深孔爆破技术在不规则台阶中的应用

为了解决废弃矿区垦造水田工程,存在采矿遗留高度3～10 m不规则台阶的问题。且因为工期紧,对这些不规则台阶不能采取浅孔台阶爆破和深孔爆破相结合的方式施工。同时,低台阶开挖采取大于50 mm孔径爆破施工缺少理论依据,工程案例也较少。为此,根据以往经验和参考多边界石方爆破药量计算原理并结合现有钻孔设备,对不规则台阶采取梅花形布孔,用φ90 mm钻机钻孔,其中钻机无法打孔的局部位置在其后侧加密倾斜孔。采取多排深孔延时爆破技术,累计14 h一次性施工。因已购非电雷管段别有限,则利用现有雷管组网,采取分区接力的起爆网路,一次性成功爆破了高低不平的不规则台阶,除了爆堆表层2 m左右范围内有大石块,其余位置岩石破碎块度较小,爆破后无根底,达到预期效果,为后续工作创造了有利条件。

Medical services for sports injuries and illnesses in the Beijing 2022 Olympic Winter Games

BACKGROUND:Beijing 2022 Olympic Winter Games was the second Games held amid the COVID-19 pandemic.To a certain extent,it has altered the way sporting activities operate.There is a lack of knowledge on injury risk and illness occurrence in elite winter sport athletes amid the COVID-19 pandemic.This study aimed to describe the incidence of injuries and illnesses sustained during the XXIV Olympic Winter Games in Beijing from February 4 to 20,2022.METHODS:We recorded the daily number of injuries and illnesses among athletes reported by Beijing 2022 medical staff in the polyclinic,medical venues,and ambulance.We calculated injury and illness incidence as the number of injuries or illnesses occurring during competition or training,respectively,with incidence presented as injuries/illnesses per 100 athlete-days.RESULTS:In total,2,897 athletes from 91 nations experienced injury or illness.Beijing 2022 medical staff reported 326 injuries and 80 illnesses,equaling 11.3 injuries and 2.8 illnesses per 100 athletes over the 17-day period.Altogether,11%of the athletes incurred at least one injury and nearly 3%incurred at least one illness.The number of injured athletes was highest in the skating sports(n=104),followed by alpine skiing(n=53),ice track(n=37),freestyle skiing(n=36),and ice hockey(n=35),and was the lowest in the Nordic skiing disciplines(n=20).Of the 326 injuries,14(4.3%)led to an estimated absence from training or competition of more than 1 week.A total of 52 injured athletes were transferred to hospitals for further care.The number of athletes with illness(n=80)was the highest for skating(n=33)and Nordic skiing(n=22).A total of 50 illnesses(62.5%)were admitted to the department of dentistry/ophthalmology/otolaryngology,and the most common cause of illness was other causes,including preexisting illness and medicine(n=52,65%).CONCLUSION:Overall,11%of athletes incurred at least one injury during the Games,which is similar to the findings during the Olympic Winter Games in 2014 and 2018.Regarding illness,2%of athletes were affected,which is approximately one-third of the number affected in the 2018 Olympic Winter Games.

Fabrication of fire-retardant building materials via a hyper-crosslinking chemical conversion process from waste polystyrenes

Polystyrene(PS)is rich in plastic materials,but it produces a large amount of waste every year,causing a huge burden on the environment.Although PS plastic is the source of a common"white pollution"in daily life,it still has a high utilization value.At the same time,the flammability of PS material determines that it cannot be applicated in places where fire accidents occur frequently.As a result,its application has been greatly limited.In order to realize the efficient utilization of waste PS and broaden its scope of application,PS was modified by hyper-crosslinking in order to improve its fire-retardant performance.In this method,the PS solution with high purity was obtained by dissolving waste PS foam with 1,2-dichloroethane(DCE),and then the hyper-crosslinked polymer with high specific surface area was prepared by adding cross-linking agent formaldehyde dimethyl acetal(FDA)and a Lewis-acid catalyst ferric chloride(FeCl_(3)).Further studies showed that the effects of the amount of cross-linking agent FDA,catalyst FeCl_(3) and PS on the reaction products were different.In addition,compared the as-prepared fire-retardant materials with PS foam from the aspects of flame retardancy and thermal insulation,it can be concluded that the fire-retardant performance of the materials prepared by this method has been significantly enhanced.And it is proved that this method is feasible towards the preparation of a large number of fire-retardant composite materials by using a scale-up experiment.

