Industrial test of a 6-m long bearing steel ingot by electroslag remelting withdrawing process

In this study, the key technologies of a 6-m long bearing steel ingot produced by electroslag remelting withdrawing(ESRW) process, including bifilar mode supply, slag system development, and design of mold, were studied based on the laboratory research achievements. The 6-m long ingot of bearing steel GGr15 with a cross-section of 300 mm × 340 mm was produced using the ESRW process with a bifilar mode and a multi-taper T-mold in a plant. The testing results show that the melting rate using the ESRW bifilar mode technology is three times faster than traditional electroslag remelting(ESR), and the power consumption is only 1,320 k Wh per ton steel. Through testing for the chemical composition, macrostructure and inclusions of remelted ingot, it can be concluded that the ESRW bifilar mode technology not only retains the characteristics of traditional ESR, but also improves the production efficiency and reduces the cost compared to traditional ESR.

Changes in neurosteroid levels and steroidogenic enzyme expression in the brain of morphine dependent and withdrawing rats

BACKGROUND： Studies have demonstrated that exogenous neurosteroid treatment prevents the development of morphine tolerance and dependence, and attenuates abstinence behavior in mice. However, there are few studies on whether the levels of endogenous neurosteroids can be changed by morphine dependence and withdrawal. OBJECTIVE： To investigate the levels of various neurosteroids in rat brain following morphine dependence and withdrawal. To evaluate the expressions of steroidogenic enzyme mRNAs and proteins. To identify the relationship between neurosteroids and morphine dependence at the whole animal behavior, neural biochemistry, and molecular levels. DESIGN, TIME AND SETTING： A randomized, controlled study. Experiments were performed at the Department of Pharmacology of Hebei Medical University and Department of Pharmacology of Beathune International Peace Hospital, China, from June 2004 to October 2007. MATERIALS： Morphine hydrochloride injection （Shenyang First Pharmaceutical Factory, China）, naloxone hydrochloride （Hunan Yiqiao Pharmaceutical Co., China） and a gas chromatography-mass spectrometry system （Agilent, CA, USA） were used in this study. METHODS： Healthy adult Sprague Dawley rats were randomly divided into three groups： a morphine dependence group, morphine withdrawal group and control group （n = 20）. The rats in the morphine dependence and morphine withdrawal groups were given increasing doses of morphine （5, 10, 15, 20, 30, 40 and 50 mg/kg, intraperitoneal） to create morphine dependence. The rats in the morphine withdrawal group were injected with 2 mg/kg naloxone to precipitate withdrawal 1 hour after the last morphine injection. Rats in the control group were treated with an equal volume of saline. MAIN OUTCOME MEASURES： Following morphine dependence and withdrawal, brain levels of the neurosteroids pregnenolone, progesterone and allopregnanolone were analyzed using gas chromatography-mass spectrometry. The mRNA expression of two key steroidogenic enzymes, P450 side-chain cleavage enzyme （P450scc） and 3[B-hydroxysteroid dehydrogenase （313-HSD）, were determined in rat brain regions using reverse transcription-polymerase chain reaction. The distribution and expression of P450scc protein were visualized in brain regions associated with addiction by immunohistochemistry. RESULTS： In brain tissue from the morphine dependence group, the levels of pregnenolone and progesterone were decreased by 62% （P 〈 0.01） and 92% （P 〈 0.01 ） respectively, compared with the control group. In the morphine dependence group, the key steroidogenic enzyme P450scc mRNA was decreased in striatum （P 〈 0.05）, while 3-HSD mRNA was decreased in amygdala （P 〈 0.05）, striatum （P 〈 0.05） and frontal cortex （P 〈 0.05） compared with the control group. Morphine withdrawal induced a significant increase in the neurosteroid levels compared with the control group （P 〈 0.01）. However, there was no significant difference in the expressions of P450scc and 36-HSD mRNAs between the morphine withdrawal and control groups （P 〉 0.05）. CONCLUSION： The neurosteroid levels and expressions of steroidogenic enzymes changed similarly in morphine dependent rats, suggesting that the morphine dependence-induced decrease in neurosteroids might depend on local expression of steroidogenic enzymes in the central nervous system. However, the changes in neurosteroids in morphine withdrawal rats were not in accordance with the changes in the expression of steroidogenic enzymes, suggesting that the effects of morphine withdrawal on brain neurosteroid levels may not depend primarily on the local expression of steroidogenic enzymes in the central nervous system.

