A Detection Algorithm for Citrus Huanglongbing Disease Based on an Improved YOLOv8n.

Given the severe impact of Citrus Huanglongbing on orchard production, accurate detection of the disease is crucial in orchard management. In the natural environments, due to factors such as varying light intensities, mutual occlusion of citrus leaves, the extremely small size of Huanglongbing leaves, and the high similarity between Huanglongbing and other citrus diseases, there remains an issue of low detection accuracy when using existing mainstream object detection models for the detection of citrus Huanglongbing. To address this issue, we propose YOLO-EAF (You Only Look Once-Efficient Asymptotic Fusion), an improved model based on YOLOv8n. Firstly, the Efficient Multi-Scale Attention Module with cross-spatial learning (EMA) is integrated into the backbone feature extraction network to enhance the feature extraction and integration capabilities of the model. Secondly, the adaptive spatial feature fusion (ASFF) module is used to enhance the feature fusion ability of different levels of the model so as to improve the generalization ability of the model. Finally, the focal and efficient intersection over union (Focal-EIOU) is utilized as the loss function, which accelerates the convergence process of the model and improves the regression precision and robustness of the model. In order to verify the performance of the YOLO-EAF method, we tested it on the self-built citrus Huanglongbing image dataset. The experimental results showed that YOLO-EAF achieved an 8.4% higher precision than YOLOv8n on the self-built dataset, reaching 82.7%. The F1-score increased by 3.33% to 77.83%, and the mAP (0.5) increased by 3.3% to 84.7%. Through experimental comparisons, the YOLO-EAF model proposed in this paper offers a new technical route for the monitoring and management of Huanglongbing in smart orange orchards.

Simple Conditional Spatial Query Mask Deformable Detection Transformer: A Detection Approach for Multi-Style Strokes of Chinese Characters.

In the Chinese character writing task performed by robotic arms, the stroke category and position information should be extracted through object detection. Detection algorithms based on predefined anchor frames have difficulty resolving the differences among the many different styles of Chinese character strokes. Deformable detection transformer (deformable DETR) algorithms without predefined anchor frames result in some invalid sampling points with no contribution to the feature update of the current reference point due to the random sampling of sampling points in the deformable attention module. These processes cause a reduction in the speed of the vector learning stroke features in the detection head. In view of this problem, a new detection method for multi-style strokes of Chinese characters, called the simple conditional spatial query mask deformable DETR (SCSQ-MDD), is proposed in this paper. Firstly, a mask prediction layer is jointly determined using the shallow feature map of the Chinese character image and the query vector of the transformer encoder, which is used to filter the points with actual contributions and resample the points without contributions to address the randomness of the correlation calculation among the reference points. Secondly, by separating the content query and spatial query of the transformer decoder, the dependence of the prediction task on the content embedding is relaxed. Finally, the detection model without predefined anchor frames based on the SCSQ-MDD is constructed. Experiments are conducted using a multi-style Chinese character stroke dataset to evaluate the performance of the SCSQ-MDD. The mean average precision (mAP) value is improved by 3.8% and the mean average recall (mAR) value is improved by 1.1% compared with the deformable DETR in the testing stage, illustrating the effectiveness of the proposed method.

[Application of single-sperm sequencing in resolving the carrier status of preimplantation genetic testing for chromosomal structural rearrangements in Robertsonian translocations].

