Search

Uranium-bearing particle analysis is an important technology in the field of nuclear safeguards. In uranium-related nuclear activities, especially in the processes of uranium enrichment, uranium-bearing aerosols are unavoidable released into the environment. There are significant differences between the uranium particles formed by uranium-bearing aerosols after drying and that from nature in terms of isotopic ratio, elemental composition, and impurity composition. Therefore, we can provide a judgment basis for the monitoring of nuclear facilities and activities by analyzing the characteristic information of micrometer or submicron sized uranium-bearing particle. After nearly 30 years of development, some relatively mature methods for the analysis of uranium-bearing particles have been developed. In this review, the process of particle analysis including sample collection, preliminary screen, particle recovery, identification and localization, and measurement is briefly introduced. The advantages and disadvantages of the commonly used technical in each process are compared. At the same time, according to the different purposes of analysis, uranium-bearing particle analysis is divided into three research directions: uranium isotope analysis, morphology and elemental composition analysis, and age-dating. Recent progress of each direction is discussed. Finally, based on the progress of the research, combined with the Development and Implementation Support Program for Nuclear Verification of the IAEA, the future research direction of uranium-bearing particle analysis technology is prospected.

Objective In order to facilitate the digital transformation and high-quality development of Shanghai rail transit, it is imperative to construct a digital twin model and create a unified, authoritative, and precise spatial database, providing spatial data service capabilities for application scenarios involving spatial geography such as line network planning, construction, operation and maintenance, and management. Method Combined actual scenes and stock data, a variety of technologies such as 3D laser point cloud, satellite remote sensing and drones are used for 3D reconstruction to generate a spatial digital base model. Urban rail transit thematic spatial data is collected using handheld 3D laser scanners, and the collected point cloud data model is monomerized. Utilizing GIS (geographic information system) technology, the urban rail transit real-world 3D model, planning and control data, and various spatial basic geographic data are integrated into a visualization platform to establish a ′full-space, full-period, and full-factor′ spatial digital base. Taking Shanghai Rail Transit Jiuting Station as example, the layered floor plans and a 3D real-world model of the station are created, and the model files are linked with various attribute information before being integrated inro the urban rail transit line spatial digital base. Result & Conclusion The urban rail transit line spatial digital base, combined with spatial basic geographic data, can provide unified spatial geographic services for the ′planning-design-management-operation′ of the network. Integrating 3D real-world models of stations and information on land acquisition ranges under construction into the spatial digital base could facilitate the daily management of urban rail transit real estate and fixed assets, providing authoritative, accurate and intuitive decision-making basis for the daily operation and management of urban rail transit.

Neutron-induced single event effects have potential influence on the reliability of electronic devices in aircraft and ground-based nuclear facilities. The white neutron source, generated by heavy metal target bombardment from proton accelerators, is an important tool for studying these effects. Neutron irradiation experiments can provide valuable information such as cross section or threshold for neutron single event effects, allowing prediction of device failure rates in neutron irradiation environments and providing data to support electronic device radiation hardening. Protons from the CYCIAE-100, a 100 MeV proton cyclotron accelerator in China Institute of Atomic Energy, bombard a tungsten target and undergo a scattering reaction, producing white neutrons. Based on nuclear reaction theory and Monte Carlo method, the yield, spectrum, and angular distribution of neutrons produced from the interaction between 100 MeV protons and a tungsten target were simulated. The results show that each 100 MeV proton can produce 0.33 neutrons on average. The neutron energy range is 0-100 MeV, the neutron fluence initially rises and then declines as the energy increases, with the peak occurring near 1 MeV. The angular distribution of the neutrons along the direction of the proton beam is observed to be axisymmetric, and as the emission angle increases, the neutron fluence first decreases and then increases, with the lowest neutron fluence occurring at 90°. The neutron beam in the emission direction of 0° is selected to carry out the single event effect experiment. The energy spectrum of white neutrons is measured by the neutron time-of-flight method based on two liquid scintillation detectors. The neutron energy spectrum is obtained in the range of 3-100 MeV, and when the proton beam is 100 MeV/1 μA, the neutron flux is 3.3×104 cm-2·s-1 at the distance of 15 m from the W target, which meets the requirements of neutron single event effect experiments. Due to the fact that the neutron energy of CYCIAE-100 white neutron source is limited to a maximum of 100 MeV, a direct simulation of the atmospheric neutron energy spectrum is unattainable. Also, disparities exist between the energy spectrum of this neutron source and that of the neutron radiation environment in nuclear industry. Therefore, it is necessary to consider the single event effect response of the device under irradiation with different energies neutron and to explore the development of an accurate approach for experimental evaluation of neutron single event effects.