Using neural network modeling to improve the detection accuracy of land subsidence due to groundwater withdrawal

Despite the high efficiency of remote sensing methods for rapid and large-scale detection of subsidence phenomena,this technique has limitations such as atmospheric impact and temporal and spatial decorrelation that affect the accuracy of the results.This paper proposes a method based on an artificial neural network to improve the results of monitoring land subsidence due to groundwater overexploitation by radar interferometry in the Aliabad plain(Central Iran).In this regard,vertical ground deformations were monitored over 18 months using the Sentinel-1A SAR images.To model the land subsidence by a multilayer perceptron(MLP)artificial neural network,four parameters,including groundwater level,alluvial thickness,elastic modulus,and transmissivity have been applied.The model's generalizability was assessed using data derived for 144 days.According to the results,the neural network estimates the land subsidence at each ground point with an accuracy of 6.8 mm.A comparison between the predicted and actual values indicated a significant agreement.The MLP model can be used to improve the results of subsidence detection in the study area or other areas with similar characteristics.

Large-Scale Carbon Dioxide Storage in Salt Caverns:Evaluation of Operation,Safety,and Potential in China

Underground salt cavern CO_(2) storage(SCCS)offers the dual benefits of enabling extensive CO_(2) storage and facilitating the utilization of CO_(2) resources while contributing the regulation of the carbon market.Its economic and operational advantages over traditional carbon capture,utilization,and storage(CCUS)projects make SCCS a more cost-effective and flexible option.Despite the widespread use of salt caverns for storing various substances,differences exist between SCCS and traditional salt cavern energy storage in terms of gas-tightness,carbon injection,brine extraction control,long-term carbon storage stability,and site selection criteria.These distinctions stem from the unique phase change characteristics of CO_(2) and the application scenarios of SCCS.Therefore,targeted and forward-looking scientific research on SCCS is imperative.This paper introduces the implementation principles and application scenarios of SCCS,emphasizing its connections with carbon emissions,carbon utilization,and renewable energy peak shaving.It delves into the operational characteristics and economic advantages of SCCS compared with other CCUS methods,and addresses associated scientific challenges.In this paper,we establish a pressure equation for carbon injection and brine extraction,that considers the phase change characteristics of CO_(2),and we analyze the pressure during carbon injection.By comparing the viscosities of CO_(2) and other gases,SCCS’s excellent sealing performance is demonstrated.Building on this,we develop a long-term stability evaluation model and associated indices,which analyze the impact of the injection speed and minimum operating pressure on stability.Field countermeasures to ensure stability are proposed.Site selection criteria for SCCS are established,preliminary salt mine sites suitable for SCCS are identified in China,and an initial estimate of achievable carbon storage scale in China is made at over 51.8-77.7 million tons,utilizing only 20%-30%volume of abandoned salt caverns.This paper addresses key scientific and engineering challenges facing SCCS and determines crucial technical parameters,such as the operating pressure,burial depth,and storage scale,and it offers essential guidance for implementing SCCS projects in China.

Hydrodynamic characteristics and particle tracking of 90° lateral intakes at an inclined river slope

Lateral intakes are common in rivers.The pump effciency and sediment deposition are determined by the local hydrodynamic characteristics and mainstream division width.The hydraulic characteristics of lateral withdrawal from inclined river slopes at different intake elevations should be investigated.Meanwhile,the division width exhibits significant vertical non-uniformity at an inclined river slope,which should be clarified.Hence,a three-dimensional(3-D)hydrodynamic and particle-tracking model was developed with the Open Source Field Operation and Manipulation(Open FOAM),and the model was validated with physical model tests for 90°lateral withdrawal from an inclined side bank.The flow fields,withdrawal sources,and division widths were investigated with different intake bottom elevations,withdrawal discharges,and main channel velocities.This study showed that under inclined side bank conditions,water entered the intake at an oblique angle,causing significant 3-D spiral flows in the intake rather than two-dimensional closed recirculation.A lower withdrawal discharge,a lower bottom elevation of the intake,or a higher main channel velocity could further strengthen this phenomenon.The average division width and turbulent kinetic energy were smaller under inclined side bank conditions than under vertical bank conditions.With a low intake bottom elevation,a low withdrawal discharge,or a high main channel velocity,the sources of lateral withdrawal were in similar ranges near the local inclined bank in the vertical direction.Under inclined slope conditions,sediment deposition near the intake entrance could be reduced,compared to that under vertical slope conditions.The results provide hydrodynamic and sediment references for engineering designs for natural rivers with inclined terrains.