OBJECTIVE: To investigate the application value of single-sperm sequencing in resolving the carrier status of preimplantation genetic testing (PGT) for chromosomal structural rearrangements in Robertsonian translocations. METHODS: Haplotypes were constructed by single-sperm isolation combined with single-sperm sequencing for a patient with 45, XY, der(13; 14)(q10; q10). Twenty single-sperm samples were isolated by mechanical braking and subjected to whole-genome amplification (WGA), and then the Asian Screening Array (ASA) gene chip was used to detect the 183 708 single nucleotide polymorphisms (SNP) of the WGA products. The single sperm associated with the translocation that could be used as haplotype inference was detected by copy number variation (CNV) sequencing, and the chromosomal haplotypes with normal and Robertsonian translocations were inferred. Three biopsy samples of embryonic trophoblast cells were used as the objects. After whole-genome amplification, high-throughput sequencing was employed to determine the status of the translocation chromosome carried by the embryos. The available blastocysts were selected for transfer, and the amniotic fluid samples were taken at 18 weeks of gestation to confirm whether the fetus carried the pathogenic mutation. RESULTS: A total of 6 037 SNP sites were screened by single-sperm sequencing, and 30 sites selected to distinguish normal and translocation haplotypes. Preimplantation haplotype analysis showed that all the three embryos were euploids without Robertsonian translocation chromosome. Genetic testing of amniotic fluid in the second trimester confirmed that the karyotype of the fetus was 46, XN, carrying no Robertsonian translocation chromosome. CONCLUSION: For male carriers of Robertsonian translocation, single sperm sequencing can be used to screen SNP sites to construct haplotypes for distinguishing normal and Robertsonian translocation embryos, and to provide a basis for embryo selection by preimplantation chromosomal structural genetic testing.

Stabilization of AlH3 Crystals by the Coating of Hydrophobic PFPE and Resulted Reactivity with Ammonium Perchlorate.

Aluminum hydride (AlH3) is a promising fuel component of solid propellant, but its stabilization is still challenging. Herein, surface functionalization of hydrophobic perfluoropolyether (PFPE) followed by ammonium perchlorate (AP) coating has been implemented. In particular, AlH3@PFPE@xAP (x = 10, 30, 50, or 64.21%) composites (AHFPs) were prepared by a spray-drying technique. The PFPE-functionalized AlH3 with a hydrophobic surface shows an increased water contact angle (WCA) from 51.87° to 113.54°. Compared with pure AlH3, the initial decomposition temperatures of AHFPs were increased by 17 °C, and the decomposition properties of AP in the AHFPs were also enhanced with significantly decreased peak temperature and fairly increased energy output. Moreover, the decomposition induction time of AHFPs-30% was improved by almost 1.82 times that of raw AlH3, which indicates that the coatings of PFPE and AP could improve the stability of AlH3. The maximum flame radiation intensity of AHFPs-30% was 21.6 × 103, which is almost 7.71 times that of pure AlH3 (2.8 × 103).

Unwitting Agents: Representations of Chinese International Students in US-China Geopolitics.

As part of a larger study, this paper presents findings from my exploration of discourses about China-US geopolitics through popular discussions on Chinese international students (CIS) who are attending American universities during the ongoing global COVID-19 pandemic. The study seeks to advance scholarship for international students attending American colleges, with particular implications for Chinese students, as agents of geopolitical relations. In doing so, it investigates (a) how these students are represented in American media and (b) the criticality of international geopolitics in the mobility of international students. The findings reveal that American popular media sources assume a tone when writing about CIS that may stem from a deeper anti-Chinese sentiment that exists in the US. They also suggest that American institutions of higher education, and American companies that employ CIS after graduation, treat these students as imported subjects/objects that support America's intellectual and economic advancement. In doing so, the media perpetuates narratives of geopolitical tensions between the United States and China, while representing CIS as unwitting agents of those tensions. The study seeks to advance scholarship on international students attending US colleges, particularly those from China, during an era of rising populism and right-wing movements in the US coupled with rapidly deteriorating US-China relations. Supplementary Information: The online version contains supplementary material available at 10.1007/s12140-023-09409-5.

Effects of group mindfulness-based cognitive therapy and group cognitive behavioural therapy on symptomatic generalized anxiety disorder: a randomized controlled noninferiority trial.

