Can laser irradiation improve the strength of weak rock mass?

Controllable rock cracking technology is crucial for the exploration and exploitation of deep underground resources.Many existing studies have been dedicated to the laser-assisted rock-weakening technology.It has been proved that laser irradiation can improve drilling and blasting efficiency when combined with mechanical rock fracturing methods,which are irrelevant for borehole stabilization.To improve the latter,this study used laser ablation for borehole reinforcement.The high-power laser was applied to typical rock samples(sandstone,mudstone and coal)in both dry and saturated conditions.Multi-technique observations and measurements were used to fully understand the peculiar modifications of the specimens under laser treatment,i.e.mechanical loading,acoustic emission(AE)monitoring,digital image correlation(DIC)strain field evaluation,infrared thermography(IRT)monitoring and X-ray computed tomography(CT)scanning.The results showed that,in addition to the effects already demonstrated,laser irradiation can improve the strength of the soft rock,especially in the saturated state.The process involved a complicated phase change including melting and evaporation of the matrix under high-temperature and high-pressure to form a glassy high strength silicate material.This process is similar to the reaction between molten lava and water,or the impact of an asteroid on the earth.Inspired by the results,a conceptual path for a new borehole stabilization technology using laser ablation was outlined.

Microwave irradiation-induced deterioration of rock mechanical properties and implications for mechanized hard rock excavation

In this study,a novel microwave-water cooling-assisted mechanical rock breakage method was proposed to address the issues of severe tool wear at elevated temperatures,poor rock microwave absorption,and excessive microwave energy consumption.The investigation object was sandstone,which was irradiated at 4 kW microwave power for 60 s,180 s,300 s,and 420 s,followed by air and water cooling.Subsequently,uniaxial compression,Brazilian tension,and fracture tests were conducted.The evolution of damage in sandstone was measured using active and passive nondestructive acoustic detection methods.The roughness of the fracture surfaces of the specimens was quantified using the box-counting method.The damage mechanisms of microwave heating and water cooling on sandstone were discussed from both macroscopic and microscopic perspectives.The experimental results demonstrated that as the duration of the microwave irradiation increased,the P-wave velocity,uniaxial compressive strength(UCS),elastic modulus(E),tensile strength,and fracture toughness of sandstone exhibited various degrees of weakness and were further weakened by water cooling.Furthermore,an increase in the microwave irradiation duration enhanced the damaging effect of water cooling.The P-wave velocity of the sandstone was proportional to the mechanical parameters.Microwave heating and water cooling weakened the brittleness of the sandstone to a certain extent.The fractal dimension of the fracture surface was correlated with the duration of microwave heating,and the water-cooling treatment resulted in a rougher fracture surface.An analysis of the instantaneous cutting rate revealed that water cooling can substantially enhance the efficiency of microwave-assisted rock breakage.

Review on synergistic damage effect of irradiation and corrosion on reactor structural alloys

The synergistic damage effect of irradiation and corrosion of reactor structural materials has been a prominent research focus.This paper provides a comprehensive review of the synergistic effects on the third-and fourth-generation fission nuclear energy structural materials used in pressurized water reactors and molten salt reactors.The competitive mechanisms of multiple influencing factors,such as the irradiation dose,corrosion type,and environmental temperature,are summarized in this paper.Conceptual approaches are proposed to alleviate the synergistic damage caused by irradiation and corrosion,thereby promoting in-depth research in the future and solving this key challenge for the structural materials used in reactors.

Neutron irradiation influence on high-power thyristor device under fusion environment

Because of their economy and applicability,high-power thyristor devices are widely used in the power supply systems for large fusion devices.When high-dose neutrons produced by deuterium–tritium(D–T)fusion reactions are irradiated on a thyristor device for a long time,the electrical characteristics of the device change,which may eventually cause irreversible damage.In this study,with the thyristor switch of the commutation circuit in the quench protection system(QPS)of a fusion device as the study object,the relationship between the internal physical structure and external electrical parameters of the irradiated thyristor is established.Subsequently,a series of targeted thyristor physical simulations and neutron irradiation experiments are conducted to verify the accuracy of the theoretical analysis.In addition,the effect of irradiated thyristor electrical characteristic changes on the entire QPS is studied by accurate simulation,providing valuable guidelines for the maintenance and renovation of the QPS.

