Search

[Objective] Tungsten plays an irreplaceable role in new energy, intelligent manufacturing and national defense and military. The novel coronavirus outbreak and other emergencies have led to a reduction in the demand for tungsten ore in various countries (regions). Clarifying the dynamic transmission mechanism of the risk of trade demand shortage in the tungsten industry chain trade provides decision-making support to avoid risks and ensure the security of tungsten resource supply in China. [Methods] Based on the complex network analysis method and the infectious disease model, this paper constructs the global tungsten industry chain trade network risk transmission model, and simulates the risk impact degree and transmission path in the multi-layer trade of tungsten industry chain when the risk of trade demand shortage occurs in the top 5 countries with China’s export trade dependence. [Results] (1) Under the impact of different demand risks, the avalanche scale of the tungsten industry chain trade network is quite different, but the overall trend is a step downward. With the intensification of the demand shock, the impact of the crisis gradually shifted upstream, and the number of affected countries gradually increased. (2) Tungsten industry chain trade network risk communication belongs to a “minority impact” phenomenon, showing the characteristics of “both robust and fragile”. That is, when key trading countries such as the United States, the United Kingdom (upstream), Germany (midstream), and Thailand (downstream) are affected by demand shocks, the network is vulnerable, while non-key trading countries are affected by demand shocks, which have little impact on other countries. (3) For China, tungsten upstream is mainly affected by the direct impact of the United Kingdom (intra-layer transmission), the United States and Germany (inter-layer transmission) and the indirect impact of Japan, Korea and the Netherlands (inter-layer transmission). Tungsten middle is mainly affected by the direct impact of Japan (intra-layer transmission) and the indirect impact of the United States and Germany (intra-layer transmission), the United States, Indonesia and Thailand (inter-layer transmission). The downstream is mainly influenced indirectly by the United States (intra-layer transmission). [Conclusion] In summary, strive to promote the diversification of China’s tungsten resource export trade, pay attention to the policies of important trading countries and the changes in supply and demand, and pay attention to the internal links between the industrial chain, constantly improve the safety review and risk assessment of tungsten resource supply chain, deepen global supply chain cooperation and improve the strategic reserve system of tungsten resources, are effective ways to promote the sustainable development of China’s tungsten industry and implement precise risk management.

This study established a comprehensive evaluation model for soil fertility in an open-pit coal mine dump in Jiuxian County of Hequ by drawing on Fuzzy Analytic Hierarchy Process (FAHP) and expert scoring theory. 4 criteria and 25 factors were applied for soil structural stability, water retention capacity, fertility retention capacity, and biological activity. Using the YAAHP calculation software, this study proposed the weights of various influencing factors on the soil fertility restoration ability of the waste dump. The results indicate that soil fertility retention ability bears the highest weight (0.547 7), followed by soil water retention ability (0.198 0), soil biological activity (0.140 8), and soil structural stability (0.113 5) in the evaluation rubric, while organic matter F1 bears the highest weight (0.116 2) among other factors; Based on on-site sampling, results showed that the soil quality in the reclaimed area outperformed the uncultivated area, but still persists at lower to medium levels. The main factor for soil resilience is soil fertility retention capacity, especially the content of soil organic matter. Soil fertility restoration model offers references for improving soil quality in waste dump, accelerating soil reconstruction, and promoting soil ecosystem restoration.

ObjectiveTo understand the awareness of knowledge about chronic obstructive pulmonary disease （COPD） and influencing factors among residents in Yangpu District， Shanghai.MethodsWe used cluster random sampling method to conduct face-to-face questionnaire surveys on selected household residents in 12 streets of Yangpu District. The survey questions included their understanding of COPD name， lung function test， and COPD related knowledge. Multivariate logistic regression analysis was used to analyze the influencing factors of awareness rate.ResultsA total of 1 440 people were ultimately included in the analysis， and the awareness rates of COPD name， lung function test， and COPD awareness were 19.93%， 18.61%， and 14.95%， respectively. Among the people who knew the name of COPD， awareness rate of shortness of breath or dyspnea was the highest （84.12%） in the three main symptoms of COPD. Among the main risk factors of COPD， second-hand smoke（86.78%）and smoking （85.82%） were the highest. The main ways to obtain knowledge of COPD names were through television （12.60%） and the internet （11.97%）. The results of multivariate logistic regression analysis showed that men were significantly higher than women in the awareness of COPD name， lung function test， and COPD knowledge， with the OR values of （OR=1.39， 95%CI：1.08‒1.79）， （OR=1.47，95%CI：1.12‒1.92） and （OR=1.37，95%CI：1.02‒1.84）， respectively. The awareness rate of COPD names and lung function tests was the highest among people aged ≥ 65 years old， while the awareness rate of COPD knowledge was the highest among people aged 35‒50 years old. The awareness rate of COPD names was the highest among people with college education or above， civil servants， teachers， and medical staff， people with an annual household income of 100 000‒200 000 yuan.ConclusionThe overall awareness rate of COPD names， lung function tests， and COPD related knowledge among residents in Yangpu District is still at a low level. We should intensify the promotion and education of COPD among key groups such as women， young people， and those with low income， in order to improve the overall awareness rate of COPD among the population.

