Protection zone in a diffusive predator-prey model with Ivlev-type functional response

The effect of a protection zone on a diffusion predator-prey model with Ivlev-type functional response is considered.We discuss the existence and non-existence of positive steady state solutions by using the bifurcation theory.It is shown that the protection zone for prey has beneficial effects on the coexistence of the two species when the growth rate of predator is positive.Moreover,we examine the dependence of the coexistence region on the efficiency of the predator capture of the prey and the protection zone.

New Normal of Environmental Protection: Our Responsibility and Action

It has become the hot topic of new normal for environmental protection to ＂ impel ecological civilization and create new way of environ- mental protection＂. In this paper, based on current severe environmental protection situation, new idea of ＂government taking the stage, research department writing a play,enterprise acting in an opera and the masses supervising＂ and action plan of ＂government having the right but can not be impulsive, research department having the talent and should discharge their duties, enterprise having the money but should keep law, and the mas- ses having the enthusiasm to strengthen supervision＂ for environmental protection are proposed,which aims to contribute ideas and exert efforts for impelling ecological civilization and environmental protection.

Plant Protection： The Risk Mitigation of Endocrine Disrupting Pesticides Use Demands the Shared Responsibility of All within the Agricultural System

The widespread use of agrochemicals and its possible negative impacts on humans and the environment remains a highly topical and controversial issue. Of particular concern here are chemicals that can disturb an organism＇s endocrine system. Referring to the precautionary principle, the objective of the research project start2 is to develop management strategies that help reduce possible risks for httmans and the environment of endocrine active agrochemicals. As an empirical basis we combined qualitative and quantitative methods and initiated two expert dialogues. Our findings underpin the well known fact that the use of agrochemicals is complex and dependent on more than the individual attitudes of farmers. Agricultural plant protection management is the collective product of a complex agricultural system, which encompasses treatment, marketing, industry and agricultural consultation as well as agricultural teaching institutions and relevant scientific disciplines. Successful management strategies for risk reduction in the context of hormonally active agrochemicals thus need to involve all actors within this system. The paper proposes a strategy that promotes participation by enabling learning processes among these actors.

A Self-Powered Nanogenerator for the Electrical Protection of Integrated Circuits from Trace Amounts of Liquid

With the increase in the use of electronic devices in many different environments,a need has arisen for an easily implemented method for the rapid,sensitive detection of liquids in the vicinity of electronic components.In this work,a high-performance power generator that combines carbon nanoparticles and TiO2 nanowires has been fabricated by sequential electrophoretic deposition(EPD).The opencircuit voltage and short-circuit current of a single generator are found to exceed 0.7 V and 100μA when 6μL of water was applied.The generator is also found to have a stable and reproducible response to other liquids.An output voltage of 0.3 V was obtained after 244,876,931,and 184μs,on exposure of the generator to 6μL of water,ethanol,acetone,and methanol,respectively.The fast response time and high sensitivity to liquids show that the device has great potential for the detection of small quantities of liquid.In addition,the simple easily implemented sequential EPD method ensures the high mechanical strength of the device.This compact,reliable device provides a new method for the sensitive,rapid detection of extraneous liquids before they can impact the performance of electronic circuits,particularly those on printed circuit board.

Optimization of Freeze-drying Protective Agents for Lactobacillus plantarum KLDS1.0391 by Response Surface Methodology

In this study, the Single Factor Test（SFT） was used to optimize the pre-freezing conditions of L. plantarum KLDS1.0391（KLDS1.0391）. Further, the Freeze-Drying Protective Agents（FDPA） of KLDS1.0391 was optimized by Response Surface Methodology（RSM）. The optimum pretreatment conditions were as the follows： initial concentration of KLDS1.0391 was 1011 CFU · m L-1 and KLDS1.0391 was pre-freezed at –80℃ for 8 h to achieve the survival rate of 46.21%. The main components of FDPA were skim milk, sucrose, sodium glutamate and Tween-80. And the influence of four factors on the survival rate of KLDS1.0391 in freeze-drying was in order as the follows： skim milk〉sucrose〉Tween-80〉sodium glutamate. The optimal FDPA composition was skim milk 11.3%, sucrose 9.8%, sodium glutamate 5.1% and Tween-80 0.2%. Under the above conditions, the survival rate of the cells was 82.98%. Comparing the predicted values, the relative error was 0.37% and the difference was not significant, which indicated that the established model could effectively reflect the actual protection of FDPA to KLDS1.0391.