By-production,emissions and abatement costeclimate benefit of HFC-23 in China's HCFC-22 plants

After the Kigali Amendment(KA)came into effect,HCFC-22 plants are obliged to limit HFC-23 emissions.Therefore,the study of costeffective mitigation pathways for HFC-23 is important for the sustainable implementation of KA in China and other HCFC-22 producing countries.This study constructed an inventory of HFC-23 by-production,emissions,and abatement for HCFC-22 plants in China from 2006 to 2020,and predicted the costs and climate benefits of HFC-23 abatement in China's compliance with the KA between 2021 and 2060.Results showed that HFC-23 emissions from HCFC-22 plants in China contributed about 60%of the growth in global atmospheric mole fraction of HFC-23 observed by Advanced Global Atmospheric Gases Experiment(AGAGE)from 2007 to 2020.Furthermore,China's cumulative HFC-23 abatement was about 109 kt(1613 Mt CO_(2)-eq)from 2006 to 2019,accounting for 53%of total by-production,which allowed the global atmospheric mole fraction and radiative forcing of HFC-23 in 2020 to avoid an uplift of 9.2×10^(-9)and i.7 mW m^(-2),respectively,contributing to climate change mitigation.Under the baseline of the Kigali Amendment,less emission(LE),and resource utilization(RU)scenarios,the cumulative HFC-23 abatement from 2021 to 2060 would be 683±29 kt(10,107±431 Mt CO_(2)-eq),694±29 kt(10,277±427 Mt CO_(2)-eq),and 702±29 kt(10,385±426 Mt CO_(2)-eq),respectively.The cumulative net abatement costs for the KA,LE,and RU scenarios would be(5.0±0.2)billion,(2.9±0.2)billion,and(-2.7±0.2)billion CNY(2021 prices),respectively.In the future,applying resource utilization technology to reduce HFC-23 emissions can achieve both climate and economic benefits.

Nasal delivery of broadly neutralizing antibodies protects mice from lethal challenge with SARS-CoV-2 delta and omicron variants

Multiple new variants of severe acute respiratory syndrome coronavirus 2(SARS-Co V-2)have constantly emerged,as the delta and omicron variants,which have developed resistance to currently gained neutralizing antibodies.This highlights a critical need to discover new therapeutic agents to overcome the variants mutations.Despite the availability of vaccines against coronavirus disease 2019(COVID-19),the use of broadly neutralizing antibodies has been considered as an alternative way for the prevention or treatment of SARS-Co V-2 variants infection.Here,we show that the nasal delivery of two previously characterized broadly neutralizing antibodies(F61 and H121)protected K18-h ACE2 mice against lethal challenge with SARS-Co V-2 variants.The broadly protective efficacy of the F61 or F61/F121 cocktail antibodies was evaluated by lethal challenge with the wild strain(WIV04)and multiple variants,including beta(B.1.351),delta(B.1.617.2),and omicron(B.1.1.529)at 200or 1000 TCID_(50),and the minimum antibody administration doses(5-1.25 mg/kg body weight)were also evaluated with delta and omicron challenge.Fully prophylactic protections were found in all challenged groups with both F61 and F61/H121 combination at the administration dose of 20 mg/kg body weight,and corresponding mice lung viral RNA showed negative,with almost all alveolar septa and cavities remaining normal.Furthermore,low-dose antibody treatment induced significant prophylactic protection against lethal challenge with delta and omicron variants,whereas the F61/H121 combination showed excellent results against omicron infection.Our findings indicated the potential use of broadly neutralizing monoclonal antibodies as prophylactic and therapeutic agent for protection of current emerged SARS-Co V-2 variants infection.

Current status and developing trends of the contents of heavy metals in sewage sludges in China

It is essential to determine the heavy metal concentrations in sewage sludge to select appropriate disposal methods. We conducted a national survey of heavy metal concentrations of sewage sludge samples from 107 municipal sewage treatment plants located in 48 cities covering the 31 provinces and autonomous regions, as well as Hong Kong, Macao and Taiwan by Xinjiang Production and Construction Corps in 2006, and identified the temporal trends of heavy metal contents in sewage sludge by comparison with surveys conducted in 1994-2001. In 2006, the average concentrations of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn in sewage sludge were 20.2, 1.97, 93.1, 218.8, 2.13, 48.7, 72.3, and 1058mg.kg-1, respectively. Because of the decreased discharge of heavy metals into industrial wastewater in China and the increasingly stringent regulations governing the content of industrial wastes entering sewers, the average concentrations of Cd, Cr, Cu, Hg, Ni, Pb, and Zn have decreased by 32.3%, 49.7%, 54.9%, 25.0%, 37.2%, 44.8%, and 27.0%, respectively, during the past 12 years. The concentrations of Cd, Cr, Cu, Ni, and Zn in the samples exceeded the heavy metal limits of the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant in China （GB 18918-2002） by 6.5%, 3.7%, 6.5%, 6.5%, and 11.2%, respectively. From these results, 85 of the 107 municipal sludges analyzed would be considered suitable for land application.