When facing two or more choices， sound decision-making is critical. In the field of clinical medical practice and public health， more and more researchers use decision-making analysis as an important tool to assist in making the optimal choices. Public health emergencies have the characteristics of group cases， sudden and uncertain. In addition to causing serious damage to public health， they may also have varying degrees of impact on socio-economic， psychological and even social stability. At present， we have not seen the application of mature and sound decision analysis in public health emergency response. This paper reviewed the development of decision analysis in the medical field and the application of common decision-making models in clinical practice. Combined with the current situation of global infectious disease outbreaks and prevention and control， this paper puts forward the concepts and prospects of establishing an auxiliary decision-making system for public health emergencies， aiming to provide a scientific method for medical and health workers to respond to public health emergencies.

Cohort studies play an important role in elucidating the association between risk factors and diseases， and are widely used in etiology research， the assessment of disease prognosis， understanding the natural history of diseases， and the surveillance following the market release of new drugs. The data produced by cohort studies possess great scientific value and can provide essential evidence for public health practice. A well-conceived scientific design is a prerequisite to conducting a cohort study， and the design should focus on aspects such as sample size， selection of exposed and non-exposed populations， follow-up procedures， outcome assessments， research duration， and the choice of analytical indicators and methods. Cohort studies have become an important way to obtain scientific evidence. Internationally renowned population-based cohorts， such as China Kadoorie biobank and the Framingham heart study cohort， have provided a wealth of scientifically valuable evidence for promoting human health. The quality of data produced by a cohort study is extremely important， and a cohort study should continuously incorporate new technologies and methods to provide objective， accurate， and reliable means to determine exposure and outcomes， as well as control for bias. Cohort studies have great potential for application and will continue to provide abundant high-quality scientific evidence for the development of strategies and measures to enhance human health.

To establish a disease risk prediction model based on genetic susceptibility genes and environmental risk factors， which can target high-risk population as early as possible， and intervene in the environmental risk factors in this population. Moreover， accurate screening of genetically susceptible populations can enhance the efficiency of health system. In recent years， with the maturation and cost reduction of high-throughput gene testing， gene testing has been widely used in individual clinical decision-making and will play a more important role in medical and health decision-making. The correlation between genetic testing and disease risk prediction is increasing， making it a prominent research topic in this field. This review summarizes the approaches for establishing and evaluating risk prediction models and discusses potential future challenges and opportunities.

Clinical research reports serve as the presentation of scientific research findings and directly reflect the quality of the research. This article describes the writing of different types of clinical research reports， such as observational studies and randomized controlled trial studies， with a particular focus on randomized controlled trials. Each scientific research design has its reporting focus， and the writing of scientific research papers has uniform requirements and a specific writing format. Mastering the proper format of drafting research reports is of practical value and significant importance for conduction high-quality clinical research.

Statistics plays an important role in medical research， and the selection of appropriate statistical methods is crucial for drawing reliable and valuable conclusions. This paper provides a brief introduction to commonly used statistical analysis methods for medical data， covering descriptive analysis， parametric test， nonparametric test， correlation analysis， regression analysis， and analysis of survival data. It focuses on discussing the assumptions of multiple linear regression， logistic regression and Cox proportional risk regression， as well as how to choose the appropriate statistical methods for analyzing and interpreting medical data based on different research objectives and data types.

To study the stability of the over-pressure reinforcement effect of the copper tube at room temperature, the burst tests for the small diameter soft TP2 copper tube at room temperature during the natural aging time of 0, 6, 12 and 24 months were carried out respectively. These results indicated that: the mean of the measured burst pressure did not change significantly for small diameter soft TP2 copper bare tube and rifled tube at the same pretreatment pressure during the natural aging time of 0, 6, 12 and 24 months, respectively. The standard deviation was gradually smaller and the over-pressure strengthening effect was obvious. The measured burst pressure was different obviously for small diameter soft TP2 copper tube at the pretreatment pressure was 4.60 MPa and 16.50 MPa respectively during the same natural aging time, the mean was significantly larger and standard deviation was significantly smaller for measured burst pressure with the increase of pretreatment pressure, the results showed that pretreatment pressure had a great influence on strengthening effect, and higher pretreatment pressure could get better strengthening effect. The burst pressure conforms to the normal distribution for the same small diameter soft TP2 copper tube at the same over-pressure reinforcement during the natural aging time shall not exceed 24 months. Over-pressure reinforcement at room temperature was a suitable method to increase burst pressure of soft TP2 copper tube, and the method could be used in engineering.

Rock burst, one of the major dynamic disasters in coal mine, which is the energy sudden release accumulated in coal and rock under elastic deformation. According to the academic viewpoint of geo-dynamic division, the internal dynamic action such as modern geological tectonic movement and tectonic stress field have an important influence on the preparation, occurrence and development of dynamic disasters in coal mines. Geo-dynamic division method is mainly used to research the impact of internal dynamic geological processes on human activities in engineerings, and it is mainly used to research dynamic disasters such as rock burst under the influence of modern tectonic movements in the field of coal mining. According to the characteristics of tectonic movement and tectonic form in the mainland of China, the geo-dynamic division researching team, Liaoning Technical University, has expanded the content of geo-dynamic division after the research and practical application on the basis of the geo-dynamic division method with fault block structure division as the core content extensively for more than 30 years, which was established by academicians I.M. Batugina and I.M. Petukhov in Russia. After that, the evaluation method of geo-dynamic environment, the analysis method of coal-rock dynamic system and energy characteristics, and the multi-factor pattern recognition method of dynamic disasters in coal mines were established. The research team developed the rock mass stress analysis system and the geo-dynamic division information management system, which enriched and deepened the theory and methods of geo-dynamic division, and further created a new system of geo-dynamic division, which providing a new research method for the risk prediction and prevention of dynamic disasters in coal mines such as rock burst, coal and gas outburst. The geo-dynamic division method and some application results in rock burst were introduced. Firstly, based on the analysis method of coal-rock dynamic system in geo-dynamic division, the “upper limit value of damage zone radius” was determined as the reference value of advance support range in working faces with rockburst risk, which provided a basis for determining the advance support range of rockburst mines. The “upper limit value of influence zone radius” was determined as the reference value of influence range of working face mining in rockburst mines, which provided a basis for the determination of the distance between two working faces. Secondly, based on the multi factor pattern recognition method of geo-dynamic division, with the support of the geo-dynamic division information system, we have realized the refined prediction of rockburst risk by units. We can provide more accurate spatial location of rockburst risk area and more accurate prediction results of rockburst risk degree for the mines, thus improving the accuracy and timeliness of rockburst risk prediction in coal mines. The geo-dynamic division method has been widely used in the risk prediction and prevention of dynamic disasters in more than 40 coal mines, such as Yima, Hebi, Hegang, Shuangyashan and other mining areas in China.