Discussion on Land Use Mode Reform in Coal Opencast Mining

The existing land supply mode of opencast mining is"land requisition first,then transfer",which lacks an effective recovery and withdrawal mechanism,and the reclaimed mining land is difficult to withdraw.According to the regular rules of coal opencast mining and the periodic characteristics of land use,this paper puts forward a new mode of temporary land use for coal opencast mining.It is conducive to im-proving the quality and scale of land use and reclamation utilization of opencast coal mining,and is of great significance for exploring and for-mulating reasonable land use policies for mineral resources development projects.

A Problem Not to Be Ignored: The Influencing Factors of Mobile Phone Addiction and Its Influence on Sleep Quality

Background and Objective: With the popularity and widespread use of mobile phones, the effects of mobile phone dependence and addiction on individuals’ physical and mental health have attracted more and more attention. The present study aims to analyze the current state of mobile phone addiction and its impact on sleep quality within the population, while also exploring the influence of related factors on sleep quality. Ultimately, this research will provide a scientific foundation for targeted intervention measures and strategies. Methods: A total of 253 permanent residents in Nanjing were randomly selected as study subjects. The Mobile Phone Addiction Index (MPAI) and Pittsburgh Sleep Quality Index (PSQI) were used to evaluate the degree of smartphone addiction and sleep quality of the study subjects. Body mass index (BMI) was measured according to standardized procedures. Independent sample t-test, Chi-square test, rank sum test and multiple linear regression were used to analyze the correlation between mobile phone addiction and sleep quality, and P Results: 117 people (46.2%) were addicted to mobile phones. Chi-square test showed that the rate of mobile phone addiction in drinking group was significantly higher than that in non-drinking group (P P P P P P P P P P Conclusion: Mobile phone addiction may lead to shorter sleep duration and reduce sleep efficiency. The withdrawal of mobile phone addiction may have a negative impact on sleep quality. According to the characteristics of the population, appropriate comprehensive intervention measures should be taken to build an effective evaluation system, so as to reduce the impact of mobile phone addiction and withdrawal problems on sleep and improve sleep quality.

Electroslag Remelting Withdrawing Technology for Offshore Jack-up Platform Rack Steel Manufacturing Process

Offshore jack up platform rack steel must exhibit high strength and toughness as well as excellent welding properties. A high-quality large ingot is a prerequisite for obtaining a high-performance rough part. The electroslag remelting withdrawing （ESRW） technology using a T-shaped mold and bifilar mode was introduced to replace casting technology. Numerical simulation of the ESRW process was performed to determine the distribution of the temperature and velocity fields and to determine the optimum process for producing rack steels. Several A514Q slab ingots with dimensions of 0.32 m×1.40 m × 4.00 m were produced using ESRW technology in an industrial plant. The industrial test indicated that slab ingots produced by the ESRW method exhibited uniform chemical compositions and compact macrostructures. A 115.4 mm thick plate was produced from the rough ingot after 11 roiling passes. Samples were obtained from different positions in the steel plate to test the mechanical performance and examine the microstructure, and the results revealed that the properties of the steel plate satisfied ASTM standards. The ESRW process improved the tensile strength and toughness of the slab ingot, enabling significant improvements in the anisotropy and low temperature toughness, which are critical for the development of rack steel for offshore platforms.

Exit strategies in inflammatory bowel disease:Looking beyond antitumor necrosis factors

The long-term management of patients with inflammatory bowel disease(IBD)is still a matter of debate,and no clear guidelines have been issued.In clinical practice,gastroenterologists often have to deal with patients in prolonged remission after immunomodulatory or immunosuppressive therapies.When planning an exit strategy for drug withdrawal,the risk of disease relapse must be balanced against the risk of drug-related adverse events and healthcare costs.Furthermore,there is still a dearth of data on the withdrawal of novel biologics,such as the anti-α4β7 integrin antibody(vedolizumab)and anti-IL12/23 antibody(ustekinumab),as well as the small molecule tofacitinib.Models for estimating the risk of disease relapse and the efficacy of retreatment should be evaluated according to the patient's age and IBD phenotype.These models should guide clinicians in programming a temporary drug withdrawal after discussing realistic outcomes with the patient.This would shift the paradigm from an exit strategy to a holiday strategy.