Objective To study the platelet transfusion predictive models in tumor patients and evaluate its application effect. Methods A retrospective study was conducted on 944 tumor patients, including 533 males and 411 females who received platelet transfusion in the Affiliated Hospital of Traditional Chinese Medicine of Xinjiang Medical University, the Affiliated Cancer Hospital of Xinjiang Medical University and Kailuan General Hospital from August 2022 to January 2023. Multivariate Logistic regression analysis was used to establish the platelet transfusion predictive models, and Medcalc15.8 software was used to draw the receiver operating curve (ROC) to evaluate the application effect of the prediction model. The actual application effect of models was verified through 162 female clinical cases and 172 male clinical cases. Results The incidence of platelet transfusion refractoriness in tumor patients was 28.9% (273/944), with 33.2% (177/533) in males, significantly higher than that in females [23.4% (96/411)] (P

Background The worldwide COVID-19 pandemic has turned into a global catastrophic public health crisis, and the conclusion about the risk factors of hospital death in COVID-19 patients is not uniform. Objective To explore risk factors of in-hospital death in patients with COVID-19 by a meta-analysis. Methods Case-control studies about risk factors of in-hospital death in COVID-19 patients were searched from databases of the Cochrane Library, ScienceDirect, PubMed, Medline, Wanfang Data, CNKI and CQVIP from inception to October 1, 2021. Literature screening, data extraction and methodological quality assessment were conducted. Meta-analysis was performed using Stata 15.1. Meta-regression was used to explore the potential sources of heterogeneity. Results Eighty studies were included which involving 405 157 cases〔349 923 were survivors (86.37%) , and 55 234 deaths (13.63%) 〕, that were rated as being of high quality by the Newcastle-Ottawa Scale. Meta-analysis showed that being male〔OR=1.49, 95%CI (1.41, 1.57) , P

Recently, the hulless barley has drawn wide attention due to its abundant nutritional composition and unique biological activities. Resistant starch, lunasin polypeptide, unique fatty acid and non-starch polysaccharide composition and rich phenolic substances make hulless barley have good development potential in anti-cancer, hypoglycemic, hypolipidemic and other aspects. However, the low degree of processing and utilization and the rare of high value-added products hinder the development of the hulless barley industry. The components, biological activities, processing and utilization technology and high-value products of hulless barley are summarized in this paper to provide support for promoting the research and sustainable industry development of hulless barley.

Coarse grain is an important part of dietary structure, but the poor palatability and processing characteristics restrict the further development of coarse grain industry. After germination, its nutrients and functional active components are enhanced, and its taste and processing characteristics are changed. It is a new food raw material with great development potential. Different kinds of coarse grain sprouts provide consumers with diversified choices, but their nutritional function differences are lack of systematic analysis. This paper compares the contents of nutritional components and functional components of different kinds of coarse grain sprouts, expounds the lipid-lowering, hypoglycemic and anti-inflammatory effects of coarse grain sprouts and their products, and expoundes the production technology and quality improvement methods of coarse grain sprouts, so as to provide reference and ideas for improving people's dietary structure and the further development and utilization of coarse grain sprouts.