Chronic diseases have become an important public health problem for people under 70 years of age worldwide， while also causing a great economic burden. The establishment of clinical prediction models can help to predict the risk of a disease or the prognostic effect of a study subject in advance by means of index testing at the early stage of chronic diseases， and plays an increasingly important role in clinical practice. This study introduces clinical diagnostic prediction models and clinical prognostic prediction models， and reviews clinical data processing， clinical prediction model building， visualization methods and model evaluation from the perspective of the application of clinical prediction models， which contribute to the correct and reasonable use of prediction models in clinical research.

Objective To study the effects and mechanisms of molecular targeted drug combination on multi-driven proliferation hepatocellular carcinoma SK-Hep-1 cells. Methods Four molecular targeted drugs (HG6-64-1, Dasatinib, Crizotinib, and Sunitinib) were used to treat SK-Hep-1 cells, and the monophasic kinetic analysis curve and two-phase analysis curve were drawn. Western blot analysis was used to detect the effects of the above drugs on key signaling pathways in SK-Hep-1 cells. MTT assay was used to detect the effects of the above drugs and their combination on the proliferation of SK-Hep-1 cells. Results Compared with the monophasic kinetic analysis curve, the biphase analysis curve could better fit the effects of molecular targeted drugs on SK-Hep-1 cells, which predicted that the combination of HG6-64-1, Dasatinib, and MK-2206 could effectively inhibit the proliferation of SK-Hep-1 cells. Conclusion Two-phase kinetic analysis can quantitatively describe the response of multi-driven proliferation hepatocellular carcinoma SK-Hep-1 cells to molecular targeted therapy. The combination of HG6-64-1, Dasatinib, and MK-2206 is a potential drug combination for the treatment of hepatocellular carcinoma.

Monkeypox， a zoonotic disease caused by monkeypox virus， can be transmitted among humans. The etiology and the clinical symptoms of monkeypox are analogous to smallpox. Before 2022， monkeypox was mainly reported in central and west Africa as an endemic. Since May 2022， the outbreak of monkeypox has been reported in many non-endemic countries and regions. Now， the number of new cases of monkeypox is increasing rapidly. The pattern of monkeypox transmission is significantly different from that in previous outbreaks， and many studies have proposed the possible influence of genetic evolution on the virulence and host range of monkeypox virus in the incident. Given its similarity to smallpox， the outbreaks of monkeypox have attracted wide international attention. In order to provide a scientific basis for the formulation of specific measures of prevention and control， we reviewed the characteristics of etiology and epidemiology of monkeypox， and made primary analysis of the global epidemic of monkeypox.

ObjectiveTo develop a method for the determination of nosiheptide residue in food animal tissues （porcine muscle， porcine liver， porcine kidney， chicken muscle， chicken liver and chicken kidney） with high performance liquid chromatography-tandem mass spectrometry （HPLC-MS/MS）.MethodsAfter extracted by 0.1% acidic acetonitrile， the nosiheptide extract was cleaned up by Captiva ND cartridge and determined by HPLC-MS/MS in negative electrospray ionization mode. Quantification was performed using corresponding matrix-matched calibration curves.ResultsNosiheptide in corresponding matrix showed good linear relationships （r>0.99） in the calibration range of 2~200 μg/L， and the limit of detection （LOD） and limit of quantification （LOQ） of the method were 2.0 and 7.0 μg/kg， respectively. The recoveries of the method ranged from 76.27% to 92.31% at the spiking level of 3.5， 7.0 and 70 μg/kg with relative standard deviations of 2.15%~8.03%.ConclusionThe proposed method is simple， rapid， accurate as well as reproducible and can be applied to monitor and determine nosiheptide residue in food animal tissues.

ObjectiveTo explore the relationship between snoring and hypertension in middle-aged and elderly residents in Yangpu District， Shanghai.MethodsThe data of this study were obtained from the project of “early screening and comprehensive intervention for high-risk of cardiovascular diseases” carried out by the National Cardiovascular Disease Center in Yangpu District in 2017. Questionnaire survey， physical examination and laboratory test were conducted among permanent residents aged 35‒75 years. Logistic regression model was used to analyze the influence of sleep snoring on hypertension.ResultsA total of 11 100 people with complete data were included in the analysis， The self-reported snoring rate of male was significantly higher than female （48.12% vs 36.21%， χ2=137.70， P60 years， male： χtrend2=9.22， P60 years， the significant association between snoring frequencies and hypertension did not exist， after adjusting for education， total family income， smoking， alcohol consumption， diabetes， BMI and waist circumference. In the males： occasional snoring OR （95%CI） was 1.31 （0.97，1.78）， frequent snoring OR （95%CI） was 1.22 （0.87，1.73）， daily snoring OR （95%CI） was 1.19 （0.94，1.73）. In the females： occasional snoring OR （95%CI） was 1.06 （0.87，1.29）， frequent snoring OR （95%CI） was 1.30 （0.99，1.72）， daily snoring OR （95%CI） was 1.19 （0.97，1.46）.ConclusionIn people ≤60 years old， snoring is significantly associated with hypertension， so more attention should be paid to sleep snoring monitoring in middle-aged people for early detection of hypertension.