Optimization of Protective Agent Formulation for Soybean Rhizobium Strain HW-05 by Response Surface Methodology

[Objective] This study aimed to investigate the protective effects of proteins, salts, sugars and trace elements on soybean rhizobium strain HW-05 by response surface methodology. [Method] Different types, combinations, ratios and concentrations of protective agents were designed. Under simulated conditions, the optimal protective agent formulation was screened for improving the survival rate and survival time of soybean rhizobium strain HW-05. The optimal combination of significant factors was determined by Box-Behnken central composite design. [Result] Three significant factors affecting effective number of viable cells were screened, including peptone, xanthan gum and NaCl. The final concentration of each compound was optimized 0. 13% peptone, 0.011% xanthan gum, 0.30% NaCl. [Conclusion] After addition of protective agent and preservation at room temperature for six months, effective number of viable cells of soybean rhizobium strain HW-05 reached 3.185 ×10^8 CFU/ml. The survival rate of HW-05 cells was improved by more than 25% compared with the control group （2.458×10^8 CFU /ml）.

Radio-protective response on the environmental pollutant induced oxidative stress

The purpose of this study was to investigate the protective effect of low dose radiation on TCE induced oxidative damage in rats. The oxidative damage of both liver and kidney was assessed by serum alkaline phosphatase (ALP), Gamma Glutamyl Trans-Peptidase (GGTP), Alanine and Aspartate Amino Transferase (ALT & AST) activities in addition concentrations of cholesterol, high density lipoprotein-cholesterol (HDL-c), low density lipoprotein-cholesterol (LDL-c), Triacyglycerols (TGs), urea and creatinine were analyzed. Liver lipid peroxidation (MDA), Nitric Oxide (NO), reduced glutathione (GSH) levels, and activities of both Super-Oxide Dismutase (SOD) and Glutathione Peroxidase (GSH-Px) were measured. Results: TCE administration increase serum ALP, GGTP, ALT, AST activities, cholesterol, triacylglycerols, LDL-c, urea and creatinine concentrations, besides liver MDA and NO, whereas it decreased SOD, GSH-Px activities, GSH level in liver, HDL-c in serum. Low dose of gamma rays (0.5 Gy) exposure significantly improved lipid peroxidation and oxidative injury induced by TCE. Conclusion: The study indicates that treatment with low dose of gamma rays ameliorate harmful effects induced by TCE taking in consideration the effect of gamma radiation as a stimulant of radical detoxification.

Econometric Study of Relationship between Change of Farmland Quantity and Policy of Farmland Protection in China

According to the data from Investigation Report of Land Use Change in China,The Land Resources Communique of China and Chronicle of Statistical Data for Five Decades of New China issued from Ministry of Land Resources,we select two indices:change of farmland quantity and policy of farmland protection.According to econometric theory,by using Eviewes 5.1 software,co-integration analysis,Granger causality test,impulse response and other analysis methods,we analyze the relationship between change of farmland quantity and policy of farmland protection in China since the reform and opening-up.The results show that there is long-term balanced relationship between change of farmland quantity and policy of farmland protection,and there is a certain mechanism restricting motion of variables between the two so as to make the two deviate from each other little and step towards balance in the long run;there is unilateral causality relationship between farmland change and policy of farmland protection,namely that the farmland change is the Granger cause of policy of farmland protection,while policy of farmland protection is not the Granger cause of farmland change;impulse response and variance decomposition indicate that farmland change plays the role of promoting policy of farmland protection continuously,and the role is strengthened along with prolonged lag period;the policy of farmland protection has strong inertia,because it is impacted by the former level of itself,and the policy of farmland protection plays insignificant role in promoting farmland quantity.Consequently,the important approach of solving problem of rapid decrease of farmland is to formulate long-term strategy,strengthen theoretical research of farmland protection and reinforce degree of formulation,implementation and surveillance of farmland protection policy.

