胚模预制混凝土穹顶施工技术

穹顶以其外形美观、结构受力合理等特点广泛运用于工业与民用建筑。但现浇混凝土穹顶实施困难,特别是穹顶模板安装、混凝土浇筑质量,严重影响穹顶外观;采用专业厂家预制,成本较高。为降低工程成本,通过施工实践及创新,胚模预制混凝土穹顶及吊装施工技术确保了穹顶形状美观并符合设计要求,施工简单可行。

模胚行业ERP系统设计和应用

建立了模胚制造企业智能ERP体系结构,在此基础上设计和实现了一个完整的ERP系统。系统涉及到了模胚行业生产运做的各个环节,包括:报价、下单、投产、生产控制、仓库、送货、财务。系统在某公司的两个模胚制造厂实施以来,运行效果良好,可以及时、准确、全面地反映企业的实时运做情况,有效地改善了人工管理效率低、出错率高的情况。

螺纹钎杆接头模胚制作研究

以往螺纹钎杆接头模胚的加工采用人工锻打,存在较多的质量缺陷,报废率较高;螺纹钎杆接头均为来料加工,大多为旧钎杆,而旧钎杆经凿岩过程的高速强有力的旋转,钎杆外径磨损大,直径达不到标准尺寸,钎杆接头模胚锻打增粗困难,加工尺寸难以保证。为克服加工过程中出现的质量缺陷,开展了螺纹钎杆接头模胚制作研究,为今后类似接头模胚加工提供了依据和有益借鉴。

螺纹钎杆接头模胚加工的质量控制技术

近年来，各类中锚杆、固结灌浆等工程量日益增多，其锚杆、固结灌浆的造孔深度往往超过隧道洞径，而狭窄的隧道内无法使一次性造孔到位，需要拼接钎杆来完成造孔工作。螺纹钎杆接头均为旧钎杆来料加工，属开源节流、废品利用项目。为此，钎杆拼接的技术成为加工业研究的新课题。

Modes of Action of Phytochromes in Establishing Different Phototropic Responsiveness of Maize Coleoptiles

Previous studies have examined the effects of red light (R) on phototropism of maize ( Zea mays L. cv. Royaldent Hit 85) coleoptiles. The R effect on time-dependent phototropism (TDP) was further studied by characterizing its fluence-response relationship. The results showed the R effect was a low-fluence-response, unlike those on pulse-induced phototropisms that show a very-low-fluence-response mode. A subsequent pulse of far-red light (FR) could reverse the R effect. TDP responsiveness, however, recovered as the following FR was extended, The FR-dependent increase in TDP responsiveness was obtained even coleoptiles were pretreated only with FR. It suggested that TDP responsiveness could also be established in response to a FR signal. The fluence-response relationship for the effect of FR was then investigated. The effect of FR depended on the time of irradiation and required high photon fluences. Because reciprocity was invalid at the higher fluence range, the effect of FR would be a high-irradiance-response mode. Relation between phytochrome action modes and possible multiple pathways for phototropic signal transduction was analyzed based on the experiment results.

Duality theorem for smash coproduct over quantum groupoids

The duality theorem of generalized weak smash coproducts of weak module coalgebras and comodule coalgebras over quantum groupoids is studied.Let H be a weak Hopf algebra,C a left weak H-comodule coalgebra and D a left weak H-module coalgebra.First,a weak generalized smash coproduct C×lH D over quantum groupoids is defined and the module and comodule structures on it are constructed.The weak generalized right smash coproduct C×rL D is similar.Then some isomorph-isms between them are obtained.Secondly,by introducing some concepts of a weak convolution invertible element,a weak co-inner coaction and a strongly relative co-inner coaction,a sufficient condition for C×rH D to be isomorphic to Cv D is obtained,where v∈WC（C,H）and the coaction of H on D is right strongly relative co-inner.Finally,the duality theorem for a generalized smash coproduct over quantum groupoids,（C×lH H）×lH H≌Cv（H×lH H）,is obtained.