In view of the problems in yarn-dyed fabric defect detection such as difficulty in obtaining a large number of labeled defect data and serious over inspection, an image reconstruction and repair model based on unsupervised adversarial learning was proposed, and the defect detection of yarn-dyed fabric was realized through the residual analysis between the reconstructed image and the original image. Firstly, the defect reconstruction and repair model based on generative adversarial networks (GAN) was constructed, and defect-free yarn-dyed fabric samples after adding Gaussian noise were used to train the model, so that the model can effectively reconstruct the defect-free samples. Then, the reconstructed image is obtained by inputting the yarn-dyed fabric sample imagel, and the residual image between the tested sample and its corresponding reconstructed image was further obtained. Finally, through the threshold segmentation and mathematical morphology operation of the residual image, the rapid detection and location of the defect region was realized. The experimental results show that the method can detect and locate the defect area of dyed fabrics by analyzing the residual between the reconstructed image and the original image without marking the defect samples.

The effects of the addition of curdlan gel with two different forms, thermal reversible curdlan gum (TRC) and thermal irreversible curdlan gum (TIRC) on the gelling properties and in vitro digestibility of myofibrillar proteins (MP) gel were investigated. The results showed that the gel strength and water holding capacity of MP gel significantly increased with increasing TRC or TIRC concentration (P<0.05), and reached the maximum value at 0.4%, which was confirmed by dynamic rheological behavior. Meanwhile, the addition of TRC or TIRC promoted the transformation of α-helix into β-sheet, and the hydrophobic interaction and disulfide bond were the primary forces of mixed gels. The microstructures revealed that the addition of TRC or TIRC promoted the formation of the dense and uniform protein network structure. However, the modes of interactions between TRC or TIRC and MP induced the different patterns for the gel formation, resulting in the differences in the microstructure of MP gels. In addition, the addition of TRC or TIRC inhibited protein hydrolysis into small peptides and amino acids, which significantly decreased in vitro protein digestibility (P<0.05). Especially when the supplemental level was 0.3% (w/w), the digestibility was reduced from 77.53% to 71.66%. However, no significant effect on the in vitro digestibility of MP gels was observed for each addition form of curdlan (P>0.05). Therefore, this study provides a theoretical basis for the effect of TRC or TIRC on the formation and in vitro digestion of MP gel, and lays a technical support for the application of curdlan gum in meat industry. [ABSTRACT FROM AUTHOR]

Nuclear fuel cycle standardization is important for the safe and innovative development of the nuclear fuel cycle industry, especially when China has currently entered a high-quality development stage. Therefore, conducting strategic research on nuclear fuel cycle standardization becomes significant for boosting China’s nuclear industry. In this article, we analyze the development status of nuclear fuel cycle standardization in China and abroad, investigate the key problems of nuclear fuel cycle standardization in China from the perspectives of working mechanism, development balance, leading role, and support ability, and propose the major tasks and relevant countermeasures. Specifically, the major tasks involve seven aspects: post-stage standards of the nuclear fuel cycle, standards for key technologies, advanced standards, frontier basic standards, safety and environmental protection standards, international standardization, and basic capacities for standardization. Furthermore, the countermeasures comprise including nuclear fuel cycle standardization into the 14th Five-Year Plan of the nuclear industry, improving the standardization mechanism, increasing investment, and strengthening the construction of standardization talent teams.

Laboratory animal and laboratory safety management in medical colleges and universities is the basic guarantee for the safe operation of teaching laboratories and serves as an important link for the successful completion of teaching tasks in laboratories. Aiming at the safety status of common experimental animals and laboratories, the Experimental Teaching Center of Basic Medical College of Zhengzhou University trained medical freshmen on the characteristics of experimental animals and laboratory safety knowledge. PowerPoint courses, short video lectures, and flipped classrooms were used for offline training. The training contents included the correct use of experimental animals, safety management and laboratory safety knowledge. After training, an online examination was conducted, which 1 061 freshmen passed, and the passing rate was 99.90%. According to the analysis of the answers of the freshmen in the examination, the error rates of knowledge on microorganisms and dangerous chemicals were 20.35% and 14.89%, respectively. This suggests that training should be strengthened in these two aspects in the future. Through the training, the new medical students mastered the correct use of experimental animals, and their knowledge of laboratory safety increased. This will help to prevent future laboratory accidents.

The steep-inclined coal seams are widely distributed in western and southern China.These coal seams are complex and difficult for fully-mechanized coal mining.Therefore, developing a novel fluidized and intelligent mining method to recovery the steep-inclined coal seam is of great significance to ensure the safety production of coal.This paper proposed a reverse-circulated excavating-drilling method.A novel fluidized reverse-circulated mining machine was designed and the composition and utilization of this machine were introduced.Afterwards, the parallel excavating and drilling method of this machine is proposed.Finally, the coal mining efficiency, recovery rate and high-pressure water jet assisted coal cutting of this method were calculated.Results show that a larger diameter of cutting head always implies a greater coal mining efficiency.It is necessary to select a suitable diameter and overlap length of the cutter head according to the geological conditions and the target recovery rate of coal seam.It is found that the annual coal production linearly increased with the increasing cutter head advancing speed.Furthermore, a suitable drilling speed parameter and the utilization of the high-pressure water jet are both important to the increase of coal production.