Numerical Estimation of the Thermal Response of Thermal Protective Clothing-Air Gap-Human Skin Micro-system

Thermal protective clothing has been recognized as the primary shielding against emergency fire hazard and inflammable gas leakage. Therefore,the thermal response of human covered with thermal protective clothing under high temperature is the key work to investigate the thermal insulation of thermal protective clothing. A coupling model composed of thermal protective clothing,air gap and human skin is established and the temperature of the micro-system is numerically solved via the finite element method( FEM).Especially,the heat transfer of air gap located between clothing and human skin considering conduction and radiation is established while the human skin layers involve the effect of blood perfusion. Then the effect of thermophysical properties( thermal conductivity and volumetric capacity) of fabric and thickness of fabric and air on the thermal response of the micro-system is elucidated and compared.The results indicate that the volumetric heat capacity of fabric is the key parameter to affect the thermal shielding performance of thermal protective clothing,and the thicker fabric thickness and air gap thickness can improve the thermal protective properties of the micro-system.

Elastic responses of underground circular arches considering dynamic soil-structure interaction:A theoretical analysis

Due to the wide applications of arches in underground protective structures, dynamic analysis of circular arches including soil-structure interactions is important. In this paper, an exact solution of the forced vibration of circular arches subjected to subsurface denotation forces is obtained. The dynamic soil-structure interaction is considered with the introduction of an interfacial damping between the structure element and the surrounding soil into the equa- tion of motion. By neglecting the influences of shear, rotary inertia and tangential forces and assuming the arch incompressible, the equations of motion of the buried arches were set up. Analytical solutions of the dynamic responses of the protective arches were deduced by means of modal super- position. Arches with different opening angles, acoustic impedances and rise-span ratios were analyzed to discuss their influences on an arch. The theoretical analysis suggests blast loads for elastic designs and predicts the potential failure modes for buried protective arches.

Optimizing the Chemical Compositions of Protective Agents for Freeze-drying Bifidobacterium longum BIOMA 5920

Freeze drying has a deleterious effect on the viability of microorganisms. In front of this difficulty, the present study adopts response surface methodology to optimize the chemical compositions of protective agents to seek for maximum viability of Bifidobacterium longum BIOMA 5920 during freeze-drying. Through the compara- tive analysis of single protectant, the complex protective agents show better effect on the Bifidobacterium viability. Human-like collagen (HLC), trehalose and glycerol are confirmed as significant factors by Box-Behnken Design. The optimized formula for these three variables is tested as follows: HLC 1.23%, trehalose 11.50% and glycerol 4.65%. Under this formula, the viability is 88.23%, 39.67% higher in comparison to the control. The viable count is 1.07×10 9 cfu·g-1 , greatly exceeding the minimum viable count requirement (10 6 cfu·g-1 ).

An Active Triggered Surge Protective Gap

A triggered surge protective device is designed and its discharge characteristics axe studied. The experimental results show that the triggered surge protective device has excellent surge protective characteristics. When the gap distance is 5 mm, p. d is 90 Pa.mm and without an active energy trigger circuit, the DC breakdown voltage of the triggered surge protective device is 2.32 kV and the pulse breakdown voltage is 5.75 kV. Therefore, the pulse voltage ratio, which is defined as the specific value of pulse breakdown voltage and DC breakdown voltage, is 2.48. With a semiconductor ZnO flashover trigger device and an active energy coupling trigger circuit, the pulse breakdown voltage can be reduced to 3.32 kV, the pulse voltage ratio is 1.43 and the response time is less than 100 ns. These results are helpful in laying a theoretical foundation for further studies on triggered surge protective devices.