Study of Rheological Characterization of Fenugreek Gum with Modified Maxwell Model

Taking into account the viscoelasticity of the fenugreek gum, a modified Maxwell model in terms of fractional derivatives is developed. Using this model, it is observed that the fenugreek gums with at least two different concentrations obey the Cox-Merz rule.

基于数学核心素养的高考数学备考建议

本文阐明基于高中数学核心素养的数学高考备考方向,总结备考的基本思想,即概括试题的具体问题,建立高考数学全国卷试题题干和设问的模胚,在模胚题的基础上建立部分变式题,形成题集,供高三学生和数学教师使用。

Cloning and expression patterns of two Smad genes during embryonic development and shell formation of the Pacific oyster Crassostrea gigas

Increasing evidence indicates that transforming growth factor β （TGF-β） signaling pathways play many important roles in the early development of mollusks. However, limited information is known concerning their detailed mechanisms. Here, we describe the identification, cloning and characterization of two Smad genes, the key components of TGF-β signaling pathways, from the Pacific oyster Crassostrea gigas. Sequence analysis of the two genes, designated as cgi-smad1/5/8 and cgi-smad4, revealed conserved functional characteristics. The two genes were widely expressed in embryos and larvae, suggesting multiple roles in the early development of C. gigas. The mRNA of the two genes aggregated in the D quadrant and cgi-smad4 was highly expressed on the dorsal side of the gastrula, indicating that TGF-β signaling pathways may be involved in dorsoventral patterning in C. gigas. Furthermore, high expression levels of the two genes in the shell fields of embryos at different stages suggested important roles for TGF-β signaling pathways in particular phases of shell development, including the formation of the initial shell field and the biomineralization of larval shells. The results of this study provide fundamental support for elucidating how TGF-β signaling pathways participate in the early development of bivalve mollusks, and suggest that further work is warranted to this end.

ONCOGENIC TRANSFORMATION OF SYRIAN HAMSTER EMBRYO CELLS BY 5．3－MeV α PARTICLES AND A TUMOR PROMOTER PHORBOL ESTER

The primary Syrian hamster embryo(SHE) cells were used to study the oncogenic transformation by ￣(238)pu α particles or X-rays alone or in combination with a chemical promoter phorbol ester.Survival curves of SHE cells following exposure to α-particles or X-rays were fitted to single-or multi-target models,respectively. Model parameters were: Do = 0. 55 Gy. n = 1 for α particles 4 Do = 1.44 Gy. Dq = 3.0 Gy. n=7.7 for X-rays.Incidence of α particles or X-rays induced cell transformation was dose-dependant.α particles were more efficient in inducing cell transformation than that of X-rays. The enhancement of SHE cell transformation by phorbol 12-myristate 13-acetate(PMA) following exposure to α particles of 0. 25-1. 00 Gy was observed.

Developmental ecology of the American horseshoe crab Limulus polyphemus

During spawning events, horseshoe crab eggs are released from the female＇s oviducts, and fertilized by one or more males. Eggs are shaped by the female into discrete clutches deposited in nests at depths of 10-20 cm on intertidal estuarine beaches. Distinguishing between fxesh eggs and the early developmental stages is obfuscated by the large amount of dense, opaque yolk. The first unambiguous confirmation of development is the formation of the rudimentary prosomatie appendages at the ＂limb bud＂ stage. Several days thereafter, the outer chorion is shed and the developing embryo expands and undergoes a series of molts within the clear inner egg membrane. The trilobite （first iustar） stage thus attained may remain within the beach sedi- ments for several more weeks, until hatching is facilitated by environmental factors such as hydration, agitation, and osmotic shock that accompany the infiltration of seawater into the nests. Trilobites exhibit endogenous eirgatidal swimming rhythms that are entrained by mechanical agitation, suggesting that peaks in larval swimming are timed to coincide with periods of high water and the inundation of the nests. Larval swimming is limited and does not appear to result in long-distance dispersal. The limited dispersal of the larvae has important implications for the population dynamics of relatively isolated populations. The rate of larval development is highly plastic and is influenced by temperature, salinity, dissolved oxygen, and the presence of pollutants. The broad environmental tolerances of horseshoe crab embryos and larvae are important in understanding their current geographic distribution and their evolutionary persistence