Demonstration of irradiation-resistant 4H-SiC based photoelectrochemical water splitting

4H silicon carbide(4H-SiC)has gained a great success in high-power electronics,owing to its advantages of wide bandgap,high breakdown electric field strength,high carrier mobility,and high thermal conductivity.Considering the high carrier mobility and high stability of 4H-SiC,4H-SiC has great potential in the field of photoelectrochemical(PEC)water splitting.In this work,we demonstrate the irradiation-resistant PEC water splitting based on nanoporous 4H-SiC arrays.A new two-step anodizing approach is adopted to prepare 4H-SiC nanoporous arrays with different porosity,that is,a constant low-voltage etching followed by a pulsed high-voltage etching.The constant-voltage etching and pulsed-voltage etching are adopted to control the diameter of the nanopores and the depth of the nanoporous arrays,respectively.It is found that the nanoporous arrays with medium porosity has the highest PEC current,because of the enhanced light absorption and the optimized transportation of charge carriers along the walls of the nanoporous arrays.The performance of the PEC water splitting of the nanoporous arrays is stable after the electron irradiation with the dose of 800 and 1600 k Gy,which indicates that 4H-SiC nanoporous arrays has great potential in the PEC water splitting under harsh environments.

In situ TEM investigation of electron irradiation and aging-induced high-density nanoprecipitates in an Mg-10Gd-3Y-1Zn-0.5Zr alloy

In-situ electron irradiation and aging are applied to introduce high-density precipitates in an Mg-10Gd-3Y-1Zn-0.5Zr(GWZ1031K,wt.%)alloy to improve the hardness.The results show that the hardness of the Mg alloy after irradiation for 10 h and aging for 9 h at 250℃ is 1.64 GPa,which is approximately 64% higher than that of the samples before being treated.It is mainly attributed to γ'precipitates on the basal plane after irradiation and the high-density nanoscale β'precipitates on the prismatic plane after aging,which should be closely related to the irradiation-induced homogenous clusters.The latter plays a key role in precipitation hardening.This result paves a way to improve the mechanical properties of metallic materials by tailoring the precipitation through irradiation and aging.

Microwave irradiation-induced alterations in physicochemical properties and methane adsorption capability of coals:An experimental study using carbon molecular sieve

In order to comprehend the applicability of microwave irradiation for recovering coalbed methane,it is necessary to evaluate the microwave irradiation-induced alterations in coals with varying levels of metamorphism.In this work,the carbon molecular sieve combined with KMnO_(4)oxidation was selected to fabricate carbon molecular sieve with diverse oxidation degrees,which can serve as model substances toward coals.Afterwards,the microwave irradiation dependences of pores,functional groups,and highpressure methane adsorption characteristics of model substances were studied.The results indicated that microwave irradiation causes rearrangement of oxygen-containing functional groups,which could block the micropores with a size of 0.40-0.60 nm in carbon molecular sieve;meanwhile,naphthalene and phenanthrene generated by macro-molecular structure pyrolysis due to microwave irradiation could block the micropores with a size of 0.70-0.90 nm.These alterations in micropore structure weaken the saturated methane adsorption capacity of oxidized carbon molecular sieve by 2.91%-23.28%,suggesting that microwave irradiation could promote methane desorption.Moreover,the increased mesopores found for oxidized carbon molecular sieve after microwave irradiation could benefit CH4 diffusion.In summary,the oxidized carbon molecular sieve can act as model substances toward coals with different ranks.Additionally,microwave irradiation is a promising technology to enhance coalbed methane recovery.

Two-dimensional particle-in-cell modeling of blow-off impulse by X-ray irradiation

Space objects such as spacecraft or missiles may be exposed to intense X-rays in outer space,leading to severe damage.The reinforcement of these objects to reduce the damage caused by X-ray irradiation is a significant concern.The blow-off impulse(BOI)is a crucial physical quantity for investigating material damage induced by X-ray irradiation.However,the accurate calculation of BOI is challenging,particularly for large deformations of materials with complex configurations.In this study,we develop a novel two-dimensional particle-in-cell code,Xablation2D,to calculate BOIs under far-field X-ray irradiation.This significantly reduces the dependence of the numerical simulation on the grid shape.The reliability of this code is verified by simulation results from open-source codes,and the calculated BOIs are consistent with the experimental and analytical results.