Proteome and transcriptome profile analysis reveals regulatory and stress-responsive networks in the russet fruit skin of sand pear

The epidermal tissues of the cuticular membrane(CM)and periderm membrane(PM)confer first-line protection from environmental stresses in terrestrial plants.Although PM protection is essentially ubiquitous in plants,the protective mechanism,the function of many transcription factors and enzymes,and the genetic control of metabolic signaling pathways are poorly understood.Different microphenotypes and cellular components in russet(PM-covered)and green(CM-covered)fruit skins of pear were revealed by scanning and transmission electron microscopy.The two types of fruit skins showed distinct phytohormone accumulation,and different transcriptomic and proteomic profiles.The enriched pathways were detected by differentially expressed genes and proteins from the two omics analyses.A detailed analysis of the suberin biosynthesis pathways identified the regulatory signaling network,highlighting the general mechanisms required for periderm formation in russet fruit skin.The regulation of aquaporins at the protein level should play an important role in the specialized functions of russet fruit skin and PM-covered plant tissues.

耕地保护考核和粮食安全考核“合二为一”的基础与推进路径

为让耕地保护目标更好地服务于保障国家粮食安全总目标,我国开始推动耕地保护考核和粮食安全考核“合二为一”。从制度基础看,修订后的《省级政府耕地保护责任目标考核办法》和《粮食安全省长责任制考核办法》都经过多年应用实践,在奖惩措施、结果运用等方面都具有较高的借鉴价值;从实践基础看,地方探索取得初步成效,典型省份的耕地面积、粮食播种面积都稳中有增。然而考核只是手段,耕地保护党政同责和粮食安全党政同责都实行不久。更好发挥这两项考核“合二为一”对确保各项政策措施落实见效的作用,还需要从根本上理顺关系、构建机制,为此,应着力从以下两方面推进:其一,推动形成党政齐抓共管的工作格局,重点是从讲政治的高度看待耕地保护和粮食安全问题,厘清党政权责界限,统筹协调各部门形成合力,充分发挥考核“指挥棒”作用和督察“利剑”作用;其二,构建以主产区为主、主销区和产销平衡区共同支撑的国家粮食安全保障格局,重点是主产区优先享有政策扶持和利益补偿,主销区对主产区承担横向利益补偿义务,加快产销平衡区经济发展。

电信诈骗案件退赔机制运行困境与出路——基于被害人教义学视角的展开

《反电信网络诈骗法》完善了多位一体的预防、打击电信诈骗活动制度建设,但是在过往电信诈骗案件办理中,因为多重主客观原因而导致的追赃挽损不及时,不仅会进一步扩大损害结果,而且极易产生因被害人的种种不满而衍生的社会治理风险。针对违法所得退赔被害人问题,各地司法呈现出多维倾向,形成被害人保护以及被告人权利保障对立立场。基于法益恢复之现实需要,被害人保护应该成为处理电信诈骗退赔问题应有立场,在此基础上应当兼顾被告人责任的合理分配。被害人保护的目标可以通过扩大责任主体范围、精准适用连带责任以及先行返还程序等具体措施实现,而公平追偿、退赔激励性制度则是实现被告人责任公平的保证。

鼠疫耶尔森菌低钙应答V抗原人源单克隆抗体筛选与鉴定

目的筛选抗低钙应答V抗原(LcrV)的人源单克隆抗体,分析抗体基因特点,检测抗体与抗原结合的特异性、亲和力及功能。方法使用PCR方法从鼠疫疫苗临床试验志愿者外周血细胞cDNA扩增抗体轻、重链可变区基因片段,构建ScFv噬菌体抗体文库。用LcrV对文库进行富集筛选,将获得的抗体基因表达成人IgG1后,测定抗体与LcrV抗原结合的特异性、亲和力、免疫调节功能以及保护能力。结果成功构建了鼠疫耶尔森菌人源ScFv抗体文库,库容量为7.54×10^(8)。抗体文库经LcrV筛选后获得了3株抗LcrV抗体,命名为RV-B4、RV-D1和RV-E8。3株抗体重链为VH1-46和VH3-30,轻链分别为VL1-51、VK3-20和VK1-39。3株抗体经ELISA及Western blot验证均与LcrV特异性结合,其与V抗原结合的解离常数(KD)分别为2.1 nmol/L、1.24 nmol/L和42 nmol/L。RV-D1体外降低人THP-1分泌TNF-α,动物攻毒试验中未发现抗LcrV抗体的保护效果。结论从鼠疫疫苗免疫人群获得了靶向低钙应答V抗原的人源抗体,以结合抗体为主,不能有效阻断病菌感染。所获得的单抗为鼠疫免疫基础研究、鼠疫诊断应用提供了候选材料。

