreased and then increased, whereas its constraint effect on HQ only decreased; as the WY increased, its constraint effect on HQ decreased and then increased, and its constraint effect on FS continued to decrease; as the FS increased, its constraint effect on HQ continued to increase. From the change in the area of ESs trade-offs and synergies, there was an increase in the area of positive synergy for four pairs of ESs in Ordos, which were CS-WY, CS-HQ, WY-HQ, and FS-HQ. These findings help in establishing a scientific foundation for the management and optimization of ESs in drylands

Single-port laparoscopic sacrospinous ligament suspension via the natural vaginal cavity (SvNOTES) for pelvic prolapse: The first feasibility study

ObjectiveThis study aims to investigate the feasibility and short-term efficacy of single-port laparoscopic-assisted transvaginal natural cavity endoscopic sacrospinous ligament suspensions (SvNOTES).MethodsA total of 30 patients diagnosed with anterior or/and middle pelvic organ prolapse Stages III and IV underwent natural vaginal cavity (SvNOTES), and 30 patients who underwent conventional sacrospinous ligament (SSLF) were used as a control group. The operation time, blood loss, postoperative POP-Q score, length of hospital stay, and complications were compared between the two groups.ResultsThe operation time for SvNOTE was (60 ± 13) min, which was longer than (30 ± 15) min for SSLF (P = 0.04). However, the bleeding amount in SvNOTE was 29.44 ± 2.56, significantly lower than that in the SSLF group (80 ± 10; P = 0.02), and the postoperative hospital stay in the SvNOTE group was (4 ± 2) days, longer than (3 ± 1) days in SSLF (P = 0.02). However, there were no intraoperative complications in the SvNOTE group, whereas one ureteral injury occurred in the SSLF group; in addition, the postoperative POP-Q score was significantly better in the SvNOTE group than that in the SSLF group with increasing time (P < 0.001).ConclusionCompared with SSLF, single-port laparoscopic sacrospinous ligament suspension via the natural vaginal cavity is visualized, greatly improving the success rate of sacrospinous ligament fixation, with less blood loss and fewer complications, arguably a safer and minimally invasive surgical approach

On-line near-infrared spectroscopy optimizing and monitoring biotransformation process of γ-aminobutyric acid

AbstractNear-infrared spectroscopy (NIRS) with its fast and nondestructive advantages can be qualified for the real-time quantitative analysis. This paper demonstrates that NIRS combined with partial least squares (PLS) regression can be used as a rapid analytical method to simultaneously quantify l-glutamic acid (l-Glu) and γ-aminobutyric acid (GABA) in a biotransformation process and to guide the optimization of production conditions when the merits of NIRS are combined with response surface methodology. The high performance liquid chromatography (HPLC) reference analysis was performed by the o-phthaldialdehyde pre-column derivatization. NIRS measurements of two batches of 141 samples were firstly analyzed by PLS with several spectral pre-processing methods. Compared with those of the HPLC reference analysis, the resulting determination coefficients (R2), root mean square error of prediction (RMSEP) and residual predictive deviation (RPD) of the external validation for the l-Glu concentration were 99.5%, 1.62g/L, and 11.3, respectively. For the GABA concentration, R2, RMSEP, and RPD were 99.8%, 4.00g/L, and 16.4, respectively. This NIRS model was then used to optimize the biotransformation process through a Box-Behnken experimental design. Under the optimal conditions without pH adjustment, 200g/L l-Glu could be catalyzed by 7148 U/L glutamate decarboxylase (GAD) to GABA, reaching 99% conversion at the fifth hour. NIRS analysis provided timely information on the conversion from l-Glu to GABA. The results suggest that the NIRS model can not only be used for the routine profiling of enzymatic conversion, providing a simple and effective method of monitoring the biotransformation process of GABA, but also be considered to be an optimal tool to guide the optimization of production conditions

Corrosion Behavior of Alloy C-276 in Supercritical Water

The corrosion behavior of Alloy C-276 in high-temperature and high-pressure water at 500°C and 25 MPa, respectively, was investigated by means of mass gain, scanning electron microscopic observation, and X-ray diffraction. The results indicated that the mass gain rate of Alloy C-276 in supercritical water obeys the parabolic law. The oxide scale was formed on Alloy C-276 with a dual-layer structure, mainly consisting of an outer Ni-rich layer and an inner Cr2O3/NiCr2O4 mixed layer. Tiny microcracks can also be found in the oxide scale if exposed for longer time. Meanwhile, higher temperature promotes oxide rate and results in thermal stress in the oxide film