Effect of high-energy Ne ions irradiation on mechanical properties difference between Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5)metallic glass and crystalline W

In this paper,high-energy Ne ions were used to irradiate Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5) metallic glass(MG)and crystalline W to investigate their difference in mechanical response after irradiation.The results showed that with the irradiation dose increased,the tensile micro-strain increased,nano-hardness increased from 7.11 GPa to 7.90 GPa and 8.62 GPa,Young’s modulus increased,and H3/E2 increased which indicating that the plastic deformability decreased in crystalline W.Under the same irradiation conditions,the Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5) MG still maintained the amorphous structure and became more disordered despite the longer range and stronger displacement damage of Ne ions in Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5) MG than in crystalline W.Unlike the irradiation hardening and embrittlement behavior of crystalline W,Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5) MG showed the gradual decrease in hardness from 6.02 GPa to 5.89 GPa and 5.50 GPa,the decrease in modulus and the increase in plastic deformability with the increasing dose.Possibly,the irradiation softening and toughening phenomenon of Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5) MG could provide new ideas for the design of nuclear materials.

Effect of three-volt moxibustion with helium-neon laser irradiation on quality of care in patients with lumbar radiculopathy spondylosis

BACKGROUND Lumbar radiculopathy spondylosis is a relatively common orthopedic disease with a high incidence rate.It most commonly occurs in the lumbar 4-5 and lumbar 5-sacral 1 vertebrae,which account for approximately 95%of cases.It mostly occurs in people aged 30-50 years old and greatly affects their quality of life.AIM To determine the effect of triple-voltage acupuncture combined with helium-neon laser irradiation on the quality of care and improvement of symptoms in patients with lumbar radiculopathy spondylolisthesis.METHODS In this study,we selected 120 patients with lumbar radiculopathy spondylosis who were treated at our hospital between June 2019 to June 2020.The patients were divided into control and observation groups according to the random number table method,with 60 patients in each group.Patients in the observation group were treated with three-volt moxibustion combined with helium-neon laser irradiation,and those in the control group were treated with lumbar traction.After 1 month of treatment,the lumbar pain scores,lumbar spine motor functions,clinical treatment effects,and nursing satisfaction of the two groups were compared.RESULTS The results showed that acupuncture combined with laser irradiation significantly improved the patients'clinical symptoms,i.e.,reduced their low back pain,significantly lower numerical rating scale pain scores in the observation group than in the control group,and better lumbar spine motility than in the control group,compared to lumbar traction.In addition,they were cared for.The treatment effectiveness rate of the observation group was 95.5%,which was significantly higher than that of the control group(81.67%).Satisfaction with care was higher than 90 points in both groups,but the difference was not statistically significant.CONCLUSION Our study provides a clinical rationale for the future treatment of patients with lumbar spine disease.However,further extensive research is needed for validation.

Development of a new irradiation-embrittlement prediction model for reactor pressure-vessel steels

Predicting the transition-temperature shift(TTS)induced by neutron irradiation in reactor pressure-vessel(RPV)steels is important for the evaluation and extension of nuclear power-plant lifetimes.Current prediction models may fail to properly describe the embrittlement trend curves of Chinese domestic RPV steels with relatively low Cu content.Based on the screened surveillance data of Chinese domestic and similar international RPV steels,we have developed a new fluencedependent model for predicting the irradiation-embrittlement trend.The fast neutron fluence(E>1 MeV)exhibited the highest correlation coefficient with the measured TTS data;thus,it is a crucial parameter in the prediction model.The chemical composition has little relevance to the TTS residual calculated by the fluence-dependent model.The results show that the newly developed model with a simple power-law functional form of the neutron fluence is suitable for predicting the irradiation-embrittlement trend of Chinese domestic RPVs,regardless of the effect of the chemical composition.