A new type of oat yogurt was developed with oat milk and reconstituted milk as raw materials and commercial yogurt fermentation strains as starter. Sensory score and acidity were served as indexes, the effects of oat milk and reconstituted milk ratio, amount of fermentation strains, fermentation time, and fermentation temperature on the quality of oat yogurt were studied by single factor experiment. Based on the results of single factor experiment, the optimal fermentation process of oat yogurt was determined by orthogonal test. The basic physical and chemical indexes of oat yogurt including protein, fat, amino acid, acidity, pH were analyzed. The antioxidant activity of oat yogurt was evaluated by ABTS and DPPH methods, and the flavor compounds in oat yogurt were determined by GC-MS. The results showed that the optimal fermentation process of oat yogurt was as follows: Oat milk/reconstituted milk was 2:1, the inoculation amount of fermentation bacteria was 0.2%, the fermentation time was 9 hours, and the fermentation temperature was 34 ℃. The oat yogurt produced by optimal fermentation process presented uniform creamy-white, moderate sour and sweet taste and rich in oat fragrance. Thirty-six aroma components of oat yogurt were detected by GC-MS, including esters, acids and aldehydes. Protein content of oat yogurt was close to commercial yogurt, but the fat content of oat yogurt was only 60% of commercial yogurt. In addition, the antioxidant activity and contents of glycine and arginine of oat yogurt were significantly higher than commercial yogurt (P

The Dafo Bay stone carvings in Baoding Mountain, Dazu District, Chongqing City, are suffering from serious capillary water damage, salt damage, biological and other derivative diseases caused by capillary water, which have brought a long-term negative effect on the protection of the world cultural heritage. Based on the field investigation of the Dafo Bay, the strata of the statuary cliff are divided into three sets: the upper sandstone of the reclining Buddha, the sandstone of the reclining Buddha and the lower sandstone of the reclining Buddha. Through a series of tests and experimental studies, the characteristics of sandstone in the Baoding Mountain area and the influence of temperature and humidity on capillary water are analyzed.The testing items include thin section identification, X-ray diffraction, chemical composition test, scanning electron microscopy, mercury injection test, Karsten tube penetration test, etc.The research results indicated that: compared with the upper and lower layers of the reclining Buddha sandstone, the Reclining Buddha body sandstone has the lowest maturity and the largest porosity and pore distribution range, which provides relatively good conditions for the migration of capillary water. The capillary water absorbability and capillary water elevation of the reclining Buddha body sandstone are the best, and the rise of capillary wateris closely related to the ambient temperature, relative humidity, and air circulation. In the tight sandstone of the Dazu Stone Carvings, a large number of interconnected micropores cannot play a role in the migration of capillary water. The effective pore diameter for capillary water migration in the reclining Buddha sandstone should be above 1 133.0 nm, and may reach 760.2 nm in extreme cases.The research results provide reliable data for an accurate understanding of the formation and evolution of capillary water in Dazu Stone Carvings, explain the formation mechanism of salt damage in Dazu Stone Carvings in winter, and provide a theoretical basis for managing capillary water in Dazu Stone Carvings.

