Electron-beam radiation effects on the structure and properties of polypropylene at low dose rates

While the high-energy radiation effects on polypropylene, which are crucial for the cable industry for nuclear power plants, have been thoroughly studied, the property changes of PP at low-dose-rate electron-beam irradiation are far from elucidated. Herein, the influence of electron-beam irradiation on the structure and properties of PP was examined. The static EB irradiation conditions were 1.2 MeV at a low dose rate of 20 kGy/h to achieve absorbed doses ranging from 45, to 60, 100, and 200 kGy.The molecular structure was first evaluated by measuring the carboxyl index and the relative radical concentrations via Fourier transform infrared spectroscopy and electron spin resonance, respectively. Mechanical, differential scanning colorimetric, and rheological tests were carried out to further investigate the changes in the properties(tensile, crystalizing, and viscoelastic properties) of irradiated PP, which showed good agreement with the structural analysis results. We found that radio-oxidative degradation(chain scission) was predominant, which can be due to the low dose rate facilitating oxygen diffusion into the PP matrix during electron-beam irradiation.

Effect of Low Dose Radiation on Intracellular Calcium and Protein Kinase C in Lymphocytes

It is first reported in the present paper that whole-body irradiation (WBI) with low dose X-rays could increase intracellular calcium ions ([Ca2+]i) and stimulate protein kinase C (PKC) activity of mouse lymphocytes. Following WBI of male Kunming micc With 75 mGy X-rays at a dose rate of 12.5 mGy/min the mobilization of [Ca2+]i with Con A in CD4+ and CD8+ Cells in the thymus and spleen was potentiated and the amplitude of [Ca2+], mobilization in thymocytes in response to anti-CD3 monoclonal antibody increased with time from 4 to 24 h following low dose radiation. The PKC activity in the homogenate of spleen was markedly stimulated 12 h after WBl with 75 mGy, reaching its peak value at 24-48 h and coming down to lower than normal on day 7. However, the PKC activity in the separated T lymphocytes reached its peak value at 12 h and that in the B lymphocytes reached its peak value on day 4, both coming down to below control on day 7. The implications of this facilitation of signal transduction in T lymphocytes in the mechanism of immunoenhancement after low dose radiation were discussed

Effects of Low Concentrations of Di-(2-ethylhexyl) and Mono-(2-ethylhexyl) Phthalate on Steroidogenesis Pathways and Apoptosis in the Murine Leydig Tumor Cell Line MLTC-1

The aim of this study was to evaluate the effects of low concentrations of DEHP and MEHP on steroidogenesis in a murine Leydig tumor cell line （MLTC-1） in vitro. The result of flow cytometry analysis revealed that the proportion of apoptotic cells was significantly increased after the exposure to DEHP. All three genes （P450scc, P450c17, and 38HSD） under study showed an increased expression following exposure to DEHP or MEHP, although some insignificant inhibitory effects appeared in the 10μmol/L treatment group as compared with the controls. It was also found that DEHP or MEHP stimulated INSL3 mRNA and protein especially in the 0.001 μmol/L treatment group. Testosterone secretions were stimulated after the exposure to DEHP or MEHP. Alterations of steroidogenic enzymes and INSL3 in MLTC-1 cells might be involved in the biphasic effects of DEHP/MEHP on androgen production.

The Promotion Effect of Low-Molecular Hydroxyl Compounds on the Nano-Photoelectrocatalytic Degradation of Fulvic Acid and Mechanism

A significant promotion effect of low-molecular hydroxyl compounds(LMHCs) was found in the nano-photoelectrocatalytic(NPEC) degradation of fulvic acid(FA),which is a typical kind of humic acid existing widely in natural water bodies,and its influence mechanism was proposed.A TiO_2 nanotube arrays(TNAs) material is served as the photoanode.Methanol,ethanediol,and glycerol were chosen as the representative of LMHCs in this study.The adsorption performance of organics on the surface of TNAs was investigated by using the instantaneous photocurrent value.The adsorption constants of FA,methanol,ethanediol,and glycerol were 43.44,19.32,7.00,and 1.30,respectively,which indicates that FA has the strongest adsorption property.The degradation performance of these organics and their mixture were observed in a thin-layer reactor.It shows that FA could hardly achieve exhausted mineralization alone,while LMHCs could be easily oxidized completely in the same condition.The degradation degree of FA,which is added LMHCs,improves significantly and the best promotion effect is achieved by glycerol.The promotion effect of LMHCs in the degradation of FA could be contributed to the formation of a tremendous amount of hydroxyl radicals in the NPEC process.The hydroxyl radicals could facilitate the complete degradation of both FA and its intermediate products.Among the chosen LMHCs,glycerol molecule which has three hydroxyls could generate the most hydroxyl radicals and contribute the best effective promotion.This work provides a new way to promote the NPEC degradation of FA and a direction to remove humus from polluted water.