The impact of^(60)Co-γirradiation on the chemical constituents of Chuanxiong Rhizoma

Background:In order to clarify the inmpat ofγirradiation on the chemical composition of traditional Chinese medicine,this paper carefully choosed Chuanxiong Rhizoma to carry on a demonstration study.Methods:Through a meticulous assessment,a comprehensive comparison was made between the irradiated and unirradiated Chuanxiong Rhizoma samples.The property characteristics were investigated by colorimeter and electronic nose.The changes in chemical structures and contents was analyzed by fourier infrared spectroscopy,high performance liquid chromatography and fingerprinting.In a quest to uncover the presence of any new radiolysis products,cutting-edge techniques like ultra performance liquid chromatography-quadrupole-time of flight-mass spectrometry and gas chromatography-mass spectrometry were employed.Moreover,the difference of antioxidant activity were investigated.Results:The irradiation doses within 12 kGy had no significant effects on the content of the main chemical components,characteristics and in vitro antioxidant activity of Chuanxiong Rhizoma,while changes in some functional groups and degradation of some volatile oil components containing olefins need further study.Conclusion:This study indicates that^(60)Co-γirradiation is a stable method for sterilization of Chuanxiong Rhizoma.It’s also provide a reference for the establishment of irradiation standards for Chuanxiong Rhizoma and other aromatic medicinal plants.

Observation of therapeutic effect of lamp irradiation combined with purple gromwell oil gauze on alleviating intestinal colic in patients

BACKGROUND Intestinal colic is a common complication in patients who have undergone radical surgery for colorectal cancer.Traditional Chinese medicine has advantages,including safety and stability,for the treatment of intestinal colic.Lamp irra-diation for abdominal ironing has been applied in the treatment of many gas-trointestinal diseases.Purple gromwell oil has the effects of clearing heat,cooling blood,reducing swelling,and relieving pain.RESULTS The general effective rate in the observation group was 95.00%,which was significantly higher than that in the control group(86.67%,P<0.05).Before treatment,there was no significant difference in the duration of symptoms between the groups(P>0.05).After 1,2,3,and 4 d of treatment,the duration of symptoms in both groups were decreased,and the duration in the observation group was significantly lower than that in the control group(96.54±9.57 vs 110.45±11.23,87.26±12.07 vs 104.44±11.68,80.45±16.21 vs 99.44±14.95,73.18±15.58 vs 92.17±14.20;P<0.05).After 1,3,5,and 7 d of treatment,the NRS scores in both groups were decreased,and the NRS scores in the observation group were significantly lower than those in the control group(3.56±0.41 vs 4.04±0.58,3.07±0.67 vs 3.74±1.02,2.52±0.76 vs 3.43±0.85,2.03±0.58 vs 3.03±0.82;P<0.05).There was no significant difference in the rate of adverse reaction occurrence between the groups(P>0.05).CONCLUSION The use of lamp irradiation combined with purple gromwell oil gauze in patients with intestinal colic after radical surgery for colorectal cancer can reduce symptom duration,alleviate intestinal colic,and improve treatment efficacy,and this approach is safe.It is worth promoting the use of this treatment in clinical practice.

Protective and Regenerative Efficacy of a Plant Oil-Based Day and Night Cream: Investigated by a Novel Approach to Reveal the Impact of Blue Light Irradiation on Epidermal Barrier Integrity and Lipid Matrix

In recent years, the harmful effects of blue light (400 - 500 nm) as a component of visible light (400 - 700 nm) have increasingly gained attention of science, industry, and consumers. To date, only a few in vivo test methods for measuring the effects of blue light on the skin have been described. A direct measurement method that can detect the immediate effects of blue light on the epidermal permeability barrier (EPB) is still lacking. In this study, we present a new methodological approach that can be used to investigate both the protective and regenerative effects of cosmetic products on the EPB after blue light irradiation. In a study with 14 female volunteers, it was investigated whether the regular application of an O/W emulsion (day cream) can strengthen and protect the epidermal barrier against damaging blue light radiation of 60 J/cm2 (protective study design) and also whether a disruption of the epidermal barrier caused by blue light radiation is restored faster and better by the regular application of another O/W emulsion (night cream) than in product-untreated skin (regenerative study design). The two O/W emulsions are different in plant oil, active ingredient composition and texture. The seven-day treatment with the day cream initially led to a significant increase in the normalized lipid lamellae length in the intercellular space, whereas the irradiation with blue light after 24 hours led to a significant decrease in the lipid lamellae length in the untreated test area, but not in the area previously treated with the product. Regarding the regenerative study design, a two-day treatment with the night cream was able to restore a blue-light-induced decrease in lipid lamellae length in the intercellular space. In summary, with the study designs presented here, the protective and regenerative effect of two cosmetic products could be demonstrated for the first time on the integrity of the EPB after blue light irradiation and the data showed that the Lipbarvis® method is suitable for investigating the damaging effects of blue light on the EPB in vivo.