Objective To investigate the cause of elevation of bile amylase level in patients with normal pancreaticobiliary junction and the effect of endoscopic treatment. Methods The clinical data of 96 patients with normal pancreaticobi-liary junction who had laparoscopic cholecystectomy from January 2016 to December 2019 were retrospectively analyzed. Gallbladder bile was gotten before gallbladder resection and the amylase in bile was measured. Duodenoscopy, endoscopic retrograde cholangiopancreatography (ERCP), endoscopic pancreaticobiliary separation (EPBS) and bile duct amylase (BDA) was done in some cases. Results Gallbladder bile amylase (GBA) in all 96 cases was (484.2±200.0) U/L. Sixty-two cases had duodenoscopy. Diagnoses was as follows: long nipple: 7 cases; papillary atrophy: 5 cases; parapapillary diverticulum: 4 cases; papillary tumor: 3 cases; papillitis: 2 cases; parapapillary diverticulum and papillitis: 26 cases; parapapillary diverticulum and long nipple: 8 cases; long nipple and papillitis: 4 cases; parapapillary diverticulum and papillary atrophy: 3 cases. Fifty-nine cases had ERCP among whom 45 cases had elevated level of BDA[(386.9±137.3) U/L] higher than normal (110 U/L), but lower than GBA [(466.3±189.4) U/L] with significant difference (t=2.276, P=0.025). EPBS was performed in all 45 cases and ERCP was performed again one month later. BDA returned to normal [(65.9±13.6) U/L] with significant difference before EPBS and after (P

Objective To compare the short-term effect of bariatric surgery on obesity patients with type 2 diabetes mellitus between laparoscopic Roux-en Y gastric bypass (LRYGB) and laparoscopic sleeve gastrectomy (LSG). Methods A retrospective study was performed from January 2011 to December 2018 for the obesity patients with type-2 diabetes who underwent LRYGB (n=38) and LSG (n=38) and matched in age, gender, body mass index, glycosylated hemoglobin A1c level, and diabetes duration to analyze the surgical effects. Results There was no any major complication and no any malnutrition during 24 months of follow-up. Both surgical procedures achieved weight loss and diabetes remission significantly. LRYGB reduced serum cholesterol levels [(4.31±0.94) mmol/L vs. (5.36±1.22) mmol/L, P

Aiming at the thermal hazards of mining face in Mengcun Coal Mine, a movable air chilled refrigeration system for coal mining face is studied based on the mine water supply and drainage system to reject heat. According to the present situation of thermal hazards in Mengcun Coal Mine, the chilling requirement of coal mining face is calculated. The applicability of two local refrigeration systems, water cooling and air cooling, in coal mining face is analyzed. The characteristics of water gushing from coal seam roof and low water temperature are analyzed. The technology of moving air-chilled refrigeration system in coal mining face is proposed, where the cooling water of refrigeration unit is taken from mine water supply pipeline and discharged to tunnel water ditch. A ZLF-450 movable air-chilled refrigeration unit was selected to test in the first mining face. The results show that: the return water temperature of the cooling water from the refrigerator is slightly higher than that of the mine water, and the water temperature rising after mixing with the water from the mining face in the ditch is only 0.4 ℃; the refrigeration unit operates normally, energy efficiency ratio reaches 3.05 and average temperature of the working face reduces by 2.8 ℃; the system uses mine water supply and drainage system to reject heat without laying any special pipeline for refrigeration system, which greatly reduces the cost of the refrigeration system.

As study on the burst pressure probability distribution of single-layer cylindrical vessels is a basic work,the establishment of pressure vessels reliability design method was carried out to build precision evaluation system of pressure vessel strength calculating formula. The burst pressure probability distribution of single-layer cylindrical vessel was analyzed by using the hypothesis test method in the mathematical statistics theory,based on 84 sets measured burst pressure data of single-layer cylindrical vessel. Research results indicated that:（ 1） Based on the engineering practice of Chinese standard,the application range of the formula can be divided into the 3 groups according to the design pressure which are no exceeding 35 MPa,between35 MPa and 100 MPa,and no more than 100 MPa,respectively;（ 2） According to the relationship between design pressure and burst pressure,the actual burst pressure of the formula application range sample was no more than 105. 5 MPa,between 91. 0 MPa and 329. 6 MPa,and no more than 329. 6 MPa,respectively;（ 3） When the significance was 0. 05,the ratio of the samples measured burst pressure and mid-diameter formula and Tresca formula calculated values is 6 random variables with the normal distribution.（ 4） When the 2-sides confidence was 98%,the distribution parameters value range of 6 random variables were obtained respectively.

[Purpose/Significance] To understand the characteristics of the first class agricultural-related universities. [Method/Process] The changes of the overall ranking and agricultural discipline ranking of top 10 and top 50 agricultural-related universities from 2017 to 2019 in US News, QS and Academic Ranking of World Universities (ARWU) University Rankings were analyzed, respectively. [Results/Conclusions] (1) most top 10 agricultural-related universities are lower-ranked, with 2/3 ranked outside of top 100, (2) top 10 agricultural-related universities' rankings are not stable, and only four universities, Cornell University, Wageningen University & Research, California University Davis and China Agricultural University are listed as top 10 agricultural universities in all three rankings, (3) top 10 agricultural-related universities come from more countries than top 10 universities do, and Chinese universities have better performance in agriculture than in other fields, and (4) numbers and position of selected fields by university rankings have more influence on overall ranking than numbers of students and teachers and their ratio. Chinese universities which take agriculture as their main field should strengthen their expertise in agricultural-related disciplines, establish new disciplines with characteristics and improve their international influence.

