In recent years, safety accidents have occurred frequently in natural gas pipelines, mostly due to leakage of natural gas pipelines. Most long-distance natural gas pipelines are large-diameter and high pressure pipelines. A large amount of natural gas is stored in the pipeline, which will have serious consequences in case of leakage. The thinning of pipeline wall thickness is an important factor causing the leakage of natural gas pipeline, so it is necessary to monitor the wall thickness of key points of the pipeline. At present, the recognized monitoring points in the industry are elbows and tees of natural gas stations, but no relevant standards have been formulated for the more detailed detection scope of monitoring points. The author uses fluent simulation software to establish the model, and then uses the pressure sensor for on-site detection to modify the model with the detection results. Then, according to the new model, the stress areas of monitoring points (elbows and tees) with different pipe diameter and curve diameter ratio are studied and summarized, and the detection ranges of different monitoring points are determined on this basis. The detection scope provides reference for the daily work of on-site operators, so as to ensure the safe and stable operation of long-distance natural gas pipeline.

As China's economic growth slows down and the pressure of the economic downward increases gradually, the agricultural and rural economic development faces more serious challenges. Fortunately, thanks to the China's rural land certification, it guarantees the security and stability of property rights of land, and provides a huge development space for rural household's entrepreneurship, which promotes agricultural and rural economy greatly. In order to investigate the impact of the land certification on rural household's entrepreneurship in China, this paper uses China Rural Household Panel Survey data for the empirical analysis based on the panel Logit model. The results show that: (1) The land certification increases the probability of agricultural entrepreneurship by at least 25%, but it has no significant influences on non-agricultural entrepreneurship. (2) The rural land certification with boundary influences agricultural entrepreneurship more significant than that without boundary, and the land certification to household is more beneficial for agricultural rural household's entrepreneurship than that without to household. (3) The land certification mainly increases probability of agricultural entrepreneurship through the land transfer, labor allocation, and capital allocation. Moreover, the research of this study highlights the importance of standardizing rural labor market and accelerating land financial reform in creating conditions for agricultural entrepreneurship, which can provide effective data support for future rural policy-making.

This paper first reports a new peninsula structure diaphragm (NPSD) piezoresistive pressure sensor, which has high sensitivity and linearity at the same time. By creating stress concentration areas and increasing the stiffness of the film, within the pressure range of 0–5 kPa, the sensitivity of the sensor reaches 22.7 mV/kPa while the nonlinearity is reduced to 0.11% FSO (full-scale output). Compared with our previous work, the sensitivity is increased by 23.4% while the nonlinearity is reduced by 69%. When the ambient temperature rises to 60°C, the sensor still has a high sensitivity of 21.5 mV/kPa.

An anodic bonding model of Si/SiO2-glass is established and demonstrated. In the theoretical part, charge movement in Si/SiO2-glass anodic bonding is studied in detail. On this basis, an equivalent circuit model of anodic bonding with SiO(2)structure is established. By solving the corresponding Poisson equation, the formulas for the width of the depletion layer and the electrostatic force during Si/SiO2-glass anodic bonding are obtained. In addition, the breakdown mechanism of SiO(2)in anodic bonding is explained with 1/E model, and the breakdown type of SiO(2)is analyzed. In the experimental part, through the analysis of the anodic bonding curve, we have concluded that soft breakdown of SiO(2)occurs in the Si/SiO2-glass structure for the first time. At a temperature of 340 degrees C, for SiO(2)with a thickness of 2000 angstrom and 3400 angstrom, the soft breakdown voltages are measured as 223.4 V and 424.3 V, respectively. At the same time, through experiments of small-area bonding SiO(2)structures, the torsional bonding strength of the Si-glass structure and Si/SiO2-glass structure are measured to be 4.14 GPa and 4.94 GPa, respectively. The proposed soft breakdown model of SiO(2)provides a theoretical basis for reliable fabrication and package of MEMS devices.