Scenario analysis of hydrofluorocarbons emission reduction in China's mobile air-conditioning sector

With the Kigali Amendment(KA)coming into effect in China,the control of hydrofuorocarbons(HFCs)emissions has become more imperative.The mobile air-conditioning(MAC)sector is one of the important HFCs consumer sectors,and therefore studying its feasible mitigation paths and costs is of great significance to Chinas successful implementation of KA.This study used the bottom-up method with updated emission factors to re-evaluate the emission inventory of HFCs from the MAC sector in China from 2005 to 2020.The average annual growth rate of HFCs consumption in the MAC sector is 9.8%,and HFCs emissions have increased from 5.8(5.3-6.2)kt in 2005 to 22.2(20.6-23.8)kt in 2020,with an average annual growth rate of 8.8%.Using the Gompertz model combined with the Weibull function of vehicle survival rate,the ownership and new registrations of internal combustion engine vehicles(ICEVs)and electric vehicles(EVs)in China are predicted.The ownership of ICEVs and EVs is projected to be 310 million and 91 million in 2030,respectively and 2 million and 641 million in 2060,respectively.HFCs emissions in the MAC sector would reach 59.8(55.3-64.3)kt(80.093.0 Mt CO_(2-eq))in 2060 if without any control measure.To implement the KA,the cumulative of 1.6 Gt CO_(2-eq) emissions would be reduced.Under the other two accelerated mitigation scenarios,the MAC sector's HFCs will reach their emissions peak in 2028 and 2025 and achieve zero emissions in 2050 and 2046,respectively.Under the accelerated mitigation with recovery scenario,the cumulative emissions are only 15.0%of the business as usual(BAU)scenario.Using HFO-1234yf as the substitute,the unit abatement cost of the MAC sector is 27.3-37.4 USD _(t)^(-1)CO_(2-eq).

Outcome of bystander cardiopulmonary resuscitation after out-of-hospital cardiac arrest in Beijing

Aim:We aimed to investigate the association between bystander cardiopulmonary resuscitation(CPR)and survival of patients with out-of-hospital cardiac arrests(OHCA)in Beiing.Methods:This observational study analyzed adult patients with OHCA treated by the Beiing emergency medical service(EMS)from January 2013 to December 2017.Data were collected in a Utstein style with a 1-year follow-up and a primary outcome 01 survival to hospital discharge.Secondary outcomes were return of spontaneous circulation(ROSC),survival to admission,favorable neurological outcome at hospital discharge,and survival and favorable neurological outcomes of up to 1 year.Results:A total of 5016 patients with OHCA from Beiing's urban area were recorded by EMS,wherein 765 patients(15.25%)underwent bystander CPR.The data were propensity score-matched forage,sex,location,witness,aetiology,initial rhythm,and call to EMS arrival to compare the difference between the occurrence and nonoccurrence of bystander CPR.The survival upon the discharge of patients who experienced bystander CPR was superior to that of patients who did not receive bystander CPR(3.7%vs 1.2%,respectively;P<0.001).Moreover,patients with OHCA resuscitated with bystander CPR achieved better outcomes of ROSC,survival to admission,favorable neurological outcome at hospital discharge,survival and favorable neurological outcome after 1 year compared with those who were not resuscitated with bystander CPR.Conclusion:Survival and neu rological outcome of patients who underwent bystander CPR was better than those who underwent nonbystander CPR in Beiing.However,the rate of bystander CPR was low.

民族情感对蒙古族服饰艺术的影响

蒙古族是古老而伟大的民族,是我国北方少数民族之一,是由北方游牧民族发展而来,素来有'马背民族'之称。蒙古族在长期的历史发展过程中,形成独特的民族气质与民族情感,如对蒙古族英雄的崇拜、对蒙古族同胞、蒙古族语言、蒙古族文化艺术,对蒙古族赖以生存的大草原的热爱。