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The North Qilian Orogenic Belt is surrounded by the Tarim Craton to the NW and the North China Craton to the NE. The Precambrian continental crust remnants that are distributed in the North Qilian Orogenic Belt are termed the North Qilian Block (NQB), and their tectonic evolution has profound implications for the evolution of the Columbia Supercontinent. Here we present major- and trace-element and Sr–Nd–Hf isotope data for (meta-) basalts from the Beidahe Group (BDHG) and Zhulongguan Group (ZLGG) in the western North Qilian Orogenic Belt, to investigate the tectonic evolution of the NQB during the Proterozoic Eon. The protoliths of Palaeoproterozoic amphibole gneisses and plagioclase amphibolites from the BDHG are calc-alkaline series basalts. These metabasalts show island-arc-basalt affinities with variable Nd and Hf isotopes (ϵNd(t) = −5.0–0.6 and 2.7–4.3; ϵHf(t) = −14.2–2.0 and 6.9–8.8) and were generated by partial melting of the asthenospheric mantle that was metasomatized by aqueous fluid and sediment melt in a continental-arc setting. The early Mesoproterozoic ZLGG basalts show features of shoshonite-series basalts and are geochemically similar to ocean-island basalts. These basalts show variable (87Sr/86Sr)i, ϵNd(t) and ϵHf(t) values of 0.70464–0.70699, −1–2.6 and −1.5–5.7, and are products of mantle plume magmatism that participated with subducted oceanic crust in an intracontinental rift setting. This study suggests that the NQB underwent tectonic evolution from palaeo-oceanic subduction to intracontinental rifting during the Palaeoproterozoic–Mesoproterozoic eras. Furthermore, the above tectonomagmatic events were in response to convergence–splitting events of the Columbia Supercontinent during the Palaeoproterozoic–Mesoproterozoic eras.
With the characteristics of full autonomy and no accumulated errors, polarisation navigation shows tremendous prospects in underwater scenarios. In this paper, inspired by the polarisation vision of aquatic organisms, a novel point-source polarisation sensor with high spectral adaptability (400 nm–760 nm) is designed for underwater orientation. To enhance the environmental applicability of the underwater polarisation sensor, a novel sensor model based on the underwater light intensity attenuation coefficient and optical coupling coefficient is established. In addition, concerned with the influence of light intensity uncertainty on sensor performance underwater, an antagonistic polarisation algorithm is adopted for the first time, to improve the accuracy of angle of polarisation and degree of polarisation in the low signal-to-noise ratio environment underwater. Finally, indoor and outdoor experiments are carried out to evaluate the performance of the designed polarisation sensor. The results show that the designed point-source polarisation sensor can acquire polarised light and be used for heading determination underwater.
Having enterprises engaged in environmentally friendly behavior is an important part of reducing negative environmental impacts. This study makes a quantitative analysis against the backdrop of China's transitional economic system. The results show that politically-connected enterprises significantly reduce environmental expenditure, but this only holds for state-owned enterprises; private enterprises with political connections spend significantly more. Analysis of the efficiency of environmental expenditure indicates that, for private enterprises, environmental spending is used as a way to maintain political connections, with rent-seeking as the likely motivation. Politically-connected private enterprises have not reduced their emissions to the same extent as state-owned enterprises, despite increased expenditure. Given the scale of environmental degradation in China during a period of massive economic and social upheaval, the results of this analysis provide a quantitative case for policy change: governments should shift focus to the results that environmental spending produces.
This paper presents geochemical and grain-size records since the early Holocene in core ECS0702 with a fine chronology frame obtained from the Yangtze River subaqueous delta front. Since ~9500 cal yr BP, the proxy records of chemical weathering from the Yangtze River basin generally exhibit a Holocene optimum in the early Holocene, a weak East Asian summer monsoon (EASM) period during the middle Holocene, and a relatively strong EASM period in the late Holocene. The ~8.2 and ~4.4 cal ka BP cooling events are recorded in core ECS0702. The flooding events reconstructed by the grain-size parameters since the early Holocene suggest that the floods mainly occurred during strong EASM periods and the Yangtze River mouth sandbar caused by the floods mainly formed in the early and late Holocene. The Yangtze River-mouth sandbars since the early Holocene shifted from north to south, affected by tidal currents and the Coriolis force, and more importantly, controlled by the EASM. Our results are of great significance for enriching both the record of Holocene climate change in the Yangtze River basin and knowledge about the formation and evolution progress of the deltas located in monsoon regions.