Pre-strain on austenitic stainless steel was a method in order to obtain good mechanical properties,the pre-strain effect evaluation was the basis of improving the production process of the steel. Applying the theory of probability and mathematical statistics,the evaluation system of pre-strain effect was established: the pre-strain effect on the mechanical properties parameter standard deviation was evaluated,using F-distribution; the pre-strain effect on the mechanical properties parameter mean value was evaluate,using t-distribution. For example of pre-strain effect on austenitic stainless steel S30408,based on the effective tensile test data at liquid nitrogen temperature,and the bilateral confidence was 99%,the effect of 9%-prestrain on the steel was evaluated: 1) 9%-pre-strain significantly increases the yield strength of steel S30408,and the standard deviation is basically unchanged; 2) for steel S30408 tensile strength,9%-pre-strain is no effect on the mean and the standard deviation.

In order to increase the burst pressure of copper pipe,save the copper material under the premise of guaranteeing safety,overpressure enhancement of TP2 copper tube was tested at room temperature,the relationship between the burst pressure of copper tube and the pretreatment pressures was studied,the changes of TP2 material tensile strength was analyzed. Based on28 groups burst test of TP2 copper tubes under different pretreatment pressure at room temperature,studies have shown that: 1)If the enhancement pretreatment pressure of TP2 copper tube is equal to the yield pressure,the thermal effect of copper tubes brazing should be improved,copper tube burst pressure and TP2 material tensile strength should be strengthened to a certain extent. 2) Compared with non overpressure enhancement at room temperature,for the burst pressure and the tensile strength of TP2 copper tube used appropriate pressure pretreatment,the means of copper tube burst pressure and the TP2 material tensile strength are increased significantly,the standard deviation and coefficient of variation are decreased significantly,and the precision is improved obvious. For the burst pressure and the tensile strength of TP2 copper tube,the fluctuation range of the average,standard deviation and coefficient of variation are smaller,and the stability is become well.

For reducing the large roof deformation and bolt failure problems in serious swelling and soft rock roadway, influence factors of roadway stability and bolting technology in serious swelling soft rock roadway are studied based on engineering analogy analysis and numerical simulation. Research results show that the low strength of soft rock roof, easy swelling and softening of water are the internal causes of roof failure and instability. The external causes are high concentration stress of surrounding rock and insufficient supporting strength. The roadway stability can be improved by optimizing the layout of roadway and strengthened support. The combined bolting scheme of resin extended anchor bolt and cable in serious swelling soft rock roadway is determined, and the row spacing is 800 mm×900 mm, the pre-tightening torque of bolt is not less than 400 N·m, and the row spacing between cables is 1 600 mm×1 800 mm, and the anchor cable preload is 200-250 kN. The bolting scheme has been tested on the field, good supporting effect has been achieved.

To explore failure mechanism of the roadway subject to dynamic pressures, a preparatory roadway influenced by mining disturbance was systematically studied in this paper.The borehole imaging method was used to explore crack propagation characteristics of surrounding rock under dynamic pressures, and numerical simulation was carried out to investigate evolution laws of the stress around the roadway.Accordingly, a dissymmetrical control technique for the preparatory roadway was proposed based on the principle that the vulnerable area should be paid more attention while proper treatment of small disturbance area is enough.The results showed that the floor and rib of the preparatory roadway were vulnerable areas of the surrounding rock where fractures were distributed by dynamic pressures.As the distance from the dynamic pressure source to the affected roadway decreased, the effects of the dynamical pressure increased.The shape of the vertical stress between the roadway and the dynamic pressure source was a dissymmetrical bimodal arch.Field tests indicated that the deformation and deformation rate of the surrounding rock reduced obviously after adopting the proposed measures, and that the control effects were satisfactory.

The design goals of VANET(Vehicular Ad-Hoc Networks) are to provide an open public road safety services，and to improve the comfort and efficiency of driving. In VANET, multi channels are employed to transmit safety information and non-safety information respectively. This paper analyzes protocols associating with VANET in detail and proposes an improved multi-channel MAC cooperation scheme. Based on the network simulation software NS2, this paper designs the simulation model for VANET, adds the multi-channel module and application layer module into the network simulation software NS2, and then simulates the single channel and multi-channel, and the improved MAC protocol. From the simulation, it shows that compared with the single channel, multi channels can obtain better throughput, and the improved MAC protocol also has lower latency and message collision ratio than the original standard.

In order to improve the design method of pressure vessels strength,applying the theory of statistical hypothesis testing,the precision comparison method for design formula expansion applied range was established. Based on 52 groups of measured burst pressure of steel wall single-layer cylinder,the precision of mid-diameter formula with the Tresca formula was compared,and the application of formulas was extended according to the principle of no precision reduction. The research shows that:（ 1） According to the design pressure,benchmark scope and plans to expand the scope of mid-diameter formula are determined,respectively.（ 2） According to the relationship between design pressure and burst pressure,sample test data of measured burst pressure of the benchmark scope and plans to expand the scope are definite,respectively.（ 3） At the saliency of0. 05,the ratio of the sample and mid-diameter formula calculated value is random variables with the normal distribution,respectively,which sample located in the benchmark scope and plans to expand the scope.（ 4） The precision of mid-diameter formula in plans to expand the scope and the benchmark scope is same basically; the precision of Tresca formula in plans to expand the scope is higher than the benchmark scope.（ 5） When suitable scope extended to the design pressure less than100 MPa,the precision of mid-diameter formula and Tresca formula is same basically.

