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Uranium content measurement is very important to nuclear material accounting and product quality control in nuclear bulk facilities. It needs high accuracy and precision. In this work, 3 different measurement steps from 2 analytical standards GB 11841—1989 and ASTM C1267-17, which were uranium content test methods by iron(Ⅱ) reduction followed by chromium(Ⅵ) titration, were discussed by simulated experiments and following uncertainty evaluation. The results show that, the total uncertainties of the 3 steps are all lower than 0.1%, which is the international target value of uranium content measurement by redox potential titration method. The step for 2.3 g sample of GB 11841—1989 is more suitable to sign value measurement in reference material production, because of its lowest uncertainty. In routine testing works, the step for 0.20-0.25 g sample of GB 11841—1989 is better in sample weighting, the step of ASTM C1267-17 is better in titration and potassium dichromate solution preparation.

The aims of this study were to understand the status quo of authors, collaborations between institutions, research hotspots, and research frontiers of fund-sponsored clinical nursing papers and to provide a reference for Chinese scholars to conduct clinical nursing studies in the future.

A novel lanthanum monazite (LaPO4) coating was applied on two-dimensional woven continuous carbon fibers by a simple hydrothermal method. Then a Cf/LaPO4/SiBCN ceramic matrix composite(CMCs) was fabricated via subsequent RTM (resin transfer moulding) & PIP (polymer impregnation and pyrolysis) technology. Microstructure observation shows that most of the carbon fibers are coated uniformly with a layer of lanthanum monazite with the thickness of 500nm and there is no obvious chemical contamination between the coating and fiber/matrix during high temperature pyrolysis process. Cf/SiBCN, Cf/PyC/SiBCN and Cf/BN/SiBCN composites were also made to be compared with Cf/LaPO4/SiBCN composites in three-point bending test, fracture toughness test and oxidation test. The results show that Cf/LaPO4/SiBCN composites obtain at least 30% improvement in fracture toughness; in 1350℃/50h oxidation test, Cf/LaPO4/SiBCN composites have the lowest mass loss and the fibers are protected effectively by the coatings, demonstrating the significant increasing in oxidation resistance. Overall, compared with other mentioned coatings, the lanthanum monazite coating enhances much more the high temperature performance of the carbon fiber reinforced SiBCN ceramic matrix composites and promotes the high temperature application potential of the composites.

The purpose of this empirical study was to investigate the evaluation indexes of nursing research results and to provide references for the optimization of nursing research results and their clinical applications.

Cadmium suffers from significant Zr and Mo based oxide/hydroxide interferences during Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) analysis of environmental samples, which can result in a significant deviation of the results. Direct determination method of Cd in environmental geological samples by ICP-MS with membrane desolvation has been developed in this study. This method can effectively eliminate the interference of Zr, Mo oxides and hydroxides, and ensure the results are accurate and reliable. Compared with the conventional method of ICP-MS, the interference of Zr and Mo oxides and hydroxides can be reduced to 0.001% when membrane desolvation is used. Meanwhile, the sensitivity of Cd can be increased 3.5 times. Under the given conditions, the detection limit of Cd was 0.28 ng/L, the lower limit of determination was 2.2 ng/L, and the precision (RSD, n=12) was 2.2%. The method was applied to analyze 20 Chinese environmental geological reference materials. The analytical results are consistent with the certificated values. It indicates that the proposed method has a great potential for the direct determination of trace or ultra-trace levels of cadmium in environmental geological samples. At the same time, the method was used to determine Cd in two comparison samples between two laboratories in 2016. This comparison was organized by the China National Nuclear Corporation. The Z-scores were 0.500 and -0.964, respectively for the two laboratories, and the absolute values of Z were less than 2.

Three continuous silicon carbide fiber reinforced SiBCN composites (SiCf/PyC/SiBCN) distinguished by different weaving methods of fibers (including two dimensional woven, 2.5 dimensional woven with the fiber tow through the thickness and three dimensional five directional braiding) were fabricated by resin transfer molding (RTM), polymer impregnation and pyrolysis (PIP) technology. In order to study the impact of waving methods, the microstructures of fabricated composites were observed and the mechanical properties such as tensile, compression strength and bending strength of the composites were tested. The results show that different distributions of fibers on different directions lead to anisotropy of mechanical properties for each composite, and fabric preform structure has a significant influence on the mechanical properties of the composites.

Objective To investigate aneurysmal bone cyst (ABC) in oral and maxillofacial of clinical appearance, clinical treatment and prognosis. Methods From July 2003 to December 2015, 8 patients with aneurysmal bone cyst in jaw bone was treated and recorded with the general condition, clinical symptoms, imaging examinations, surgical treatment and prognosis. Results Among the 8 patients, there were 5 females and 3 males with the age from 5 to 48 years old. 5 cases happened in mandibular bone and 3 cases originated from the maxillary bone. All the patients were primary lesions and diagnosed by pathology. CT scan showed multilocular cystic expansive space occupying lesions, sep⁃ ta, residual bone crest and liquid⁃liquid form; enhanced imaging showed the tortuous and dilated small blood vessels. Cystic wall composed of spindle shaped fiber cells, tissues and cells, broken bone like multinucleated giant cells and chronic inflammatory cells form and a ribbon like structure, cysts separated by fibrous tissue containing bone and bone fragments, hemorrhage and hemosiderin deposition was observed which was confirmed under the light microscope. The main treatment of aneurysmal bone cyst was radical operation. After 1～6 years of follow⁃up, no patient was found recur⁃ rence. Conclusion The imaging findings of aneurysmal bone cyst in jaw bone was distintive, with diagnosis of the dis⁃ ease depended on pathology; the main treatment was radical operation with good prognosis.