this paper reported the effect of SiO2 on the silicon-on-glass anodic bonding theoretically and experimentally for the first time. Silicon glass bonding mechanism based on soft break-down of SiO2 is established and demonstrated. The electrical model of Si-SiO2-Glass anodic bonding stated clearly that anodic bonding voltage must be higher than the break-down voltage of SiO2 to start bonding. The break-down voltage of SiO2 is proportional to its thickness. Bonding strength is finally extracted by a customized on-chip testing device. It is found that the thin SiO2 layer on the silicon surface affects the bonding strength seriously. The bonding strength of anodic bonding with SiO2 layer is 25% stronger than that of typical Si-Glass anodic bonding near the periphery of the silicon wafer, and 8% stronger than that of typical Si-Glass anodic bonding in the central region of the silicon wafer.

A dual parameter on-chip test platform (- tester) based on thermal actuator is introduced in this paper, used to extract static tensile fracture strength and dynamic impact bending fracture strength. Process quality can be evaluated based on the extracted fracture strength parameters. The tester has the characteristics of quantifiable readout without relying on precision equipment. This paper describes the structure and manufacturing process of the tester. It is found in scanning electron microscope (SEM) picture of the tester that there is line width loss during the etching process, which had an important influence on test results. The test results show that the tester successfully achieves quality inspection of the micro-beam, and achieves accurate detection and extraction of static tensile fracture strength and impact bending fracture strength.

Most female birds develop only a left ovary, whereas males develop bilateral testes. The mechanism underlying this process is still not completely understood. Here, we provide a comprehensive transcriptional analysis of female chicken gonads and identify novel candidate side-biased genes. RNA-Seq analysis was carried out on total RNA harvested from the left and right gonads on embryonic day 6 (E6), E12, and post-hatching day 1 (D1). By comparing the gene expression profiles between the left and right gonads, 347 differentially expressed genes (DEGs) were obtained on E6, 3730 were obtained on E12, and 2787 were obtained on D1. Side-specific genes were primarily derived from the autosome rather than the sex chromosome. Gene ontology and pathway analysis showed that the DEGs were most enriched in the Piwi-interactiing RNA (piRNA) metabolic process, germ plasm, chromatoid body, P granule, neuroactive ligand-receptor interaction, microbial metabolism in diverse environments, and methane metabolism. A total of 111 DEGs, five gene ontology (GO) terms, and three pathways were significantly different between the left and right gonads among all the development stages. We also present the gene number and the percentage within eight development-dependent expression patterns of DEGs in the left and right gonads of female chicken.

This paper presented a novel 0-3 kPa piezoresistive pressure sensor with high sensitivity and linearity. A shuriken-structured diaphragm (SSD) is designed for the first time to solve the conflict between the sensitivity and linearity for piezoresistive pressure sensors. A trade-off between the stress on the diaphragm edge and the deflection of the diaphragm was achieved by this SSD design according to the numerical simulation. The effects of the glass substrate and the passivation films on the sensing performance were also studied numerically and experimentally. The experimental results indicated the present pressure sensor had a sensitivity of 4.72 mV/kPa/V and a linearity of 0.18 % FSO (full scale output) in the pressure range of 0-3 kPa, which were 28.3% and 50% better than the previous works.

This paper presents a universal self-aligned in situ on-chip micro tensile fracture strength tester designed for tensile strength extraction and process evaluation, which will provide, for the first time as far as the authors know, great force(above 100mN) to in situ on-chip specimen without the introduction of precise instrument, especially suitable for bulk micromachining related tests. The whole structure and process is simple, so it meets the requirements of various process in massive production, the feasibility and universality have been proved by practical evaluation of the several foundries. Its advantages also include self-position, self-measure and self-adaption for loading. In our tests, tensile fracture strength of the etched Si film is between 0.13 to 1.2GPa.