Effects of Hydrogen on Behaviour of Low Cycle Fatigue of 2.25Cr-1Mo Steel

The effects of hydrogen atoms on behaviour of low cycle fatigue of 2.25Cr-1Mo steel have been investigated in present work. The results indicate that the cyclic softening rate and low cycle fatigue life are respectively increased and reduced remarkably by hydrogen atoms. In addition, hydrogen atoms make the original stress amplitude of low cycle fatigue increase, which is because of the drag effect of hydrogen atoms on the moving dislocations. Analyses using electron microscopy show that hydrogen atoms accelerate crack initiation of low cycle fatigue from inclusion and transfer the source of low cycle fatigue crack from the surface of specimen to the inclusion, which results in the marked decrease of low cycle fatigue life. The increase of cyclic softening rate for hydrogen charged specimen is due to hydrogen atoms accelerating the initiating and growing of microvoids from the secondary phase particles in the steel. The reducing of the drag effect of hydrogen atoms on moving dislocations is also helpful to the increase of the cyclic softening rate.

Effect of Cycloheximide on the Adaptive Response Induced by Low Dose Radiation

Human lymphocytes pre-exposed to 10 mGy or 50 mGy of X-rays become less sensitive to subsequent large dose irradiation, exhibited lower rate of chromosome aberration than expected. This adaptive response could be inhibited by cycloheximide, a protein synthesis inhibitor for successive 2 h period ranging from 0.5h before to 4h after the low dose exposure, indicating that the adaptive response was directly related with the protein synthesis.

Effects of Low-Power Microwave Fields on Seed Germination and Growth Rate

Experiments were conducted to investigate the effects of low power microwave radiation on germination and growth rate in seeds. In the present paper, the bioeffects of low power (non-thermal intensity) microwave modulated with 1 KHz square wave have been studied. Experiments were performed in X-band frequencies using klystron based microwave test bench. Microwave parameters like frequency, power, exposure time and power density were varied while irradiating seed samples to study their influence on germination. The seed samples used for the experiment included wheat (Triticum aestivum), bengal gram (Cicer arietinum), green gram (Vigna radiate) and moth bean (Vigna Aconitifolia). Seed germination %, plant height, root length and dry matter % (biomass %) were recorded and compared with control seeds. The effects of different treatments were found to be stimulating the germination and seedling vigour of plants especially in power and exposure time treatments while increase in frequency and power density has reduced the seed germination and seedling vigour. The effect also varied with the nature of seeds.

Incubation Effect on Eggs of Tibetan Chicken under Low Altitude Condition

[ Objective] In order to study incubation conditions of Tibetan chickens in low altitude areas. [ Method] Eggs of Tibetan chicken were transported to low altitude areas in highland areas for artificial hatching. [ Results] The results showed that the average hatching rate of fertilized eggs was 85.33% ; the average healthy chick rate was 91.77 % ; the average primary body mass was 31.2l g. Hatching rate of eggs in group 2 was the highest, which reached 90.52%, the aver- age egg mass was 43.25 g and the average egg shape index was 1.32. Hatching rate of eggs in group 2 was 13.11% and 2.47% higher than that in group 1 and group 3 respectively, which was 5.19% higher than the average value. Hatching rate and healthy chick rate of eggs in group 2 also showed the same trend. [ Conclusion] High hatching effect could be obtained under the better hatching condition in low altitude areas in highland areas.

Evaluation of a gate-first process for AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors with low ohmic annealing temperature

In this paper, TiN/A1Ox gated A1GaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors （MOS- HFETs） were fabricated for gate-first process evaluation. By employing a low temperature ohmic process, ohmic contact can be obtained by annealing at 600 ℃ with the contact resistance approximately 1.6 Ω.mm. The ohmic annealing process also acts as a post-deposition annealing on the oxide film, resulting in good device performance. Those results demonstrated that the TiN/A1Ox gated MOS-HFETs with low temperature ohmic process can be applied for self-aligned gate AIGaN/GaN MOS-HFETs.

Effect of long-term low dose of aspirin on severity of disease following onset of acute cerebral infarction

