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.

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.

Determination of Timer Error and Evaluation of Its Effect on Dose for OB6, GammaBeam X200 and X-Ray Irradiators at the Secondary Standard Dosimetry Laboratory in Nigeria

Timer error as well as its convention is very important for dose accuracy during irradiation. This paper determines the timer error of irradiators at Secondary Standard Dosimetry Laboratory (SSDL) in Nigeria. The irradiators are Cs-137 OB6 irradiator and X-ray irradiators at the Protection level SSDL;and Co-60 irradiator at the Therapy Level SSDL. PTW UNIDOS electrometer and LS01 Ionization chamber were used at the Protection Level to obtain doses for both Cs-137 OB6 and X-ray irradiators while an IBA farmer type ionization chamber and an IBA DOSE 1 electrometer were used at the Protection Level SSDL. Single/multiple exposure method and graphical method were used in the determination of the timer error for the three irradiators. The timer error obtained for Cs-137 OB6 irradiator was 0.48 ± 0.01 s, the timer error for the X-ray irradiator was 0.09 ± 0.01 s while the timer error obtained for GammaBeam X200 was 1.21 ± 0.04 s. It was observed that the timer error is not affected by source to detector distance. It was also observed that the timer error of Co-60 Gamma X200 irradiator is increasing with the age of the machine. Source to detector distance and field size do not contribute towards the timer error of the irradiators. The timer error of the Co-60 Gamma X200 irradiator (the only irradiator among the irradiators with a pneumatic system) increases with the age of the irradiator.

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.

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.

Study on γ-Ray Irradiation Mutation of Bacillus subtilis NCD-2

[Objective] To study the effect of 60Co γ-rays irradiation on Botrytis cinerea biocontrol strains—Bacillus subtilis NCD-2. [Method] NCD-2 cells were irradiated at different doses of γ-rays from 100 to 2 000 Gy. The strains were screened by plate confrontation method and Oxford cup diffusion. [Result] The curves of the relationship of irradiation dose and mutation and lethal rate were obtained. The results showed that lethal rate increased with the increasing of irradiation dose. The lethal rate of 1 000 Gy irradiation dose reached 99.50%. The mutation rate increased below 500 Gy and decreased above 500 Gy. The highest mutation rate occurred when the irradiation dose was between 400 and 700 Gy, and the average mutation rate was above 15%. The optimal irradiation dose was 500 Gy, when the average mutation rate was 26.51% and lethal rate was 77.71%. [Conclusion] This study provided references for γ-rays irradiation mutation of Bacillus subtilis.

SRAP Marker Analysis of Genomic Mutation Induced by ^(60)Coγ-Ray Irradiation in Potato (Solanum tuberosum)

[Objective] This study was to explore the mutagenic effect of 60Co γ-ray on Solanum tuberosum chromosomes.[Method] The 60Co γ-ray at different irradiation doses was applied to treat the minitubers of potato variety ＇Favorita＇,and the genomic mutations in VM1 and VM2 gene rations in treatments with different doses were analyzed by SRAP markers.[Resalt] Thirty pairs of SRAP primers out of 88 pairs exhibited polymorphism with a rate of 34.1％ in the bulked selection of VM1 generation.A total of 225 bands were obtained,of which 64 were polymorphic with a rate of 28.4％.The polymorphism was reflected in the forms of deleted bands and added bands.Based on the result of the bulked selection of VM1 generation,25 primers with polymorphism were selected to scan VM2 generation.Five primers performed poorly,and nine of the rest 20 pairs revealed polymorphism and obtained nine polymorphic bands,of which only four bands were detected in VM1 generation and the other five ones were newly deleted bands.Only 9.8％ of the bands detected in VM1 generation were obtained in VM2 generation.Eventually,nine stable and dear polymorphic bands were recovered and cloned,and DNA sequences of six bands of them were acquired by sequencing.According to the comparative analysis,five fragments sequences were similar to potato chromosome with a similarity rate of 77％-89％,three of them located at the resistance gene cluster; another one fragment had a similarity of 93％ with some regions of the No.5 chromosome in tomato.[Conclusion] 60Co γ-ray irradiation can cause mutation of genomic DNA in potato;there is no significant correlation between the number of polymorphic bands and the irradiation dose; potymorphic bands are characterized by a larger number of deleted bands than that of the added ones.