A central step in the initiation of chromosomal DNA replication in eukaryotes is the assembly of pre-replicative complex (pre-RC) at late M and early G(1) phase of the cell cycles. Since 1973, four proteins or protein complexes, including cell division control protein 6 (Cdc6)/Cdc18, minichromosome maintenance protein complex, origin recognition complex (ORC), and Cdt1, are known components of the pre-RC. Previously, we reported that a non-ORC protein binds to the essential element Delta 9 of the Schizosaccharomyces pombe DNA-replication origin ARS3001. In this study, we identified that the non-ORC protein is Sap1. Like ORC, Sap1 binds to DNA origins during cell growth cycles. But unlike ORC, which binds to asymmetric AT-rich sequences through its nine AT-hook motifs, Sap1 preferentially binds to a DNA sequence of 5'-(A/T)(n)(C/G)(A/T)(9-10)(G/C)(A/T)(n)-3' (n >= 1). We also found that Sap1 and ORC physically interact. We further demonstrated that Sap1 is required for the assembly of the pre-RC because of its essential role in recruiting Cdc18 to DNA origins. Thus, we conclude that Sap1 is a replication-initiation factor that directly participates in the assembly of the pre-RC. DNA-replication origins in fission yeast are defined by possessing two essential elements with one bound by ORC and the other by Sap1.

This paper reported a high-resolution non-contact thickness test method of ultra-thin silicon diaphragm fabricated by KOH cavity erosion. For the first time, the test sensitivity increases when film thickness decreases, so the novel method is especially suitable for ultra-thin film measurement. Traditional test methods, like optical microscope, step profiler and optical profiler, are incapable of measuring thin films due to silicon wafer total thickness variation (TTV). Employing the deformation mechanism for multi-layer materials, a film thickness and film deformation curvature radius (Curve) relationship model is established and optimized to realize high-resolution and non-contact thickness measurement. Only by measuring membrane curvature radius, film thickness will be handily got. The stress release structure (SRS) on KOH mask is the key to the thickness measurement. For 5.01 μm thickness thin film (480 μm × 480 μm), Curve is measured as −18.77 mm. In addition to the high precision (3 nm) of vertical deformation measurement of optical profiler, the resolution of the film thickness measurement method is very high (< 0.1 μm).

This paper reported a novel high sensitivity and linearity 0-3 kPa piezoresistive pressure sensor by carefully trading off the stress on the beam edge and the deflection of the sensing diaphragm. A shuriken-structured diaphragm (SSD) was proposed for the first time to improve both sensitivity and linearity for the piezoresistive pressure sensor. The fabricated sensor showed a sensitivity of 4.72 mV/kPa/V and a nonlinearity of 0.18% FSO (full scale output) in the pressure range of 0-3 kPa. Compared with our previous work, the sensitivity was increased by 28.3%, while the nonlinearity was reduced by 50%.

This paper reported a novel impact tester which was, for the first time as far as the authors know, able to generate an in situ impact acceleration high than 120000 g to evaluate the shock reliability of microfabricated structures. And the experiment results of the novel tester show a nearly linear relationship with the results obtained from the traditional drop test, which prove it promising for a substitute. Besides, the tester was fabricated with the same process as those widely used for comb-based MEMS sensor, which made it suitable for in situ process quality monitoring and basic structure property evaluation in mass production.

In this study, a one-step method of fabricating nano to micro structures was reported. Monte Carlo (MC) simulation and a fluid equation were employed to study the formation and evolution mechanism. To verify the fundamental simulation and hypothetical mechanism, standard surface technology (STS) was used with a phase delay producer to build the etching system. Also, throughout the practical experiment, the relationship between the structure scale and the process parameter was recorded. Lastly, the reflectance was measured to be only 0.9%, proving that this method was very promising for optical application. (C) 2015 The Japan Society of Applied Physics

This paper reported an on-chip sensing method to record the highest processing temperature that the structure experienced by using the autofluorescence of Parylene C. Temperature properties of Parylene C autofluorescence was studied, that with the increment of processing temperature, the fluorescence intensity kept increasing. Therefore, the Parylene C was deposited on the chip as a temperature indicating label to sensing the highest temperature in a plasma etching process. Test results showed that the heating effect of 5min to 25min plasma etching was successfully presented by the Parylene C autofluorescence. As the deposition process of Parylene C was conformal and fabrication compatible, this method was promising to achieve temperature sensing on micron and submicron scaled structure.