Forced regression is common during geological history, but due to mismatched sources andsupplies, there are fewer geological records and fewer research cases. Taking the 4th member of Weizhouformation in the Early Oligocene of Weixi'nan Sag in the Beibu Gulf Basin in the northwest of the South China Sea as the research object, the restoration of paleo-water-depth is carried out by using the seismic reflectionstructure method, the variation characteristics of paleowater depth under the background of forcedregression are clarified, and the restoration method of paleowater depth by using the delta progradationstructure method is further discussed. The research shows that during the deposition of 4th member of Weizhou Formation in the Early Oligocene, the provenance of Weixi'nan Sag was sufficient, a large incisedvalley was developed around it, and a large oblique progradation reflection structure was developed in thesag, which has typical Forced Regression characteristics, forming a large-scale forced regression systemtract. Through the fine dissection of typical progradation sections, six typical progradation reflection layersare identified. Combined with seismic, drilling and compaction coefficient, the paleo-water-depth of thelake basin is restored to be 111.2-286.5 m, with an average of 218.5 m. From the edge of the paleo-laketo the center, the height and dip angle of the progradation layers increase slowly and then decrease rapidly.In terms of water depth, it is about 230 m in the early stage, gradually deepened to about 280 m in themiddle and late stage, and rapidly decreased to 110 m in the last stage, with a change range of 61.5% comparedwith the maximum water depth; The dip angle of progradation layer is about 10° in the early stage, gradually decreases after reaching 14.5° in the middle stage, and changes rapidly to 2.9° in the final stage, with a change range of 79.8%. Combined with the regional geological research, it is considered that thegeological period experienced during the deposition of 4th member of Weizhou Formation is less than 2 Ma, and the paleowater depth and paleodip angle of progradation layers change rapidly and violently in lessthan 2 Ma, which is basically consistent with the characteristics of forced regression, which confirms theresponse characteristics of seismic reflection structure. Further, the feasibility and future research directionof paleo-water-depth restoration using delta progradation structure are discussed from the perspectiveof theoretical model simplification and restoration parameter optimization. The research results provide animportant reference for enriching the understanding of the variation characteristics of paleowater depth underthe background of forced regression.

The reliability of the planetary cycloidal reducer directly affects the overall performance and service life of industrial robots，among which the reliability of two-stage drive subcomponents has an important influence on the reliability of the whole planetary cycloidal reducer. Taking a heavy-duty planetary cycloidal reducer as the research object，the reliability mathematical model of each subcomponent is constructed based on the force analysis of two-stage transmission system subcomponents，and the reliability is correlated and coupled by Copula function to construct a system reliability model considering failure correlation； on this basis，a multi-objective optimization model with minimum volume and maximum reliability is constructed，and NSGA-Ⅱ（Non-dominated sorted genetic algorithm-Ⅱ） algorithm is used to solve the model，and it is compared and analyzed with the system reliability model considering the independence assumption. The results show that， after optimization，the volume of the reducer is reduced by 11.27%，and the reliability is improved by 5.29%，and the optimal design method considering failure correlation can effectively improve the reliability of the planetary cycloidal reducer with higher comprehensive performance.

The traditional air defense and anti-missile operation effectiveness evaluation is restricted to the physical dimension. Under the view of multi-dimensional battlespace, this paper establishes a multi-dimensional operation effectiveness evaluation model based on the four stages of perception, cognition, decision-making and action of joint air defense and anti-missile. The effectiveness of joint air defense and anti-missile operation is evaluated from two aspects: the elements and system of joint air defense and anti-missile operation, that is, the comprehensive evaluation is carried out through the six dimensional spatial elements of surface-to-air dimension, vertical dimension, network-electricity dimension, information system dimension, decision knowledge dimension and strategy decision dimension. According to the actual operational situation of the joint air defense and anti-missile operation, weights of three group indexes are established, and the overall effectiveness of the joint air defense and anti-missile operation is evaluated through grey correlation analysis, then the simulation experiments and countermeasures are analyzed.

To analyze samples without using standard, the energy dispersive X-ray fluorescence analysis (EDXRFA) of unknown samples was studied. The ratio R of coherent and incoherent scattering peaks of Kα in the original spectrum of target Rh was got through the measurement of Ti, Fe, Ni, Cu, Zn, Sr, Sn, Pb single element standard samples, then the relationship between R and the effective atomic number of the corresponding single element standard samples was established, and the fitting curve of Zeff-R was obtained. When it comes to solve the unknown samples, measure the unknown samples and get the R, then the effective atomic number of the unknown samples was obtained by substituting the R of unknown samples into the Zeff-R fitting curve, and then the atomic number could be used in the fundamental parameters method iteration to calculate its mass attenuation coefficient. The Ti, Fe, Ni, Cu, Zn, Sr, Sn, Pb single element standard samples were again used to calibrate the instrument and obtain Gi parameter which was applied in the fundamental parameters method iteration of the corresponding element when it comes to solve the unknown samples. In order to verify the reliability of the algorithm, the 15 national soil standard samples were analyzed through the algorithm of this article. The results showed that the calculated content of Ti, Fe, Ni, Cu, Zn were close to the standard content, and some low content element’s content errors were a little larger because of the scattering background and other factors. The results showed that this algorithm could be used in the situ energy dispersive X-ray fluorescence analysis.