雷公藤多苷片对IgA肾病大鼠LIGHT-HVEM/LTβR通路的影响

目的 基于炎症相关通路探讨雷公藤多苷片对IgA肾病大鼠肾脏的作用机制。方法 雄性SPF级SD大鼠,随机分为空白组、造模组。造模组采用联合“牛血清白蛋白+四氯化碳+脂多糖”建立IgA肾病大鼠模型。造模成功的大鼠随机分为模型组、泼尼松组、雷公藤多苷片组,于第13周开始治疗组灌胃给药,给药4周后留取大鼠24 h尿液、血液、肾组织并检测尿红细胞数、24 h-UTP、BUN、Scr;ELISA检测血清IL-1β、TNF-α水平;HE染色观察各组大鼠肾组织病理学变化;Western blot及RT-PCR检测大鼠肾组织LIGHT、HVEM、LTβR蛋白及其mRNA的表达。结果 雷公藤多苷片明显降低IgA肾病大鼠尿红细胞数、24 h-UTP、BUN、Scr水平,改善肾组织病理,降低血清炎症因子IL-1β、TNF-α水平,降低肾组织中LIGHT、HVEM、LTβR蛋白及其mRNA表达水平。结论 雷公藤多苷片可能通过下调LIGHT-HVEM/LTβR信号通路,抑制免疫反应,减少炎症因子释放,从而减轻炎症反应,降低尿红细胞及尿蛋白,改善肾脏病理损伤,保护肾功能。

行人腿型冲击器肌肉材料参数反求

aPLI先进行人腿型冲击器在碰撞测试中的生物仿真度,在很大程度上取决于其几何结构及其模拟腿部肌肉的合成橡胶的超弹性力学特性。根据橡胶准静态单轴压缩试验数据,分别对用于表述橡胶超弹性的Ogden和Mooney-Rivlin本构模型进行材料参数拟合,得到相应的材料参数并将拟合曲线与试验曲线进行比较,对比不同本构模型的拟合精度。结果表明,2阶Ogden材料模型更符合试验结果。为提高有限元模型中肌肉橡胶材料参数的准确性,重构压缩试验有限元模型,以拟合得到的2阶Ogden本构模型材料参数为初始值,通过将有限元与优化策略相结合,基于自适应响应面法对2阶Ogden模型中μ1、α1、μ2、α2这4个材料参数进行优化,获得该材料在准静态压缩状态下的一组最佳材料参数。

利用换流器构建有源边界的单端全线速动保护原理

换流器技术变革导致线路边界的无源元件弱化甚至被取消,仅凭单端电气量特征难以实现全线范围内的故障识别。针对该问题,文中充分发挥换流器的高可控性,主动构建换流器对区内外故障的特异性响应特征,建立与单端量保护具有配合关系的有源边界,进而实现单端全线范围的故障识别。在此基础上,进一步讨论有源边界特性的附加控制策略和关键参数的选择依据,并分析有源边界响应在故障回路中的传播规律,进而设计与之配合的单端全线速动保护判据。仿真验证结果表明,所提方法在高阻故障时仍能够可靠识别,提高了传统单端量保护的可靠性和灵敏性。

面向无线互联的云计算网络安全架构设计与实现

随着云计算技术的广泛应用和无线网络技术的快速发展,面向无线互联的云计算网络安全架构设计与实现成为一个重要议题。文章针对无线互联环境下云计算的网络安全挑战,提出了一种新的网络安全架构。首先,分析了无线互联环境特有的安全挑战,如数据传输的安全性、网络访问控制以及针对多样化威胁的防御机制。随后,提出了一种结合云计算特性的网络安全架构,这一架构包括但不限于数据加密技术、访问控制策略、虚拟安全技术以及基于云的监控和响应机制。文章研究的网络安全架构可以提高无线互联环境下云计算网络的安全性,确保数据的保密性和网络的完整性。