BACKGROUND: Mindfulness-based cognitive therapy (MBCT) is a promising alternative treatment for generalized anxiety disorder (GAD). The objective of this study was to examine whether the efficacy of group MBCT adapted for treating GAD (MBCT-A) was noninferior to group cognitive behavioural therapy (CBT) designed to treat GAD (CBT-A), which was considered one of first-line treatments for GAD patients. We also explored the efficacy of MBCT-A in symptomatic GAD patients compared with CBT-A for a variety of outcomes of anxiety symptoms, as well as depressive symptoms, overall illness severity, quality of life and mindfulness. METHODS: This was a randomized, controlled, noninferiority trial with two arms involving symptomatic GAD patients. Adult patients with GAD (n = 138) were randomized to MBCT-A or CBT-A in addition to treatment as usual (TAU). The primary outcome was the anxiety response rate assessed at 8 weeks after treatment as measured using the Hamilton Anxiety Scale (HAMA). Secondary outcomes included anxiety remission rates, scores on the HAMA, the state-trait anxiety inventory (STAI), the Hamilton Depression Scale (HAMD), the Severity Subscale of the Clinical Global Impression Scale (CGI-S), and the 12-item Short-Form Health Survey (SF-12), as well as mindfulness, which was measured by the Five Facet Mindfulness Questionnaire (FFMQ). Assessments were performed at baseline, 8 weeks after treatment, and 3 months after treatment. Both intention-to-treat (ITT) and per-protocol (PP) analyses were performed for primary analyses. The χ2 test and separate two-way mixed ANOVAs were used for the secondary analyses. RESULTS: ITT and PP analyses showed noninferiority of MBCT-A compared with CBT-A for response rate [ITT rate difference = 7.25% (95% CI: -8.16, 22.65); PP rate difference = 5.85% (95% CI: - 7.83, 19.53)]. The anxiety remission rate, overall illness severity and mindfulness were significantly different between the two groups at 8 weeks. There were no significant differences between the two groups at the 3-month follow-up. No severe adverse events were identified. CONCLUSIONS: Our data indicate that MBCT-A was noninferior to CBT-A in reducing anxiety symptoms in GAD patients. Both interventions appeared to be effective for long-term benefits. TRIAL REGISTRATION: Registered at chictr.org.cn (registration number: ChiCTR1800019150 , registration date: 27/10/2018).

Revealing the Heavy Quasiparticles in the Heavy-Fermion Superconductor CeCu_{2}Si_{2}.

The superconducting order parameter of the first heavy-fermion superconductor CeCu_{2}Si_{2} is currently under debate. A key ingredient to understand its superconductivity and physical properties is the quasiparticle dispersion and Fermi surface, which remains elusive experimentally. Here, we present measurements from angle-resolved photoemission spectroscopy. Our results emphasize the key role played by the Ce 4f electrons for the low-temperature Fermi surface, highlighting a band-dependent conduction-f electron hybridization. In particular, we find a very heavy quasi-two-dimensional electron band near the bulk X point and moderately heavy three-dimensional hole pockets near the Z point. Comparison with theoretical calculations reveals the strong local correlation in this compound, calling for further theoretical studies. Our results provide the electronic basis to understand the heavy-fermion behavior and superconductivity; implications for the enigmatic superconductivity of this compound are also discussed.

Fully gapped d-wave superconductivity in CeCu2Si2.

The nature of the pairing symmetry of the first heavy fermion superconductor CeCu2Si2 has recently become the subject of controversy. While CeCu2Si2 was generally believed to be a d-wave superconductor, recent low-temperature specific heat measurements showed evidence for fully gapped superconductivity, contrary to the nodal behavior inferred from earlier results. Here, we report London penetration depth measurements, which also reveal fully gapped behavior at very low temperatures. To explain these seemingly conflicting results, we propose a fully gapped [Formula: see text] band-mixing pairing state for CeCu2Si2, which yields very good fits to both the superfluid density and specific heat, as well as accounting for a sign change of the superconducting order parameter, as previously concluded from inelastic neutron scattering results.

Long-term follow-up of HCV patients with sustained virological response after treatment with pegylated interferon plus ribavirin.

BACKGROUND: The progress of liver diseases may not stop after viral eradication. This study aimed to provide data on long-term prognosis of patients with hepatitis C virus (HCV) infection who underwent pegylated interferon plus ribavirin (PR) regimen and achieved a sustained virological response 24 weeks post-treatment (SVR24). METHODS: Responders to the PR regimen in our hospital from January 2011 to June 2014 were enrolled and prospectively followed up. Baseline characteristics were profiled. The incidence of hepatocellular carcinoma (HCC), progression of liver disease (increase in liver stiffness or occurrence of decompensated complication), and HCV recurrence was all monitored. The accumulative and annualized incidence rates (AIRs) of these adverse events were analyzed, and the risk factors were also examined. RESULTS: In total, 151 patients reached a median follow-up time of 103 weeks. Among them, two had an incidence of HCC during the surveillance with AIR of 0.68% (95% CI: 0.00-1.63%). Six patients showed progression of liver disease with AIR of 2.05% (95% CI: 0.42%-3.68%). Three patients who had risky behaviors encountered HCV reinfection. The cirrhotic patients faced higher risk of poor prognosis than non-cirrhotic patients, including HCC and progression of liver disease (AIR: 6.17% vs. 1.42%, P = 0.039). CONCLUSIONS: The incidence of HCC and progression of liver disease was evident in PR responders during the long-term follow-up period, but the risk level was low. Cirrhotic responders were more vulnerable to develop HCC post SVR24 compared with non-cirrhotic ones. HCV recurrence was rare in responders with SVR24 who had corrected their risky behaviors.