Objective To investigate the clinical and EEG features of ischemic stroke patients with abnormal discharges. Methods Clinical data and 24-hour EEG monitoring of 162 ischemic stroke patients were analyzed retrospectively. One-year follow-up was carried out and post-ischemic epilepsy was diagnosed. Results Among 162 ischemic stroke patients, 24-hour EEG was abnormal in 87 cases (53.70%). According to the correspondence of site of infarcts and abnormal discharges, these 87 cases were classified into 2 groups: matched group (N = 24, 27.59%) and unmatched group (N = 63, 72.41%). There was no significant difference between 2 groups in terms of Oxfordshire Community Stroke Project (OCSP) and TOAST classification (P = 0.792, 0.111), while there was significant difference between 2 groups on the site of infarcts (P = 0.000). In matched group, the infarcts were mainly located in cortex (N = 23, 95.83%). However, in unmatched group, the infarcts were mainly located in cortex and basal ganglia (N = 27, 42.86%), or in basal ganglia only (N = 24, 38.10%). In matched group, 24-hour EEG showed slowing of background activities, and sharp waves and sharp and slow wave complex which were corresponding to the infarct sites. The abnormal discharges could only be recorded around the infarct unilaterally. In unmatched group, the epileptiform discharges were recorded in both contralateral and ipsilateral ischemic hemispheres, usually with widespread slow waves and asymmetric background. The infarcts were limited, but abnormal discharges were widespread. For example, the infarct was located in deep brain, while scalp abnormal discharges were recorded. Although there was no significant difference in terms of epilepsy incidence between 2 groups (P = 0.908), the types of epilepsy were statistically different between 2 groups (P = 0.000). In matched group, the main type was partial seizure. But in unmatched group, the main types of epilepsy were secondary generalized seizure and generalized seizure. Conclusions Infract site has an influence on the abnormal EEG pattern, and the unmatched location of ischemic region and abnormal EEG may be indicative for the seizure type of post-ischemic epilepsy. DOI: 10.3969/j.issn.1672-6731.2016.05.008

Objective To explore the techniques and curative effect of microsurgical procedures assisted by minimal exposure tubular retractor system (METRx) in the treatment of lumbar disc herniation (LDH). Methods A total of 51 LDH patients, including 24 patients with L4-5 herniation and 27 patients with L5-S1 herniation, underwent discectomy assisted by METRx system. The operation time, intraoperative blood loss, postoperative complications and hospital stay were recorded. Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI) were used to evaluate the degree of low back pain before operation, one week, 3 months after operation, and in the last follow-up. Lumbar MRI was used to evaluate the decompression of spinal canal. Results The success rate of operations in 51 cases was 98.04% (50/51). The average operation time was 125 min, the average intraoperative blood loss was 50 ml, the mean hospital stay was 5 d, all patients were followed up for 6-48 months (average 24 months). Compared with preoperation, both VAS and ODI scores decreased significantly one week after operation (P = 0.036, 0.029), 3 months after operation (P = 0.018, 0.023) and in the last follow-up (P = 0.007, 0.013). The improvement rate of ODI was 35.37% in the last follow-up. No infection, postoperative cerebrospinal fluid (CSF) fistula, neurological defects or incision infection was found. One patient presented acute abdominalgia on the 2nd day after operation, and was diagnosed as annexitis. One patient showed nerve root irritation symptoms after operation caused by thick nerve root during the surgery. They were cured after symptomatic treatment. Conclusions Microsurgical procedures for treating LDH assisted by METRx system can effectively relieve nerve root compression, protect the dural sac and nerve roots, and reduce surgical complications. DOI: 10.3969/j.issn.1672-6731.2016.04.008