A case of phenibut withdrawal and treatment with baclofen

Phenibut(β-phenyl-γ-aminobutyric acid)is a psychoactive gamma-aminobutyric acid(GABA)analog marketed online as a nutritional and nootropic(cognition enhancing)supplement.Phenibut consumption poses a high risk of potential abuse.Withdrawal from phenibut mimics benzodiazepine and alcohol withdrawal and can be dangerous.A number of approaches have been described for phenibut withdrawal,including protocols that include baclofen,but for inpatient and outpatient use.Here we describe a 30-year-old male who presented to an emergency department(ED)with insomnia,anxiety and palpitations after he stopped taking phenibut.

Withdrawal Intention of Farmers from Vacant Rural Homesteads and Its Influencing Mechanism in Northeast China: A Case Study of Jilin Province

The effective use of land in Northeast China is of great significance for ensuring national food security and regional rural revitalization.In this study,based on the survey data collected from Jilin Province,Northeast China,we analyzed the vacancy rates of rural homesteads in suburban,outer suburban,and remote villages,as well as the withdrawal intention of rural-settled farmers,urbansettled farmers,and farmers with urban and rural dual residency from vacant homesteads.From the perspective of farmers’perceptions,this study constructed a theoretical framework of the influence mechanism of their withdrawal intention and analyzed such mechanism by constructing a structural equation model.The results indicated that:1)rural homestead vacancy rates increased with distance from the village to the city.2)rural-settled farmers showed a low withdrawal intention for vacant rural homesteads,followed by urban and rural dual-residence farmers,and urban-settled farmers showed the highest withdrawal intention.3)the relative importance of the factors influencing withdrawal intention is in the following order:policy awareness>interest perception>living environment perception>family characteristics.Finally,this study discussed the reformation of the homestead system and rural homestead transition in Northeast China,which can provide policy support to increase the potential of cultivated land and promote sustainable rural development and urban-rural coordination.

Improving polyp detection at colonoscopy: Non-technological techniques

Colonoscopy and polypectomy remain the gold standard investigation for the detection and prevention of colorectal cancer.Halting the progression of colonic adenoma through adequate detection of pre-cancerous lesions interrupts the progression to carcinoma.The adenoma detection rate is a key performance indicator.Increasing adenoma detection rates are associated with reducing rates of interval colorectal cancer.Endoscopists with high baseline adenoma detection rate have a meticulous technique during colonoscopy withdrawal that improves their adenoma detection.This minireview article summarizes the evidence on the following simple operator techniques and their effects on the adenoma detection rate;minimum withdrawal times,dynamic patient position change and proximal colon retroflexion.