An Outline of Multi-Sensor Fusion Methods for Mobile Agents Indoor Navigation.

Indoor autonomous navigation refers to the perception and exploration abilities of mobile agents in unknown indoor environments with the help of various sensors. It is the basic and one of the most important functions of mobile agents. In spite of the high performance of the single-sensor navigation method, multi-sensor fusion methods still potentially improve the perception and navigation abilities of mobile agents. This work summarizes the multi-sensor fusion methods for mobile agents' navigation by: (1) analyzing and comparing the advantages and disadvantages of a single sensor in the task of navigation; (2) introducing the mainstream technologies of multi-sensor fusion methods, including various combinations of sensors and several widely recognized multi-modal sensor datasets. Finally, we discuss the possible technique trends of multi-sensor fusion methods, especially its technique challenges in practical navigation environments.

Real-Time 3D Reconstruction Method Based on Monocular Vision.

Real-time 3D reconstruction is one of the current popular research directions of computer vision, and it has become the core technology in the fields of virtual reality, industrialized automatic systems, and mobile robot path planning. Currently, there are three main problems in the real-time 3D reconstruction field. Firstly, it is expensive. It requires more varied sensors, so it is less convenient. Secondly, the reconstruction speed is slow, and the 3D model cannot be established accurately in real time. Thirdly, the reconstruction error is large, which cannot meet the requirements of scenes with accuracy. For this reason, we propose a real-time 3D reconstruction method based on monocular vision in this paper. Firstly, a single RGB-D camera is used to collect visual information in real time, and the YOLACT++ network is used to identify and segment the visual information to extract part of the important visual information. Secondly, we combine the three stages of depth recovery, depth optimization, and deep fusion to propose a three-dimensional position estimation method based on deep learning for joint coding of visual information. It can reduce the depth error caused by the depth measurement process, and the accurate 3D point values of the segmented image can be obtained directly. Finally, we propose a method based on the limited outlier adjustment of the cluster center distance to optimize the three-dimensional point values obtained above. It improves the real-time reconstruction accuracy and obtains the three-dimensional model of the object in real time. Experimental results show that this method only needs a single RGB-D camera, which is not only low cost and convenient to use, but also significantly improves the speed and accuracy of 3D reconstruction.

Depressive Symptoms in Elderly Chinese Primary Care Patients: Prevalence and Sociodemographic and Clinical Correlates.

OBJECTIVE: To estimate the prevalence of depressive symptoms (depression thereafter) and to identify the sociodemographic and clinical correlates of depression in a sample of elderly patients treated in the primary care setting in Wuhan, China. BACKGROUND: Primary care is an opportune setting for the management of late-life depression in China, but there have been no representative studies on the clinical epidemiology of depression in elderly Chinese primary care patients. METHODS: In total, 752 elderly patients (≥ 65 years) were consecutively recruited from 13 primary care centers in Wuhan, China, and interviewed with a standardized questionnaire. Depression was assessed with the 15-item Geriatric Depression Scale (GDS-15). RESULTS: Of the elderly Chinese primary care patients, 30.6% had depression (GDS-15 ≥ 5). Correlates of depression were an education level of primary school or less (odds ratio [OR]: 1.94, 95% confidence interval [CI]: 1.36-2.77, P < .001), poor financial status (OR: 2.19, 95% CI: 1.16-4.15, P = .016), lack of an exercise habit (OR: 1.40, 95% CI: 1.06-1.74, P = .023), 2 or more chronic medical conditions (OR: 1.90, 95% CI: 1.34-2.69, P < .001), and loneliness (OR: 3.53, 95% CI: 2.46-5.08, P < .001). CONCLUSIONS: Depression is prevalent among elderly Chinese primary care patients, indicating that elderly patients treated in primary care have a high level of need for mental health services in China. There is an urgent need to integrate mental health services into primary health care.