To predict the reliability of gold electrode, interdiffusions in Cr/Au, Ti/Au and TiW/Au multi-layers when thermally treated were investigated by depth profiling of auger electron spectroscopy (AES). The primitive measuring results suggest that all the under-layer metals diffuse in gold layer when thermally treated and the rise of temperature enhances these diffusions. Cr and Ti accumulate at the surface of gold layer in Cr/Au and Ti/Au samples. And it seems that the introduction of W prevents these accumulations in TiW/Au sample. The measurement of nanohardness indicates that the interdiffusion of under-layer metals increase the nanohardness, while annealing decreases the nanohardness of metal films.

肿瘤转移日渐成为肿瘤治疗的重要靶标.本研究采用肿瘤转移靶向肽(TMT)与脂质材料(PEG-DSPE)偶联获得靶向化合物(TMT-PEG-DSPE),用以构建靶向阿霉素脂质体(TMT-LS-DOX).结果表明,TMT-LS-DOX呈现出良好的药剂学性质.选用高转移性乳腺癌细胞(MDA-MB-435S和MDA-MB-231)对该转移特异性递送系统进行评价,采用非转移性乳腺癌细胞(MCF-7)作为对照.游离TMT多肽浓度达100 μg/mL时仍未显示出细胞毒性.与MCF-7相比,MDA-MB-435S及MDA-MB-231细胞对TMT-LS-DOX摄取增加,并经受体竞争性实验证明该促进作用由TMT介导.因此,TMT修饰的纳米载体可能成为增加化疗药物对高转移性乳腺癌特异性的一种新策略.

This paper discussed a novel design of the piezoresistive pressure sensor with high sensitivity and high linearity. Partially structured diaphragm with four peninsulas and a center boss was applied to improve the sensor performance for low pressure measurement. Finite element analysis (FEA) was applied to evaluate the sensor design. Simulation results indicated that a sensitivity of 25.3 mV/V full-scale output and a nonlinearity error of 0.11 %FSS in the pressure range 0-5 kPa. Through comparisons with other typical sensors, the proposed sensor design exhibited the best overall performance.

A novel therapeutic strategy combining mTOR inhibitor rapamycin (RAPA) and doxorubicin (DOX)-loaded cyclic octapeptide liposomes for targeting integrin alpha 3 was expected to combat the triple-negative breast cancer (TNBC). RAPA was loaded into PEG-PCL polymer micelles (M-RAPA) to realize solubilization. Flow cytometry analysis and laser confocal microscopy were used to evaluate the in vitro cellular uptake. The in vivo tumor targeting and bio-distribution were investigated by living fluorescence imaging. As the results, LXY modification significantly enhanced the cellular uptake of liposomal DOX in integrin alpha 3 overexpressed TNBC cells (MDA-MB-231) in vitro and accordingly improved the tumor accumulation of liposomes in vivo. When used alone or in combination with IXY-LS-DOX, M-RAPA could greatly inhibit the expression of HIF-1 alpha protein, which is always highly expressed in malignant cancers and involved in tumor angiogenesis, proliferation, therapeutic resistance and poor prognosis. Meanwhile, the improved efficacy of combined targeted therapy with LXY-LS-DOX and M-RAPA was demonstrated by the in vitro cytotoxicity against model TNBC cells and in vivo anti-tumor activity against mouse bearing TNBC model. These results suggested that the targeted combinational therapy based on LXY-LS-DOX and M-RAPA systems may provide a rational strategy to improve therapeutic outcomes of TNBC. (c) 2014 Elsevier Ltd. All rights reserved.