Clonidine use during dexmedetomidine weaning:A systematic review

BACKGROUND Dexmedetomidine is a centrally acting alpha-2A adrenergic agonist that is commonly used as a sedative and anxiolytic in the intensive care unit(ICU),with prolonged use increasing risk of withdrawal symptoms upon sudden discontinuation.As clonidine is an enterally available alpha-2A adrenergic agonist,it may be a suitable agent to taper off dexmedetomidine and reduce withdrawal syndromes.The appropriate dosing and conversion strategies for using enteral clonidine in this context are not known.The objective of this systematic review is to summarize the evidence of enteral clonidine application during dexmedetomidine weaning for prevention of withdrawal symptoms.AIM To systematically review the practice,dosing schema,and outcomes of enteral clonidine use during dexmedetomidine weaning in critically ill adults.METHODS This was a systematic review of enteral clonidine used during dexmedetomidine weaning in critically ill adults(≥18 years).Randomized controlled trials,prospective cohorts,and retrospective cohorts evaluating the use of clonidine to wean patients from dexmedetomidine in the critically ill were included.The primary outcomes of interest were dosing and titration schema of enteral clonidine and dexmedetomidine and risk factors for dexmedetomidine withdrawal.Other secondary outcomes included prevalence of adverse events associated with enteral clonidine use,re-initiation of dexmedetomidine,duration of mechanical ventilation,and ICU length of stay.RESULTS A total of 3427 studies were screened for inclusion with three meeting inclusion criteria with a total of 88 patients.All three studies were observational,two being prospective and one retrospective.In all included studies,the choice to start enteral clonidine to wean off dexmedetomidine was made at the discretion of the physician.Weaning time ranged from 13 to 167 h on average.Enteral clonidine was started in the prospective studies in a similar protocolized method,with 0.3 mg every 6 h.After starting clonidine,patients remained on dexmedetomidine for a median of 1-28 h.Following the termination of dexmedetomidine,two trials tapered enteral clonidine by increasing the interval every 24 h from 6 h to 8h,12h,and 24 h,followed by clonidine discontinuation.For indicators of enteral clonidine withdrawal,the previously tolerable dosage was reinstated for several days before resuming the taper on the same protocol.The adverse events associated with enteral clonidine use were higher than patients on dexmedetomidine taper alone with increased agitation.The re-initiation of dexmedetomidine was not documented in any study.Only 17(37%)patients were mechanically ventilated with median duration of 3.5 d for 13 patients in one of the 2 studies.ICU lengths of stay were similar.CONCLUSION Enteral clonidine is a strategy to wean critically ill patients from dexmedetomidine.There is an association of increased withdrawal symptoms and agitation with the use of a clonidine taper.

Artificial intelligence fails to improve colonoscopy quality:A single centre retrospective cohort study

BACKGROUND Limited data currently exists on the clinical utility of Artificial Intelligence Assisted Colonoscopy(AIAC)outside of clinical trials.AIM To evaluate the impact of AIAC on key markers of colonoscopy quality compared to conventional colonoscopy(CC).METHODS This single-centre retrospective observational cohort study included all patients undergoing colonoscopy at a secondary centre in Brisbane,Australia.CC outcomes between October 2021 and October 2022 were compared with AIAC outcomes after the introduction of the Olympus Endo-AID module from October 2022 to January 2023.Endoscopists who conducted over 50 procedures before and after AIAC introduction were included.Procedures for surveillance of inflammatory bowel disease were excluded.Patient demographics,proceduralist specialisation,indication for colonoscopy,and colonoscopy quality metrics were collected.Adenoma detection rate(ADR)and sessile serrated lesion detection rate(SSLDR)were calculated for both AIAC and CC.RESULTS The study included 746 AIAC procedures and 2162 CC procedures performed by seven endoscopists.Baseline patient demographics were similar,with median age of 60 years with a slight female predominance(52.1%).Procedure indications,bowel preparation quality,and caecal intubation rates were comparable between groups.AIAC had a slightly longer withdrawal time compared to CC,but the difference was not statistically significant.The introduction of AIAC did not significantly change ADR(52.1%for AIAC vs 52.6%for CC,P=0.91)or SSLDR(17.4%for AIAC vs 18.1%for CC,P=0.44).CONCLUSION The implementation of AIAC failed to improve key markers of colonoscopy quality,including ADR,SSLDR and withdrawal time.Further research is required to assess the utility and cost-efficiency of AIAC for high performing endoscopists.

中国疫苗供应管理现状及挑战

目的分析全国31个省(自治区、直辖市)和新疆生产建设兵团(以下简称“兵团”)的疫苗供应管理现状,总结我国疫苗供应管理的经验及面临的挑战,为疫苗供应管理决策提供参考。方法对全国31个省(自治区、直辖市)的省(自治区、直辖市)级疾病预防控制中心和兵团疾病预防控制中心进行机构问卷调查,调查内容为疫苗供应管理情况。结果全国31个省(自治区、直辖市)和兵团均出现过疫苗供应不及时的情况,供应延迟的平均天数普遍较长。疫苗配送的及时性总体良好。相比东中部地区,西部地区更需要采购应急疫苗。结论我国疫苗配送的及时性总体良好,对疫苗需求把控准确。但部分疫苗供应紧张,二类疫苗退出机制有待建立,西部地区在疫苗调动及库存把控方面有较大提升空间。

Effect of solidification rate on MC-type carbide morphology in single crystal Ni-base superalloy AM3