Improved Convolutional Pose Machines for Human Pose Estimation Using Image Sensor Data.

In recent years, increasing human data comes from image sensors. In this paper, a novel approach combining convolutional pose machines (CPMs) with GoogLeNet is proposed for human pose estimation using image sensor data. The first stage of the CPMs directly generates a response map of each human skeleton's key points from images, in which we introduce some layers from the GoogLeNet. On the one hand, the improved model uses deeper network layers and more complex network structures to enhance the ability of low level feature extraction. On the other hand, the improved model applies a fine-tuning strategy, which benefits the estimation accuracy. Moreover, we introduce the inception structure to greatly reduce parameters of the model, which reduces the convergence time significantly. Extensive experiments on several datasets show that the improved model outperforms most mainstream models in accuracy and training time. The prediction efficiency of the improved model is improved by 1.023 times compared with the CPMs. At the same time, the training time of the improved model is reduced 3.414 times. This paper presents a new idea for future research.

Impact of cardiovascular disease deaths on life expectancy in Chinese population.

OBJECTIVE: We aimed to analyze the impact of cardiovascular disease (CVD) deaths on life expectancy (LE) in Chinese population and estimate the percentage reduction in CVD mortality needed to increase LE by 1 year from the current level, a national target of health improvement. METHODS: We used life tables, cause-elimination life tables, and age decomposition of LE with corrected mortality data from the National Disease Surveillance System in 2010. RESULTS: LE at birth of Chinese people was 73.24 years in 2010. Women had a longer LE than men, and urban population had a longer LE than rural population. CVD deaths resulted in a 4.79-year LE loss and premature deaths in people aged 25 to 64 years were responsible for a substantial part of LE loss from CVD. Death from ischemic heart disease and cerebrovascular diseases accounted for 69.2% of LE loss from CVD deaths and death from cerebrovascular diseases was the largest contributor. In rural men, 51.1% LE loss from CVD deaths was caused by cerebrovascular diseases. If there were no changes in mortality rates for all other diseases, a 27.4% reduction in CVD mortality would increase LE by 1 year in Chinese population. CONCLUSION: There is a considerable impact of CVD deaths on LE. A 1-year LE increase in the future requires at least a 27.4% reduction in CVD mortality from the current level. Targeting the rural population and tackling cerebrovascular diseases are important for reaching the national goal of health improvement.

Impact of cerebrovascular disease mortality on life expectancy in China.

OBJECTIVE: To evaluate the impact of cerebrovascular disease mortality on life expectancy (LE) in China in 2010 compared with 2005, and to identify the high-risk population (age, sex, and region) where cerebrovascular disease mortality has had a major impact on LE. METHODS: LE and cause-eliminated LE were calculated by using standard life tables which used adjusted mortality data from the Death Surveillance Data Sets in 2005 and 2010 from the National Disease Surveillance System. Decomposition was used to quantitate the impact of cerebrovascular disease in different age groups. RESULTS: LE in China was 73.24 years in 2010, which was higher in women and urban residents compared with men and rural residents. The loss of LE caused by cerebrovascular disease mortality was 2.26 years, which was higher in men and rural residents compared with women and urban residents. More than 30% of the loss of LE were attributed to premature death from cerebrovascular disease in people aged <65 years. Compared with 2005, LE in 2010 increased by 0.92 years. The reduction of cerebrovascular disease mortality in urban residents contributed 0.45 years to the increase of LE, but the increase of cerebrovascular disease mortality caused a 0.12-year loss of LE in rural residents. CONCLUSION: Cerebrovascular disease mortality had a major impact on LE in China, with a significant difference between urban and rural residents. LE is likely to be further increased by reducing cerebrovascular disease mortality, and special attention should be paid to reducing premature deaths in people aged <65 years.