辐照技术在提升盐水鹅卫生安全中的应用

盐水鹅是中国传统鹅肉制品,其营养丰富、水分含量高,在生产、运输、贮存过程中极易被有害微生物污染,而生产技术落后、标准不配套、食品安全隐患、货架期短等是盐水鹅产业发展的主要瓶颈。因此,开展延长货架期、提升卫生安全性的研究至关重要。食品辐照技术是非热杀菌技术,具有高效、节能、安全、绿色、便捷等特点,是国家大力支持的高新技术。文章结合盐水鹅卫生安全现状,介绍食品辐照杀菌技术的应用概况,阐述辐照技术在提升盐水鹅卫生安全性方面应用的工艺要求,分析影响盐水鹅辐照效果的因素,提出辐照技术与其他技术结合在盐水鹅生产中的应用,以期为盐水鹅产品提供安全、简便、快捷的技术支撑,同时为推动盐水鹅产业化快速发展提供参考。

光谱辐射照度国际关键比对装置、方法与结果分析

基于高温黑体辐射源和双光栅光谱辐射比较测量系统,中国计量科学研究院自主研制了新一代光谱辐射照度国家基准装置,波长范围覆盖230~2550 nm,以一组稳定的卤钨灯作为副基准灯组,保存和传递光谱辐射照度量值。黑体的温度溯源至铂-碳Pt-C和铼-碳Re-C共晶点黑体,在3021 K采用钨碳-碳WC-C共晶点黑体进行验证。采用新基准装置,2017年-2019年NIM参加国际计量局组织的光谱辐射照度国际关键比对CCPR-K1.a,比对由全俄光学物理学测量研究院(VNIIOFI)主导,共有12个实验室参加。比对结果表明:除少数实验室外,在250~290、300~1300、1500~2500 nm波长范围,各参比实验室之间的一致性分别为±2.0%、±1.0%和±2.0%。在紫外、可见和近红外波段,NIM与国际比对参考值的平均相对偏差分别为0.13%、0.28%和0.15%。在250~2500 nm全波段,NIM与国际比对参考值的平均相对偏差为0.17%,与2004年平均相对偏差0.9%相比,测量能力提升显著。

高聚焦性双梯形双层经颅磁线圈的设计

基于聚焦性能对经颅磁线圈的影响,针对聚焦型线圈商用不足的问题,设计一种具有高聚焦性的单通道双梯形双层线圈。首先使用球头模型分析不同尺寸、相同结构的线圈性能,得到较优的线圈尺寸;为进一步提升聚焦度,再以中尺寸线圈为研究目标,探讨五种不同结构的双层线圈与两种商用8字形线圈的性能差异,得到最优线圈的结构;最后使用50组存在个体差异性的真实脑模型进行仿真验证,分析球头模型结果的可靠性。仿真结果表明:使用球头模型时,优化后的新型线圈对比70 mm figure-8 coil的聚焦度提升了69.48%,刺激深度减少了27.18%;对比25 mm figure-8 coil的聚焦度提升了44.78%,刺激深度减少了8.5%;使用50组真实脑模型时,优化后的新型线圈对比70 mm figure-8 coil的聚焦度提升了62.07%,刺激深度减少了25.71%;对比25 mm figure-8 coil的聚焦度提升了39.49%,刺激深度减少了9.5%。两种模型仿真数据结果趋于一致,证实了仿真可靠性的同时也证明了新型线圈具有更强的刺激强度和聚焦度,能大大提升TMS治疗的安全性,减少不适感,同时单通道设计易于实现,具有较高的性能优势。