Paediatric Mycoplasma pneumoniae pneumonia (MPP) is a major cause of community-acquired pneumonia in China. Data on epidemiology of paediatric MPP from China are little known. This study retrospectively collected data from June 2006 to June 2016 in Beijing Children's Hospital, Capital Medical University of North China and aims to explore the epidemiological features of paediatric MPP and severe MPP (SMPP) in North China during the past 10 years. A total of 27 498 paediatric patients with pneumonia were enrolled. Among them, 37.5% of paediatric patients had MPP. In this area, an epidemic took place every 2–3 years at the peak, and the positive rate of MPP increased during these peak years over time. The peak age of MPP was between the ages of 6 and 10 years, accounting for 75.2%, significantly more compared with other age groups (χ2 = 1384.1, P < 0.0001). The epidemics peaked in September, October and November (χ2 = 904.9, P < 0.0001). Additionally, 13.0% of MPP paediatric patients were SMPP, but over time, the rate of SMPP increased, reaching 42.6% in 2016. The mean age of paediatric patients with SMPP (6.7 ± 3.0 years old) was younger than that of patients with non-SMPP (7.4 ± 3.2 years old) (t = 3.60, P = 0.0001). The prevalence of MPP and SMPP is common in China, especially in children from 6 to 10 years old. Paediatric patients with SMPP tend to be younger than those with non-SMPP. MPP outbreaks occur every 2–3 years in North China. September, October and November are the peak months, unlike in South China. Understanding the epidemiological characteristics of paediatric MPP can contribute to timely treatment and diagnosis, and may improve the prognosis of children with SMPP.
In the Venus capture period, it is difficult for celestial autonomous navigation to satisfy the requirement of high precision. To improve autonomous navigation performance, a Direction, Distance and Velocity (DDV) measurements deeply integrated navigation method is proposed. The “deeply” integrated navigation reflects the fact that the direction and velocity measurements suppress the Doppler effects in the pulsar signals. In the pulsar observation period, the direction and velocity measurements are utilised to compensate for Doppler effects in the pulsar signals. By these means, the residual effects can be ignored. When the direction, distance or velocity measurements are obtained, they are fused to improve the navigation performance. Simulation results demonstrate that the DDV measurements deeply integrated navigation filter converges very well, and provides highly accurate position estimation without a high quality requirement on navigation sensors.
This study examined the mediating effects of future social expectations and interpersonal distrust on the relationship between individual relative deprivation and intention to rebel. Data were gathered from 807 people from multiple occupational backgrounds in a municipality in southwest China. Structural equation modelling showed that individual relative deprivation predicted intention to rebel directly and also that it predicted intention to rebel indirectly via negative future social expectations, interpersonal distrust, and a chain mediating effect of negative future social expectations and interpersonal distrust. These results highlight the importance of the associations between future social expectations and interpersonal distrust with intention to rebel in people who report relative deprivation. The findings also indicate that prevention and intervention programs related to relative deprivation and intention to rebel in China are worthy of further research.
The feature distinguishing typical angiosperms from gymnosperms is that their ovules are enclosed before pollination. Bennettitales were formerly related to angiosperms because of the flower-like organisation of the former's reproductive organs. There is little information on how the naked ovules of Bennettitales became enclosed in angiosperms because fossil evidence for such a transition, if it exists, has not been described. Here, we report a reproductive organ, Zhangwuia gen. nov., from the Middle Jurassic of Inner Mongolia, China. Like many Bennettitales, the arrangement of the foliar parts around the female part in Zhangwuia demonstrates a resemblance to typical angiosperm flowers. It is noteworthy that the ovule is secluded from the exterior space in Zhangwuia, therefore implying the existence of angio-ovuly. Although Bennettitales have been related to angiosperms for more than a hundred years, their way of ovule-enclosing was not previously revealed. The discovery of Zhangwuia prompts a rethinking of the relationship between Bennettitales and angiosperms, as well as of the origin of angiosperms.