Effect of Postoperative Prolonged sedation with Dexmedetomidine after successful reperfusion with Endovascular Thrombectomy on long-term prognosis in patients with acute ischemic stroke (PPDET): study protocol for a randomized controlled trial.

BACKGROUND: Endovascular thrombectomy (EVT) is a standard treatment for acute ischemic stroke (AIS) with large vessel occlusion. Hypertension and increased blood pressure variability within the first 24 h after successful reperfusion are related to a higher risk of symptomatic intracerebral hemorrhage and higher mortality. AIS patients might suffer from ischemia-reperfusion injury following reperfusion, especially within 24 h. Dexmedetomidine (DEX), a sedative commonly used in EVT, can stabilize hemodynamics by inhibiting the sympathetic nervous system and alleviate ischemia-reperfusion injury through anti-inflammatory and antioxidative properties. Postoperative prolonged sedation for 24 h with DEX might be a potential pharmacological approach to improve long-term prognosis after EVT. METHODS: This single-center, open-label, prospective, randomized controlled trial will include 368 patients. The ethics committee has approved the protocol. After successful reperfusion (modified thrombolysis in cerebral infarction scores 2b-3, indicating reperfusion of at least 50% of the affected vascular territory), participants are randomly assigned to the intervention or control group. In the intervention group, participants will receive 0.1~1.0 µg/kg/h DEX for 24 h. In the control group, participants will receive an equal dose of saline for 24 h. The primary outcome is the functional outcome at 90 days, measured with the categorical scale of the modified Rankin Scale, ranging from 0 (no symptoms) to 6 (death). The secondary outcome includes (1) the changes in stroke severity between admission and 24 h and 7 days after EVT, measured by the National Institute of Health Stroke Scale (ranging from 0 to 42, with higher scores indicating greater severity); (2) the changes in ischemic penumbra volume/infarct volume between admission and 7 days after EVT, measured by neuroimaging scan; (3) the length of ICU/hospital stay; and (4) adverse events and the all-cause mortality rate at 90 days. DISCUSSION: This randomized clinical trial is expected to verify the hypothesis that postoperative prolonged sedation with DEX after successful reperfusion may promote the long-term prognosis of patients with AIS and may reduce the related socio-economic burden. TRIAL REGISTRATION: ClinicalTrials.gov NCT04916197. Prospectively registered on 7 June 2021.

Brain microglia were activated in sporadic CJD but almost unchanged in fatal familial insomnia and G114V genetic CJD.

BACKGROUND: Microglial activations have been described in different subtypes of human prion diseases such as sporadic Creutzfeldt-Jakob disease (CJD), variant CJD, Kuru and Gerstmann-Sträussler-Scheinker disease (GSS). However, the situation of microglia in other genetic prion diseases such as fatal familial insomnia (FFI) and familial CJD remains less understood. The brain microglia was evaluated comparatively between the FFI, G114V and sCJD cases in the study. METHODS: Specific Western blots, immunohistochemical and immunofluorescent assays were used to detect the changes of microglia and ELISA tests were used for levels of inflammatory cytokines. RESULTS: Western blots, immunohistochemical and immunofluorescent assays illustrated almost unchanged microglia in the temporal lobes of FFI and G114V gCJD, but obviously increased in those of sCJD. The Iba1-levels maintained comparable in six different brain regions of FFI and G114V cases, including thalamus, cingulate gyrus, frontal cortex, parietal cortex, occipital cortex and temporal cortex. ELISA tests for inflammatory cytokines revealed significantly up-regulated IL-1ß, IL-6 and TNF-α in the brain homogenates from sCJD, but not in those from FFI and G114V gCJD. CONCLUSION: Data here demonstrates silent brain microglia in FFI and G114V gCJD but obviously increased in sCJD, which reflects various pathogenesis of different human prion diseases subtypes.

[An evaluation of the impact of cerebrovascular disease deaths on life expectancy in China].