Expression Pattern of Chlamys farreri sox2 in Eggs, Embryos and Larvae of Various Stages

The SOX2 protein is an important transcription factor functioning during the early development of animals. In this study, we isolated a full-length c DNA sequence of scallop Chlamys farreri sox2, Cf-sox2 which was 2194 bp in length with a 981 bp open reading frame encoding 327 amino acids. With real-time PCR analysis, it was detected that Cf-sox2 was expressed in unfertilized oocytes, fertilized eggs and all the tested embryos and larvae. The expression level increased significantly(P < 0.01) in embryos from 2-cell to blastula, and then decreased significantly(P < 0.01) and reached the minimum in umbo larva. Moreover, location of the Cfsox2 expression was revealed using whole mount in situ hybridization technique. Positive hybridization signal could be detected in the central region of unfertilized oocytes and fertilized eggs, and then strong signals dispersed throughout the embryos from 2-cell to gastrula. During larval development, the signals were concentrated and strong signals were restricted to 4 regions of viscera mass in veliger larva. In umbo larva, weak signals could be detected in regions where presumptive visceral and pedal ganglia may be formed. The expression pattern of Cf-sox2 during embryogenesis was similar to that of mammal sox2, which implied that Cf-SOX2 may participate in the regulation of early development of C. farreri.

Establishment of a transplantation tumor model of human osteosarcoma in chick embryo

Objective: We established a transplantation tumor model of human osteosarcoma in chick embryo, studied its morphological and biological characteristics, and observed its dynamic process of angiogenesis induction so that a simple and practical model can be provided for studying osteosarcoma. Methods: Human osteosarcoma cells at different concentrations were inoculated in chorioallantoic membrane (CAM) of chick embryos at different embryonic ages to observe the factors affecting the survival of the transplanted osteosarcoma in chick embryo, growth characteristics of the transplantation tumor, and the morphological characteristics and biological characteristics of the transplantation tumor. Results: The transplantation tumor model of human osteosarcoma in chick embryo was successfully established. It was found that the transplantation tumor was easy to grow and it showed strong angiogenesis-inducing effects. Under the light microscope, the transplantation tumor showed a similar tissue structure to human osteosarcoma. Conclusion: It is feasible to establish a transplantation tumor model of human osteosarcoma in chick embryo. The model can be easily duplicated with a simple operation, which provides a useful animal model for studying osteosarcoma.

The Study on the Gene Expression of Preimplantation IVF Bovine Embryos

The cattle different stage embryos obtained from in vitro was studied using the technology of single preimplantation embryo mRNA different display:single 8-cell and blastocyst stage embryos were studied using technology of mRNA different display and one different fragment was found. The result suggested that this fragment displayed high homology (99%) to cattle mRNA for ribosomal protein L31. Then to detect the expression of RPL31mRNA in 8 cell and blastocyst stage embryos by real-time quantitative PCR,the result showed the relative amount of 8 cells was 3.2 times of blastocyst's.

Differentiation of mouse embryonic stem cells into insulin-secreting cells in vitro

Regenerative medicine, including cell-replacement strategies, may have an important role in the treatment of type 1 diabetes which is associated with decreased islet cell mass. To date, significant progress has been made in generating insulin-secreting 13 cells from pluripotent mouse embryonic stem cells （ESCs）.The aim of this study is to explore the potential of regulating the differentiation of ESCs into pancreatic endocrine cells capable of synthesizing the pancreatic hormones including insulin, glucagon, somatostatin and pancreatic polypeptide under proper conditions. Undifferentiated ES cell line was stably transfected with mouse RIP-YFP plasmid construction in serum-free medium using LipofectamineTM 2000 Reagents. We tested pancreatic specific gene expression and characterized these ESC-derived pancreatic endocrine cells. Most of these insulin-secreting cells co-expressed many of the phenotypic markers characteristic of 13 cells such as insulinl, insulin2, Isletl, MafA, insulinoma-associated antigen 1 （IA1） and so on, indicating a similar gene expression pattern to adult islet 13 cells in vivo. Characterization of this population revealed that it consisted predominantly of pancreatic endocrine cells that were able to undergo pancreatic specification under the appropriate conditions. We also demonstrated that zinc supplementation mediated up-regulation of insulin-secreting cells as an effective inducer promoted the development of ESC-derived diabetes therapy. In conclusion, this work not only established an efficient pancreatic differentiation strategy from ESCs to pancreatic endocrine lineage in vitro, but also leaded to the development of new strategies to derive transplantable islet-replacement 13 cells from embryonic stem cells for the future applications of a stem cell based therapy of diabetes.