Objective To investigate the clinical effect of simultaneous and delayed surgery with cranial and maxil⁃ lofacial fractures with multiple systemic injuries. Methods From January 2013 to January 2015, 85 cases of patients with multiple systematic injuries and maxillofacial fractures were treated in our hospital. Fractures of the maxillofacial parts and other parts of body were divided into 2 groups, 37 cases of delayed surgery, 48 of simultaneous surgery. The degree of neurologic impairment, occlusion, mouth opening, the time in hospital, postoperative complication rate were compared between two groups. Results There was no significant difference in the prognosis of the patients on the item of Glasgow outcome scale (GOS) in the simultaneous group and the delay group at 3 months after the operation (Z = ⁃1.545, P = 0.122). The excellent occlusion rate of simultaneous group (93.75%) was significantly higher than the delayed group (75.68%) (c2 = 5.630, P = 0.018). The mouth opening of simultaneous group (34.5 ± 3.6) mm is signifi⁃ cantly higher than the delayed group (28.9 ± 3.3) mm (c2 = 7.370, P < 0.001); The time in hospital of simultaneous group (28.5 ± 5.2) d was significantly shorter than delayed group (40.1 ± 5.7) d (c2 = 9.778, P < 0.001). The postopera⁃tive complication rate of simultaneous group (8.33%) was significantly lower than that in the delay group (24.32%) (c2 = 4.124, P = 0.042). Conclusion In the case of patients with appropriate trauma degree, for patients with cranial and maxillofacial fractures and multiple systematic injury, we can take multiple department combined surgical treatment, which can shorten hospitalization time. It is beneficial to the recovery of patients􀆳 maxillofacial appearance and function. And combined operation will not affect the other combined injuries in the treatment effect.

A mesoporous SBA-15/silica composited aerogel was prepared by a two-step acid-alkali method with SBA-15 as an additive. The effects of the amount of SBA-15 on the formation process and the performance of the eomposited aerogel were investigated. The microstructure of the composited aerogel was characterized by scanning electron microscopy and N2 adsorption-desorption isotherms, and the mechanical properties and thermal conductivity were tested. It is found that as a small amount of SBA-15 is added, the gelation time of silica greatly shortens, the mechanical properties improves, the thernlal conductivity still keeps small, while the specific surface area slightly decreases.

For the asymmetry property of the passive tag UHF RFID system’s up/down link,PIE and FM0/Miller encod-ing were used in the reader and tag baseband respectively.The power spectral density（PSD） and the first null bandwidth of these encoding were characterized by analysis and calculation.The PSD and adjacent channel power ratio（ACPR） of DSB-ASK,SSB-ASK and PR-ASK modulated PIE data after pulse shaping were given by simulation.And the optimized data rate was proposed for a given channel bandwidth.

BackgroundHeart failure (HF) is highly prevalent in the United States. Approximately one-third to one-half of HF cases are categorized as HF with reduced ejection fraction (HFrEF). Patients with HFrEF are at risk of worsening HF, have a high risk of adverse outcomes, and experience higher health care use and costs. Therefore, it is crucial to identify patients with HFrEF who are at high risk of subsequent events after HF hospitalization.ObjectiveMachine learning (ML) has been used to predict HF-related outcomes. The objective of this study was to compare different ML prediction models and feature construction methods to predict 30-, 90-, and 365-day hospital readmissions and worsening HF events (WHFEs).MethodsWe used the Veradigm PINNACLE outpatient registry linked to Symphony Health's Integrated Dataverse data from July 1, 2013, to September 30, 2017. Adults with a confirmed diagnosis of HFrEF and HF-related hospitalization were included. WHFEs were defined as HF-related hospitalizations or outpatient intravenous diuretic use within 1 year of the first HF hospitalization. We used different approaches to construct ML features from clinical codes, including frequencies of clinical classification software (CCS) categories, Bidirectional Encoder Representations From Transformers (BERT) trained with CCS sequences (BERT + CCS), BERT trained on raw clinical codes (BERT + raw), and prespecified features based on clinical knowledge. A multilayer perceptron neural network, extreme gradient boosting (XGBoost), random forest, and logistic regression prediction models were applied and compared.ResultsA total of 30,687 adult patients with HFrEF were included in the analysis; 11.41% (3184/27,917) of adults experienced a hospital readmission within 30 days of their first HF hospitalization, and nearly half (9231/21,562, 42.81%) of the patients experienced at least 1 WHFE within 1 year after HF hospitalization. The prediction models and feature combinations with the best area under the receiver operating characteristic curve (AUC) for each outcome were XGBoost with CCS frequency (AUC=0.595) for 30-day readmission, random forest with CCS frequency (AUC=0.630) for 90-day readmission, XGBoost with CCS frequency (AUC=0.649) for 365-day readmission, and XGBoost with CCS frequency (AUC=0.640) for WHFEs. Our ML models could discriminate between readmission and WHFE among patients with HFrEF. Our model performance was mediocre, especially for the 30-day readmission events, most likely owing to limitations of the data, including an imbalance between positive and negative cases and high missing rates of many clinical variables and outcome definitions.ConclusionsWe predicted readmissions and WHFEs after HF hospitalizations in patients with HFrEF. Features identified by data-driven approaches may be comparable with those identified by clinical domain knowledge. Future work may be warranted to validate and improve the models using more longitudinal electronic health records that are complete, are comprehensive, and have a longer follow-up time.