The Degradation of FB1 in Aqueous Acetonitrile and Corn Following γ-ray Irradiation

To investigate the degradation of FB1 in aqueous acetonitrile and corn af-ter γ-ray irradiation, the radiolytic products of FB1 was detected preliminarily. The results showed that γ-ray irradiation could degrade FB1 in aqueous acetonitrile;When the radiation dose was below 9 kGy, the degradation of FB1 in corn was not significant. The degradation rates of FB1 with concentrations of 0.8 mg/ml, 10.0 μg/ml, 1.0 μg/ml and 50 ng/ml after irradiation at 9 kGy were 22.5%, 51.0%, 59.0% and 64.8% respectively; when irradiation dose was increased to 100 kGy, the degrada-tion rate of FB1 with concentration of 0.8 mg/ml was up to 90%, and it was nearly 100% when irradiation dose was increased to 200 kGy. No representative products of FB1 were detected by LC/MS/MS analysis.

Enhanced Enzymatic Hydrolysis of Miscanthus sinensis Following Synergic Pretreatment with ^(60)Co γ-ray Irradiation and Alkaline Hydrogen Peroxide

[Objective] This study aimed to investigate the effects of different pretreat- ments on enzymatic saccharification of Miscanthus sinensis and improve reducing sugar yield in the enzymolysis process. [Method] M. sinensis was pretreated with 60Co y-ray irradiation and alkaline hydrogen peroxide, to analyze their effects on re- ducing sugar yield of enzymatic hydrolysis. [Result] After pretreatment with 400 kGy 60Co y-ray irradiation, reducing sugar yield in the enzymolysis process of M sinensis was 76.24 mg/g; after synergic pretreatment with 400 kGy 60Co y-ray irradiation and alkaline hydrogen peroxide, reducing sugar yield in the enzymolysis process of M. sinensis was 505.08 mg/g, which was improved by 5.6 times compared to that in pretreatment with 400 kGy 60Co y-ray irradiation. Based on process optimization, the optimal hydrolysis conditions were obtained： pretreatment temperature 30 ℃, NaOH concentration 1.2%, hydrogen peroxide concentration 2%, pretreatment time 6 h. [Conclusion] Synergic pretreatment with 60Co y-ray irradiation and alkaline hydrogen peroxide could significantly improve reducing sugar yield in the enzymolysis process of M. sinensis, which provided a new theoretical basis for preparing fuel ethanol with M. sinensis.

Simple synthesis of silver nanocluster composites AgNCs@PE-g-PAA by irradiation method and fluorescence detection of Cr^(3+)

Silver nanoclusters(AgNCs)are a new type of nanomaterials with similar properties to molecules and unique applications.The applications of AgNCs can be significantly expanded by combining them with different matrix materials to obtain AgNC composites.Using irradiation techniques,we developed a simple two-step method for preparing silver nanocluster composites.First,polyacrylic acid(PAA)chains were grafted onto the surface of a PE film as templates(PE-g-PAA).Subsequently,silver ions were reduced in situ on the surface of the template material to obtain the AgNC composites(AgNCs@PE-g-PAA).The degree of AgNC loading on the composite film was easily controlled by adjusting the reaction conditions.The loaded AgNCs were anchored to the carboxyl groups of the PAA and wrapped in the graft chain.The particle size of the AgNCs was only 4.38±0.85 nm,with a very uniform particle size distribution.The AgNCs@PE-g-PAA exhibited fluorescence characteristics derived from the AgNCs.The fluorescence of the AgNCs@PE-g-PAA was easily quenched by Cr^(3+)ions.The composite can be used as a fluorescence test paper to realize visual detection of Cr^(3+).