In order to study the effect of the withdrawing rate on carbide morphology,MC-type carbide in single crystal superalloy AM3 was systematically investigated with sample growth rates from 3.5 μm/s to 500 μm/s.The carbide morphologies were investigated by scanning electron microscopy(SEM),and the electron probe microanalysis(EPMA) was used to characterize the carbide composition.The results indicate that the solidification rate is the important factor governing MC carbide growth morphology,size and distribution,composition and growth mechanism.With the increase of withdrawing rate,nodular,rod-like,Chinese script types of carbide morphology are observed.For the low withdrawing rate,with the increase of withdrawing rate,the carbide size becomes larger.For the case of dendritic interface,the carbide size becomes smaller with refinement of dendrites as withdrawing rate increases.The volume fraction of carbides increases with the withdrawing rate increasing.

Non-fused medium bandgap electron acceptors for efficient organic photovoltaics

The cost-effective organic semiconductors are strongly needed in organic photovoltaics(OPVs). Herein,two medium bandgap(MBG) electron acceptors, TPT4F and TPT4Cl are developed via the new design of multi-noncovalent interaction assisted unfused core, flanked with two electron withdrawing end groups. These fullly non-fused MBG acceptors adapt the planar and rigid conformation in solid, therefore exhibiting the ordered face-on stacking and strong photoluminescence in films. As results, TPT4Cl^(-)based OPVs, upon blending with the PBDB-TF polymer donor, have achieved a power conversion efficiency of 10.16% with a low non-radiative loss of 0.27 e V, representing one of the best fullly non-fused medium bandgap acceptors with desirable cost-efficiency balance.

Thomas Chao’s Journalistic Activities and Influence on Increasing China’s Voice Worldwide

In the 1930s and 1940s,Thomas Chao,an internationally-renowned Chinese journalist,influenced Chinese journalists’way of covering and writing news with his own prominent experience in international news reporting.Based on his long-term news practice,Chao analyzed the differences between Chinese and Western press and explored the way for improvement.He called on the government to set up a national news agency so as to establish itself in the field of international communication,and helped the Central News Agency to take back Reuters’right to publish in China.Chao also actively promoted the exchange and cooperation between Chinese newspapers and news agencies and foreign press in international communication activities,striving to increase China’s voice worldwide.

Microstructure optimization of directionally solidified hypereutectic Nb-Si alloy

Nb-16Si-24Ti-10Cr-2A1-2Hf alloy was directionally solidified with withdrawal rates of 1.2, 6, 18, 36 and 50 mrn/min and then heat treated at 1400, 1450 and 1500℃with withdrawal rate of 50 mm/min for 10 h. The effects of withdrawal rate and heat treatment temperature on the microstructure were studied. The microstructure of directionally solidified alloy was composed of the primary NbsSi3, Nbss/NbsSi3 eutectic cells and Cr2Nb, which distribute paralleled to the growth direction. The microstructure becomes more refined with the increasing withdrawal rate, accompany with the evolution of eutectic cells morphology. After heat treatment, Nbss phase connects and forms a continuous matrix, and the Cr2Nb phase becomes smaller and distributes more dispersedly. After heat treatment at 1450 ℃ for 10 h, the alloy achieves balance between the optimization of microstructure and alleviation of solute segregation.

Recent Progress in Studies of the Variabilities and Mechanisms of the East Asian Monsoon in a Changing Climate

Located in a monsoon domain,East Asia suffers devastating natural hazards induced by anomalous monsoon behaviors.East Asian monsoon(EAM)research has traditionally been a high priority for the Chinese climate community and is particularly challenging in a changing climate where the global mean temperature has been rising.Recent advances in studies of the variabilities and mechanisms of the EAM are reviewed in this paper,focusing on the interannual to interdecadal time scales.Some new results have been achieved in understanding the behaviors of the EAM,such as the evolution of the East Asian summer monsoon(EASM),including both its onset and withdrawal over the South China Sea,the changes in the northern boundary activity of the EASM,or the transitional climate zone in East Asia,and the cycle of the EASM and the East Asian winter monsoon and their linkages.In addition,understanding of the mechanism of the EAM variability has improved in several aspects,including the impacts of different types of ENSO on the EAM,the impacts from the Indian Ocean and Atlantic Ocean,and the roles of mid-to high-latitude processes.Finally,some scientific issues regarding our understanding of the EAM are proposed for future investigation.