Lung adenocarcinoma with micropapillary pattern (MPP) is a kind of rare high invasive malignant tumor, which has been noticed because of high mortality. In 2011, the new pathological classification of lung adenocarcinoma classify it as an independent pathological type, researches on the individual treatment of the disease had been gradually expanded. Recent studies have demonstrated that lung adenocarcinoma with MPP has obvious heterogeneities in metastasis mechanism, clinical pathology, imageology, therapeusis and prognosis. In this paper, we discuss the progress of metastasis mechanism and clinical relevance in lung adenocarcinoma with MPP.

According to the analysis of cerebrospnial fluid (CSF) cytological examination (by slide centrifugation) results of 15 940 central nervous system infectious cases, this cytologic examination method shows definite diagnostic values as follows: 1) better etiological diagnostic value for central nervous system infectious diseases, such as purulent, viral, tuberculous, fungus and parasitic encephalitis meningitis and meningoencephalitis; 2) better differential diagnostic value for acute infectious toxic encephalopathy, meningeal carcinomatosis and central nervous system non⁃infectious diseases such as tumorous, leukemic and hemorrhagic meningoencephalitis and encephalopathy; 3) better clinical value for severity monitoring and prognostic judgement of central nervous system infectious diseases.

doi: 10.3969/j.issn.1672-6731.2014.08.001

Objective To evaluate the correlation between asymptomatic intracranial arterial stenosis and extracranial carotid atherosclerosis in patients with Type 2 diabetes mellitus (DM). Methods Transcranial Doppler ultrasonography (TCD) and carotid ultrasonography were performed in 194 consecutive Type 2 DM patients who had no history of stroke to determine intracranial arterial stenosis and extracranial carotid atherosclerotic lesions. Extracranial carotid atherosclerotic lesions were divided into increased intima⁃media thickness (IMT), plaque and stenosis (≥ 50% stenosis or occlusion). The correlation between intracranial arterial stenosis and carotid atherosclerosis were assessed. Risk factors were also evaluated in the presence of intracranial arterial stenosis. Results Intracranial arterial stenosis (≥ 50% stenosis or occlusion) was found in 42 patients (21.65%). The middle cerebral artery (MCA) was involved in 30 patients (15.46%), which was the most affected intracranial artery. One hundred and twenty⁃three of 194 patients (63.40%) had extracranial carotid atherosclerosis. Age (t = ⁃ 3.054, P = 0.003), duration of DM (U = 2172.500, P = 0.002) and concomitant hypertension (χ2 = 9.986, P = 0.002) and carotid artery lesion (χ2 = 14.086, P = 0.000) in patients with intracranial arterial stenosis were significantly higher than those without intracranial arterial stenosis. The prevalence of intracranial arterial stenosis and middle cerebral artery (MCA) stenosis were correlated with the severity of carotid atherosclerosis (U = 1929.000, 1519.000, respectively; P = 0.000, for all). After adjustment for cerebrovascular risk factors, multivariate Logistic regression analysis showed that concomitant hypertension (OR = 2.849, 95% CI: 1.247-6.508; P = 0.013) and carotid artery lesion (OR = 4.838, 95% CI: 1.778-13.167; P = 0.002） were significant independent risk factors associated with asymptomatic intracranial arterial stenosis in Type 2 DM patients. Conclusion Asymptomatic intracranial arterial stenosis is correlated with carotid atherosclerosis in Type 2 DM patients, and extracranial carotid atherosclerosis may be an independent predictive factor for asymptomatic intracranial arterial stenosis in Chinese patients with Type 2 DM. DOI：10.3969/j.issn.1672-6731.2010.03.016

DOI：10.3969/j.issn.1672-6731.2011.05.001