Introduction: The mortality of Parkinson’s disease (PD) and its associated risk factors among clinically definite PD patients in China has been rarely investigated. Our study aimed to identify the mortality rates and predictors of death in PD patients in China. Methods: 157 consecutive, clinically definite PD patients from the urban area of Shanghai were recruited from a central hospital based movement disorder clinic in 2006. All patients were regularly followed up at the clinic until December 31, 2011, or death. Mortality and associations with baseline demographics, health and medical factors were then determined within the cohort. Results: After 5 years, 11(7%) patients had died. The standardised mortality ratio was 0.62 (95% CI 0.32 to 1.07, P=0.104). The main causes of death were pneumonia (54.5%, 6/11) and digestive disorders (18.2%, 2/11), respectively. Age at onset, independent living, the mini mental state examination score, the Parkinson’s disease sleep scale score and the Epworth sleepiness scale score at baseline were statistically significantly different between the survival group and the deceased group (P<0.05). Across all participants, risk factors for death included low mini mental state examination score, and high Epworth sleepiness scale score according to a binary variable logistic regression analysis. Conclusions: This study confirms the similar survival of patients with PD to the control population up to a follow-up of 5 years. Interventions tailored to potential risk factors associated with death may offer further benefits.
A 50-yr resolution reconstruction of climate and environment variability during the period 43–14 ka was developed using 26 high-precision U/Th dates and 390 oxygen isotope (δ18O) data of a stalagmite (SJ1) collected from Songjia Cave in central China, which is close to the northwestern boundary of the Asian summer monsoon (ASM). The δ18O record in SJ1 displays significant millennial-scale changes that correlate well in timing and duration with Dansgaard/Oeschger (D/O) events 5–10 and Heinrich event 4 (H4) identified in high-latitude regions of the Northern Hemisphere. Four 230Th dates constrain the H4 event precisely to the period of 39.7 to 38.3 ka. Notable centennial variations of the ASM activity could be observed within the H4 event. The magnitude and duration of D/O event 4.1 recorded in SJ1 are similar to those archived in east China but different from those documented in southwest China, suggesting that the manifestation of this event may be regionally different. The timing, duration and structure of D/O events 5–10 and Heinrich event 4 suggest that temperature changes in both hemispheres have exerted significant influences on the ASM variations in central China.
Tesla transformers are widely used in short pulse, repetition pulsed power generators. In this paper, a high repetitive rate intense electron beam accelerator (IEBA) based on high coupling (~1) Tesla transformer, which consists of a primary charging system, coaxial pulse forming line (PFL) charged by Tesla transformer and gas spark switch is described, especially stressed on the high coupling Tesla transformer. By introducing magnetic core to enhance the coupling factor between the primary and secondary windings, the transformer is capable of producing high voltage pulse up to 1.4 MV in approximately 45 µs. A coaxial pulse forming line is closely attached to the transformer that the outer and inner magnetic cores are parts of the PFL's outer and inner conductors respectively. In addition, the parameters of the Tesla transformer and PFL are calculated, including the dimension of the PFL and Tesla transformer. Some experiment results showed that the IEBA is capable of producing electron beams of 300–700 kV/7–13 kA at repetitive rate 100 Hz, with the pulse width 35 ns. The maximal energy efficiency of the Tesla transformer is 83%.
The strategies of repair of tetralogy of Fallot change with the age of patients. In children older than 4 years and adults, the optimal strategy may be to use different method of reconstruction of the right ventricular outflow tract from those followed in younger children, so as to avoid, or reduce, the pulmonary insufficiency that is increasingly known to compromise right ventricular function.
From April, 2001, through May, 2008, we undertook complete repair in 312 patients, 180 male and 132 female, with a mean age of 11.3 years ±0.4 years, and a range from 4 to 48 years, with typical clinical and morphological features of tetralogy of Fallot, including 42 patients with the ventriculo-arterial connection of double outlet right ventricle. The operation was performed under moderate hypothermia using blood cardioplegia. The ventricular septal defect was closed with a Dacron patch. When it was considered necessary to resect the musculature within the right ventricular outflow tract, or perform pulmonary valvotomy, we sought to preserve the function of the pulmonary valve by protecting as far as possible the native leaflets, or creating a folded monocusp of autologous pericardium.
