Crack initiation rate of brittle rock under thermal-hydro-mechanical coupling condition

A calculation formula of thermal-hydro-mechanical(THM)coupling crack initiation rate for brittle rock was derived based on the energy conservation law.The self-designed THM coupling fracture test with conductive adhesive electrical measurement method was applied to measuring the THM coupling crack propagation rate of brittle rock continuously.Research results show that both calculation and test results of crack initiation rate increased with increase of the temperature and the hydraulic pressure.They are almost in good agreement,which can prove validity of the calculation formula of THM coupling crack initiation rate.

Catalytic performance of biological method seeds on jarosite process

The catalytic performance on jarosite process of jarosite seeds via biosynthesis and chemical processes were studied, respectively. The SEM and XRD results showed that biosynthetic jarosite seeds （BIO seeds） had smooth surface and mainly consisted of potassium jarosite. The chemical synthesis jarosite seeds （CHM seeds） had a loose cauliflower-like surface and mainly consisted of hydronium jarosite. The catalytic performance of BIO seeds was better than that of CHM seeds on the formation of final jarosite product. The induction time can be shortened to 20 min, the reaction temperature can be reduced to only 75 ℃, and the initial reaction speed was enhanced obviously, up to 3.933%/min. The crystallinity of final jarosite product using BIO seeds can achieve 97.22%, while it was only 12.89% without seeds. This indicates that the precipitation process of jarosite is more complete with BIO seeds.

Study on Growth and Development of Early Postembryonic Stage of Onychostoma sima

[Objective] The paper was to study the growth and development of Onychostoma sima in postembryonic development stage. [Method] The oosperm was obtained by artificial spawning and artificial insemination method, and hatched under laboratory condition. The indexes such as body weight, body length, length in front of anus and body height were measured to establish larvae growth model. [Result] When the water temperature was （20±1.5） ℃, the body length and body weight of newly hatched larvae were （10.28±0.05） mm and （7.79±0.08） mg, respectively. O. sima larvae begin to feed on the 4 th day after hatching, the initial feeding rate was 48%, the highest feeding rate was 100% on the 6 th d. The-point-of-no-return （PNR） was 13.5 d. In addition, it was also observed that the appearance time of PNR point of O. sima larvae was close to death time of completely starved group, being only 2 d, indicating that once O. sima larvae reached the PNR point, they would face death threats within short time. Therefore, various growth conditions for O. sima larvae should be satisfied to ensure full development of all organs, thereby reducing death and growth stagnation caused by adverse environment in early postembryonic stage. [Conclusion] The study provided theoretical basis for solving the problems in artificial breeding.

Kinetics of Degradation of Eosin Y by One of the Advanced Oxidation Processes (AOPs)—Fenton’s Process

Kinetics of homogeneous degradation of Eosin Y (EY), also known as Acid red 87 (CI 45380), are studied, mostly using Fenton’s process, at 30℃ by monitoring its absorbance at 517 nm (λmax of EY). This process is one of the advanced oxidation processes (AOPs). Mixture of H2O2 and Fe(II) ion in acetate buffer medium (pH 2.74 - 4.56) generates hydroxyl free radicals (?OH) which attack the dye molecules, resulting in degradation of the dye molecules. Results show that the initial rate of EY degradation decreases with the increasing of solution pH because of removal of kinetically important Fe (iron) species through formation of ferric hydroxide. On the other hand, the rate increases with increasing the concentrations of H2O2, Fe(II) and EY at low solution pH. The initial rate increases with increasing of concentration of H2O2 and, subsequently remains unaffected with further increase of its concentration at a constant Fe(II) concentration because of the enhanced scavenging environment created by H2O2 at its higher concentration. The initial rate also increases with increasing of concentration of Fe(II) at a constant H2O2 concentration and remains unaffected with its further increase. EY concentration also enhances the initial rate at low pH. However, the initial rate is significantly enhanced by UV light. This is because of formation of additional hydroxyl radicals through excitation of the dye molecules by UV light. During the period of experiment, EY in aqueous solution alone hardly suffered any degradation. Degradation mechanism of EY by the Fenton and photo-Fenton’s processes is also discussed. Statistical analysis was used to validate the experimental results. Low values of the standard deviation for both the initial rate and % degradation indicated the consistency of the experimental data.