Serial imaging of human embryonic stem-cell engraftment and teratoma formation in live mouse models

Two new types of lentiviral vectors expressing a reporter transgene encoding either firefly luciferase （fLuc） for bioluminescence imaging or the HSV1 thymidine kinase （HSV1-TK） for radiopharmaceutical-based imaging were constructed to monitor human embryonic stem cell （hESC） engraftment and proliferation in live mice after trans- plantation. The constitutive expression of either transgene did not alter the properties of hESCs in the culture. We next monitored the formation of teratomas in SCID mice to test （1） whether the gene-modified hESCs maintain their developmental pluripotency, and （2） whether sustained reporter gene expression allows noninvasive, whole-body imaging of hESC derivatives in a live mouse model. We observed teratoma formation from both types of gene-modified cells as well as wild-type hESCs 2-4 months after inoculation. Using an optical imaging system, bioluminescence from the fLuc-transduced hESCs was easily detected in mice bearing teratomas long before palpable tumors could be detected. To develop a noninvasive imaging method more readily translatable to the clinic, we also utilized HSV1-TK and its specific substrate, 1-（2＇-deoxy-2＇-fluoro-β-D-arabinofuranosyl）-5-[^125I]iodouracil（[^125I]FIAU）, as a reporter/ probe pair. After systemic administration, [^125I]FIAU is phosphorylated only by the transgene-encoded HSV1-TK enzyme and retained within transduced （and transplanted） cells, allowing sensitive and quantitative imaging by single-photon emission computed tomography. Noninvasive imaging methods such as these may enable us to monitor the presence and distribution of transplanted human stem cells repetitively within live recipients over a long term through the expression of a reporter gene.

A Helm model for microRNA regulation in cell fate decision and conversion

microRNAs （miRNAs） constitute a unique class of endogenous small non-coding RNAs that regulate gene expression post-transcriptionally. Studies over the past decade have uncovered a r^curring paradigm in which miRNAs are key regulators of cellular behavior under various physiological and pathological conditions. Most surprising is the recent observation that miRNAs have emerged as competent players in somatic cell reprogramming, suggesting an especially significant role for these small RNAs in cell fate settings. Here, we discuss the possible mechanisms underlying miRNA-mediated cell programming （i.e., the development and differentiation of embryonic stem cells） and reprogramming （i.e., turning somatic cells into pluripo- tent stem cells or other lineages）, and provide a ＂Helm＂ model of miRNAs in cell fate decision and conversion.

Identification and expression of amphioxus AmphiSmad1/5/8 and AmphiSmad4

Smad family proteins are identified as intracellular signal mediators of the TGF-β superfamily.In this study,we identified two novel members of the Smad family,termed as AmphiSmad1/5/8 and AmphiSmad4,from Chinese amphioxus.Both AmphiSmad1/5/8 and AmphiSmad4 showed a typical domain structure of Smad proteins consisting of conserved MH1 and MH2 domains.Phylogenetic analysis placed AmphiSmad1/5/8 in the Smad1,5 and 8 subgroup of the R-Smad subfamily,and AmphiSmad4 in the Co-Smad subfamily.The spatial and temporal gene expression patterns of AmphiSmad1/5/8 and AmphiSmad4 showed that they may be involved in the embryonic development of notochord,myotome and alimentary canal,and may help to establish the specification of dorsal-ventral axis of amphioxus.Moreover,AmphiSmad1/5/8 and AmphiSmad4 showed extensive distribution in all adult tissues examined,suggesting that these two genes may play important roles in the morphogenesis of a variety of tissues especially notochord and gonad.