Objective To evaluate five types of DIC scoring systems based on sepsis patients, to explore the values of different DIC scoring systems in the occurrence and prognosis of DIC in sepsis patients, and to compare the applicability of different DIC scoring systems for sepsis complicated with DIC. Methods Laboratory indexes and clinical data from sepsis patients who had been hospitalized in Gansu Provincial People's Hospital from December 1, 2019 to December 31, 2021 were retrospectively analyzed within 24 hours. Five types of DIC scoring systems were used to score, and the difference of diagnostic rate and discharge outcome in sepsis patients with different severity was compared. The ROC curves of five DIC scoring systems were established to evaluate the accuracy of DIC in sepsis patients. Results The fatality rate of sepsis increased with the severity of sepsis (P < 0.05). There were statistically significant differences in discharge outcomes between DIC and non-DIC in the five scoring systems (P < 0.05). JMHW, CDSS and part of ISTH were detected in JAAM cases, while ISTH was detected in non-dominant ISTH cases. ISTH, JAAM, JMHW, CDSS, and non-dominant ISTH5 scoring systems were used to diagnose DIC, and absence of full health restoration and death were 3.0, 3.8, 4.2, 3.9, and 3.0 times higher than non-DIC cases, respectively. Conclusion JAAM scoring system has higher diagnostic rate and sensitivity for adult sepsis. CDSS and JMHW scoring systems are more accurate in predicting the prognosis of sepsis patients. [ABSTRACT FROM AUTHOR]

A random variable with statistical property was built; by means of the statistical theory hypothesis testing,and using the sample data,the change rule of random variable distribution parameter was analyzed,the evaluation method of the pressure vessel burst pressure calculation formula precision was established. Based on 27 groups of steel thin-wall single-layer cylinder burst pressure measured data,related factors influence on the precision of mid-diameter formula and Faupel formula were studied. The research shows that:（ 1） For thin-wall single-layer cylinder,with the vessel materials yield ratio ranging from0. 488 9 to 0. 0. 966 0,and the diameter ratio ranging from 1. 010 to 1. 5,the yield ratio value is not obviously affect the standard deviation and mean value of mid-diameter formula corresponding to random variable; although yield ratio value is no significant effect on mean value of Faupel formula corresponding to random variable,but if experimental data of yield ratio was lower than0. 499 7,Faupel formula corresponding to random variable standard deviation is significant increase;（ 2） In above scope,middiameter formula corresponding to random variable coefficient of variation is less than Faupel formula ’s,and mid-diameter formula with higher concentration,for calculating steel thin-walled single layer cylinder burst pressures,mid-diameter formula is better than Faupel formula;（ 3） Adjust the materials yield ratio ranging from 0. 538 8 to 0. 966 0,and the diameter ratio ranging from 1. 013 3 to 1. 5 accordingly,the variation coefficient of Faupel formula corresponding to random variable is significantly decreased,and the concentration of Faupel formula is significantly improved.

The microstructure of DZ8 after solid solution treatment at 1260 ℃ and 1240 ℃ was observed, and the tensile and stress rupture properties were compared. The results show that less than 1% γ+γ' eutectic remains in the microstructure of DZ8 after solid solution treatment at 1260 ℃, while incipient melting takes place in the Hf-rich phase; about 12% γ+γ' eutectic exists in the microstructure of DZ8 after solid solution treatment at 1240 ℃, but no incipient melting phase is discovered. After solid solution treatment at 1260 ℃, the stress rupture property of DZ8 in 980 ℃/725 MPa and the tensil property of DZ8 at room temperature, 700 ℃ and 980 ℃ show little different compared with those treated at 1240 ℃, but the stress rupture property in 760 ℃/725 MPa decreases to some extent.

In order to effectively improve the efficiency of robot automation production line design and commissioning, solve the problems of high commissioning risk and high cost of trial and error of actual equipment. Taking packaging production line of three-degree of freedom manipulator as an example, a virtual commissioning system of parallel robot digital twinning based on SIMIT, PLCSIM Advanced and mechatronics concept designer (MCD) is designed and a digital workstation of robot packaging is built by using MCD. TIA Portal is used for hardware configuration, process object configuration and PLC control program design. Finally, SIMIT is used to simulate the behavior model of electrical components and data communication to realize the process simulation and optimization of packaging workstation. The results show that this system can effectively verify the motion control of parallel robot and complete the collaborative commissioning of the production line. [ABSTRACT FROM AUTHOR]

According to the problem of insufficient air content and poor bubble stability of concrete in cold and high altitude areas, prenyl alcohol polyoxyethylene ether (TPEG), methoxypolyethylene glycol 600 acrylate (MPEGA-600), acrylic acid (AA) and sodium p-styrene sulfonate(SSS) are used as monomers to synthesize polycarboxylic acid water-reducing agent by the free radical copolymerization of aqueous solution under the combined action of composite initiators and mercaptopropionic acid. The effect of the molar ratio of MPEGA-600, AA and SSS to TPEG on the performance of synthetic water reducer and the adaptability of water-reducing agent to different cements were studied, and comparative study on the performance of water-reducing agent on concrete under standard atmospheric pressure and low atmospheric pressure conditions. The results show that the prepared polycarboxylic acid water-reducing agent has high air-introducing, high bubble stability, high adaptability, and the performance is the best when its Mw is 82109 and PDI is 1.37. [ABSTRACT FROM AUTHOR]