Early development and the point of no return in pikeperch( Sander lucioperca L.) larvae

The objectives of the present study were to evaluate the yolk-sac and oil globule absorption and point of no return （PNR） ofpikeperch （Sander lucioperca L.） larvae. Artificial propagation ofpikeperch was performed at （15±2）℃. Yolk-sac absorption, oil globule absorption, larval growth and the first initial feeding rate were observed to analyze the early growth and to determine the PNR of pikeperch larvae. The total length of newly hatched （0 day after hatching, DAH） pikeperch larvae was （4.25±0.22） mm and the volume of the yolk-sac and the oil globule was （0.30±0.12）mm^3 and （5.14±2.28） 10-2 mm^3 respectively. The yolk-sac and the oil globule were exhausted at 11 DAH and 14 DAH, respectively. Pikeperch larvae began feeding at 8 DAH with an initial feeding rate about 10.0%. From 9 to 14 DAH, the initial feeding rate increased rapidly, and reached its highest （about 82.7%） at 14 DAH. It declined thereafter, 48.9% at 15 DAH and 35.6% at 16 DAH, thus the pikeperch larvae reached PNR by 15-16 DAH. The appropriate first feeding time for the pikeperch larvae is 11-12 DAH, when the initial feeding rate is higher than half of the maximum initial feeding rate.

Controlling of weld hot cracks of aluminum alloy sheets by transverse pre-stressing

A new ideological and theoretical model—a technology to control weld hot cracks by transverse compressive pre-stress in the welding of aluminum alloy was put forward,which was further proved by the subsequent self-designed test setup.Experiments are conducted on the fishbone shaped specimen under conventional welding and welding with various pre-stress values.The experimental results turn out that,the initiation rate of the weld hot cracks decreases with increasing values of the compressive pre-stress.When the pre-stress reaches 0.3-0.4 of the yield stress,the cracks even disappear.In mechanical viewpoint,the researches here develop a new way to control weld cracks.

ANALYSIS OF THE TRENDS OF THUNDERSTORMS IN 1951-2007 IN JIANGSU PROVINCE

Based on the 1951-2007 thunderstorms in Jiangsu,a study is conducted for their climate trends,periodicity,spatiotemporal patterns,and the distributions of the first and last days of the thunderstorms at different guarantee rates (GRs) using climate tendency rate,wavelet analysis,and GR for diagnosis.Results suggest that the inter-annual number of thunderstorm days (TSDs) exhibits a decreasing trend in this province.The trend is displayed mainly in the decreasing TSD number in summer and autumn except in spring,when the variation is not significant in the study period.In this province,the TSD number declines by ～2 days per 10 years.On an inter-annual basis,the pronounced positive departures of the number take place chiefly in the early 1960s,the late 1960s to the early-mid-1970s,the late 1980s,and the late 1990s compared with the negative anomalies dominant in the late 1970s to the mid-1980s,the mid-to-late-1990s,and the late 1990s to 2007.There are vast differences in the initial and ending days at diverse GRs in different areas of the province.At 50% GR,the earliest (last) days occur from mid-March to early April (early to late September) while at 80% GR,the initial (last) days are from late March to early May (early to late October).For the distribution of periods,the periods >8-10 years are relatively stable for the entire province.Based on 1951-2007 period analysis,the region north (south) of the Huaihe River experiences TSDs less (more) than normal days in recent years.

Control of ribosome synthesis in bacteria:the important role of rRNA chain elongation rate

Bacteria growth depends crucially on protein synthesis,which is limited by ribosome synthesis.Ribosomal RNA(rRNA)transcription is the rate-limiting step of ribosome synthesis.It is generally proposed that the transcriptional initiation rate of rRNA operon is the primary factor that controls the r RNA synthesis.In this study,we established a convenient GFP-based reporter approach for measuring the bacterial rRNA chain elongation rate.We showed that the rRNA chain elongation rate of Escherichia coli remains constant under nutrient limitation and chloramphenicol inhibition.In contrast,rRNA chain elongation rate decreases dramatically under low temperatures.Strikingly,we found that Vibrio natriegens,the fastest growing bacteria known,has a 50%higher rRNA chain elongation rate than E.coli,which contributes to its rapid ribosome synthesis.Our study demonstrates that r RNA chain elongation rate is another important factor that affects the bacterial ribosome synthesis capacity.