BACKGROUND： Aspirin can decrease the incidence risk of high-risk crowdgroup of cerebral infarction, but there are still controversy if it might decrease the degree of disease in degree of patients with acute cerebral infarction. OBJECTIVE： To observe the effect of lower dose of aspirin during taking for a long time on disease degree of disease following onset of acute cerebral infarction. DESIGN： Grouping according to the admission time and 1：1 paired observation.SETTING ： Department of Neurology, Qilu Hospital of Shandong University.PARTICIPANTS ： The participants in present study were 321 patients with acute cerebral infarction who received treatments in the Department of Neurology, Qilu Hospital of Shandong University from January 1999 to June 2000. There were 190 male and 131 female ,with mean （65±11 ）years of age. Inclusive criteria： ① A focal neurological disturbance occurred suddenly and had lasted for more than 24 hours, patients were admitted within 3 days after onset of disease; ② A computed tomography of the brain was performed and excluded hemorrhage in all patients; ③ The patients were proved internal carotid occlusions by clinical features and image findings; ④ The functions of limbs were normal （before the first stroke） or almost normal （before the second stroke）. Exclusive criteria：①The patients who had have cardiogenic cerebral embolism; ②The patients who had taken warfarin orally and other platelet agglutination drugs. METHODS ：①All the patients were divided into 2 groups according to whether they had taken aspirin before： aspirin-treated group （n=110） and blank control group （n=211）. there were 70 male and 40 female in aspirin-treated group, with average（65±10） years of age.All patients had taken 50-100 mg/d aspirin for 6 months to 10 years before onset. There were 120 male and 91 female in blank control group, with average （65±13） years of age. Patients received a clinical scoring within 3 days and similar therapeutic measures （such as anti-platelet agglutination, improving cerebral circulation and metabolism-promoting reagent）. Two groups of patients had the same basic conditions except for taking aspirin or not before. ②The matched pairs were made between 50 cases selected from aspirin-treated group and 50 cases from non-aspirin-treated groups according to age, gender, and other stroke risk factors. ③ Evaluation： Degree of disease after onset was evaluated by means of Acute Cerebral Infarction Clinical Neurologic Impairment Degree Scoring Standard of Carotid Artery System. MAIN OUTCOME MEASURES： Acute Cerebral Infarction Clinical Neurologic Impairment Degree Scoring Standard of Carotid Artery System. RESULTS ： All 321 patients entered the stage of analysis with no loss in the midway. ① The symptom following onset of acute cerebral infarction was evaluated with clinical neurologic impairment scoring criteria, there were no significant differences between aspirin group and blank control group [（17.39±9.90） vs （16.22 ± 9.98） （t=1.025, P〉 0.05）]. ② No significant differences were found in 1：1 matched pairs of 100 cases from aspirin group and blank control group （t=1.74, P 〉 0.05）. CONCLUSION ： Taking a lower dose of aspirin during long time may not decrease the degree of disease following onset of acute cerebral infarction.

Damaging Effect of Low Energy N^+ Implantation on Aspergillus niger Spores

The mutant effects of a keV range nitrogen ion （N＋） beam on enzyme-producing probiotics were studied, particularly with regard to the induction in the genome. The electron spin resonance （ESR） results showed that the signal of ESR spectrum existed in both implanted and non-implanted spores, and the yields of free radicals increased in a dose-dependent manner. The ionic etching and dilapidation of cell wall could be observed distinctly through the scanning electron microscope （SEM）. The mutagenic effect on genome indicated that N＋ implantation could make base mutation. This study provided an insight into the roles low-energy ions might play in inducing mutagenesis of micro-organisms.

不同粗糙度煤岩界面超低摩擦效应与声发射特征试验研究

为了揭示动载扰动作用下煤岩界面粗糙度对超低摩擦型冲击地压影响机制,采用自行研制的煤岩界面超低摩擦试验装置,以沈阳红阳三矿1082 m采深煤岩体为研究对象,通过改变煤块与砂岩块体表面粗糙度来模拟煤岩界面不同粗糙特性,以粗糙度系数表征煤岩界面粗糙程度,工作块体水平位移表征冲击过程中超低摩擦效应强度,声发射能量为工作块体摩擦滑动过程中的信号参数,进行应力波扰动下不同粗糙度煤岩界面超低摩擦试验.研究结果表明:(1)超低摩擦滑动过程中,工作块体水平位移、声发射能量计数以及累计能量曲线呈现出孕育阶段、激发阶段、稳定阶段变化特征;(2)煤岩界面粗糙度越小,工作块体水平位移和声发射能量峰值越大,煤岩界面越易发生超低摩擦效应;(3)不同煤岩界面粗糙度下,相比于其他扰动频率, 2 Hz时更易发生超低摩擦效应;(4)给出了声发射能量峰值与煤岩界面粗糙度系数对应关系.声发射能量峰值可以有效表征超低摩擦效应强度,可以用声发射能量峰值预测超低摩擦效应强度.

Modeling and Analysis of Low Frequency Noise in Ion-Field-Effect Transistors Sensors

Ions Sensitive Field Effect Transistors (ISFETs) are becoming the platform sensors for important chemical and biomedical applications. However, the accuracy of ISFET output measurement is greatly affected by the presences of low-frequency noise, drift and slow response of the device. This requires more safety in measured results and the tools of analysis. In this paper, we present fundamental limits on the sensitivity of ISFETs micro-sensors, arising from intrinsic and extrinsic noise sources. We developed an algorithm in MATLAB in order to model the frequency analysis of the 1/f noise in ISFET sensor using Hooge theory. We have shown that the 1/f noise of the ISFETs sensors is due to both the electrochemical system (pH solution) and the MOS component (canal size, insulator thickness). The temperature effect on the ISFET noise and the signal conditioning are also performed.