The repair was achieved completely through right atrium in 192, through the right ventricular outflow tract in 83, and through the right atrium, the outflow tract, and the pulmonary trunk in 36 patients. A transjunctional patch was inserted in 169 patients, non-valved in all but 9. There were no differences regarding the periods of aortic cross-clamping or cardiopulmonary bypass. Of the patients, 5 died (1.6%), with no influence noted for the transjunctional patch. Of those having a non-valved patch inserted, three-tenths had pulmonary regurgitation of various degree, while those having a valved patch had minimal pulmonary insufficiency and good right ventricular function postoperatively, this being maintained after follow-up of 8 to 24-months.
Based on our experience, we suggest that the current strategy of repair of tetralogy of Fallot in older children and adults should be based on minimizing the insertion of transjunctional patches, this being indicated only in those with very small ventriculo-pulmonary junctions. If such a patch is necessary, then steps should be taken to preserve the function of the pulmonary valve.
Nano-sized cerium-doped lutetium aluminum garnet (LuAG:Ce) powders were prepared via a sol-gel combustion process from a mixed solution of metal nitrates, using organic glycine as a fuel. The purified crystalline phase of LuAG:Ce was obtained after calcination at 1000 °C for 2 h. The obtained phosphors were agglomerated and had a foamy-like morphology, consisting of pointed crystallites with uniform size of about 40 nm. Both the photoluminescence and the radioluminescence of the calcined powders showed the same two emission bands, corresponding to transitions from the lowest 5d excited state (2D) to the 4f ground state of Ce3+ (2F5/2, 2F7/2). Using the prepared powders, polycrystalline LuAG:Ce optically transparent ceramics were successfully fabricated at 1850 °C for 10 h under vacuum without sintering aids and annealed at 1450 °C for 20 h in air. The sintered ceramics are transparent with an in-line light transmittance in the visible wavelength range of about 50% and have a uniform microstructure with an average grain size of about 8 μm. The radioluminescence of the transparent ceramics is similar to that for calcined powders, except higher in intensity.
Genomic RNA was extracted from the subcutaneous adipose tissue of piglets (Duroc×Landrace×Tai-hu) at 1, 14, 28, 42 and 56 days of age, and obese gene (ob) mRNA was amplified using reverse transcriptase-polymerase chain reaction (RT-PCR). A DNA fragment of about 504 bp was obtained and the PCR product was cloned into a pGEM-T vector. The ob gene was isolated and sequenced from the positive clones screened. Sequence analysis suggested that this fragment was a partial sequence of ob cDNA, coding 167 amino acid residues, which constituted the major part of leptin mature protein. The gene homology of the fragment obtained in this study compared to the reported ob cDNA sequence in adipocytes of pig was 99.405%, and amino acid homology was 98.94%. Based on the ob gene clone, we successfully constructed an optimal semi-quantitative RT-PCR method. Using β-actin as the internal control, we investigated the difference of ob gene expression at different ages of piglets. Results showed that ob mRNA levels increased steadily at postnatal days 1–28 (preweaning), peaked at postnatal day 28, when piglets were weaned, and decreased from day 28 to 56.
An investigation of insect parasitoids of the diamondback moth, Plutella xylostella(Linnaeus), in brassica vegetable crops in the suburbs of Hangzhou was conducted during five periods from 1989 to 1997. Eight species of primary parasitoids were recorded: Trichogramma chilonis Ishii, Cotesia plutellae Kurdjumov, Microplitis sp., Oomyzus sokolowskii Kurdjumov, Diadromus collaris(Gravenhorst), Itoplectis naranyae (Ashmead), Exochus sp. and Brachymeria excarinata Gahan. Seven species of hyperparasitoids were also collected. Rates of parasitism of eggs of P. xylostella were usually very low. However, rates of parasitism of larvae and pupae were substantial and showed two peaks each year, around June–July and September–November respectively. Rates of parasitism during peaks were usually 10–60% and reached over 80% on a few occasions. Cotesia plutellae, O. sokolowskii and D. collaris were the major larval, larval-pupal and pupal parasitoids respectively. In the field, C. plutellae was active throughout the year. Oomyzus sokolowskii was active from May to October, entered a quiescent pupal stage in October–November to overwinter and did not emerge until next April–May. Diadromus collariswas recorded from April to July and October. Rates of parasitism of P. xylostellain radish and mustard fields were usually higher than those in cabbage and Chinese cabbage fields in the same locality. Negative correlations of parasitism rates between C. plutellae and O. sokolowskii indicate a competitive relationship for host larvae between these two larval parasitoids.
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