OBJECTIVE: To evaluate the impact of cerebrovascular death on the life expectancy of Chinese residents in recent years and explore the difference in the subgroups. METHODS: Life expectancy and cause-elimination life expectancy were calculated by standard life table techniques using the adjusted mortality data from the Death Surveillance Data Sets in 2005 and 2010 provided by the National Disease Surveillance System. Decomposition method was used to quantitatively evaluate the impact of cerebrovascular disease. RESULTS: The life expectancy of Chinese residents was 73.23 years old in 2010. The loss of life expectancy caused by cerebrovascular death was 2.26 years in 2010, with about 97% of that came from the elimination of deaths in the residents aged over 40 years old. Compared with 2005, the reduction of cerebrovascular deaths contributed to a total of 0.04 years increase in the life expectancy of Chinese residents in 2010, with 0.45 years for urban residents. However, for the rural residents, cerebrovascular death increased and caused 0.12 years decrease of life expectancy. CONCLUSIONS: The impact of cerebrovascular death on the life expectancy of Chinese residents is still great. Significant difference is showed between the urban and rural areas with reduction in the urban but increase in the rural. The life expectancy is likely to be further increased by reducing cerebrovascular death in the Chinese residents aged over 40 years old.

[Distribution Characteristics, Source Analysis and Potential Ecological Risk Assessment of Soil Heavy Metals in Typical River Source Areas of Northeastern Hunan Province].

Soil environmental quality in water source areas related to the residents' life, health and safety, has been the hotspot issues in science of ecological environment protection. A total of 87 surface soil samples were collected from typical river source areas in northeastern Hunan Province, using GIS technique and potential ecological risk assessment index to study the spatial distribution characteristics and Potential ecological risk of soil heavy metals (Cd, Pb, Cr, Hg and As), and the means of multivariate statistical analysis and positive definite matrix factor analysis models (PMF) were used to explain the possible sources and its contribution rates of heavy metals. The results show that:① The soil located in the typical river source area of northeastern Hunan Province was acidic, and the meant of ω(Cd), ω(Pb), ω(Cr), ω(Hg), and ω(As) in soil was 0.20, 41.07, 130.51, 0.29, and 11.63mg·kg-1, respectively. And except As, all of them had enrichment tendency. ② The comprehensive potential ecological risk of soil heavy metals was at a medium level, among which Cr, Pb and As were at a slight level of potential ecological risk, and Cd and Hg all reached a strong level of risk. ③ Cd and Pb of soil had significant homology, which were derived from agricultural activity, Cr and As of soil were affected by both domestic waste discharge and natural parent material, and Hg of soil was mainly derived from fossil combustion and transportation. ④ There were four pollution sources which included household waste discharge source, natural parent material source, Fossil burning and transportation sources, as well as sources of agricultural activities in typical river source area in northeastern Hunan Province, which contributed the rates of heavy metals were 21.36%, 35.92%, 19.30% and 23.42%, respectively, and the contribution rate of man-made sources was higher than that of natural sources. To sum up, this study has reference value for pollution prevention, ecological restoration and beautiful village construction in river source area of northeastern Hunan Province.

High-Energy Composite Fuels with Improved Combustion Efficiency by Using AlH3 Embedded with Al Particles.

Aluminum hydride (AlH3) has attracted much attention due to its potential to replace aluminum (Al) as a novel energetic material in solid propellants. In this research, ammonium perchlorate (AP) and perfluoropolyether (PFPE) as functionalized coatings and a combination of acoustic resonance and spray drying technology have been employed to prepare AlH3@Al@AP (AHAPs) and AlH3@Al@AP@PFPE (AHAPs-F) energetic composite particles. The formulations of composite propellants and modified AlH3 particles were designed and fabricated. Their thermal reactivity, reaction heat, density, vacuum stability, combustion performance, and condensed combustion products (CCPs) have been systematically investigated. The results show that the solid propellants containing AHAPs (SP13) and AHAPs-F (SP14) composites can significantly enhance the reactivity and energy output compared to conventional solid propellants with the mechanical mixture Al/AlH3 (SP12). In particular, the total heat releases of SP13 and SP14 are almost 1.2 and 1.7 times higher than those of conventional ones (SP12, 1442 J g-1), respectively. Among the AlH3-based propellants, SP14 propellants exhibit the highest reaction heat of 5887 J g-1, the most intensive flame radiation of 31.4 × 103, and the highest combustion wave temperature of 2495 °C. Moreover, the particle size distribution of CCPs from SP14 propellants is much narrower and smaller than that of SP12, resulting in higher combustion efficiency.