“安息香和二苯乙二酮的制备及表征”实验的改进与创新

安息香及二苯乙二酮的制备与表征是综合化学实验中涉及到有机合成的经典实验项目。然而现有的实验方案存在反应原料需要减压蒸馏纯化、安息香产率低、二苯乙二酮的合成时间较长的不足,为此,进行了创新设计和改进。用饱和碳酸氢钠溶液洗涤纯化了原料苯甲醛,调控氢氧化钠的滴加速度和滴加温度,并且采用逐步升温法优化合成了安息香,进而以安息香为原料,运用微波辐射法合成了二苯乙二酮。结果表明:用饱和碳酸氢钠可纯化原料苯甲醛;在室温下控制氢氧化钠溶液的滴加时间在20 min,逐步加热至70℃,反应60 min合成的安息香产率约为50%,产率提高了15%;再以制备的安息香为原料,优化了二苯乙二酮的合成条件,微波辐射反应16 min时,其产率约为90%,反应时间明显缩短。通过改进和创新,实验设计更加合理,培养了学生综合实验技能和自主探究的能力。

《涉及精神障碍临床研究的伦理审查指南》解析

科技伦理治理中涉及精神障碍临床研究的伦理审查具有明显的特殊性,尤其在人工智能与脑机接口领域,体现在对精神自主性的影响、严重精神障碍研究参与者参加研究的知情同意能力受损等方面;另外,临床研究中的病耻感、安慰剂应用及心理评估的方法等,也使得精神医学伦理审查备受关注。2020年,北京市卫生健康委员会发布了《涉及精神障碍临床研究的伦理审查指南》,《沈渔邨精神病学》(第七版)对《涉及精神障碍临床研究的伦理审查指南》在伦理治理背景下的应用进行了修订,对其印发和修订的目的和意义、适用范围、医疗卫生机构伦理审查的主体责任、精神医学伦理审查的重点内容进行了分析,以提高涉及精神障碍临床研究的伦理审查质量,推动精神医学临床研究的规范发展。

缺血性脑损伤中铁死亡及中药干预调控的作用与机制

背景:铁死亡是一种铁依赖性脂质过氧化调控的程序性细胞死亡方式,与缺血性脑损伤的发生、发展及转归密切相关。近年来,随着对铁死亡研究的不断深入,发现中药复方、中药单体可通过减轻铁超载、减少活性氧产生、调控脂质合成等方式调节铁死亡,减轻脑缺血损伤,促进神经功能恢复。目的:探讨铁死亡与缺血性脑损伤的关系及中药调控铁死亡治疗缺血性脑损伤的作用机制。方法:以“铁死亡,缺血性中风,脑损伤,活性氧,脂质代谢,中药复方,萜类,黄酮,酚类,生物碱,苯酞类等”为中文检索词,以“Iron death,ischemic stroke,brain injury,reactive oxygen species,lipid metabolism,traditional Chinese medicine formulas,terpenes,flavonoids,phenols,alkaloids,phthalides,etc”为英文检索词,检索2018年1月至2024年5月中国知网和PubMed数据库中有关铁死亡与缺血性脑损伤及中药调控机制的文献,排除与文章相关性不高及重复、过时的文献。共检索出1526篇相关文献,最终纳入87篇文献进行综述。结果与结论:大量实验研究证实,铁死亡在缺血性脑损伤中具有重要作用,中医方药可通过多种方式调节铁死亡,如三七总皂苷可调节铁代谢,抑制脂质过氧化;香芹酚通过增加谷胱甘肽过氧化物酶4表达,抑制神经元铁死亡;中药复方和单体有效成分可调控铁死亡相关通路——谷胱甘肽/谷胱甘肽过氧化物酶4(GPX4)、核因子E2相关因子2(Nrf2)/血红素加氧酶1(HO-1)、铁死亡抑制蛋白1(FSP1)/CoQ10及鸟苷三磷酸环水解酶1(GCH1)/四氢生物喋呤(BH4)等,减少神经元损伤和死亡,发挥脑保护作用。