Copyright of Foreign Literature Studies is the property of Foreign Literature Studies and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Foam drilling has been widely used both at home and abroad, but the method for optimized design of hydraulic parameters has not been improved. This paper concluded the method for optimized design of hydraulic parameters for foam drilling based on multi-phase flow theory and sand carrying theory, and through theoretical calculation and analysis. That is, to determine the optimum gas/liquid ratio through the linear relation between critical gas/liquid ratio and wellhead backpressure; to determine the optimum wellhead backpressure through minimum bottom hole pressure in different depths; to determine the optimum foam flow rate by combining the optimum gas/liquid ratio, optimum wellhead backpressure, bottom pressure and cuttings concentration; and finally to determine the optimum gas injection flow rate and liquid injection flow rate according to optimum foam flow rate. Example calculations were conducted for optimum hydraulic parameters corresponding to 200 mm hole diameter, 114.3 mm out diameter of drill pipe, 1980 m well depth and 9 m/h, 18 m/h and 27 m/h drilling rate. The optimized method presented in this paper has a practical guiding significance for optimizing hydraulic parameters of foam drilling. [ABSTRACT FROM AUTHOR]

Objective: To construct and validate a nomogram model for predicting the risk of 28-day mortality in sepsis patients., Methods: A retrospective cohort study was conducted. 281 sepsis patients admitted to the department of intensive care unit (ICU) of the 940th Hospital of the Joint Logistics Support Force of PLA from January 2017 to December 2022 were selected as the research subjects. The patients were divided into a training set (197 cases) and a validation set (84 cases) according to a 7 : 3 ratio. The general information, clinical treatment measures and laboratory examination results within 24 hours after admission to ICU were collected. Patients were divided into survival group and death group based on 28-day outcomes. The differences in various data were compared between the two groups. The optimal predictive variables were selected using Lasso regression, and univariate and multivariate Logistic regression analyses were performed to identify factors influencing the mortality of sepsis patients and to establish a nomogram model. Receiver operator characteristic curve (ROC curve), calibration curve, decision curve analysis (DCA), and clinical impact curve (CIC) were used to evaluate the nomogram model., Results: Out of 281 cases of sepsis, 82 cases died with a mortality of 29.18%. The number of patients who died in the training and validation sets was 54 and 28, with a mortality of 27.41% and 33.33% respectively. Lasso regression, univariate and multivariate Logistic regression analysis screened for 5 independent predictors associated with 28-day mortality. There were use of vasoactive drugs [odds ratio (OR) = 5.924, 95% confidence interval (95%CI) was 1.244-44.571, P = 0.043], acute physiology and chronic health evaluation II (APACHE II: OR = 1.051, 95%CI was 1.000-1.107, P = 0.050), combined with multiple organ dysfunction syndrome (MODS: OR = 17.298, 95%CI was 5.517-76.985, P < 0.001), neutrophil count (NEU: OR = 0.934, 95%CI was 0.879-0.988, P = 0.022) and oxygenation index (PaO 2 /FiO 2 : OR = 0.994, 95%CI was 0.988-0.998, P = 0.017). A nomogram model was constructed using the independent predictive factors mentioned above, ROC curve analysis showed that the AUC of the nomogram model was 0.899 (95%CI was 0.856-0.943) and 0.909 (95%CI was 0.845-0.972) for the training and validation sets respectively. The C-index was 0.900 and 0.920 for the training and validation sets respectively, with good discrimination. The Hosmer-Lemeshoe tests both showed P > 0.05, indicating good calibration. Both DCA and CIC plots demonstrate the model's good clinical utility., Conclusions: The use of vasoactive, APACHE II score, comorbid MODS, NEU and PaO 2 /FiO 2 are independent risk factors for 28-day mortality in patients with sepsis. The nomogram model based on these 5 indicators has a good predictive ability for the occurrence of mortality in sepsis patients.

Objective: To explore the genetic etiology of a child with Hypomagnesemia, epilepsy and mental retardation syndrome (HSMR)., Methods: A child who was admitted to the Children's Hospital of Shandong University on July 9, 2021 due to repeated convulsions for 2 months was selected as the study subject. Clinical data of the child was collected. Peripheral blood samples of the child and his pedigree members were collected for the extraction of genomic DNA. Whole exome sequencing was carried out, and candidate variant was verified by Sanger sequencing and bioinformatic analysis., Results: The child, a 1-year-and-7-month-old male, had presented with epilepsy and global developmental delay. Serological testing revealed that he has low serum magnesium. Genetic testing showed that the child has harbored a heterozygous c.1448delT (p.Val483GlyfsTer29) variant of the CNNM2 gene, which was de novo in origin. The variant has caused substitution of the Valine at position 483 by Glycine and formation of a termination codon after 29 amino acids at downstream. As predicted by Swiss-Model online software, the variant may alter the protein structure, resulting in a truncation. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c.1448delT (p.Val483GlyfsTer29) was predicted as a pathogenic variant (PVS1+PS2+PM2&#95;Supporting+PP4)., Conclusion: The heterozygous c.1448delT variant of the CNNM2 gene probably underlay the HSMR in this child. Above finding has enriched the phenotype-genotype spectrum of the CNNM2 gene.