Low-carbon technology innovation responding to climate change from the perspective of spatial spillover effects

China's technological efforts to tackle climate change have lasted for many years. It is necessary to test the effect of these efforts with quantitative method. To be exact, whether and how China's low-carbon technology innovation responds to climate change should be tested. Based on the2004-2015 panel data of 30 provinces in China, we use the method of ESDA analyzing the spatial correlation of China's low-carbon innovation technology. Furthermore, we use the spatial Durbin model empirically analyzing the spatial spillover effects. The results obtained are as follows: first,supply and demand of Chinese low-carbon innovation has some deviation in the spatial distribution. The low-carbon technology innovation as the supply factor shows the characteristics of expanding from the east to the west. Innovation in eastern China has always been the most active, but innovative activities in the middle and western China are gradually decreased.However, carbon emissions have the characteristics of moving westward, implying the change of technology demand different from technology supply. Second, China's low-carbon innovation actively responds to the trend of climate change, indicating China's technological efforts have paid off. However, the spatial spillover effects are not significant, showing that the efforts in each region of China still work for himself. Third, environmental regulation and market pull are important factors for low-carbon technology innovation. Among them, both supporting policy and inhibitory policy have significant impact on the local low-carbon technology innovation, but no significant spatial spillover effects. It shows that environmental policies in different regions are competitive and lack of demonstration effects. Economic growth and export as market pull have higher level of effect on low-carbon technology innovation for both local and adjacent areas.Some policy implications are proposed based on these results finally.

Effects of low dose Glibenclamide on secondary damage after acute spinal cord injury in rats

Objective To investigate the effects of Glibenclamide on reduction of secondary damage after acute spinal cord injury in rats.Methods Ninety rats were randomly divided into control group(laminectomy alone),spinal cord injury group(injury group),and treatment group(treated

A PROBABILISTIC ASSESSMENT OF TEMPERATURE EFFECTSON THE LOW CYCLE FATIGUE BEHAVIOUR OF 1Cr_(18)Ni_9Ti STEEL WELD METAL

Based on the test results obtained from the single-step test and the incremental-step test at room temperature and 240℃, a probabilistic assessment of temperature effects on the cyclic stress-strum response and the fatigue life of 1Cr18Ni9Ti steel weld metal is performed. In orber to assess the temperature effect on cyclic stress amplitude where there is a scatter of the material cyclic constitution, a probabilistic assessment approach on the basis of probabilistic modified Ramberg-Osgood relations is introduced.The investigation shows that the cyclic stress amplitude and the scatter of cyclic stress amplitude data are decreased at 240℃. Similarly, from the consideration of the fatigue life scatter a probabilistic assessment of temperature effect on the fatigue life is suggested on the basis of probabilistic Langer S-N relations. The investigation shows that the crack initiation life is increased and the scatter of crack initiation life data is decreased at 240℃.

STIMULATING EFFECT OF LOW DOSE ^(147)Pm ON DNA REPAIR IN SPERMIOGENIC STAGES

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近朱者赤:被纳入碳排放权交易试点的客户能否影响企业ESG表现?

绿色是实现高质量发展最亮的底色。以“双碳”目标为背景,基于企业与客户的二元供应链关系,实证检验被纳入碳排放权交易试点的客户对企业ESG表现的影响。研究表明:被纳入碳排放权交易试点的客户能够显著提升企业ESG表现。对企业ESG表现的分维度研究表明,被纳入碳排放权交易试点的客户对企业E和S维度的表现具有显著的提升作用,而对企业G维度表现的提升作用不显著。被纳入碳排放权交易试点的客户通过倒逼效应提升企业ESG表现。短期内,被纳入碳排放权交易试点的客户倒逼企业“末端治理”;长期内,被纳入碳排放权交易试点的客户倒逼企业“前端预防”。当企业位于低碳试点城市、处于高碳排放行业时,被纳入碳排放权交易试点的客户对企业ESG表现的提升作用更显著。企业ESG表现提升并不能直接增加企业价值,但被纳入碳排放权交易试点的客户能够倒逼企业提高环保投资水平和绿色技术创新水平,进而推动企业ESG表现显著增加企业价值,而且长期更有效。基于被纳入碳排放权交易试点的客户这一新研究视角,揭示了低碳减排与ESG实践的激励相容机制,不仅为深入理解我国碳试点的微观作用效果提供了新思路,而且对推进美丽中国建设、实现经济高质量发展具有重要的实践意义。