Bi-LSTM-Based Deep Stacked Sequence-to-Sequence Autoencoder for Forecasting Solar Irradiation and Wind Speed

Wind and solar energy are two popular forms of renewable energy used in microgrids and facilitating the transition towards net-zero carbon emissions by 2050.However,they are exceedingly unpredictable since they rely highly on weather and atmospheric conditions.In microgrids,smart energy management systems,such as integrated demand response programs,are permanently established on a step-ahead basis,which means that accu-rate forecasting of wind speed and solar irradiance intervals is becoming increasingly crucial to the optimal operation and planning of microgrids.With this in mind,a novel“bidirectional long short-term memory network”(Bi-LSTM)-based,deep stacked,sequence-to-sequence autoencoder(S2SAE)forecasting model for predicting short-term solar irradiation and wind speed was developed and evaluated in MATLAB.To create a deep stacked S2SAE prediction model,a deep Bi-LSTM-based encoder and decoder are stacked on top of one another to reduce the dimension of the input sequence,extract its features,and then reconstruct it to produce the forecasts.Hyperparameters of the proposed deep stacked S2SAE forecasting model were optimized using the Bayesian optimization algorithm.Moreover,the forecasting performance of the proposed Bi-LSTM-based deep stacked S2SAE model was compared to three other deep,and shallow stacked S2SAEs,i.e.,the LSTM-based deep stacked S2SAE model,gated recurrent unit-based deep stacked S2SAE model,and Bi-LSTM-based shallow stacked S2SAE model.All these models were also optimized and modeled in MATLAB.The results simulated based on actual data confirmed that the proposed model outperformed the alternatives by achieving an accuracy of up to 99.7%,which evidenced the high reliability of the proposed forecasting.

Effects of Corticosterone, cAMP, cGMP, Ca^(2+), and Protein Kinase C on Apoptosis of Mouse Thymocytes Induced by X-ray Irradiation

Objective To observe the effects of signal factors of corticosterone （CS）, cAMP, cGMP, Ca^2＋ and protein kinase C （PKC） on lymphocyte apoptosis in mouse thymus induced by X-rays of 4 Gy in vitro. Methods The DNA lyric rate for thymocytes was measured by fluomspectrophotometry. Results The DNA lyric rate for thymocytes 4-8 hours after irradiation with 2-8 Gy was significantly higher than that in the control （P〈0.01）. As compared with the control, the DNA lyric rate for thymocytes treated with 0.01 μnol/L CS （P〈0.01）, 50 ng/mL cAMP （P〈0.01）, 0.05-0.4 μg/mL ionomycin （Iono, P〈0.05 or P〈0.01） or 0.05-0.4 ng/mL phorbol myristate acetate （PMA, P〈0.05 or P〈0.01）, respectively, was significantly increased, while the rate for thymocytes treated with 50 ng/mL cGMP was not significantly increased. The DNA lyric rate for thymocytes treated with 0.01 μmol/L CS （P〈0.01）, 50 ng/mL cAMP （P〈0.01）, 0.2 and 0.4 μg/mL Iono （P〈0.05）, and 0.2 and 0.4 ng/mL PMA （P〈0.05） plus 4-Gy irradiation, respectively, was significantly higher than that treated with single 4-Gy irradiation, while the rate for thymocytes treated with 50 ng/mL cGMP plus 4-Gy irradiation was not increased. When both 0.4 I.tg/mL Iono and 0.4 ng/mL PMA acted on the thymocytes, the DNA lyric rate for thymocytes was significantly higher than that in the control （P〈0.01）, the DNA lytic rate for thymocytes treated with both 0.4 μg/mL Iono and 0.4 ng/mL PMA plus 4-Gy irradiation was significantly higher than that treated with single 4-Gy irradiation （P〈0.05）, but was Iono plus 4-Gy irradiation or 0.4 ng/mL PMA plus 4-Gy irradiation. can promote thymocyte apoptosis induced by larger dose X-rays. not significantly higher than that treated with 0.4 μg/mL Conclusion CS, cAMP, Ca^2＋, and PKC signal factors can promote thymocyte apoptosis induced by larger dose X-rays.