Kinetics of Soil Potassium Release Under Long-Term Imbalanced Fertilization in Calcareous Soils

Knowledge on potassium ion(K^+) release from soils makes K fertilizer recommendation more efficient and profitable.Kinetics of K^+release under continuous fertilization of no fertilizer(CK), urea(N), triple superphosphate(P), and urea + triple superphosphate(NP) without K fertilizer was investigated in calcareous(chloritic and kaolinitic) soils on the Miandarband Plain in Kermanshah Province of Iran.The results showed that the kinetics of K^+release included an initial reaction and a slow reaction.The phosphateand NH_4^+-induced K^+release followed the same rate process during the rapid(2–192 h) and slow release periods(192–1 090 h).There were no significant differences in the cumulative K^+released from the chloritic and kaolinitic soils among all the treatments.The cumulative K^+released was positively correlated with P adsorption capacity for the chloritic(r = 0.461, P < 0.05) and kaolinitic soils(r = 0.625, P < 0.01), and negatively correlated with K fixation potential for the chloritic(r = 0.720, P < 0.01) and kaolinitic soils(r =-0.513, P < 0.01).There was a significant(P < 0.001) interactive effect of K fixation potential × P adsorption capacity on the cumulative K^+released for both soil groups.The initial release rate(IRR) index(a·b, where a and b are the rate coefficients of the power function equation) for the chloritic soils was significantly(P < 0.05) higher under applications of P and NP than N and CK.The IRR index values among different fertilization treatments were in the order of NP = P > N = CK for the chloritic soils, and N =P > NP > CK for the kaolinitic soils.This study showed that K fixation potential and P adsorption capacities controlled K^+release from soils.This information will be helpful for precise fertilizer recommendations for the studied soils.

Regulation of Torpor in the Gray Mouse Lemur:Transcriptional and Translational Controls and Role of AMPK Signaling

The gray mouse lemur（Microcebus murinus） is one of few primate species that is able to enter daily torpor or prolonged hibernation in response to environmental stresses. With an emerging significance to human health research, lemurs present an optimal model for exploring molecular adaptations that regulate primate hypometabolism. A fundamental challenge is how to effectively regulate energy expensive cellular processes（e.g., transcription and translation） during transitionsto/from torpor without disrupting cellular homeostasis. One such regulatory mechanism is reversible posttranslational modification of selected protein targets that offers fine cellular control without the energetic burden. This study investigates the role of phosphorylation and/or acetylation in regulating key factors involved in energy homeostasis（AMP-activated protein kinase, or AMPK, signaling pathway）, m RNA translation（eukaryotic initiation factor 2a or e IF2 a, eukaryotic initiation factor 4E or e IF4 E, and initiation factor 4E binding protein or 4EBP）, and gene transcription（histone H3） in six tissues of torpid and aroused gray mouse lemurs. Our results indicated selective tissue-specific changes of these regulatory proteins. The relative level of Thr172-phosphorylated AMPKa was significantly elevated in the heart but reduced in brown adipose tissue during daily torpor, as compared to the aroused lemurs, implicating the regulation of AMPK activity during daily torpor in these tissues. Interestingly, the levels of the phosphorylated e IFs were largely unaltered between aroused and torpid animals. Phosphorylation and acetylation of histone H3 were examined as a marker for transcriptional regulation. Compared to the aroused lemurs, level of Ser10-phosphorylated histone H3 decreased significantly in white adipose tissue during torpor, suggesting global suppression of gene transcription. However, a significant increase in acetyl-histone H3 in the heart of torpid lemurs indicated a possible stimulation of transcriptional activity of this tissue. Overall, our study demonstrates that AMPK signaling and posttranslational regulation of selected proteins may play crucial roles in the control of transcription/translation during daily torpor in mouse lemurs.